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Elements African Music

Women from the Masai tribe, singing.

The music of Africa is as vast and varied as the continent’s many regions, nations, and ethnic groups. The African continent comprises approximately 20 percent of the world’s land mass and has a population of roughly 934 million. African music is as diverse as its cultures and peoples and has flowered in many indigenous forms as well as been shaped by foreign influences.

Although there are many different varieties of music in Africa, there are a number of common elements to the music, especially within regions. The concept of music in Africa, especially in sub-Saharan Africa bears a difference from other regions and cultures. The roles of musicand dance are tightly woven together in sub-Saharan Africa, and music intersects with every aspect of life, expresses life through the medium of sound. By helping mark the important moments in life, music helps to underscore the divine and eternal value of human life.

African music also helps to connect people together in a variety of ways, strengthening the fabric of the community, which in turn reinforces people’s commitment to support each other and the community, toward mutual health and prosperity. Another crucial role of music in Africa is as a mode of communication. Talking drums, signal drums, songs, and the sagas of the historian griots each communicate different types of important information.

Contents [hide1 Traditional music2 Musical components2.1 Form2.2 Rhythmic Structure2.3 Texture2.4 Text/lyrics2.5 Polyphony2.6 Repetition2.7 Call and response2.8 Hocketing3 Musical instruments3.1 Membraphones4 Drum gallery4.1 Chordophones4.2 Idiophones4.3 Aerophones4.4 Musicians5 Regional styles6 Music and culture6.1 Relationship to language6.2 Relationship to dance7 Popular music7.1 African music during colonization7.2 African music after independence7.3 African music in the twenty-first century7.4 Influence on American music8 Gallery9 Notes10 References11 Credits

As African society has changed in response to the forces of colonization, independence, and globalization, the role of music changed as well, adapting to the new situation in which the people of Africa find themselves. Though there have been changes in some of the forms of the music, including the infusion of instruments, musical styles, and genres from outside the African continent, music remains very important in Africa today. Also, as Africans traveled from Africa to other parts of the world, both as a result of African slave trade and later migrations, the music and dance forms of the African diaspora have influenced a number of international musical styles and genres, including many Caribbean and Latin American music genres like rumba and salsa, as well as providing the foundation of musical tradition behind African American music.

Traditional music

Drummers, part of a large celebration marking the arrival of running water to their village, Ojumo Oro, Kwara State, Nigeria, in April 2004.

When discussing African music, the term “traditional music” is used to refer to the characteristics of African music prior to the colonization of the continent by European countries, which was most widespread during the late nineteenth century. This pre-colonial period was full of social changes and dynamism. Great African empires and kingdoms rose and fell, many of their traditions and cultures still prevalent to this day throughout African villages.

Because of the extensive Arabian influence of the music on north Africa, which gives it a separate and distinct style, this discussion will be focused on the music of sub-Saharan Africa, which shares many characteristics from region to region. A great deal of African traditional music as it occurred in African life and culture throughout the years, was performed by full-time musicians. Although the terms “traditional music” and “folk music” are often used interchangeably in the literature describing this music, the term “traditional music” is more accurate, because some of it belongs to court music or sacral music traditions, therefore the term “folk music” is not always appropriate.

Music is an integral part of African ethnic life, accompanying many kinds of events, including childbirth, marriage, hunting, and even political activities. Many cultures use song and dance to ward off evil spirits, and pay respects to good spirits, the dead, and ancestors. The majority of sub-Saharan African folk music and traditional music is functional in nature. There are, for example, many different kinds of work songs, ceremonial or religious music, and courtly music performed at royal courts, and typically none of these are performed outside of their intended social context.

Musical components

Despite their diversity, traditional African musical forms share some common traits. The emphasis is placed more strongly on rhythms than on melody and harmony. Repetition is use as an organizing principle on top of which improvisation is built. African music is mostly performed by groups of musicians, frequently employing polyphony, polyrhythm, and a conversational style of music and interlocking.

Gospel singers, N’Gaoundere, Cameroon.

Form

The most frequently used form in African musical traditions consists of the use of ostinato, or repeated short musical phrases with the accompaniment of melodic-rhythmic patterns. For example, in the call and response method, a leader usually sings a phrase with a chorus singing back a response. Two or more melodies may be combined to form larger sectional formations. Contrast is achieved through a series of musical movements or “acts,” each consisting of a section repeated several times.

Rhythmic Structure

Rhythm is the most distinguishing characteristic of African music tradition. Four basic elements characterize African rhythmic structure. They are an equal pulse base, a metric time arrangement, a specific organizing principle unifying a diversity of simultaneous rhythmic patterns together, and an exact starting point for rhythmic groupings.

Texture

African music, from the communal nature of African society, is marked by the simultaneous sounding of two or more pitches. Melody and rhythm are interwoven within this dense structure of various instrumental and metric combinations. Ornamental devices, either vocal or instrumental, are commonly used to create additional layers, providing a richer density to the texture. Another important feature of African music is its related movements or body percussion, such as hand clapping, foot stamping, and dance. Body movement is strongly encouraged by this type of music.

Text/lyrics

African music is often used to transmit messages and ideas; and to record and recount historical events. Consequently, the meaning of the texts and their relation to the music especially important.

Musician from the northern Nigerian Housa ethnic group plays a two stringed ‘harp’ made from half a calabash (gourd) covered in skin.

Polyphony

The composition of African music employs polyphony. Polyphony is defined as the composition of multiple simultaneously sounding and rhythmically independent parts. In such a composition, the originating melody carries given more importance than the resultant harmony. The Zulu choral music of South Africa is an example of vocal polyphony. When this music is performed, individual voices will enter at different moments in a cyclic and continuous manner, giving rise to a complex and constantly shifting texture.

Repetition

Most African composition is based on the repetition of a musical unit. It is that repetition that holds together the other musical units of the composition. These other unit are structured with great freedom relative to the first unit, producing their own rhythmic pattern that coincides only occasionally with that of the other units and with the basic pulse. For example, in the mbira music of the Shona people of Zimbabwe, a repeated pattern is established by the interaction of various parts, and the musician develops an improvisation out of this core pattern.

Call and response

The call and response is a form of music composition wherein a vocalist or instrumentalist will sing or play a phrase and another vocalist or instrumentalist will answer with another phrase creating a lively exchange.

Hocketing

Hocketing is the sharing of rhythmic or melodic lines between two or more players, one part resting while the other part performs a note or notes. An essential element of hocketing is integration—the working together and interlocking of the parts. In a more general sense, fast alternation short groups of notes between voices, instruments and timbres is a key element in the polyphonic and polyrhythmic structure that is distinctive to much of the music in sub-Saharan Africa.

Musical instruments

Besides using the voice, which has been developed to use various techniques such as complex melisma and yodel, a wide variety of musical instruments are used in African music.

Elmina, Ghana. A West African man plays the kora, an African chordophone, of the resonator bow type.

These include a wide array of drums. Drums used in African traditional music include tama talking drums, bougarabou and djembe in West Africa, water drums in Central and West Africa, and the different types of ngoma drums (pronounced by some “engoma”) in Central and Southern Africa.

Besides the numerous drums, African percussion instruments can be divided into two broad categories: Instruments with rhythmic functions and instruments with melodic functions. Large gongs, twin gongs, slit gongs, and ritual gongs; rattles and foot rattle; woodblocks, bells, and double bells are examples of instruments with rhythmic functions. Other percussion instruments used for rhythmic parts include shakers, such as the kosika, rainsticks, and woodsticks. The melodic instruments include string instruments, (musical bows, different types of harps and harp-like instruments like the Kora as well as fiddles), many types of xylophone and lamellophone such as the mbira and different types of wind instrument like flutesand trumpets.

A more specific classification can be made by categorizing them into groups namely, chordophones, idiophones, aerophones and membraphones, following the Hornbostel-Sachs system of classification for musical instruments.

Membraphones

Membraphones are instruments that produce sound by a vibrating membrane. The most prevalent type of membranophone, drums, are utilized as both melodic and rhythmic instruments and come in a variety of shapes and sizes. Some of these drums are beaten with the hand, while other are beaten with a stick or rubbed. Some are single-headed and some double-headed and they are played in ensembles of varying sizes. These include the ngoma kettledrums of South Africa, the West African hourglass pressure drum, bompiliclay pot drums usually played by women, frame drums, and countless other drums are played throughout Africa.

Drum gallery

  • Signal drum, Ndebu, southeast Senegal (West Africa)
  • Drums of an African band in Germany.
  • Drummer for a Rwandan dance troupe.
  • Drum found near Lake Tengrela, Banfora, Burkina Faso.
  • Burundi drummers, performing on drums carved from tree trunks.
  • An African Talking drum, a type of pressure drum
  • A Lenke wood djembe from Guinea in west Africa
  • Village Drummers from a village on the shores of Volta Lake.

Chordophones

Obu man playing a mouth bow. Photo dates from about 1910, Obubra, Nigeria.

Chordophone are instruments that produce sounds with vibrating strings, sometimes plucked, sometimes struck, sometimes with a bow. One of the simplest and the most widespread of these instruments is the musical bow. Types of the musical bow included the earth bow, the mouth bow, and the resonator bow. An earth bow is made by planting one end of a flexible pole in the ground and bent it at an angle to the ground. To the end of the pole, attach a string and on the other end of the string attach a stone, or a small piece of wood which is planted in the ground. The mouth bow is formed of a string that is attached to both ends a flexible pole such that the pole is shape to form a bow with the string. The string is held in the mouth and struck on a spot along its length. The mouth will help alter the amplification of the original sound of the struck string.

The resonator bow is a type of mouth bow, but with a calabash resonator fixed at the middle.

The kora, a multiple resonator bow, is one of the most important musical instruments in West Africa, usually played by the griot, or village historian. The kora is made from a natural calabash cut in half and partially covered with cow skin, with a hardwood post running through it. Between twenty and twenty-five strings run the length of the instrument, passing over a bridge that rests on the stretched skin cover.

Idiophones

Idiophones are instruments that produce sound by vibrating themselves, without the aid of a vibrating string, membrane or reed. These include the xylophone and many kinds of shaken, struck and scraped percussion instruments. Idiophones include both melodic and rhythm instruments, and the most abundant type of instrument found in Africa.

The marimba is a melodic idiophone (Malawi).

The African thumb piano, also known as the Mbira or Karimba.

Rattles are shaken to create sound and are principally rhythm instruments. Of the many rattles found in Africa, two categories may be observed: Those rattles that are played by the hands and those that are worn on the body and shaken by the movements of the player’s body.

Those rattles that are played by the hands include the gourd variety which may be either container in nature (objects such as pieces of bone, bamboo shoots or metal placed inside a gourd) or may be surrounded by nets of objects such as sea shells or beads.

Friction idiophones, such as pieces of notched bamboo, are played by scraping another stick across the bamboo. Other idiophones such as bracelets of metal or a notched stick being passed through a dried fruit shell also exist and are used to create rhythmic sound. Stamped sticks and stamped tubes also form another category of idiophones (in this case concussion idiophones). These sticks and tubes are held in the player’s hand and performed by being held at an angle and striking the ground or a slab of stone at an angle. On occasion three tubes are played at the same time each of which is playing a different rhythm. The adenkum (a long gourd with one end cut open to allow for resonance) is a stamped idiophone usually played in the vertical position by hitting the ground.

All of the above idiophones are rhythm instruments and play no melodic function. They may, however, be tuned to a complex of pitches or even to a specific pitch in some cases; for example, the adenkum. However, no attempt is made to use these instruments melodically by creating a graduated scale of pitches.

There are two basic types of tuned idiophones that can be used for playing melodies: The mbira or sansa (“hand piano”) and the xylophone and the marimba. The mbira is made by arranging a graduated series of strips (wood or metal) on a flat sounding board and placed inside a resonating gourd or box. A unique quality is added to the instrument by the addition of rattling pieces of metal or possibly a chain of sea shells or other small articles to create noise. Mbiras may consist of from one to three manuals and range from five to twenty keys per manual. The Keys are attached to a sound resonator, either a hollow box, as in this case, or placed in an open large gourd to enhance the volume of sound.

There are three main forms of tuned xylophones and marimbas found in Africa: (1) wooden slabs arranged in a graduated scale are mounted over a resonance box (a pit, a clay pot or an open trough may be used). Iboland in Nigeria and the Zaramo of Tanzania make xylophones of this type. (2) In the Kissi country in Guinea and in the Ivory Coast, xylophones are made by laying keys over two pieces of banana stems. (3) Gourd resonators are used to resonate keys placed above the open gourd and mounted in a wooden frame. These gourd resonating xylophones and marimbas are found in west, central and east Africa. Xylophones and marimbas may be played by themselves or in combination with other instruments. It is common among the Vatapa (Shona) of Zimbabwe to hear large ensembles involving as many as ten to fifteen players performing in large xylophone ensembles consisting of xylophones ranging in size from small (those that are strapped over the back and carried) to large (those that are large enough to have the player stand on a riser to reach).

Aerophones

Bamboo flute players from Rwanda.

African instruments include a number of aerophones, which produce sound by vibrating columns of air. The three broad categories of African aerophones are: (1) Flutes, (2) reed pipes, and (3) trumpets and horns.

Although flutes may be made from a husk of cane or the end of an animal horn or gourd, the most common material in use to make flutes is bamboo. They may be open-ended or closed, they may be played in the vertical or horizontal (transverse) positions. Although most African flutes are made with a number of holes (from two to six), some flutes are made with a single hole. A number of these flutes are made so that the technique of melodic playing known as hocket can be employed. Using the hocket technique melodies are formed by each flute sounding single tones in a melodic chain.

Trumpets and horns are made from the horns of many animals which include elephant tusks and are used in various ensembles. Here again, instruments are often arranged in families. Babembe horns are made in human likeness in the Congo. In the case of the Babembe horns, a dorsal opening is cut in the back of each likeness and the player buzzes his/her lips to create a single tone.

Musicians

African musicians can be divided into three categories: The non professional, the semiprofessional, and the professional. Most African traditional music is a participative performance. There is a perpetual give and take between the main performer and the public, and the public is fully part of the performances. Tradition and culture helped each participant to know how it should respond to a particular rhythmic. Other people in the African society, even though not fully musician, have music as one of the requirements to fulfill their social responsibility. These include people like healers, who on certain occasions are called upon to perform sacred songs. The last group of musicians are the full time musicians. Often their position in the society is inherited. In the West African Malinke region, historian Griotsare full time musicians who used to travel from village to village, singing for dignitaries and rich traders or merchants.

Regional styles

As has been mentioned, North Africa—EgyptLibyaAlgeriaTunisia and Morocco—has a distinctive musical style, different from the southern regions; this music bears a strong Arab and Islamic stamp thanks to medieval Islamic expansion.

Islamic worshipers with African drums, Lamu, Kenya.

African music and Christian traditions combine as Ethiopians celebrate the ancient Ethiopian Orthodox Christian festival of Timket.

Egypt, in particular, has deep musical connections to the rest of the Arab world, being one of the epicenters of Arab classical and popular music for hundreds of years. While Arabic traditions are more preeminent, a Coptic musical tradition adopted from the music of the ancient Egyptian is also existent. Coptic music is characterized by a strong vocal and the use of cymbals and triangles.

Moroccan classical music style is Arab-Andalusian, featuring an orchestra of traditional stringed instrument such as the rabab (a bowed two-stringed instrument), oud (Arab lute), and qanun (zither). Songs in Arabic often accompany this music. West Africa, below the expanse of the Sahara Desert, is one of the most musically fertile areas of the world, containing such musical powerhouses as MaliSenegalNigeriaGhana, and Guinea. Once the home to various Empires that grew rich from trans-Saharan trade, the region is home to some of the most sophisticated classical and court music traditions in sub-Saharan Africa.

For thousands of years, professional musicians called griots played an important role as historian in the kingdoms that developed in the Saharan region of west Africa.

In addition to the griot, music in Senegal is also characterized by the complex drumming that often accompanies dance.

East Africa also has deep musical ties to the Islamic world; from the Egyptian-influenced taraab music of the Swahili coast to the oud-driven music of the Nubian people of Northern Sudan. Additionally, Ethiopia and Eritrea have their own ancient, unique, and interrelated musical cultures that date back more than 1000 years. The khoisan (AngolaNamibiaBotswanaSwazilandSouth AfricaLesotho, and parts of ZambiaZimbabwe, and Mozambique) is the anglicized name of two tribes, the Khoi and the San. The music of this area is simpler than the music of other African cultures, both in types and variety of instruments and stylistically. More prominent harmonically are vertical fifths and octaves alongside rhythms less complex than those of Western Africa. In fact, percussive instruments are not as prominent in the Khoisan area as they are in other areas of Africa. Remarkable, however, is the presence in the music of the “hocket” technique, where individual notes of a melody are sung by different musicians, and a technique similar to yodeling. Because of the nomadic nature of the people, the music is played throughout the day and not associated with any rituals relating to the harvest.

Music and culture

Relationship to language

Many African languages are tonal languages, leading to a close connection between music and language in many African cultures. In singing, the tonal pattern or the text puts some constraints on the melodic patterns. On the other hand, in instrumental music a native speaker of a language can often perceive a text or texts in the music. This effect also forms the basis of drum languages (talking drums).[1]

Relationship to dance

Nigerian dancers, with their own drums and other instruments.

The treatment of “music” and “dance” as separate art forms is a European idea. In many African languages there is no concept corresponding exactly to these terms. For example, in many Bantu languages, there is one concept that might be translated as ‘song’ and another that covers both the semantic fields of the European concepts of “music” and “dance.” So there is one word for both music and dance (the exact meaning of the concepts may differ from culture to culture).

For example, in Kiswahili, the word “ngoma” may be translated as “drum,” “dance,” “dance event,” “dance celebration,” or “music,” depending on the context. Each of these translations is incomplete. The classification of the phenomena of this area of culture into “music” and “dance” is foreign to many African cultures. Therefore, African music and African dance must be viewed in very close connection.

Popular music

The popular African music refers to the music with compositions started during the colonization and after the colonization era.

African music during colonization

The colonization era saw the emergence of a new urbanization. The cities where inhabited mostly by Africans who were working for members of the occupying country, primarily as servants, clerks, or cooks. People closer to the occupier where also ranked higher in the social ladder, and this precipitated the beginning of the decline of traditional African music.

Traditional African music lost its appeal as these new urban dwellers and the occupiers brought new musical instruments and styles that were quickly adopted by Africans. Musicians did their best to mimics songs and and musical genres from the occupier’s country. One new genre of music, the Palm Wine, grew out the Krou people of Liberia and Sierra Leone. It was a genre played on the guitar by sailors while they enjoyed a glass of palm wine. As sailors, they traveled the west coast of Africa up to the coastal regions of today’s DRC (Democratic Republic of Congo) and on the way introduced the Palm Wine genre and the guitar to these regions. With the appearance of recording studio and the radio in 1924, musicians were now able to reach a wider audience. This also allowed new musical genres to spread more easily throughout the continent. The end of World War II saw a new trend in the African musical sphere, the importation of music from Latin America, like the rumba, chachas boleros, and the mambo. Musicians easily adopted these styles of music. They were well appreciated by the occupiers and also very close to their native musical style. This started a Latin craze, especially in the French colonies and the Belgium colony of Congo.

This Latin craze helped shape and give rise to other new musical genres. Highlife, a new genre that originated in Ghana, holds E.T. Mensah as one of its hero. The highlife was a truly popular musical genre with influence that spread across the border of Ghana to other, mainly English speaking countries, like Nigeria. Highlife is characterized by jazzy horns and multiple guitars. In Congo, the melding of the palm wine style of playing the guitar with the Latin musical genre, led to the appearance of a style known popularly as the Congolese Rumba or Soukous with prominent figures like Antoine Kolossay (Papa Wendo), Joseph Kabasele Tshamala (Grand Kale), and Francois Luambo Makiadi (Franco). This style, like highlife, exerted a widespread influence in sub-Saharan colonized Africa.

African music after independence

South African band, with a typical instrumentation of percussion, including marimba.

The independence period, in the 1960s, was a vibrant period both politically and culturally for the emergence of a free and proud Africa. The hopes and many moments of disillusionment that followed were witnessed by African musicians. African modern musician have incorporated more freedom into their musical composition and begun to blend traditional music with foreign musical styles. The African style that emerged during the occupation developed and gave rise to new varieties and sub genres. Musicians reverted to the use local instruments and sang in their local languages.

Thus, the music itself made its own contribution to the liberation of the African mind. In Guinea, Salif Keita, incorporating its electric kora, adapted and blended old traditional songs and instruments with modern instruments. Fela Kuti of Nigeria, around 1970, brought highlife to a new dimension and create a new genre, the afrobeat. Afrobeat is a fusion of stylistic elements from its own musical culture, afro-American pop music, and Latin American music, with a prominent modal jazz. Some lyrics in afrobeat were very critical of the ruling juntas, making some outspoken musicians into local folk heroes.

African music in the twenty-first century

Modern African music has developed further and national musical genres have emerged throughout the continent. Global musical styles such as jazz, R&B, hip hop, rock ’n’ roll, country, and reggae have all make their impact on today’s African musicians. Successful musicians are usually the one who successfully blend these foreign musical style with the musical traditions of their country. Hip hop started in the 1970s, among the black youth of New York. The lyrics and delivery style of hip hop borrow heavily, like most other African American style of music, from African tradition.

A contemporary African band, combining traditional percussion instruments with contemporary brass instruments.

Since the 1980s and early 1990s, Hip hop has entered the African scene and is now being adapted by African youth throughout the continent. At first, African hip hop artists were mostly mimicking their American counterparts, which gave a bad name to hip hop as a deculturalization and Americanization of the youth of Africa. In those early days, hip hop was more a style of the youth in the upper strata of the society. The second wave of hip hop artists took the musical style closer to home, creating local flavors of the hip hop genre, and singing in their local language. This period started in the mid 1990s, and can be called the Africanization of hip hop, with distinct styles emerging from country to country. In Ghana, the highlife merged with hip hop to create “hiplife.” In South Africa, hip hop lyrics have been used to express the struggles of the youth in post apartheid society.

Reggae music is well represented in Africa. The influence of reggae took firm root sometime after Bob Marley‘s concert in support of Zimbabwean independence in Harare in 1980. The main centers of reggae are South Africa, the Ivory Coast and Nigeria. The sound is aligned with current trends in African music and bands often experiment with the use of traditional musical instruments. Askia Modibo, a native of Mali, merged reggae with the pentatonic music of the region, the Wassoulou, on “Wass-Reggae” was released in 1995. The lyrics follow the tradition laid by Bob Marley back in Zimbabwe, very concerned with the society in which the artist is living and the problem of the world. Alpha Blondy, a native of the Ivory Coast, released an album in 1986, with the virulent title Apartheid is Nazism, asking for U.S. intervention to stop apartheid in South Africa.

The music of the independence, like highlife and rumba Congolese, have further inspired and given rise to new local musical genres that are emerging in the twenty-first century. “Ndombolo” is a fast-paced derivative of “soukous.” In contrast to the Congolese Rumba which has its origin in the fusion of musical forms, Ndombolo has its origin in the dance of the same name the Ndombolo (“Gorilla dance”). The dance was started as a satyr of the late regime of Congolese president L.D. Kabilla and soon became a continental craze. It is promoted by lead singers like Awilo Longomba, Aurlus Mabele, Koffi Olomide, and groups like Extra Musica and Wenge Musica, among others.

Watoto Children’s Choir from Kampala, Uganda, founded in 1994.

In the Ivory Coast, during the political riots of the 1990s, “zouglou,” a new musical genre emerged with roots in the urban and the local youth culture. Zouglou originates from small groups of youth that performed during social get-togethers like football (soccer) competitions. Using traditional percussive style, zouglou is especially popular with the Bete people of the Ivory Coast, because it bears similarities to their own local style, Alloucou. Zouglou groups formed bands, borrowing some elements from Congolese popular music. Zouglou lyrics heavily emphasize humor, wordplay, and sharp social commentary. This genre, which was promoted by bands like Les Garagistes, Magic System, Soum Bill, among others, gave rise to other local styles. The now famous coupe-decalle, mapouka, and gnakpa are all derived from Zouglou and can be heard throughout Africa.

The global movement of world music is also present in Africa. This movement includes musicians who are experimenting with a wider usage of African musical composition and instrument mixed with foreign style of music. Manu Dibengo, jazz composer from Cameroon is one of the longest proponents of the fusion of African and foreign style of music. He is well known for his “Africanized” jazz composition since the 1960s. He will be renowned worldwide with its album “Soul Makossa” in 1972. Renown vocalist Cesaria Evora is from Cap Verde. She has popularized and brought to global recognition the Cape Verde traditional musical genre of Morna. In 2003, her album Voz Amor received a Grammy Awards for Best World Music Album.

Influence on American music

African music has been a major factor in the shaping of a number of American musical styles, including what we know today as bluesand jazz. These styles have all borrowed from African rhythms and sounds, brought over the Atlantic ocean by slaves. Paul Simon, on his album Graceland used African bands and music along with his own lyrics.

As the rise of rock ‘n’ roll music is often credited as having begun with 1940s blues music, and with so many genres having branched off from rock—the myriad sub genres of heavy metal, punk rock, pop music, and many more—it can be argued that African music has been at the root of a very significant portion of all contemporary music.

Gallery

  • This young man is playing the k’ra, a traditional instrument of Ethiopia. The name is very similar to the kora of West Africa.
  • African beaded calabash rattles for sale in New York.
  • Cow bells, a type of African percussion instrument.
  • These dancers, at the Swazi Cultural Village, South Africa, are wearing rattles on their ankles.
  • Singing group of the Masai Mara Tribe, Kenya.
  • A form of African harp built on a calabash.
  • A band from South Africa.
  • Closeup of a Tehardent, a three stringed African chordophone with a carved wood resonant chamber covered with goatskin.
  • An eight stringed Nyatiti Lyre from Kenya.
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Agriculture in West Africa in the Twenty-First Century: Climate Change and Impacts Scenarios, and Potential for Adaptation

Benjamin Sultan1,* and Marco Gaetani2Author informationArticle notesCopyright and License informationDisclaimerThis article has been cited by other articles in PMC.Go to:

Abstract

West Africa is known to be particularly vulnerable to climate change due to high climate variability, high reliance on rain-fed agriculture, and limited economic and institutional capacity to respond to climate variability and change. In this context, better knowledge of how climate will change in West Africa and how such changes will impact crop productivity is crucial to inform policies that may counteract the adverse effects. This review paper provides a comprehensive overview of climate change impacts on agriculture in West Africa based on the recent scientific literature. West Africa is nowadays experiencing a rapid climate change, characterized by a widespread warming, a recovery of the monsoonal precipitation, and an increase in the occurrence of climate extremes. The observed climate tendencies are also projected to continue in the twenty-first century under moderate and high emission scenarios, although large uncertainties still affect simulations of the future West African climate, especially regarding the summer precipitation. However, despite diverging future projections of the monsoonal rainfall, which is essential for rain-fed agriculture, a robust evidence of yield loss in West Africa emerges. This yield loss is mainly driven by increased mean temperature while potential wetter or drier conditions as well as elevated CO2concentrations can modulate this effect. Potential for adaptation is illustrated for major crops in West Africa through a selection of studies based on process-based crop models to adjust cropping systems (change in varieties, sowing dates and density, irrigation, fertilizer management) to future climate. Results of the cited studies are crop and region specific and no clear conclusions can be made regarding the most effective adaptation options. Further efforts are needed to improve modeling of the monsoon system and to better quantify the uncertainty in its changes under a warmer climate, in the response of the crops to such changes and in the potential for adaptation.Keywords: West African monsoon, climate change, impacts, adaptation, agricultureGo to:

Introduction

Climate has a strong influence on agriculture, considered as the most weather-dependent of all human activities (Hansen, 2002) with impacts on food security (Schmidhuber and Tubiello, 2007). Both variability and change in climate affect food production availability, stability of food supplies, food utilization, access to food and food prices everywhere in the world (Schmidhuber and Tubiello, 2007). It is especially true in Sub-Saharan Africa which is known to be particularly vulnerable to climate change due to a combination of naturally high levels of climate variability, high reliance on rain-fed agriculture and limited economic and institutional capacity to cope with and adapt to climate variability and change (Challinor et al., 2007; Müller et al., 2010; Roudier et al., 2011). Indeed, under its current climate Sub-Saharan Africa is already facing recurrent food crises and water scarcity triggered or exacerbated by climate variability and extreme events such as droughts, excessive rains and floods which affect agricultural productivity and hence rural household food security (Dilley et al., 2005; Haile, 2005). This chronic food insecurity may even increase in the future since the food demand is expected to be multiplied by more than five in Africa by 2050 (Collomb, 1999).

Climate change and its impact on food security are additional strains on the agriculture sector in Africa. The last Intergovernmental Panel on Climate Change (IPCC, 2014) highlighted that: “warming of the climate system is unequivocal, and since the 1950s, many of the observed changes are unprecedented over decades to millennia. The atmosphere and ocean have warmed, the amounts of snow and ice have diminished, and sea level has risen. Changes in many extreme weather and climate events have been observed since about 1950. Recent climate changes have had widespread impacts on human and natural systems.” Moreover, “continued emission of greenhouse gases will cause further warming and long-lasting changes in all components of the climate system, increasing the likelihood of severe, pervasive and irreversible impacts for people and ecosystems.” In this context, crop productivity, which is directly tied to climate variability, appears particularly exposed to current and future climate change impacts. Indeed, “many studies covering a wide range of regions and crops show that negative impacts of climate change on crop yields have been more common than positive impacts.” Moreover, “rural areas are expected to experience major impacts,” and “all aspects of food security are potentially affected by climate change, including food production, access, use, and price stability.” At the turn of the twenty-first century, West Africa has been identified among the primary observed climate change hot-spots, and among the most persistent and early emerging prominent hot-spots foreseen for the twenty-first century, because of the observed and projected widespread increase in mean temperature and extreme hot-season occurrence (Turco et al., 2015). Given the particularly strong deep connection between crop production and climate variability in West Africa since agriculture is mostly rain-fed and crop management (use of fertilizers and pesticides combined with modern cultivars) remains low (Dingkuhn et al., 2006), the detected sensitivity to recent and future climate change makes the region a hotspot even in terms of food production and security.

In the context described above, better knowledge of how climate will change in West Africa and how such changes will impact crop productivity is crucial to inform policies that may counteract the adverse effects. Furthermore, the ability to identify the most suitable crop varieties and practices with the most robust characteristics for withstanding climate change, is crucial for formulating adaptation strategies in this region where farmers are already able to select adapted varieties (e.g., late or early millet) or to adapt their practices (e.g., delayed or early sowing) to a changed environment (Dingkuhn et al., 2006). However, although there is a growing literature on the impact of climate change on crop productivity in Africa, there are large uncertainties in climate change projections, in the response of crops to such changes and in the adaptation of agricultural systems to future climate conditions (Challinor et al., 2007; Roudier et al., 2011). Thus, this paper provides a comprehensive overview of climate change impacts on agriculture in West Africa based on the recent scientific literature.

This review is based on a wide review of the literature on climate variability and change in West Africa and associated impacts on crop productivity. Given the sensitivity of the topic, the available literature is vast (more than 200 papers are cited in the references), the review presented here does not claim to be exhaustive and certainly misses many studies. However, an effort has been done to present a selection of the most important results, with a special attention to the recent studies. Moreover, the extensive and coordinated discussion of the crop productivity problem and the related climate dynamics aspects represents the noticeable novelty of this review. Section Climate Change Scenarios of this review paper provides observed evidences of climate change in West Africa and gives some robust features about expected changes in the next decades. Section The Impact on Crop Yield and Potential for Adaptation investigates how such climate changes affect crop production as well as potential for adaptation for the major crops in West Africa. Each section attempts to stress the most robust results in the screened literature but, more importantly, includes a discussion about limitations and uncertainties. The reader is invited to read the cited papers for more details on any specific aspects discussed in this review.Go to:

Climate change scenarios

West african climate and monsoon dynamics

The West African climate is deeply tied to the West African monsoon (WAM) system, which develops in May over the Guinean coast (~5–10°N), reaches the maturity in August in the Sahel (~10–15°N), and finally retreats to the coast in October (Sultan and Janicot, 2003; Cook, 2015), concentrating in this period more than 70% of the annual precipitation in the region (CLIVAR, 2015). The monsoonal rainfall is a key element of the regional climate, especially in the semiarid Sahel, where vegetation is highly sensitive to precipitation variability, at time scales from intraseasonal to interannual (Philippon et al., 2007; Martiny et al., 2010; Taylor, 2011). Moreover, the atmospheric circulation characterizing the monsoonal system is associated with mineral dust emission (Bou Karam et al., 2007; Wang et al., 2015) and thermal anomalies (Guichard et al., 2009; Fontaine et al., 2013) in the region.

The WAM is the response to the land-sea thermal contrast triggered by the seasonal cycle of incoming insolation at the surface, which favors the inland penetration of the deep convection associated with the intertropical convergence zone (ITCZ; Thorncroft et al., 2011). In the lower troposphere, the atmospheric circulation is characterized by a southwesterly moist flow from the Gulf of Guinea, contrasting a dry northeasterly flow crossing the Sahara desert. This intertropical front can be regarded as the northern boundary of the WAM, and at the peak of the monsoonal season it is displaced around 20°N (Issa Lélé and Lamb, 2010). In the mid troposphere, the circulation is dominated around 12°N by the African easterly jet, originated by the meridional thermal gradient between the vegetated Guinean coast and the Sahara desert (Thorncroft and Blackburn, 1999). The African easterly jet is the wave guide for synoptic disturbances propagating westward along the Guinean coast and the Sahelian belt, known as African easterly waves (Poan et al., 2015). These disturbances are particularly important in triggering the monsoonal precipitation through the initiation and organization of mesoscale convective systems and squall lines during the monsoonal season (Cretat et al., 2015). The annual evolution of the WAM thermodynamic features (moisture fluxes and convergence), and of the associated rainfall distribution, is strongly impacted by the emergence of the Atlantic cold tongue, and the installation of the Saharan heat low. The Atlantic cold tongue is a cold pool which characterizes the equatorial eastern Atlantic Ocean from boreal spring to early summer, and its variability influences the timing of the monsoon onset over the Guinean coast and the intensity of the inland precipitation (Druyan and Fulakeza, 2015). The Saharan heat low is a lower tropospheric thermal depression over the Sahara desert west of 10°E, developing in response to the surface heating over West Africa in boreal summer (Lavaysse et al., 2009). The Saharan heat low onset is closely linked to the WAM onset in late June, and its variability modulates the longitudinal distribution of the monsoonal precipitation in the Sahel, being strong Saharan heat low phases associated with wet/dry anomalies in eastern/western Sahel (Lavaysse et al., 2010).

Multi-time scales variability

In the twentieth century, the West African climate has been characterized by the variability of the WAM, showing a succession of long lasting wet and dry periods. This climate variability has been particularly relevant in the Sahel, where a large scale drought during the 70s–80s has been followed by a partial recovery of precipitation at the turn of the twenty-first century (Trenberth et al., 2007). The main driver of the WAM variability at time scales from intraseasonal to multidecadal is the global ocean sea surface temperature (SST; Pomposi et al., 2015; Rodríguez-Fonseca et al., 2015).

The observed 40-day variability of the WAM is mainly related to SST anomalies in the Indian Ocean associated with the Madden-Julian oscillation, which trigger convection disturbances traveling along the Equator and modulating the WAM precipitation (Pohl et al., 2009; Mohino et al., 2012).

The SST variability in the Tropical Atlantic is the main driver of the monsoonal circulation at the interannual time scales, through the land-sea thermal gradient which influences the meridional displacement of the precipitation belt, with the strongest impact on the Guinean coast (Polo et al., 2008; Losada et al., 2010). The Mediterranean Sea plays a role in modulating the interannual variability of the monsoonal precipitation over the Sahel, by feeding the convergence over the Sahel with moisture transported across Sahara (Fontaine et al., 2010; Gaetani et al., 2010). The WAM interannual variability is also remotely influenced by the SST variability in the Tropical Indian/Pacific Oceans, which may induce stationary waves propagating along the Equator and interacting over the Sahel (Rowell, 2001; Mohino et al., 2011b). These regional and remote connections are not stationary and are modulated at decadal and multidecadal time scales (Fontaine et al., 2011a).

The multidecadal variability of the WAM dynamics results from the combination of diverse low frequency global ocean signals (Mohino et al., 2011a). On the one hand, the warming of the Tropical Ocean, associated with global warming and positive phases of the interdecadal Pacific oscillation, favors dry conditions in the Sahel, through the inhibition of the tropical convection (Bader and Latif, 2003; Villamayor and Mohino, 2015). On the other hand, positive phases of the Atlantic multidecadal variability, by displacing northward the ITCZ, favor precipitation in the Sahel (Zhang and Delworth, 2006; Ting et al., 2009). The severe drought that affected the Sahel during the 70s–80s has been attributed to a negative Atlantic multidecadal variability phase, concomitant with a positive interdecadal Pacific oscillation phase, in a global warming context (Mohino et al., 2011a).

Other than to the SST forcing, the West African climate is highly sensitive to land surface conditions and processes. Vegetation-associated land surface processes have in West Africa the largest climate impact worldwide, especially in summer (Ma et al., 2013), and the Sahel shows the strongest soil moisture/climate coupling (Koster et al., 2006). In this context, it has been shown that the vegetation degradation has a role in the drought events in the Sahel, through the increase in albedo and the reduction of evaporation, leading to reduced net radiation and inhibited convection, respectively, which in turn weaken the monsoonal circulation (Xue, 2004).

Modeling the west African climate

In the last 15 years, a big effort has been made to understand climate variability and change in West Africa. The African Monsoon Multidisciplinary Analysis program (AMMA; http://amma-international.org/), launched in 2002 and involving a number of research institutions in the international scientific community, was the first large scale coordinated program aiming to improve the understanding of the WAM system and its influence on the physical, chemical and biological environment, regionally, and globally. The AMMA community is still active to provide the underpinning science to assess the impacts of WAM variability on health, water resources, food security and demography in the West African countries, and to define and implement monitoring and prediction strategies (Redelsperger et al., 2006). Specifically addressed to climate modeling issues, the WAM Modeling and Evaluation project (WAMME; Druyan, 2011) is an initiative designed to evaluate the performance of global and regional climate models (GCMs and RCMs, respectively) in simulating the WAM dynamics and associated precipitation.

In the context of the Coupled Model Intercomparison Project Phase 3 and 5 (CMIP3 (Meehl et al., 2007) and CMIP5 (Taylor et al., 2012), respectively, a World Climate Research Programme (WCRP, http://www.wcrp-climate.org/) standard experimental protocol for studying the output of coupled atmosphere-ocean GCMs, climate variability in West Africa is extensively studied, with promising but still unsatisfying results. Specifically, state-of-the-art climate models in both CMIP3 and CMIP5 exercises show low skill in simulating the observed WAM variability (amplitude, phases, and trends), and sizable uncertainties affect projections in the twenty-first century, ranging from dry to wet conditions in the Sahel (Biasutti, 2013). Although coupled models generally well reproduce the relationship between the regional atmospheric circulation and the monsoonal precipitation, during both the twentieth and the twenty-first century, the same models show discrepancies in future projections (Biasutti et al., 2009). Therefore, model shortcomings can be firstly related to the ability in reproducing the large scale mechanisms which influence the regional atmospheric circulation, and especially the teleconnections with the global SST teleconnections (Biasutti et al., 2009; Rowell, 2013). An important source of uncertainty in the modeling of climate change in West Africa is also the model responses to the direct and indirect CO2 radiative forcing in the atmosphere: the former rapidly warms the continental surface, inducing a positive response in the WAM precipitation; the latter slowly warms the ocean surface, inducing dry conditions (Giannini, 2010). It has been shown that wet and dry model biases over West Africa may be related to an unbalanced model response to the direct and indirect CO2 forcing (Gaetani et al., 2016). At a regional scale, limitations in the model representation of SST in the Tropical Atlantic (Roehrig et al., 2013), surface heat fluxes (Xue et al., 2010), vegetation feedback (Kucharski et al., 2013), land use (Bamba Sylla et al., 2016), and mineral dust atmospheric concentration (Tompkins et al., 2005) are sources of incorrect simulations of the temporal and spatial variability of the WAM precipitation. Finally, the coarse resolution typical of GCMs limits the model ability to simulate the intense and organized convection characterizing the WAM (Vellinga et al., 2016). The assessment of model performances is critical to understand the sources of errors and limit uncertainties, but an overall and objective evaluation is a particularly difficult task, because results may differ depending on the specific variable analyzed and the metrics used. In the CMIP5 archive, a discrimination in the model performances for the historical climate may be achieved, but uncertainty in the projections is not reduced when skillful models are selected (Rowell et al., 2016). This suggests that the underlying assumption relating the model shortcomings in simulating past, present and future climate in West Africa is incorrect, being the assumption that the same modeled processes lead to errors in the simulation of the historical climate and uncertainty in projected change (Rowell et al., 2016). Therefore, further research, based on the understanding of the mechanisms that drive the errors and uncertainty in projected changes, is needed to discriminate model performances.

In the CMIP5 exercise, a specific effort had been devoted to climate prediction at decadal time scales (10–30 years), which is recognized as a key planning horizon in a socioeconomic perspective (Doblas-Reyes et al., 2013). Results demonstrate that the WAM variability at decadal time scales is influenced by both the global SST natural variability and the green-house gases (GHG) external forcing, and the prediction skill is highly model dependent (Gaetani and Mohino, 2013; Martin and Thorncroft, 2014; Otero et al., 2015). Specifically, highest skill models are characterized by the ability in reproducing the WAM connection with, primarily, the Atlantic multidecadal variability (Gaetani and Mohino, 2013) and, secondly, with the relative SST difference between the subtropical North Atlantic and the tropics and Mediterranean SST (Martin and Thorncroft, 2014).

In the framework of the Coordinated Regional Climate Downscaling Experiment (CORDEX, http://www.cordex.org/), a WCRP initiative for the assessment and comparison of RCM skills in diverse regions, CORDEX-Africa provides a set of state-of-the-art simulations and predictions for the West African climate at high resolution (Nikulin et al., 2012). The availability of reliable climate simulations at high spatial-temporal resolution is crucial for a robust assessment of climate impacts at regional scale, and the CORDEX-Africa exercise shows encouraging results for West Africa. The dynamical downscaling of GCMs, operated at higher resolution by the RCMs, leads to improvements in the simulation of the atmospheric circulation, temperature and precipitation climatology, as well as the occurrence of wet and dry spells, the frequency of heavy rain events, and the drought geographical distribution (Laprise et al., 2013; Bucchignani et al., 2016; Buontempo et al., 2015; Diasso and Abiodun, 2015; Dosio et al., 2015), although the biases in the lateral boundary conditions provided by the driving GCMs may significantly affect the RCMs outputs (Laprise et al., 2013; Dosio et al., 2015). Being the GCM biases more pronounced over the Tropical Atlantic, the RCM performances are in general better over the Sahel than in the Guinean coast, which is more influenced by the local SST variability (Paxian et al., 2016). Uncertainties in the simulation of daily precipitation are also observed, mainly related to the diverse convection schemes utilized in the CORDEX-Africa models (Klutse et al., 2016). However, the spread in the individual model performances is substantially improved when the ensemble mean is computed (Klutse et al., 2016).

Recent climate change

After the devastating drought of the 70s–80s, West Africa is nowadays experiencing a partial recovery of precipitation, with a coherent increase in the annual rainfall in the Sahel (29–43 mm/year per decade in the period 1983–2010; Maidment et al., 2015). This recovery is characterized by a modification of the seasonal cycle, showing a delay of the monsoon retreat in the Sahel (two days per decade in the period 1983–2010; Sanogo et al., 2015), and by a change in the rainfall regime, showing a decrease in the number of rainy days and an increase in the proportion of annual rainfall associated with extreme events (17% in the period 1970-1990 and 21% in the period 2001–2010; Panthou et al., 2014). This precipitation recovery is accompanied by a stable rainfall/vegetation trend (Hoscilo et al., 2015). The recent climate change is also characterized by modifications in terms of atmospheric circulation and surface temperature. The meridional overturning cell associated with the monsoonal circulation is shifted ~1° northward, with changes in the convection belt in West Africa and the subsidence over the Mediterranean region (Fontaine et al., 2011b). Moreover, an amplified warming of the Sahara desert is detected (Cook and Vizy, 2015), and the Saharan heat low shows an intensification (Lavaysse et al., 2015) with reduced desert dust emission in summer (Wang et al., 2015). The origin of this climate change signal in the Sahara region has been related to the direct radiative forcing of the increased CO2 concentration (Gaetani et al., 2016) and to an augmented moisture availability in the lower troposphere over the desert, triggering a water vapor-temperature feedback (Evan et al., 2015). The changes in the regional atmospheric dynamics accompanies positive temperature anomalies and extremes in spring and summer in the Sahel (Fontaine et al., 2013; Russo et al., 2016). Using a network of 90 in situ observations in West Africa, Moron et al. (2016) found that the linear trends of annual mean maximum and minimum temperature equal respectively +0.021°C/year and +0.028°C/year.

The debate on the origin of the recent precipitation recovery in West Africa and the associated modifications in the regional atmospheric dynamics is open and heated, and the positions may be conveyed into two main arguments. On the one hand, the recovery is ascribed to the northward migration of the ITCZ in response to the SST warming at end of the twentieth century, which was stronger in the Northern Hemisphere than in Global Tropical Ocean (Park et al., 2014). A role of the warming of the subtropical North Atlantic in providing the moisture to feed the monsoonal system has been identified (Giannini et al., 2013). On the other hand, a dominant role of the direct GHG radiative forcing is hypothesized, acting by warming the surface and increasing evaporation over the continental surface (Dong and Sutton, 2015).

Future projections

In the CMIP5 exercise, a positive trend in the WAM precipitation results from the multi-model mean in the twenty-first century, though the individual model projections are characterized by a large spread (Biasutti, 2013). Indeed, about 50% of the model runs in the CMIP5 archive shows a robust positive trend, about 25% shows a robust decreasing trend, while the trend is negligible in the remaining 25% (Biasutti, 2013). In the models predicting wet conditions, these are related to the direct radiative effect of the increase in GHG concentration, leading to local increased evaporation and vertical instability (Hoerling et al., 2006; Giannini, 2010). On the contrary, models projecting dry conditions simulate reduced moisture transport and deep convection over land as a response to the global ocean warming, which heats the troposphere and imposes stability (Held et al., 2005; Caminade and Terray, 2010). Therefore, the competition between the response of the land-atmosphere system to the local GHG radiative forcing, and the response mediated through the warming of the global SST, emerges as a key component of the West African climate change (Bony et al., 2013; Gaetani et al., 2016), and understanding the relative impact of these two diverse forcings represents a task of primary importance for the climate modeling community.

The future projection in precipitation simulated by climate models in the twenty-first century is not spatially homogeneous over the Sahel. Indeed, future wet conditions in central-eastern Sahel (east of ~0°E) contrast with dry anomalies over western Sahel (west of ~0°E), and these sub-regional trends are more robust than the trend simulated in the extended Sahelian belt (Monerie et al., 20122013; Biasutti, 2013). The rainfall excess expected in central-eastern Sahel is mainly linked to a strengthening and northward shift of the meridional overturning circulation over West Africa, reinforcing the monsoonal flow, with a feedback in the lower levels from the increased temperature and evaporation associated with the GHG radiative forcing (Monerie et al., 2012). The projected dry spot over western Sahel is associated with a reinforcement of the African easterly jet and modifications in the overturning zonal circulation connecting the Indian and Atlantic Oceans, which result in anomalous subsidence on its descending branch over subtropical North Atlantic (Monerie et al., 2012). Moreover, this east-west anomaly dipole in precipitation is consistent with the recently observed long term intensification of the Saharan heat low (Lavaysse et al., 2015). The projected rainfall trends result to be gradually enhanced and extended in future scenarios with a global warming of 2–4°C and beyond, showing an approximately linear amplification with no tipping points being reached (James and Washington, 2013; James et al., 2014). The twenty-first century evolution of the WAM precipitation simulated by a subset of the CMIP5 models is illustrated in Figure ​Figure11.

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Open in a separate windowFigure 1

WAM precipitation evolution in the twenty-first century, simulated by 12 CMIP5 models in the RCP8.5 scenario (van Vuuren, 2011). (A) Projected change in multi-model mean of the July-to-September (JAS) precipitation [mm/day] at the end of the twenty-first century (2081-2100), represented by computing the difference with the period 2006-2025. Significance is estimated through a Student’s t-test at 90% level of confidence. Time series of the WAM precipitation averaged in (B) Sahel [15°W-30°E, 7-20°N], (C) western Sahel (west of 5°W) and (D) central-eastern Sahel (east of 5°E). The twenty-first century anomalies are computed regarding the period 2006-2015. The models analyzed are: BCC-CSM1-1, CanESM2, CCSM4, CNRM-CM5, FGOALS-g2, HadGEM2-CC, IPSL-CM5A-LR, IPSL-CM5B-LR, MIROC5, MPI-ESM-LR, MPI-ESM-MR, MRI-CGCM3. For data availability and accessibility, the reader may refer to the CMIP5 web portal at http://cmip-pcmdi.llnl.gov/cmip5/availability.html.

The WAM seasonal cycle is also affected by climate change in the twenty-first century. The projected precipitation increase in the central-eastern Sahel is characterized by a robust increase of the rainfall amounts in September-October (70% of the CMIP5 model runs; Biasutti, 2013). This results in a delay of the monsoon withdrawal, with a lengthening of the monsoon season (Monerie et al., 2016). The moisture transport dominates the water budget change in September, while the local recycling role is prominent in October (Monerie et al., 2016). Conversely, the drying of the western Sahel appears to be concentrated in June-July in 80% of the CMIP5 model runs (Biasutti, 2013). The future modifications in the WAM seasonal cycle are accompanied by coherent changes in the African easterly wave activity, showing a reduction in late spring and early summer and a large increase between July and October, although large differences exists in African easterly wave projections between high- and low-resolution models (Skinner and Diffenbaugh, 2014; Martin and Thorncroft, 2015).

In contrast to the uncertainties affecting the future projection of the West African rainfall, a broad consensus characterizes the model simulations of the surface temperature for the twenty-first century. The future change in the monsoonal regime will be accompanied by a general warming of the African continent, with a maximum over the Sahara desert, ranging between 3 and 7°C, depending on the model and the emission scenario (Monerie et al., 2012; Dike et al., 2015). Boreal winter in West Africa will be also affected by a 2–3°C warming, with the strongest anomalies over the Guinea coast (Dike et al., 2015).

High resolution RCMs provide a detailed description of the future climate change in West Africa, generally agreeing with GCMs on the temperature projection in the region. A robust warming is predicted throughout the twenty-first century, although even large differences (more than 1°C) with the driving GCMs exist locally (Laprise et al., 2013; Dosio and Panitz, 2016). This will be accompanied, in the mid-twenty-first-century, by an increase in the number of heat wave days, by 20–120 days per year over the Sahel, by 20–60 days over Western Sahara, and by 5–40 days over eastern Sahara (Vizy and Cook, 2012). Moreover, half of the CORDEX-Africa projections suggests that heat waves that are unusual under present climate conditions in West Africa, will occur on a regular basis by 2040 under high emission scenarios (Russo et al., 2016). Finally, in the mid-twenty-first-century, daily maximum and minimum temperatures are projected to increase, and the daily diurnal temperature range to decrease, by 0.3–1.2°C during boreal spring and fall over West Africa, and by 0.5–1.5°C during boreal summer over the Sahel (Vizy and Cook, 2012).

The number of dry days is predicted to decrease by 3–7% over central Africa in spring and over eastern Sahel in summer. Conversely, the occurrence of extreme wet days will increase over West Africa by 40–60% (1–4 days) and the southern Sahel by 50–90% (1–4 days), uniformly during boreal summer. The associated changes in extreme wet rainfall intensity show a regional response, including a 30–70% decrease over northern Niger and northeastern Mali, and a 10–25% increase over Senegal, southern Mali, Burkina Faso, northern Nigeria, and southern Chad (Vizy and Cook, 2012). However, future RCM rainfall projections are affected by large uncertainties. On the one hand, RCMs tend to inherit the biases of the driving GCMs, so that a RCM downscaling several GCMs reproduces the inter-GCM spread, though with a reduced amplitude (Buontempo et al., 2015; Dosio and Panitz, 2016). On the other hand, a RCM may project its own trend regardless the inter-model spread of the driving GCMs, due to the differences in the specific physical formulation of RCMs and GCMs (Laprise et al., 2013; Buontempo et al., 2015; Saini et al., 2015).

Finally, it has been recently pointed out that the projected modification in the atmospheric dynamics over North Africa may impact the Saharan dust emission and atmospheric concentration, leading to a significant negative trend in the twenty-first century (Evan et al., 2016). Other than on human health in the region, expected to be benefitted, the reduction in dust concentration may have a positive feedback on the monsoonal precipitation, through a reduction in the associated surface cooling and lower troposphere heating, favoring atmospheric instability (Yoshioka et al., 2007; Ji et al., 2016).Go to:

The impact on crop yield and potential for adaptation

Predicting crop yield from GCM simulations

Crop models

Predicting the potential impacts of climate change on crop yields requires a model of how crops respond to future conditions induced by anthropogenic climate change, such as: warmer temperatures, more frequent extreme temperatures, possible changes in rainfall mean, seasonality spatial and temporal distribution. In addition, there is a direct impact of atmospheric composition on crops with elevated levels of carbon dioxide acting to increase crop yields through the stimulation of photosynthesis and reduction of drought stress (Tubiello et al., 2007; Leakey, 2009) while elevated levels of atmospheric ozone which are expected in developing countries like Africa (Royal Society, 2008) can lead to yield losses (Van Dingenen et al., 2008). Crop models typically simulate the response of the crop to variability and change in weather and climate related to temperature, precipitation and radiation, and atmospheric CO2concentration (Ewert et al., 2015). There are numerous crop models with different levels of sophistication (Di Paola et al., 2016) and several reviews can be found in the literature, describing the concepts and limitations (see for instance Boote et al., 1996; White et al., 2011; Affholder et al., 2012; Ewert et al., 2015; Di Paola et al., 2016). Crop models can be roughly divided into two categories: statistical models trained on historical yields and some simplified measurements of weather, such as growing season average temperature and precipitation (Lobell and Burke, 2009) and process-based crop models which simulate explicitly the main processes of crop growth and development (see for instance Ewert et al., 2015). Table ​Table11shows a selection of models that have been used to assess the impact of climate change on yields of various crops in West Africa. If the use of process-based models for climate change impact and risk assessment studies has become increasingly important (Tubiello and Ewert, 2002; Challinor et al., 2009; White et al., 2011; Rötter et al., 2012; Angulo et al., 2013; Ewert et al., 2015) since they are able to simulate impacts of climate, CO2 concentrations on bio-physical processes (e.g., phenology, photosynthesis, respiration, transpiration, and soil evaporation) and other production constraints such as N limitations, these models require extensive input data on cultivar, management, and soil conditions as well as calibration and validation data that are often unavailable in Africa (Lobell and Burke, 2010). Even in the presence of such data these models can be very difficult to calibrate because of a large numbers of uncertain parameters (Iizumi et al., 2009; Tao et al., 2009). Furthermore, research effort in crop modeling has focused on the world’s major food crops such as wheat, maize, rize, and sorghum and the simulation of crops common in African farming systems (sorghum, millets, yam) is less well developed as well as simulations of crops grown as intercrops across Africa (Challinor et al., 2007; White et al., 2011). Ensemble modeling including a variety of crop models is thus highly recommended to enable a quantification of the uncertainty (Challinor et al., 2009). In this context, extensive model intercomparisons such as the ones conducted throughout the Agricultural Model Intercomparison and Improvement Project (AgMIP; http://www.agmip.org/; Rosenzweig et al., 2014), which includes Sub-Saharan Africa as one of the target region (Adiku et al., 2015), are likely to improve substantially the characterization of the threat of crop yield losses and food insecurity due to climate change.

Table 1

A selection of crop models (including combination between crop models) that have been used to assess the impact of climate change on yields of various crops in West Africa in the recent scientific literature.

Crop modelAreaCropReferences
EPICNigeriaCassava, maize, millet, rice, sorghumAdejuwon, 2006
EmpiricalNigerMilletBen Mohamed et al., 2002
EPIC + PHYGROW + NUTBALMaliCotton, cowpea, groundnut, maize, millet, sorghumButt et al., 2005
AEZ + BLSSub-Saharan AfricaGlobalFischer et al., 2005
IMPACT + DSSATSub-Saharan AfricaGlobal, maize, millet, rice, sorgum, wheat, soybean, groundnutNelson et al., 2009
CERES − maizeWest AfricaMaizeJones and Thornton, 2003
CERES − maize + EmpiricalNiger, Nigeria, Mali, Guinea, Ivory Coast, CamerounMaizeLobell and Burke, 2010
GEPICSub-Saharan Africa, West AfricaGlobal, cassava, maize, millet, rice, sorghum, wheatLiu et al., 2008
EmpiricalWest AfricaCassava, groundnut, maize, millet, rice, sorghum, wheat, yamsLobell et al., 2008
LPJmLWest AfricaGlobalMüller et al., 2010
MOS (empirical)BeninBeans, cassava, cotton, groundnut, maize, rice, sorghum, yamsPaeth et al., 2008
Empirical + BLSWest AfricaGlobalParry et al., 2004
DSSATNiger, Burkina FasoMillet (two cultivars), sorghumSalack, 2006
EmpiricalWest AfricaCassava, groundnut, maize, millet, sorghumSchlenker and Lobell, 2010
DSSATGambiaGroundnut, maize, millet late, millet earlySmith et al., 1996
CropsystCameroonBambara nut, groundnut, maize, sorghum, soybeanTingem and Rivington, 2009
EmpiricalNigerCowpea, groundnutVanduivenbooden et al., 2002
SARRA-H + APSIMWest AfricaSorghum (two cultivars)Sultan et al., 2014
SARRA-HWest AfricaMillet (three cultivars), Sorghum (three cultivars)Sultan et al., 2013
CROPGROCameroonCottonGerardeaux et al., 2013
EPIC + GEPIC + LPJ-GUESS + pDSSAT + PEGASUSBurkina Faso, SenegalMaize, Wheat, Soybean, Rice, Millet, Sorghum, Sugarcane, Beans, Cassava, Cotton, Sunflower, GroundnutDeryng, 2015
SARRA-H + EPICNiger, BeninMaize, MilletRamarohetra et al., 2015
DSSATNigerMilletRezaei et al., 2014
EPICBeninYam (early and late cultivars)Srivastava et al., 2015
EPICBeninMaizeGaiser et al., 2010
ORCHIDEEWest AfricaC4 cropBerg et al., 2013
GLAMWest AfricaGroundnutParkes et al., 2015
GEPICSub-Saharan AfricaMaizeFolberth et al., 2014
DSSAT + APSIMSenegal, GhanaMaize, Millet, PeanutAdiku et al., 2015
EcoCropAfricaMaize, millets, sorghum, banana, and beansJarvis et al., 2012

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Link with climate

The use of climate projections from GCMs to force crop models is challenging and raises several important issues. First, combining GCMs and process-based crop models raises a scale mismatch since climate models typically operate on spatial scales much larger than the processes governing the yields at the plot scale and most factors affecting crops such as soil properties and farming practices (Baron et al., 2005; Challinor et al., 2009). To overcome this issue, climate data can be downscaled to the scale of a crop model with two types of downscaling approaches that can be sometimes combined (see for instance Zorita and von Storch, 1999). Statistical downscaling relies on the use of empirical relationships between mesoscale and local climate observed variables to relate GCM output to local climate (Zorita and von Storch, 1999). An alternative approach is the use of dynamical downscaling which offers a self-consistent approach that captures fine-scale topographic features and coastal boundaries by using regional climate models (RCMs) with a fine resolution (~10–50 km) nested in the GCM (Paeth et al., 2011; Glotter et al., 2014). The use of dynamical downscaling in long-range climate projections has recently increased with the growth of computing resources and large simulations databases of downscaled climate outputs are available for intercomparison and impacts assessment (Glotter et al., 2014). For instance the international Coordinated Regional Climate Downscaling Experiment Africa (CORDEX Africa) simulations are now publicly available and used in the literature, including a downscaled subset of GCMs simulations with different RCMs (Diallo et al., 2016). However, although it can improve weather and climate variability (Feser et al., 2011; Gutmann et al., 2012) as well as crop yield projections (e.g., Mearns et al., 19992001; Adams et al., 2003; Tsvetsinskaya et al., 2003), it is important to keep in mind that downscaling is an additional source of errors and uncertainties to crop yield projections. For example, when different RCMs were used to downscale atmospheric re-analyses to force the SARRA-H crop model in Senegal, Oettli et al. (2011), large differences were found in the simulated sorghum yields depending on the RCM used. More recently, Ramarohetra et al. (2015) conducted a sensitivity analysis of the WRF model and found that a change in the physical parameterizations of a single RCM as well as internal variability of the RCM can lead to major changes in the simulation of crop yields of millet and maize in West Africa. As alternative to downscaling, the use of large-area crop modeling has grown in recent years (Challinor et al., 20042009; Tao et al., 2009). This approach offers the possibility of using the outputs from climate models directly in a process-based way, suppressing the needs for downscaling, has grown in the literature (Challinor et al., 20042009). Several models have been used in West Africa like the GLAM model used to simulate groundnut (Parkes et al., 2015) or LPJ-ml (Müller et al., 2010) and ORCHIDEE (Berg et al., 20112013) which are part of Earth System vegetation models in which they account for tropical croplands.

The second issue raised by the use of GCM for assessing climate impacts is that climate models show significant biases in simulating current climate with sometimes insufficient skill for GCM outputs to be used directly as inputs for impact models without prior bias correction (Semenov and Barrow, 1997). If bias-correction is often included into statistical downscaling, the skill of representing the present-day climate can be very low using regional downscaling (Oettli et al., 2011). Since impact models ultimately rely on the accuracy of climate input data (Berg et al., 2010), the errors inevitably propagated into the combined climate/crop modeling (Oettli et al., 2011; Glotter et al., 2014; Ramarohetra et al., 2015). For instance, using two RCMs and the DSSAT-CERES-maize crop model over the United States, Glotter et al. (2014) showed that although the RCMs correct some GCM biases related to fine-scale geographic features, the use of a RCM cannot compensate for broad-scale systematic errors that dominate the errors for simulated maize yields. Moreover, Ramirez-Villegas et al. (2013) suggested that the use of raw GCM outputs can even affect the estimation of the climate change impact on crop yields by significantly under- or overestimate cropping system sensitivity by 2.5–7.5% for precipitation-driven areas and 1.3–23% for temperature-driven areas. Thus, careful evaluation of climate models using regional key drivers of crop yields (Berg et al., 2010; Ramirez-Villegas et al., 2013; Guan et al., 2015) is needed to make the best use of climate change simulations for impact research. Large errors have been found in the simulation of the WAM rainfall by climate models which usually suffer from too much drizzle and a large bias in rainfall frequency, large errors in simulating seasonal rainfall as well as an underestimation of the interannual variability which can subsequently bias simulated crop yield (Baron et al., 2005; Berg et al., 2010; Ramirez-Villegas et al., 2013; Guan et al., 2015). Significant biases have also been found CMIP5 simulations for mean temperature and diurnal temperature ranges in West Africa (Ramirez-Villegas et al., 2013). To overcome this issue, climate impact studies generally require some level of climate data bias correction. The simplest correction method is the delta method used by Müller et al. (2010) or Sultan et al. (2013) which consists to add a computed mean annual anomaly between future and current simulated climates of a given GCM to a current observation-based dataset. Promising results are obtained by Oettli et al. (2011) when applying a more complex bias correction technique (Michelangeli et al., 2009) to climate model outputs. In particular the authors showed that means and standard deviations of simulated yields of sorghum in Senegal are much more realistic with bias corrected climate variables than those using raw climate models outputs.

Another important issue which has already been discussed in Section Climate Change Scenarios is the large plausible range of future climate changes at the regional scale of West Africa. Although there are some robust features in climate change scenarios in the region (see Section Climate Change Scenarios), there is a wide spread in current climate model projections of regional rainfall changes over West Africa, especially with respect to summertime rainfall totals (Druyan, 2011) which are crucial for yields of staple food crops in West Africa (Berg et al., 2010; Guan et al., 2015). Up to now, using the largest number of GCMs from the CMIP5 ensemble of around 36 GCMs remains the best way to represent the range of climate futures in impact assessment. Knox et al. (2012) showed that increasing the number of climate models used to force crop models reduces the median range and outliers about the mean change in future yields. Important biases or underestimation of uncertainties can be expected from climate impact assessments based on subsets of CMIP datasets, and similarly from downscaled or bias-corrected datasets (like CORDEX) which are based on a restricted subset of GCMs. This point is illustrated by McSweeney and Jones (2016) who investigated how well the widely used Inter-Sectoral Impact Model Inter-comparison Project (ISI-MIP) subset of five CMIP5 models (see for instance Adiku et al., 2015) represent the plausible range of future climate changes. They found that the fraction of the full range of future projections captured by the ISI-MIP subset is sometimes very low depending on the variable, the season and the region especially for summer rainfall and temperatures in the Western part of West Africa (McSweeney and Jones, 2016).

Assessing climate impacts

The overall signal

Although there is a growing literature on the impact of climate change on crop productivity in tropical regions, it is difficult to provide a consistent assessment of future yield changes because of large uncertainties in regional climate change projections, in the response of crops to environmental change (rainfall, temperature, CO2 concentration), in the coupling between climate models and crop productivity functions, and in the adaptation of agricultural systems to progressive climate change (Challinor et al., 2007; Roudier et al., 2011). These uncertainties result in a large spread of crop yield projections indicating a low confidence in future yield projections. As an example of the diversity of yield scenarios that have been produced, Roudier et al. (2011) found that the response of crop yield to climate in change in West Africa can vary from −50% to +90% in a selection of 16 publications. This range is even larger in the review made by Müller et al. (2010) which showed that projected impacts relative to current African production levels range from −100% to +168%. This range reflects the variety of regions, crops, climate scenarios and models and crop models chosen in the studies.

To identify the main sources of uncertainty and establish robust estimates of the aggregate effects of climate change on crop yields, meta-analyses were conducted at the global scale by Challinor et al. (2014) to contribute to the food security and food production systems chapter of the Fifth Assessment Report (AR5) of the IPCC and at the regional scale, including West Africa (Roudier et al., 2011; Knox et al., 2012). Meta-analyses that combine and compare results from numerous studies are widely used in epidemiology and medicine and can be a useful way of summarizing the range of projected outcomes in the literature and assessing consensus. The meta-analysis conducted by Challinor et al. (2014) used a data set of more than 1700 published simulations to evaluate yield impacts of climate change and adaptation which is the largest pool of data from diverse modeling studies ever used for a global synthesis of this kind (Rötter, 2014). The meta-analyses published by Knox et al. (2012) and Roudier et al. (2011) are based on a smaller data set (1144 and 347 published simulations respectively) but concern specific regions: Asia and Africa in database compiled by Knox et al. (2012) and only West Africa in the database compiled by Roudier et al. (2011). These latter two meta-analyses also include the response of relevant crops in Africa (maize, sorghum, millet, rice, cotton, cassava, groundnut, yam) while the meta-analysis conducted by Challinor et al. (2014) includes only major crops such as maize, rice and wheat; maize and rice being the only crops of the study grown in West Africa. Interestingly, while there are all based on different approaches and different samples, the three studies came out with similar conclusions on how climate change will affect crop yield in West Africa and how this response varies across the different assumptions and methodological choices. While the magnitude of the response of crop yield to climate warming scenarios varies considerably in the simulations reported by Challinor et al. (2014), Knox et al. (2012) and Roudier et al. (2011), the sign of the change is mostly negative with a mean yield reduction of −8% was identified in all Africa (Knox et al., 2012) and −11% in West Africa (Roudier et al., 2014). Maize was found to be the most affected crop in West Africa and in the Sahel by Knox et al. (2012). Without adaptation, the mean response of major crops (mostly maize and rice) to climate change depicted by Challinor et al. (2014) in tropical regions is a yield reduction. This robust yield loss is already significant at moderate levels of local warming (+2°C) but is more consensual and stronger in the second half of the century when the additional radiative forcing is amplified. If this negative impact on crop yield was already depicted in the previous IPCC report, it suggested such yield loss would only occur when exceeding 3–4°C local warming which might be due to an overestimation in previous studies of the yield benefits of enhanced atmospheric CO2 (Rötter, 2014).

Such robust evidence of future yield loss in West Africa also confirmed in previous review of the literature (Challinor et al., 2007; Kotir, 2010; Müller et al., 2010) can be surprising in regards to the diverging projections in a warmer climate of summer monsoon rainfall. This is because of the adverse role of higher temperatures in shortening the crop cycle duration and increasing evapotranspiration demand and thus reducing crop yields, irrespective of rainfall changes (Schlenker and Lobell, 2010; Roudier et al., 2011; Berg et al., 2013; Sultan et al., 2013). Potential wetter conditions or elevated CO2 concentrations hardly counteract the adverse effect of higher temperatures (Sultan et al., 2014) while dryer conditions can strongly amplify the yield losses (Schlenker and Lobell, 2010; Roudier et al., 2011; Sultan et al., 20132014).

Crop model differences

The response of the crop to climate change is subject to uncertainty that can arise from several sources (Challinor et al., 2009). In particular, significant differences were found in yield response from process-based vs. statistical models. Knox et al. (2012) and Roudier et al. (2011) both found that the dispersion around the mean is greater using process-based crop models. Furthermore, Challinor et al. (2014) found that statistical models predict a greater negative impact of climate on crop yields. The review of Müller et al. (2010) based on recent climate change impact assessments (14 quantitative, six qualitative) in Africa also stressed this larger dispersion with projected impacts relative to current production levels range from −84% to +62% in process-based and from −57% to +30% in statistical assessments. The larger dispersion of process-based crop models can be induced by the fact that they incorporate more complex factors in the yield response to climate change (CO2 effect, rainfall distribution, extreme temperatures) but also that the lack of sufficient data for accurate calibration and validation (Lobell and Burke, 2010; Lobell et al., 2011) and site specific parametrization of the crop management options and cultivars (Müller et al., 2010) in developing countries such in as Africa increase uncertainty in the crop response. More recently, systematic intercomparison studies of climate change impacts in West Africa were conducted using five process-based crop models (EPIC, GEPIC, LPJ-GUESS, pDSSAT, and PEGASUS; see Deryng, 2015) and two process-based crop models (DSSAT and APSIM in Adiku et al., 2015; SARRA-H and APSIM in Sultan et al., 2014) using the same forcing climate datasets. They all found a general agreement in the sign of the crop yield response to climate change scenarios while the amplitude of the impact varied strongly across models and simulated crops.

Regional differences

Important regional differences have been found in the response of crop yield to climate change. Roudier et al. (2011) found that cropped areas in the Soudano-Sahelian zone are likely to be more affected by climate change than those located in the Guinean zone. This difference can be explained by the projections of future climate in Africa which show a greater warming over continental Africa (particularly in the Sahel and Sahara) while the temperatures of the Guinean zone, which are influenced by the Atlantic Ocean, are expected to increase more slowly.

Using simulations of nine bias-corrected CMIP5 climate models and two crop models (SARRA-H and APSIM), Sultan et al. (2014) found a West-East dipole in the impacts of crop yield to climate change in West Africa. Indeed, in broad agreement with the full CMIP5 ensemble, their subset of bias-corrected climate models depicted a robust change in rainfall in West Africa with less rain in the Western part of the Sahel (Senegal, South-West Mali) and more rain in Central Sahel (Burkina Faso, South-West Niger) in the decades of 2031–2060 compared to a baseline of 1961–1990. In response to such climate change, but without accounting for direct crop responses to CO2, mean crop yield of sorghum decreases by about 16–20% and year-to-year variability increases in the Western part of the Sahel, while the eastern domain sees much milder impacts. This West-East dipole is confirmed by the study of Deryng (2015) which uses a set of five global climate models and six different global gridded crop models to assess climate change impacts on crop productivity in semi-arid croplands by the 2030s under the RCP 8.5 scenario. Without including the effect of elevated CO2 on crop photosynthesis and water demand, the author shows in Senegal, where three over five GCMs simulate drier conditions a median decrease of rainfed crop (−8.5 ± 9.9%) while in the Eastern part of West Africa in Burkina Faso, where four of the five GCMs simulate wetter conditions, the results show a slight decrease (−3.9 ± 4.3%). This dipole was also found in the study of Adiku et al. (2015) which used DSSAT and APSIM to simulate climate change impacts on crop yields in two locations in Nioro (Senegal) and Navrongo (Ghana). The effect of climate change was higher in the Senegalese site than in the one in Ghana using both crop simulation models.

The effect of elevated CO2

If rising atmospheric CO2 concentrations directly contributes to climate change, it has the potential to increase crop water productivity by enhancing photosynthesis and reducing leaf-level transpiration of plants (Tubiello et al., 2007; Leakey, 2009; Deryng et al., 2016). Significant increases of crop yield due to elevated levels of CO2 have been reported in experiments for different crops (Kimball, 1983; Kimball et al., 2002) and most of the recent modeling studies simulate the effect of elevated CO2(Deryng et al., 2016). However, there is an ongoing debate about the extent of impacts of CO2 fertilization on crop yields in observations and models (Long et al., 2006; Ainsworth et al., 2008), especially in Africa where few field observations are unavailable to validate and further improve the models. In particular there is no free air carbon dioxide enrichment (FACE) experiments in Africa. Yet, the impact of higher atmospheric CO2 concentration is a major source of uncertainty in crop yield projections (Soussana et al., 2010; Roudier et al., 2011). For instance, by conducting a systematic comparison between yield response to climate change with, or without, CO2 fertilization effect, Müller et al. (2010) found a yield increase of 8% in Africa (percent change in 2046–2055 relative to 1996–2005) with full CO2 fertilization, and a yield loss of −8% without the CO2 effect. More recently, Deryng (2015) found that simulated median yield of rain-fed crops in six countries of semi-arid areas (including Senegal and Burkina Faso in West Africa) increases by 4.7 ± 9.6% when including the effects of both climate change and elevated CO2 concentrations while median yield decreases by 4.5 ± 7.3% when excluding the effects of elevated CO2 concentrations. Sultan et al. (2014) also found that CO2 fertilization would significantly reduce the negative climate impacts, increasing sorghum yields on average by 10%, and drier regions would have the largest benefits. However, other studies show lower differences between full and no CO2 fertilization scenarios (Berg et al., 2013). Overall most studies conclude that benefits of elevated CO2 will be greater for C3 crops (e.g., soybean, groundnut) which are likely to accumulate more biomass and for C4 crops in arid regions through increased water use efficiency (Berg et al., 2013; Sultan et al., 2014; Deryng et al., 2016). However, while showing benefits of higher CO2 concentrations on water crop productivity, Deryng (2015) and Sultan et al. (2014) both show that it partially offsets the impacts from climate changes especially in the Western part of Africa where yield losses are expected even after accounting for CO2 fertilization effect. Deryng (2015) found a decrease of crop yield of groundnut, millet, sorghum, and maize in Senegal by the 2030s even when including the effects of CO2. The author also found a slight increase of crop yield of millet and sorghum in Burkina Faso when including CO2 but yield of groundnut and maize decreases. Moreover, even if we can expect benefits from increasing CO2 on crop productivity, nutritional value may nevertheless be compromised (Müller et al., 2014). Indeed, a meta-analysis conducted by Myers et al. (2014) demonstrated that CO2 fertilization is likely to have adverse effects on the nutritional value of many key food crops by reducing the concentrations of essential minerals and protein with potential serious consequences in food security (Müller et al., 2014).

Adaptation studies

Despite large uncertainty, there is a robust conclusion from the above section: agriculture in West Africa is at risk to be negatively affected by climate change. These potential adverse negative climatic changes effects are superimposed on top of high natural variability in seasonal rainfall, which historically has produced large inter-annual variations in rainfall and prolonged droughts (Giannini et al., 2008) and the recent increase in rainfall intensity and extreme heavy-rainfall events (Panthou et al., 2014). Both climate variability and trend pose a challenge for the primarily rain-fed agriculture systems in West Africa. Since the 1970’s, the largest food crises in Africa that required large-scale external food aid (1974, 1984/1985, 1992, and 2002) have been attributed fully or partially to extreme weather events (Dilley et al., 2005). Thus, any successful adaptations should be able to cope with the short-term climate variability as well as reduce the negative impacts of climate change in the long term (Saba et al., 2013; Lobell, 2014). Hertel and Lobell (2014) distinguished between three categories of adaptation: (i) adaptation options based on current technology which can also identified as autonomous adaptation, (ii) adaptation involving a new technologies, and (iii) adaptations involving the institutional environment within which the producer is operating such as markets and policy and resulting from planned adaptation. Adjustments in planting and harvesting dates, varieties of crops to be grown (including combination between crops and cultivars as intercrop or the use of existing varieties more resistant to climate-induced stress), increase planting density and/or fertilizers use, use of crop residue as mulch are examples of options already available to farmers in West Africa to adapt to climate variability and change. Breeding more resilient crop varieties (Rötter et al., 2015), advanced breeding methods including more effective root system size, dehydrin genes, phenotyping (Araus et al., 2012; Setter, 2012; Vadez et al., 2012; Amelework et al., 2015); innovating water harvesting techniques (Lebel et al., 2015; Rockström and Falkenmark, 2015) belong to the second category of adaptation options. In the third category defined by Hertel and Lobell (2014), fertilizer subsidies, crop insurances (Berg et al., 2009), credits, climate services (access and use of weather and seasonal forecasts; Sultan et al., 2010; Roudier et al., 201220142016) are such important changes in the institutional and market environment of West Africa that would affect producer decisions. Assessing various possible adaptation options and their uncertainties is crucial for optimal prioritization of adaptation investments for supporting adaptation strategies in West Africa that may counteract the adverse effects of climate change. However, pointing out the most promising adaptation options remains challenging since there is a large scatter of possible results across locations and situations, indicating the need for a more contextual approach on regional and local scales (Challinor et al., 2014). We will thus give some examples of some recent studies who quantified the potential of adaptation for major crops in West Africa showing sometimes apparent contradictory and crop-specific results.

Millet and sorghum

These two crops are among the main staple crops of sub-Saharan West Africa (64% of the total cereal production in 2000; FAOSTAT, 2012 data). On-farm surveys have shown the dominance of traditional cultivars of sorghum and millet characterized by a strong sensitivity to photoperiod (Traore et al., 2011). Photoperiod sensitivity would likely present some advantages in the event of future change in the timing of the rainy season. Indeed, it allows for flowering at the end of the rainy season for a wide range of planting dates and avoids incomplete grain filling, a problem for late maturing varieties faced with water shortage at the end of the rainy season (Dingkuhn et al., 2006). Furthermore, Sultan et al. (2013) found that traditional photoperiod-sensitive cultivars are less affected by temperature increase since the photoperiod limits the reduction of the crop duration. On the opposite, adverse impacts of climate change have been found to be the lowest on mean yield and yield variability for photoperiod-insensitive cultivars, as their short and nearly fixed growth cycle appears to be more resilient to the seasonality shift of the monsoon, thus suggesting shorter season varieties could be considered a potential adaptation to ongoing climate changes (Sultan et al., 2014). This result is consistent with the study from Kouressy et al. (2008), which demonstrated that potentially high-yielding and photoperiod-insensitive cultivars display an advantage where the rainy season is short. Modeling studies (Turner and Rao, 2013; Sultan et al., 2014) suggest that while increasing fertilizer inputs and restoring nutrients imbalance in low-input, smallholder, sorghum farmers of Africa would increase overall food production and have fundamental benefits increasing food security (Vitousek et al., 2009), the trade-off is that it would increase the sensitivity of those systems to climate variability and increase adverse impacts of climate change.

Several studies also investigated new technologies for mitigating the adverse impacts of climate change on millet and sorghum production. Adiku et al. (2015) used two crop models DSSAT and APSIM to simulate millet cultivars adapted to future climate conditions. They found positive effects on crop yield whereas the benefits depend on the location, the crop and the climate model used for the simulation. Sultan et al. (2013) also found advantages of breeding varieties with higher thermal requirements which can partly counteract the shortening of crop-cycle duration in a warmer climate. Guan et al. (in press) used two crop models APSIM and SARRA-H to assess five possible and realistic adaptation options for the production of sorghum (late sowing, increase planting density and fertilizer use, increasing cultivars’ thermal time requirement, water harvesting, and increase resilience to heat stress during the flowering period). They found that most proposed adaptation options are not more beneficial in the future than in the historical climate so that they do not really reduce the climate change impacts. Increased temperature resilience during grain number formation period is the main adaptation that emerges from this study.

Maize

Maize is the most important staple food and accounts for nearly 20% of total calorie intake in sub-Saharan Africa (SSA) (FAOSTAT, 2012, data). In their meta-analysis, Challinor et al. (2014) compared the effect of climate change on maize yields in the Tropics with and without adaptation; adaptation options including changes in planting dates, fertilizer use, irrigation, cultivar or other agronomic options. They concluded that in contrast to what has been published for wheat and rice in the temperate latitudes, there is no effect of adaptation in the Tropics and little evidence for the potential to avoid yield loss in maize yield since the varieties of crop grown are already adapted to high temperatures. Similar results were also found by Deryng et al. (2011) who reported substantial yield losses in developing countries located in the Tropics for maize even after allowing for adjustment of planting dates and varieties grown. Using simulations from the GEPIC model in Sub-Saharan Africa, Folberth et al. (2014) investigated different intensification options for growing maize under climate change. They found that intensive cultivation is predicted to result in lower yields under future climate conditions and increased soil erosion while eco-intensification shows better yields. However, yield losses are simulated in all management scenarios toward the end of the century suggesting a limited effect of eco-intensification as a sole means of adapting agriculture to climate change. Finally, promising results of rainfall harvesting have been found by Lebel et al. (2015) which found that applying this technique to maize cultivation across Africa could mitigate 31% of yield losses attributable to water stress and increase maize yields by 14–50% on average under the projected climatic conditions of the 2050s.

Groundnut and yam

Groundnut is an important crop for Nigeria, southern Mali, Ivory Coast, Burkina Faso, Ghana, and Senegal. Parkes et al. (2015) investigated the benefits of breeding cultivars of groundnuts with heat and water stress resistance as well as the potential of marine cloud brightening to reduce the rate of crop failures in West Africa using the GLAM model. The authors found that climate change will increase mean yields of groundnut and reduce the risk of crop failure in West Africa. This projected increase in yields is due to the carbon dioxide fertilization effect also to increased seasonal rainfall in the unique GCM simulation used in this study. Parkes et al. (2015) investigated the benefits of breeding cultivars of groundnuts with heat and water stress resistance as well as the potential of marine cloud brightening to reduce the rate of crop failures in West Africa. They found that water stress, rather than heat stress, is the main cause of crop failure in current and future climate and also demonstrated a positive impact of marine cloud brightening.

Yam is the second most important crop in Africa in terms of production after cassava. Srivastava et al. (2015) simulated the advantages of specific adaptation strategies using the EPIC model. They found that changing solely sowing date may less effective in reducing adverse climatic effects than adopting late maturing cultivars. Yet, combining different options such as coupling irrigation and fertilizer application with late maturing cultivars, highest increase in the yields could be realized.

Cassava

Using the EcoCrop model to investigate the response of important staple food crops for Africa including maize, millets, sorghum, banana, and beans to climate projections by 2030, Jarvis et al. (2012) found that cassava reacted very well to the predicted future climate conditions compared to other crops. Whilst most simulated crops in Africa were predicted to experience decreases in overall suitability in Africa, cassava always outperformed or (in the worst case) equaled the average and appeared as a highly resilient staple crop. Crop improvements toward greater drought tolerance and heat tolerance in localized pockets of West Africa and the Sahel could bring some additional benefits.Go to:

Summary and conclusions

In this paper, an extensive review of the recent literature on the West African climate and impacts is used to draw a general picture of the main features of the regional climate, the associated observed variability, the future change as well as expected impacts and potential for adaptation in the agriculture sector.

The dominant role of the WAM in determining the regional climate is highlighted, and the importance of the global SST in driving the multi-time scales variability is described (Rodríguez-Fonseca et al., 2015). In particular, the relationship of the WAM precipitation variability with the tropical ocean SST at the interannual time scales (Rowell, 2001; Polo et al., 2008; Losada et al., 2010; Mohino et al., 2011b), and with the extratropical ocean SST at multidecadal time scales (Zhang and Delworth, 2006; Ting et al., 2009; Mohino et al., 2011a; Villamayor and Mohino, 2015), is illustrated. The long lasting wet phase characterizing the Sahelian precipitation in the twentieth century up to the 70s, and the following severe drought affecting the Sahel culminating in the 80s, have been related principally to the SST variability associated with the Atlantic multidecadal variability (Mohino et al., 2011a). At the turn of the twenty-first century, the Sahel experienced a slight recovery of precipitation (Panthou et al., 2014; Maidment et al., 2015; Sanogo et al., 2015), but the attribution of this recovery is still debated. On the one hand, it is attributed to the differential warming between extratropical and tropical SST in the Northern Hemisphere, favoring the northward displacement of the ITCZ (Park et al., 2014). On the other hand, the recovery is attributed to the regional radiative warming produced by the CO2 direct forcing, inducing a thermodynamic feedback on the monsoon system (Dong and Sutton, 2015). The rainfall recovery has been characterized by a modification of the precipitation regime, with higher intensity rainfall events concentrated in less rainy days (Panthou et al., 2014). Moreover, a widespread warming of the North African subcontinent, and an increase in the occurrence of climate extremes, such as heat waves ad hot summers, has been observed (Fontaine et al., 2013; Moron et al., 2016).

The same tendencies in temperature, precipitation and climate extremes are projected in the twenty-first century, in all the moderate-to-high emission scenarios, with the amplitude of the climate change signal growing proportionally with the projected global warming. The intensification of the hydrological cycle in the recent decades and in future projections has also been detected in in the world’s dry and wet regions, leading to an increased risk of flooding in dry regions as the climate warms (Donat et al., 2016). However, the future projections of the West African climate are affected by large uncertainties, especially regarding the monsoonal precipitation. Indeed, although around 50% of the CMIP5 GCMs agrees on the future positive trend, around 25% of the models project the opposite situation, weakening the prevision (Biasutti, 2013). The origin of this uncertainties is two-fold. On the one hand, the biases characterizing the SST simulated by the atmosphere-ocean climate models, which affect the mechanisms driving the multidecadal variability of the WAM system (Roehrig et al., 2013; Rowell, 2013). On the other hand, the diverse sensitivity of climate models to the effect of the projected increase in CO2 concentration, which induces wet anomalies through the direct radiative warming of the surface at the regional scale, but at the same time inhibits the precipitation when the radiative forcing is mediated by the global SST warming (Bony et al., 2013; Gaetani et al., 2016). Climate modeling of West Africa at the regional scale shows promising improvements of the GCM performances, although large uncertainties still persist. Firstly, RCMs are inevitably affected by the biases of the driving GCMs (Dosio et al., 2015). Secondly, RCMs experiments show high sensitivity to the physical parametrization, especially regarding convection (Klutse et al., 2016), which is crucial for the simulation of the monsoonal rainfall. Therefore, the climate modeling community is pushed for a further effort to improve the modeling of West African climate, in the direction of both understanding the physical mechanisms and reducing the climate model shortcomings.

There are many complex processes that drive the response of crop yield to such climate changes. These processes can act in a competing way as we can expect from the role of increased atmospheric CO2concentration which increase crop yield while warmer mean temperatures are likely to lead to crop yield losses. Such processes can interact together and their importance might depend on the region, the scale and the crop. The complexity of the risk posed by climate change and possible adaptation strategies have called for a number of climate change assessment studies especially in Africa where this risk can severely affect food security and impede development. Despite a large uncertainty in the published results and diverging future projections of summer monsoon rainfall which is key for rain-fed agriculture, a robust evidence of yield loss in West Africa emerges from these studies. This yield loss is mainly driven by increased mean temperature while potential wetter conditions as predicted in Central Sahel or elevated CO2 concentrations for C3 crops and C4 crops in the arid zones of the Sahel can partly or totally counteract this effect. On the opposite, yield losses will be the highest for C4 crops in the Soudano-Sahelian zones and in areas where rainfall is expected to decrease like in the Western part of the Sahel. Identifying the most promising adaptation options is even more uncertain since uncertainty about climate impacts is then cumulated with uncertainty about the effectiveness of adaptations. Most adaptation options illustrated in this review are implemented in process-based crop models to adjust cropping systems (change in varieties, sowing dates and density, irrigation, fertilizer management) to future climate. Results of the cited studies are crop and region specific and no clear conclusions can be made regarding the most effective adaptation options.

Although substantial progress has been made in the assessment of the effect of climate change on crop yield and potential for adaptation in West Africa, large gaps still exist. Important processes like the effect of heat stress or ozone are missing in crop models (Ewert et al., 2015), most effort on model development and intercomparison are biased toward major crops in temperate regions and the African region generally suffers from a lack of sufficient data for accurate calibration and validation of crop models (Lobell and Burke, 2010). Furthermore, specific crop management options and cultivars of low intensive systems as mainly found in West Africa (mulching, species mixtures, intercropping and reduced tillage technologies) are not well represented in crop models (Hertel and Lobell, 2014; Ewert et al., 2015). If recent progress has been made to quantify the potential for adaptation in integrated assessment and modeling approaches linking biophysical and economic models (Patt et al., 2010; Ewert et al., 2015), these approaches are built on assumptions which are more appropriate for the high income and developed countries with high adaptive capacity. Hertel and Lobell (2014) concludes that they present a risk to underestimate the impacts of climate change in the Tropics and a risk of overstating the efficiency of adaptations in regions like Sub-Saharan Africa.

As suggested by Challinor et al. (2009), an objective quantification of impacts uncertainty is a necessary step to go beyond syntheses or meta-analyses of published studies with large heterogeneity resulting from inherently uncoordinated studies. Large ensemble of climate simulations, downscaling techniques and crop simulation ensembles including different modeling approaches and sensitivity analyses are necessary for improved understanding of how climate uncertainties and errors propagate into impact estimates, a better quantification of crop model uncertainty as well as a better quantification of downscaling and bias-correction uncertainty (Ramirez-Villegas et al., 2013). In this respect, coordinated efforts such as the AgMIP initiative which aims to improve agricultural models including biophysical and socio-economic approaches at various scales and develop common protocols to systematize modeling for the assessment of climate change impacts on crop production represents a promising way toward more robust results (Rötter, 2014). While they are crucially lacking in Sub-Saharan Africa, observations are also a key to go forward in the quantification of uncertainty and possible reduction of its range. Most modeling work on climate impacts assessment needs quality data to validate and bias-correct climate simulations, calibrate, validate and force crop models or evaluate cropping systems adaptation. Improvement of quality, accessibility of data (including weather, soil, on-farm and experimental crop data, socio-economic data) as well as support for maintaining data over time and collecting long-term time series is of high importance in Sub-Saharan Africa. Finally, if there is evidence that farmers and farming systems are highly resilient to environmental changes, adaptation to climate change needs to be supported and facilitated by governmental, institutional and macro-economic conditions (Challinor et al., 2007). Adaptation to climate change cannot be achieved without a considerable institutional and political commitments for technical support or access to credit for instance (Thornton et al., 2011) and many of institutional, economic, informational, and social constraints are still ignored in modeling approaches of adaptation (Hertel and Lobell, 2014) which need to better account for both the biophysical and socio-economic determinants and specificities of agricultural systems in Africa.Go to:

Author contributions

All authors listed have made substantial, direct and intellectual contribution to the work, and approved it for publication.

Conflict of interest statement

The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.Go to:

Acknowledgments

This work has been funded by the NERC/DFID Future Climate For Africa programme under the AMMA-2050 project, grant number NE/M020126/1. MG was also supported by the LABEX (Laboratoire d’Excellence) L-IPSL (LABEX of the IPSL), which was funded by the French Agence Nationale de la Recherche under Programme Investissements d’Avenir Grant ANR-10-LABX-18-01.Go to:

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West African Animals

Facts About Animals of West Africa

Pygmy hippos are West African endemics, found nowhere else.

Anup Shah/Digital Vision/Getty Images

Africa is home to an extremely wide variety of animals, from the very tiny army ant to the towering giraffe. West Africa, which stretches from harsh desert to fertile seacoast, lays claim to an impressive share of that faunal diversity. From the West African manatee and pygmy hippopotamus to the Diana monkey and zebra duiker, there is no dearth of interesting critters in this corner of the continent.

West African Manatee

The large gray West African manatee, also called along with its relatives a “sea cow,” has tiny flippers and a flat, rounded paddle for a tail. Weighing in at nearly 500 kilograms (1,100 lbs.), adult manatees can grow to as long as 4 meters (13 feet). They inhabit coastal areas including lagoons, rivers, estuaries and lakes. Manatees feed on overhanging vegetation, from grasses to mangrove foliage. They can be found from southern Mauritania to Angola, though their population is in decline due to hunting and capture in fishing nets: West African manatees are legally protected animals, but poaching continues to impact them. While manatees the world over are in danger of extinction, this species is the most threatened of all.

Pygmy Hippopotamus

The West African pygmy hippopotamus can be found in the lowland and wet forests of Sierra Leone and Cote d’Ivoire, specifically in and near the Bandama River. Typically about 1.5 meters (5 feet) long, the pygmy hippo is much smaller than the more widespread common hippo, one of the biggest mammals on the planet. The species is also substantially less social than its giant relative: Pygmy hippos tend to be found alone or in small groups, whether resting in rivers or swamps or foraging onshore.

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Black Colobus Monkey

Portions of Cameroon, Equatorial Guinea, Gabon and the Republic of the Congo are home to the black colobus monkey – one of the 10 most endangered monkey species in all of Africa. These primates reside in the high canopies of the rain forest and can jump up to 15.2 meters (50 feet) between trees, using their mantle hair and tails as parachutes. Colobus monkeys rarely descend to the ground and eat the leaves from the trees in which they live. They lack thumbs; the name “colobus” comes from the Greek word meaning “docked” or “mutilated.” The monkeys have black fur that contrasts with a white mantle and tail. They’re usually found living in “troops” of between five and 10 monkeys, including a dominant male, females and young.

Niger Stingray

The Niger stingray, also known as the smooth freshwater stingray, is endemic to three West African drainages: particularly the Niger/Benoue system, but also the Sanaga and the Cross rivers. Possessed like most stingrays of venomous barbs, this cartilaginous fish, which may be 40 centimeters (15.7 in.) long, feeds upon aquatic insects. The International Union for the Conservation of Nature lists the global population as on the decline, suggesting overfishing and habitat modification as probable culprits.

West African Dwarf Crocodile

From Togo to Burkina Faso, Benin to Mali, the West African dwarf crocodile can be found in all West African countries in freshwater, tropical rain forests and tropical grassland alike. This reptile eats fish, frogs, birds, small mammals and crustaceans. The name reflects its status as the world’s smallest crocodile: Adults are typically a mere 1.9 meters (74.8 in.) long. Usually solitary or associating in pairs, dwarf crocodiles hole up at the water’s edge in burrows. They hunt at night along riverbanks. Conservation-wise, the species is not as vulnerable as other crocodiles, hunted for their hides, since the dwarf’s skin is not considered valuable. Their lifespan can be anywhere from 50 to 100 years.

Zebra Duiker

Sierra Leone and Cote D’Ivoire are home to the zebra duiker, an antelope species found in low-lying forests and river valleys. It has black, vertical stripes over cream colored skin on its mid-torso; the head, neck, rear and limbs are usually red-brown in color. The animals weigh some 17.7 kilograms (39 lbs.) on average and around 46 centimeters (18 in.) in height. The zebra duiker has short limbs in relation to its body, as well as short, rounded horns. It mates monogamously, preferring solitude before it finds a partner. Its diet consists of fruit, leaves and shoots. The animal’s habitat is threatened due to logging and habitat degradation.

White-Breasted Guinea Fowl

Forest destruction has also negatively impacted the white-breasted guinea fowl, resulting in a swift decline in population in the early 21st century in Sierra Leone, Liberia, Cote D’Ivoire and Ghana. They may utilize both primary and secondary tropical forests. The birds are around 43 centimeters (17 in.) in length with a bare red head and upper neck above a white lower neck, upper back and breast; the rest of their feathers are black. They live in pairs or groups of up to 24 individuals. The guinea fowl lives on a diet of seeds and berries as well as insects and other small invertebrates.

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Popular West African Dishes

West African cuisine

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Senegalese Chicken Yassa, a tangy-spicy dish which is enjoyed throughout the West African region. Made with Dijon mustard, onions, lemon juice, olives and scotch bonnet peppers

West African cuisine encompasses a diverse range of foods that are split between its 16 countries. In West Africa, many families grow and raise their own food, and within each there is a division of labor. Indigenous foods consist of a number of plant species and animals, and are important to those whose lifestyle depends on farming and hunting.

The history of West Africa also plays a large role in their cuisine and recipes, as interactions with different cultures (particularly the Arab world and later Europeans) over the centuries have introduced many ingredients that would go on to become key components of the various national cuisines today.

Contents

History[edit]

Centuries later, the Portuguese, French and British further influenced regional cuisines, but only to a limited extent. However, as far as it is known, it was European explorers and slaves ships who brought chili peppers and tomatoes from the New World, and both have become ubiquitous components of West African cuisines, along with peanutscorncassava, and plantains. In turn, these slave ships carried African ingredients to the New World, including black-eyed peas and okra. Around the time of the colonial period, particularly during the Scramble for Africa, the European settlers defined colonial borders without regard to pre-existing borders, territories or cultural differences. This bisected tribes and created colonies with varying culinary styles. As a result, it is difficult to sharply define, for example, Senegalese cuisine. Although the European colonists brought many new ingredients to the African continent, they had relatively little impact on the way people cook in West Africa. Its strong culinary tradition lives on despite the influence of colonization and food migration that occurred long ago.

Ingredients[edit]

Klouikloui, rings of fried peanut butter as served in Benin

Though there are obvious differences among the local cuisines in West Africa, there are also many commonalities, mainly in the ingredients used. Many dishes are enriched with a base of tomatoesonions and chili peppers.[1] Considered an essential and even “sacred” cooking technique in the region, the combination of these three ingredients sauteed in oil is analogous to similar concepts such as the holy trinity of Cajun and Creole cooking in the United Statessofrito used in the Spanish-speaking worldsoffritto in Italy, and the mirepoix of France. The most prevalent cooking oil is palm nut oil, traditionally associated with the coastal regions and contributes a distinctive colour, flavour and texture to food, while shea butter is more commonly used in the Sahel. Called karité in French, which comes from the Arabic word ghartī, it is prized for the rich mouthfeel it imparts.

There are certain ingredients that go with certain countries as well. In Ghana, the most commonly used ingredients are hot pepper, ginger, and maize. Ghanaians use hot pepper because they believe the hot peppers will cool the body and cleanse/purify it. (Salm, 106-108). In Senegal, the main ingredients are among many others gumbo, hot pepper, ricemilletpeanut, ginger, tamarind leaves, and baobab fruit, and cooking oil (Ross, 75). Those are the few that have a slight difference of what they commonly use for their dishes. For an overall view of West Africa, according to Fran Osseo-Asare, the common ingredients for the West African region are the leaves from a baobab tree, cereal grains: sorghummillet, and fonioCola nutsegusi seeds, guinea fowlmelegueta pepperoil palmokra, and rice. Other ingredients used are okra (thickener)basis for soups stew, black-eyed peas, and sesame according to Harris in High on the Hog.

Seasonings[edit]

Spices play a relatively less prominent role in West African cooking compared to say, North African cuisine. Cooks use spices and herbs like ginger, coriander, and thyme sparingly but knowingly. Chilli peppers however are immensely loved in West Africa, both in fresh or dried and powdered form, particularly in the more hot-and-humid lands of the region. Introduced to Africa probably sometime soon after Christopher Columbus sailed to America by European sailors, it is said that the sweating induced by the spicy heat of chilli helps to air-conditions your skin. More than in other regions of Africa, West Africans utilize Scotch bonnet chile peppers with a liberal hand in many of their sauces and stews. The bite and fire of these extremely hot peppers (Scoville rating 200,000 – 300,000) add a unique flavor as well as heat. The chilli is also supposed to help preserve food, as well as adding flavour to relatively bland tropical staples like root vegetables.

The seeds of Guinea pepper (Aframomum melegueta; also called grains of paradise or melagueta pepper), a plant indigenous to West Africa, are also widely used. This native spice tastes and looks somewhat like a peppercorn, but has cardamom and coriander seed flavor notes. The grains of paradise was once a prized commodity reaching Europe through North African middlemen, during the Middle Ages.

Sumbala or soumbala is a flavouring used widely across West Africa, used in a manner not unlike a bouillon cube. It is usually prepared by women over the course of several days, traditionally from néré (Parkia biglobosa) seeds. It can be made from other kinds of seeds, and the use of soybeans for this purpose is increasing due mainly to inadequate supply of néré seeds. The fabrication process involves boiling, cleaning and then packing away to ferment – the fermentation process giving it a pungent smell and at the same time a rich, deep umami or savory flavour is developed. Salt can be added to the finished product to facilitate storage life. This condiment is traditionally sold in balls or patties that can be kept for several months at a time in the case of the best quality. It is a traditional cooking ingredient used across West Africa, although the less traditional bouillon cube, specifically the Maggi brand rivals it in popularity. African Potash (potassium carbonate) is a native salt used for flavoring and to expedite the cooking time for some foods by cooks, it is made from wood-fire ashes in an ancient process that was once used by pioneer settlers in North America.

Vegetables[edit]

Vegetables are a part of any West African meal. Some commonly eaten vegetables include black-eyed peaseggplantpumpkin and other squashes, okra, as well as a staggering variety of both farmed and foraged green leafy vegetables, little known or used outside of the African continent. Baobab leaves, pumpkin leaves, rosella leaves, sweet potato leaves, and cassava leaves (which contain cyanide in their raw state, and are always blanched with boiling water before use to remove the toxins) are just some of the greens that are commonplace in a West African kitchen. Black-eyed peas form the basis for a popular fried snack, the well-loved akara fritter.

Starchy tubers and root vegetables are used as staple food, to be served with their meat and vegetable dishes, often as a foil to the hotness of the peppers. Cassavacocoyamssweet potatoesplantains, and yams are ubiquitous in the local diet, and they are usually boiled and then pounded with a pestle and mortar into a thick starchy paste called fufu.

Other starch staples eaten throughout West Africa besides root vegetables and tubers include fonioricemilletsorghum, and maize.

Meat[edit]

Although West Africans ate far more vegetables and much less meat in the past, today their diet is heavier in meats, salt, and fats. Seafood is especially popular along the coast and many dishes combine both fish and meat. Dried and smoked fish flavor a number of sauces, stews, and other dishes, including condiments, in much the same way that anchovies and bacon flavour food in a number of other cuisines. It is often flaked and fried in oil, and sometimes cooked in sauce made with the base of hot peppers, onions and tomatoes, various spices (such as soumbala) and water to produce an incredible combination of subtle flavors. Chicken is eaten nearly everywhere and chicken eggs are a common food and source of protein. Guinea Fowl eggs also popular. In some inland areas, beefpork and mutton are preferred, with goat meat being the dominant red meat. Suya, a popular grilled spicy meat kebab flavored with peanuts and other spices, is sold by street vendors as a tasty snack or evening meal and is typically made with beef or chicken.

Representative dishes[edit]

Some dishes are a prevalent feature in most West African societies, but bearing different names in different locales.

Fufu[edit]

A plate of fufu accompanied with peanut soup

As above, fufu is usually made from cassava, yams, and sometimes combined with cocoyam, plantains, or cornmeal. In Ghana, fufu is mostly made from boiled cassava and unripe plantain beaten together, as well as from cocoyam. Currently, these products have been made into powder/flour and can be mixed with hot water to obtain the final product hence eliminating the arduous task of beating it in a mortar with a pestle until a desired consistency is reached. Fufu can also be made from semolina, rice, or even instant potato flakes. Often, the dish is still made by traditional methods: pounding and the base substance in a mortar with a wooden spoon. In contexts where poverty is not an issue, or where modern appliances are readily available, a food processor may also be used.

In Western and Central Africa, the more common method is to serve a mound of fufu along with a soup (ọbẹ). After washing hands, the diner pinches off a small ball of fufu and makes an indentation with the thumb. This reservoir is then filled with soup, and the ball is eaten. In Nigeria and Ghana, the ball is often not chewed but swallowed whole – in fact, chewing fufu is considered a faux pas. Therefore, fufu not only serves as a food but also as a utensil. One of the low points of Fufu was the smell which lingers on long after the meal, however new and improved species of cassava and improved cassava processing has eliminated the smell of Fufu making it more accepted as a meal.

A selection of soups that could be served with fufu includes but not limited to: light (tomato) soup, Palm Nut Soupgroundnut souppeppersoup,[2] and other types of soups with vegetables such as okra, nkontomire (cocoyam leaves). Soups are often made with different kinds of meat and fish, fresh or smoked.

Groundnut stew[edit]

Maafe, prepared by a Senegalese cook.

Groundnut stew (Maafe), (var. MaféMafféMaffesauce d’arachidetigadèguèna or tigadene), is a peanut-based stew common to much of West Africa, and very popular in Senegalthe GambiaMaliGuinea and Cote d’Ivoire. Variants of the Maafe appear in the cuisine of nations throughout West Africa and Central Africa. With the huge expansion of groundnut cultivation during the colonial period, Maafe has become a popular dish across West Africa, and as far east as Cameroon.

Recipes for the stew vary wildly, but groundnut stew at its core is cooked with a sauce based on groundnuts (peanuts),[3] the West African trinity of tomatoes, onion and chillies, and common protein components are mutton, beef or chicken. In the coastal regions of Senegal, maafe is frequently made with fish. Maafe is traditionally served with white rice (in Senegambia), couscous (as West Africa meets the Sahara) or Fufu and sweet potatoesin the more tropical areas.[4]

Jollof rice[edit]

Jollof rice

Jollof rice, also called Benachin is a popular dish all over West Africa. It originated in Senegal but has since spread to the whole of West Africa, especially Nigeria and Ghana amongst members of the Wolof ethnic group, from whom the word “Jollof” originated. There are many variations of Jollof Rice. The most common basic ingredients are: rice, tomatoes and tomato paste, onion, salt, and red pepper. Beyond that, nearly any kind of meat, vegetable, or spice can be added. The Senegalese version of Jollof rice is a bit different and is called Ceebu Jen. It is the national dish of Senegal. A variation, “thiebou yapp,” or “rice meat” is made with beef, mutton or other red meat.

Jollof rice dish consists of rice, tomatoes or tomato paste, onion, chill pepper, and spices (such as nutmeg, ginger, Guinea pepper or cumin), to which various ingredients can be added such as vegetables, meats and fish.

List of other West African dishes[edit]

Beverages[edit]

Local Distillation of palm wine in Ghana

As for alcoholic drinks, palm wine is a common beverage made from the fermented sap of various types of palm trees and is usually sold in sweet (less-fermented, retaining more of the sap’s sugar) or sour (fermented longer, making it stronger and less sweet) varieties. Beer from millet is also common, and popular.

Etiquette[edit]

Dining is communal, and diners would use their fingers to eat. Water has a very strong ritual significance in many West African nations (particularly in dry areas), and water is often the first thing an African host will offer his/her guest.

By country[edit]

For more specific styles, refer to the articles on each national or regional cuisines:

See also[edit]

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Most Popular Tribes in West Africa

Fulani herdsmen

From Wikipedia, the free encyclopediaJump to navigationJump to search

Fulani wedding

Fulani herdsmen or Fulani pastoralists are nomadic or semi nomadic Fulani herders whose primary occupation is raising livestock.[1] The pure Fulani pastoralist engages in random movement of cattle while the semi-nomadic makes transhumance migration and return to their camps or homes.[2] The Fulani herdsmen are largely located in the Sahel and semi arid parts of West Africa but due to changes in climate patterns many herdsmen have moved further south into the savannah and tropical forest belt of West Africa. The herdsmen are found in countries such as NigeriaNigerSenegal, Guinea, Mauritania, Mali, Burkina Faso, Ghana, Benin, Côte d’Ivoire and Cameroon. In Senegal they inhabit northeastern Ferlo and the southeastern part of the country. In many of these countries the Fula often constitute a minority group.

In Nigeria, the livestock supplied by the herdsmen provides a bulk of the beef consumption in the country. However in 2018 they killed nearly 1700 Nigerians in that one year alone. A number that has consistenly increased since President Muhammadu Buhari came into power in 2015, and will most likely increase if he remains in power for another 4 years.

Contents

History[edit]

Herding system[edit]

A pastoral Fulani family is the traditional herding unit. Tasks are divided by gender and age among the members of the family.[3] The main work of men is to manage the herd, find grazing sites, build tents and camps and make security tools such as knives, bow and arrows and guns. Women in the unit take on traditional roles such as sourcing food produce in the market, milking cows, weaving and mat making.[4] Some women are also involved in farming such as growing vegetables and raising poultry.

Cattle is the dominant composition of the Fulani herd in countries such as Nigeria and camel is the least liked animal.[3] The livestock is largely female with close to 60% of cattle being female, the male species are usually reduced by selling them.

Movements[edit]

Fulani herdsmen’s engage in both random and planned transhumance movements. Random movements are usually taken by the pure nomadic Fulani herdsmen while planned movements are taken by the semi nomadic pastoralist. A primary reason for the migratory nature of the herdsmen is to reach areas with abundant grass and water for the cattle.[2]The herdsmen also move to avoid tax collectors, harmful insects and hostile weather and social environment. A major benefit of the movement for the herdsmen is to maximize the availability food resources for the cattle and reduce excessive grazing.[5] Before moving new areas, the herdsmen send a reconnaissance team to study the area for availability of resources such as grass and water.

Source of income[edit]

The sale of goat, sheep and dairy products such as milk constitute the primary source of income and livelihood of the herdsmen. Their wealth and riches are often measured by the size of the Cattle herd being the most treasured animal they herd.[6] Traditionally, the herdsmen often loaned a cow (habbanaya) to another until she calves and after weaning the calf, the cow is returned to its owner. These herdsmen herds several species of cattle species of cattle, but the zebu cattle is the most common in the West African hinterland because of its drought resistant traits. The dwarf Ndama cattle is commonly herd in the wetter areas of Fouta Djallon and Casamance as result of their resistant to trypanosomiasisand other conditions directly associated with high humidity.[7]

Residence[edit]

Fulani herdsmen build domed houses called “Suudu hudo” or “Bukkaru” made from grasses. During the dry season, it is often supported with compact millet stalk pillars, and by reed mats held together and tied against wood poles, in the wet or rainy season.[8][9] The advantage of the “Bukkaru” house is that it is mobile, easy to set up and dismantle as a typical house of nomadic societies. When it is time to relocate, the houses are dismantled and loaded onto a camel, horses, donkeys and sometimes cattle for transport.[9][10] In recent times several herdsmen now live in mud or concrete block houses.[11]

Conflict with farmers[edit]

Historically Fulani pastoralists have grazed in lands around the arid and sahel regions of West Africa partly because of the environmental conditions that limit the amount of land for agricultural purposes leading to less intense competition for land between farmers and herders. However, after recurrent droughts in the arid and sahel regions, Fulani pastoralists have gradually moved southwards to the guinea savanna and the tropical forest areas resulting in competition for grazing routes with farmers.[12]

Nigeria[edit]

See also: Communal conflicts in Nigeria § Herder-farmer conflicts

Fulani pastoralists started migrating into Northern Nigeria from the Senegambia region around the thirteenth or fourteenth century.[12] After the Uthman dan Fodio jihad, the Fulani became integrated into the Hausa culture of Northern Nigeria. Thereafter, during the dry season when tsetse fly population is reduced, Fulani pastoralists began to drive their cattle into the middle belt zone dominated by non Hausa groups returning to the north at the onset of the rainy season. But while managing the herd and driving cattle, cattle grazing on farmlands sometimes occur leading to destruction of crops and becoming a source of conflict.

Nigeria’s implementation of the land use act of 1978 allowed the state or federal government the right to assign and lease land and also gave indigenes the right to apply and be given a certificate of occupancy to claim ownership of their ancestral lands.[13] This placed the pastoral Fulani in a difficult position because most did not apply for lands of occupancy of their grazing routes and recurring transhumance movement will lead to encroachment of the properties of others. The Nigeria government designed some areas as grazing routes but this has not reduced clashes. From 1996 to 2006 about 121 people lost their lives in Bauchi and Gombe states as a result of conflicts between pastoralists and farmers.[14]

Ghana[edit]

Fulani migrant groups and pastoralist are usually considered strangers and foreigners because of their Senegambia origin,[13] as a result their rights to use the areas termed ancestral lands by indigenous ethnic groups have met with some reservatins. Conflicts in some regions in Northern Ghana arise due to cattle destroying the crops of farmers

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Top fascinating facts about West Africa

04/10/2018Tell your friends  From the ancient Nok civilization and the Benin Empire to culturally diverse groups, here are some amazing facts to know about these groups of countries.


West Africa is a hidden gem the world should focus on.

From the ancient Nok civilization and the Benin Empire to culturally diverse groups, here are some amazing facts to know about these groups of countries.1. The Kingdom of Ghana/Ghanata/Wagadugu was one of the most powerful African empires for thousands of years.

It was one of the first of the great medieval trading empires of western Africa during the 7th–13th century and was situated between the Sahara and the headwaters of the Sénégal and Niger rivers. At that time it was far more developed than any European country.

ALSO READ: 5 happiest countries in the world to travel to

2. The Nok Civilization is considered to be one of the most advanced ancient sub-Saharan civilizations in African history. Beginning sometime around 1500 BC and was largely concentrated in Nigeria. It produced some of the first sub-Saharan iron smelting and terracotta architecture. They mysteriously disappeared around 200 AD.

3. Mansa Musa I of Mali is the richest human being in all history. The 14th-century king was named the richest person in all history by the Celebrity Net Worth website.

Mansa Musa I ruled West Africa’s Malian Empire in the early 1300s, making his fortune by exploiting Mali’s salt and gold production.

4. West Africa is more culturally diverse than the whole of Asia. Nigeria alone has over 500+ languages. More languages are spoken in Taraba state than in 30 countries.

ALSO READ: 5 extraordinary discoveries in Nigeria

5. Liberia is Africa’s first independent country. It was found by freed American slaves when they started settling around 1820.

The country was declared independent in 1847 by the United States, thereby marking Liberia as Africa’s first independent republic. That’s 101 years before India got free from British rule.

6. Sokoto Caliphate is an Islamic empire in Nigeria, led by the Sultan of Sokoto, Sa’adu Abubakar. Founded during the Fulani Jihad in the early 19th century, it was one of the most powerful empires in sub-Saharan Africa prior to European conquest and colonization. The caliphate remained extant through the colonial period and afterwards, though with reduced power.

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The Cultural Legacy of West Africa

The complexity, diversity and significance of West African culture is well worth exploring. This lesson will explain in detail how the cultural legacy of West Africa influences our culture today in the areas of art and music,as well as oral traditions.

West African Countries

West Africa has, for a long time, impacted the history of the United States. This is the area of Africa were historical records indicate numbers of men and women were captured and enslaved. This is also the area where musical and artistic traditions have influenced the culture of our country. The countries of West Africa include: Benin, Burkina Faso, Ivory Coast, Cape Verde, Gambia, Ghana, Guinea, Guinea-Bissau, Liberia, Mali, Mauritania, Niger, Nigeria, Senegal, Sierra Leone and Togo.

Traditional West African art forms that have influenced our culture are: folktales, the griot, proverbs, music, and visual arts. The following paragraphs will discuss each topic more closely and explain how they have influenced American art forms. Many of them continue to do so even today.

Folktales

In West Africa, people used folktales to teach their history to young people, so they would develop a respect for their elders, and pass beliefs, values and morals to other generations. Many traditional folktales were brought to our country by slaves from West Africa in the 1500s. As a result, the oral tradition of sharing folktales became part of North American culture.

A popular example of this is a type of folktale called a ‘trickster tale’. Trickster tales tell of a clever animal or human who outsmarts another character in the story. Brer Rabbit is one such character. This story was brought to our country by West Africans and in the 19th century a writer named Joel Chandler Harris made this story popular along with other African stories that eventually became a part of our culture.

Griot

griot is a skilled poet-musician who tells stories as well as performs music, dances, and drama, to also help preserve West African history and its legacy. Every village in West Africa had its own griot. Griots are considered human record keepers, living libraries of history and traditions. Their job was to preserve the oral tradition of storytelling which could last for hours, even days.

A griot was known to have the ability to recite accounts of births, marriages, deaths, hunts, the succession of kings and even battles. Every village in West Africa had its own griot. However, it was not unusual for a griot from one village to actually know the ancestry of other villages. Currently, griots are still famous as artists in West Africa recording popular songs as well as performing new and old work on radio broadcasts impacting cultures worldwide.

Proverbs and Music

‘Every time an old man dies, it is as if a library has burned down’. This is an example of a West African proverb. Another says ‘A good story is like a garden carried in the pocket’. The first proverb represents the importance of oral traditions in West African culture. The other represents the importance of stories. As a West African oral tradition, proverbs demonstrate the values and wisdom of West Africans. Proverbs like these were brought to our country by enslaved West Africans.

West African music portrays feelings, ideas and values, much like our own music in the United States. This music is also noted for commemorating special occasions and celebrating historical events, as well as similar characteristics of American music. Music has always been an important part of West African lives. The West African music traditions continue to influence art in our country. Two in particular are a technique called ‘call and response’ and the custom of playing drums.

Call and response is a typical style of music in West Africa where a leader sings or plays a short musical phrase (the call) and then the chorus (a group of people) give the response, by playing or singing another short musical phrase. This pattern is repeated throughout the song. This technique is often used in American music such as rap, gospel, jazz, blues, and rock and roll. Enslaved West African brought this musical technique to our country and used the technique to celebrate social events, to lessen the burden of hard labor and, at times, to relay their displeasure with certain life events.

Drum playing is an important part of life West African culture. Drums made from logs or pieces of wood, then covered with animal skin were played by West Africans who later became slaves when brought to our country. Drum playing functioned as an important role at religious meetings, weddings, parties, funerals and other ceremonies. West African drum music is a popular element of music in our country evident in the music forms used by various bands and musical groups.

Visual Arts

Many beautiful and symbolic textiles, sculptures, baskets and masks were created in West Africa, and have influenced our culture. Stamped fabrics, story fabrics and ‘kente’ cloth are all representative of Western African culture.

Textiles from West Africa influenced the American use of applique and quilting, that is still practiced in rural areas of the south, as well as other places in our country. Applique is where shaped pieces of cloth are sewn on to a fabric to create a picture or design.

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THE PROGRESSION FROM ARABLE CROPPING TO INTEGRATED CROP AND LIVESTOCK PRODUCTION

Current Agricultural Production Systems in West Africa

The existing agricultural or farming systems in different ecological zones of West Africa are designed to produce subsistence food, cash sales and materials for local or industrial use. There is no generally accepted classification of farming systems in tropical Africa, but for convenience a classification which is based on intensity of cultivation and/or animal rearing is presented in Table 11. The various production systems are grouped under (i) traditional and transitional systems, and (ii) modern systems and their local adaptations.

Traditional and Transitional Agricultural Systems

The majority of the farming systems of West Africa belong to this group which range from the extensive (shifting cultivation and nomadic herding) to more permanent and specialized types of farming (compound farms and terrace farming). Shifting cultivation is an extensive agricultural production system in which a cultivation phase on ‘slash-and-burn’ cleared land alternates with a fallow period (Okigbo, 1982). The clearing is done using axes or matchetes and usually only herbaceous plants, saplings and undergrowth are cut. When dry the cut material is burned and the cleared area is planted on the flat or on mounds with crops like yams, rice, sorghum, millet, maize and cassava depending on the ecological zone. The land is cultivated for one to four years after which it returns to fallow. The regrowth of natural vegetation rejuvenates the soil through nutrient cycling, addition of litter and suppression of weeds. The cultivation phase alternates with a much longer fallow phase, ideally 10–20 years. Marked variation in the relative lengths of cultivation and fallow periods have been reported by Nye and Greenland (1960) and Ruthenberg (1974).

In classical shifting cultivation, the homestead of the farmer is relocated near the cultivated fields after each cultivation phase. In practice the situation varies from where the farmer may never return to the same piece of land to situations where cultivation is repeated on the same plots. This cultivation system is ecologically viable in frontier situations where population density is low and fallow periods are long enough to restore soil fertility. Shifting cultivation in the classical sense has all but disappeared in West Africa and Morgan (1980) reported it to be restricted to parts of Ivory Coast and small areas between Nigeria and Cameroon (Figure 10). Nomadic herding is the extensive animal rearing counterpart of shifting cultivation in the savannah and more arid areas is discussed separately.

Fig. 10

Fig. 10 WEST AFRICA: MAIN AGRICULTURAL OR FARMING SYSTEMS.

Pastoralism and sabel fringe cultivation
Shifting cultivation
Rotational woody bush fallow
Rotational bush/grass land fallow
Permanent cultivation
Floodland cultivation
Mixed farming

TABLE 11

CLASSIFICATION OF FARMING SYSTEMS IN AFRICA1
(Okigbo & Greenland, 1977)

A.Traditional and TransitionalB.Modern Farming Systems and
Systems their Local Adaptations
1.(a) Nomadic Herding 1.Mixed Farming
(b) Shifting Cultivation (Phase I), L 10*
2.Livestock Ranching
2.Bush fallowing or Land Rotation Shifting Cultivation (Phase II) L = 5 – 10
3.Intensive Livestock Production (Poultry, Pigs, Dairying)
3.Rudimentary Sedentary Agriculture. Shifting Cultivation (Phase III) L = 2 – 4
4.Large Scale Farms and Plantations
4.Compound Farming and Intensive Subsistence Agriculture. Shifting Cultivation (Phase IV) L 2 (a) Large scale food and arable crop farms based on natural rainfall.
(b) Irrigation projects involving crop production.
5.(a) Terrace Farming: L = 1 – 2 (c) Large scale tree crop plantations.
(b) Floodland agriculture L ≤ 1
5.Specialized Horticulture
(a) Market gardening.
(b) Truck gardening and fruit plantations.
(c) Commercial fruit and vegetable production for processing.

1 Adapted from Whittlesey, 1936; Morgan and Pugh, 1969; Floyd, 1979; Laut, 1971; Benneh, 1972; Greenland, 1974.

*

where C = Cropping period
F = Fallow period
L = Land use factor

Shifting cultivation has been replaced by more intensive farming systems as the result of increasing population pressure and the shortening of the fallow period. The intensity of cultivation can be measured using the Land Use Factor (L) of Allan (1965) where:

where
C = number of years of cultivation
F = number of years of fallow

Greenland (1974) reported that intensification of cultivation (Table 11) passes through the following phases:

SystemIntensity of Cultivation
Phase I – Shifting cultivationL = 10
Phase II – Recurrent cultivationL = 3 – 10
(a) Long-term
(b) Middle-term
(c) Short-term

L = 7 – 10
L = 5 – 7
L = 3 – 5

Phase III – Semi-permanent cultivationL = 2.5 – 3
Phase IV – Permanent cultivationL = 2

The intensification of production in the farming systems shown in Table 11 can be assessed by relating their L values to those above. Based on the foregoing, the traditional and transitional West African farming systems in which crops are grown and some animals reared are characterized as follows:

Objectives

Originally farming in West Africa was subsistence orientated. During the colonial era trade in spices, forest products and later cash crops led to increased cash cropping and with increasing industrialization, the production of export orientated raw materials (palm oil, palm kernels, groundnuts, rubber, cotton, etc.). With increasing domestic industrialization many of these raw materials can be sold locally. With increasing urbanization and mobility, the market economy has become well established in West Africa, particularly the need by farmers for money to purchase goods, services and farm inputs which can only be obtained through sales of farm produce. By products of farming (manure, fuel wood, etc.) can also be used. Therefore the objectives of traditional farmers are various and, although food crops still have priority, some commodities are produced specifically for sale.

Spatial Arrangement and Structure

Traditional West African farming systems consist of several fields in more or less concentric circles round a compound or homestead-garden. (Figures 11 and 12). The homestead-garden is under intensive, permanent production and contains a mix of perennial and annual crops grown in a complex agroecosystem. In the tropical rain forest zone this may attain a multistoried structure approaching that of the tropical rain forest (Plates 2 and 3). In the savannah, it is not so complex owing to lower rainfall but the diversity index usually exceeds that of the surrounding woodland. Fertility is maintained by applying household refuse, crop residues and animal manure. The fields are located at varying distances from the homestead and have fallow periods which increase with increasing distance from the homestead (Plate 4).

In areas where population densities are low, L values on the farthest fields can exceed 10. Where population densities are high, as in southeastern Nigeria or Kano, L values are much lower than 10. Most fields outside the homestead-garden contain useful semi-wild or indigenous trees; these include the oil palm (Elaeisguineensis), the oil bean (Pentaclethra macrophylla) and the African mango (Irvingia gabonensis) in the rain forest zone, and the shea butter (Butyrospermum paradoxum), locust bean (Parkia spp), Acacia albida andBalanites aegyptiaca in the savannah. Fields near the intensively cultivated homestead-garden are generally impoverished and under short periods of fallow (L = 1 – 3) because they are constantly being cropped or grazed with no manure or fertilizer application. More distant fields are more fertile mainly because the period of fallow is longer. There is a tendency for these fields to carry crops which are grown for sale or those which are more easily harvested.

There are specialized cropping systems that take advantage of topographical or microenvironmental variations which occur within the farm. The homestead-garden is usually sited in a dry, upland situation, but nearby may be lowland or valley bottoms (called fadamain the savannah areas of Nigeria or boliland in Sierra Leone) (Plate 5) where rice, vegetables, yams, sugar cane, bananas, taro, etc. may be grown depending on the ecological zone. Crops which require high levels of fertility or greater care like yams, vegetables and cocoyam in the forest zone or tobacco and vegetables in the savannah, are grown nearest to the homestead. The homestead-garden system includes varying numbers of small ruminants, pigs and poultry; cattle, donkeys, camels and horses are kept in tsetse-free savannah areas. Livestock are a feature of the homestead and adjacent areas and they graze on fallows and residues on the harvested fields.

The different production systems compete for labour and resources and to maximize these, different crops or varieties of a crop are grown in the different fields. With distance from the homestead, fishing, hunting and some food gathering increase in importance. This concentric field system is sometimes called ‘land zoning’ (Grove and Klein, 1979), or the ‘ring system of cultivation’ (Ruthenberg, 1980; and Norman, et al., 1982).

Fig. 11 SIMPLIFIED MODEL OF SPATIAL ORGANIZATION OF FIELDS AND FARMING SYSTEMS IN TROPICAL AFRICA. (Adapted from Grove & Klein 1979)

Fig. 11

NOTE: Specialised field on land use systems include valley bottoms, terraces, termite mounds etc.

Fig. 12 Schematic diagram of compound farms in relation to associated fields systems in traditional farming systems of the humid tropics of West Africa.

Fig. 12
PLATE 2

PLATE 2 – Compound or homestead-garden in the Humid Zone, Nigeria

PLATE 3

PLATE 3 – Compound or homestead-garden and adjacent plot in the Subhumid Zone, Nigeria

PLATE 4

PLATE 4 – Distant open cultivated field in the Humid Zone, Nigeria

PLATE 5

PLATE 5 – Distant cultivated lowland fadama in the Subhumid Zone, Nigeria. Note bananas, maize and beds of onions in foreground

Farms and Production Methods

Farm sizes are small, generally less than 2 ha, but farms in the savannah are larger than those in the forest zone; in Nigeria in 1965, 82 percent of the farms were less than 2 ha.

Tools are simple and hand operated. There is very limited mechanization although since the early 1930s use of animal power for cultivation, planting and transportation on the farm has been increasing in areas free from tsetse. Use of tractors and tractor-drawn implements is increasing but is of no general significance.

Land is almost always universally cleared by manual cutting and burning. Thereafter there is little or no tillage and crops are grown on the flat, or on mounds or ridges which are manually constructed. Weeding is usually carried out manually. There is increasing mechanical land clearing as a result of the high cost of labour.

West African agriculture is characterized by a division of labour between the sexes, with women specializing is some operations and the men in others. There is often acute shortage of labour on farms due largely to seasonal demand peaks for farm operations and division of labour between sexes and age groups. Shortage of labour is aggravated by rural-urban migration, children attending schools and competition from the non-agricultural sector.

Apart from organic and animal manures very little use is made of chemical fertilizers. Physical and cultural methods are used to control pests and diseases although pesticides are used on some cash crops (e.g. cocoa).

Traditional farming systems are designed by the timing of operations, species grown and resource manipulation to make best use of the prevailing rainfall regime. Although there is some traditional use of water to supplement crop growth very limited use is made of irrigation. It has been estimated that West Africa is currently using less than 10 percent of its irrigation potential.

Many believe that shifting cultivation and nomadic herding are the dominant farming systems in West Africa but, according to Morgan and Pugh (1969), Gleave and White (1972) and Grove and Klein (1979), true shifting cultivation has almost disappeared apart from isolated areas. It has been replaced by the farming systems listed in Table 11.

Crops are usually grown as mixtures, relay intercrops or associated sequences. Crop rotations and sole crops are rare apart from rice and to some extent cash crops like groundnuts, cotton and sugar cane; the more a crop is grown for sale the greater the likelihood of its being grown in pure culture.

While productivity per unit of energy may be high, yields per unit of area are low in traditional farming systems. There is not only a wide gap between attainable yields on farms as compared to experimental stations but also as compared to average and recorded yields in other parts of the world.

Traditional and transitorial farming systems in West Africa are complex and not only involve several species of crop but often include livestock. Although crop production is not a component of nomadic herding there are many examples of complementary and symbiotic interrelationships between farmers and herders (Ruthenberg, 1980; Dyson-Hudson (1972) and Norman,et al., 1982).

Traditional farmers, their wives and farm family members in rural areas usually engage in many paid non-farm activities. Earnings from these activities significantly contribute to family income.

Changes in Traditional Farming Systems

Farming systems in West Africa have reacted to changing circumstances. Changes have resulted from (i) introduction of Asian and New World Crops; (ii) population expansion; (iii) European colonization of Africa and the need for spices and agricultural raw materials for industry; (iv) improved means of transportation and communication; (v) expansion of cassava production into marginal areas where other crops often fail, and (vi) introduction of mechanization into farming and adoption of new techniques. Modern farming systems and their local adaptations, as listed in Table 11, often exist side by side with traditional systems.

Progression towards Integrated Crop and Livestock Production Systems

The first system of crop production which replaced hunting and gathering was shifting cultivation. In West Africa, as elsewhere, it was an efficient and reliable production system in situations where population density was low. As population density increased, however, fallow periods became shorter and more intensive and semi-sedentary agricultural production systems replaced shifting cultivation. Sedentary agriculture involved settlement in villages and communities in which the homestead became a permanent feature associated with a homestead-garden. The outlying fields associated with each homestead were subjected to different periods of cropping but, when population became very dense, these fields were permanently cropped. It would appear that in almost all parts of the world traditional farming systems centred around a homestead-garden where livestock were kept. The various stages in the evolution of farming systems in which crop production constitutes an integral component are shown in Table 12. Continued intensification of production often resulted in more specialized production systems which required more inputs, more capital, specialized practices and new tools and technology. Animals rarely feature in the specialized crop production systems, except where mixed farming is possible, but Lagemann (1977) showed that animal populations increase with increasing human population density. The animal component of the traditional farms plays a crucial role in the maintenance of soil fertility, without which the permanent farming system used on the homestead-garden and adjacent areas would be impossible. Livestock provide meat and other animal products, form a savings account, utilize household waste and fulfil social and cultural obligations. In almost all the ecological zones of West Africa livestock make a significant contribution to farm income.

Interactions between Cultivators and Herders

According to Monod (1975) “no nomad can exist for long without contact with sedentary peoples.” Monod also observed that even the Tuareg nomads of the Sahara maintain contact with oasis dwellers. Contact with sedentary cultivators makes it possible for pastoralists to obtain food (grains, legumes and vegetables) and sometimes water, fodder, grazing land or even cash for part-time work on their farms. Pastoralists are individuals of distinct ethnic groups and in West Africa they consist of (i) Fulani (or Fulbe) who rear cattle and sheep in the Sudan/Sahel, savannah extends from Senegal to parts of Ethiopia; (ii) Tuaregs with herds of cattle and camels who sometimes live in oases in Mali and Niger; (iii) the Toubou who rear cattle and camels and who may also live in oases in Mali and Niger; (iv) Moors in the Sahara comprising a northern group that keeps herds of camels and a southern one rearing cattle and camels, and (v) Shuwa Arab cattle herders near Lake Chad.

It is common practice for herders to arrange with arable farmers to graze stubbles or crop residues from harvested fields, in return for animal manure. It is also the common practice for farmers like the Hausa, the Mossi or Mende to arrange with the pastoralists to look after their livestock and sometimes graze them during the dry season in distant pastures. Arable farmers, on the other hand, obtain animal products (milk, cheese, leather goods), animal transportation and manure from the pastoralists. The importance of manure in maintaining soil fertility in the absence of fertilizer cannot be overemphasized. Even when cattle owned by arable farmers are grazed by herders, a kind of mixed farming is being practised in which, according to Monod (1975), the herders facilitate the combination of crop production and animal production rather than integrating them.

TABLE 12

CHANGES IN CROPPING SYSTEMS IN RELATION TO THE INTENSIFICATION
OF CULTIVATION AND INTEGRATION OF ANIMAL AND CROP PRODUCTION

Stages in Evolution of Crop Based
Farming Systems
Remarks and Extent of Livestock
Association
Per-humid to Sub-humid Tropics
1. Collecting, hunting and fishingNo permanent settlement, some camping places. No cultivation, no rearing of stock
2. Shifting cultivationHomesteads moved as fields shift. Cultivation practised. Some animals especially the dog may be kept. Hunting and fishing still substantial. Has almost disappeared or confined to small areas.
3. Recurrent cultivation, bush fallow land rotationHomesteads permanent and associated with fields and temporary huts in new plots. Fields shift or rotate may be in secondary forest, bush, thicket, woodland or grassland fallow. Homestead or compound garden present with some livestock and cultivated trees and shrubs. Protected or semi-cultivated trees and shrubs present in fields.
4. Permanent cultivation
(i) lowlands
(a) uplands
– compound gardens
– planted short-term fallows and rotations

(b) lowlying areas

– wet rice cultivation
– flood plains cultivation
– valley bottoms and ‘fadamas’

(ii) highland areas

(a) terrace farming
(b) mixed farming

Most widespread permanent farming system. Arable crops, spices, tree crops, etc. and livestock present (cattle mainly in savannah zona). In areas of high population density or confined sites, southeastern Nigeria or Kano close settled zone. Rice zone – Sierra Leone, Senegal, Mali Inland Niger delta decrue and crue systems. Very common in the savannah; animals present in 4 (i) in association with farmers compound.

In defensive positions in highland areas – mountains in Togo, Mandara mountains, and Maku in southeastern Nigeria. Livestock usually present. Mixed farming practised by sedentary Fulani in Futh and Mambilia plateau in Adamawa. Monod (1975) reported expansíon of cattle rearing among horticulture people, e.g. Hausa, Kanuri, Borgu, Waja, Kilka, Kaka and Mambila.

5. Specialized Cash Cropping
(a) Smallholder tree crop plantations
(b) Smallholder arable crops

These cropping systems grow cash crops such as cocoa, groundnuts or cotton almost in pure culture in rotation with other crops.
6. Non-agricultural workLivestock may graze residues of arable crops after harvest but may not belong to the farmer. Some peoples whose ancestors were cultivators often move to other professions and some farmers engage in multiple occupations.

Based on Ruthenberg (1980), Monod (1975) White and Ybeave (197) Gallais and Sidikou (1978)

When this relationship does not exist the herders may plant a crop of millet before migrating north during the rains, which will be harvested when they return during the dry season. Arable farming peoples like the Kanuri, Hausa, Borgu, Waja, Kibba, Chamba, Kaka and Mambilla often rear cattle and other animals and produce their own manure. With the rapid changes now taking place ethnic groups which were traditionally arable farmers are ready to acquire cattle and pastoralists are increasing their arable farming.

Relevant National Policies

In almost all countries of West Africa national policies in agricultural development have changed very little with respect to integration of crop production and livestock rearing. There has, however, been a shift of emphasis since independence. During the colonial era, priority was given to research, extension, marketing and infrastructural development that enhanced production of cash or export crops to the detriment of the major staples. Since independence many African countries have experienced rising food import bills at a time when they are already having balance of payment problems with high petroleum prices and/or the result of adverse effects of drought. Consequently, emphasis has been shifted from cash crops to food crops. Although during the colonial era higher priority was given to crops than to livestock, considerable efforts were made to control major livestock diseases like rinderpest, bovine pleuropneumonia, trypanosomiasis, East Coast fever, anthrax, contagious abortion and parasites such as helminths and ticks. The alarming losses caused by these pests and diseases reached such a magnitude that greater emphasis was given to veterinary services than to the equally important animal husbandry practices and nutrition. Veterinarians dominated policy concerned with animal production and, even when many of these diseases had been brought under control, low productivity attributable to nutrition and husbandry remained neglected. Sometimes animal breeding and production were grouped into a separate Ministry while crop production, which should include forage and pasture crops, belonged to the Ministry of Agriculture. Thus integration of crop husbandry with livestock production was as difficult as integration of veterinary services with animal husbandry, even though animal health and husbandry were very closely related. Various aspects of agricultural development policies and trends in West Africa were reviewed by a number of authorities including Hance (1958 & 1975), FAO (1961 & 1966), Stenning (1969), Dumont (1966), Wells (1974), etc.

Close to, and following, independence a Society for Rural Development (SONADER) was founded in Benin (then Dahomey) and a similar one (SODEPALM) in Ivory Coast for the production of oil palms. Since independence many agricultural production projects involving government corporations, parastatals, state farms and farm settlement schemes have been implemented; most have been unsuccessful. Very few of these projects were aimed at the smallholder who produced most of the food crops and also some of the cash crops. During the last decade, however, special projects aimed at increased food crop production have been launched and include the Operation Feed Yourself (OFY) in Ghana, The National Accelerated Food Production Programme (NAFPP) in Nigeria which was followed by the Operation Feed the Nation (OFN) and, in 1979, the Green Revolution Programme. Of these the most successful was the NAFPP which aimed at making Nigeria self-sufficient in the production of basic staples (rice, maize, sorghum, millet, cassava and wheat) by (i) encouraging farmers to use fertilizers through a 75 percent subsidy; (ii) improved seed; (iii) construction of agro-service centres for input distribution, processing, storage and purchase of produce, and (iv) provision of loans to farmers. It also involved minikit trials which provided the farmers with the opportunity of becoming involved in on-farm trials and evaluation of technology thereby significantly speeding up adoption and feed-back to research. The programme, however, suffered from shortage of small farmer credit and being followed too closely by OFN and the Green Revolution Programme.

There are currently policy guidelines which could act as an umbrella under which effective integrated crop and livestock strategies could be employed in the development of improved alternatives to traditional agricultural production systems. The current Lagos Plan of Action (OAU, 1981) to which all Economy Community of West African States (ECOWAS) countries, as members of OAU, are signatories, provides such policy guidelines. Pertinent provisions of the Plan which accepts ICL research and development strategies as components of a planned national and integrated natural resources management and utilization programme are:

  1. Self-reliance and self-sustainment in economic growth and development.
  2. Putting science and technology at the service of African development.
  3. Achievement of self-sufficiency in food production and supply.
  4. Preservation, protection and improvement of the environment.
  5. Reduction of reliance on export raw materials and priority to development and growth based on Africa’s considerable resources within a coordinated strategy.
  6. Achievement of self-sufficiency in cereals, livestock and fish products.
  7. Realistic agrarian reform as the basis for improved agricultural production.
  8. Enhanced utilization of water for irrigation based on existing and new irrigation schemes.
  9. Integrated development of areas freed from the tsetse fly and improvement of trypanotolerant breeds of cattle.
  10. Intensification of programmes to integrate woodlots and trees in land use and agricultural practices at village level.
  11. Priority in research and development to be given to:
    • increased production of plants and animals through improved husbandry techniques;
    • assessment and development of natural resources;
    • alternative energy sources including use of draught animals, biogas, etc.;
    • maintenance of the carrying capacity of arid lands and soil conservation;
    • incorporation of agri-silviculture practices into shifting cultivation.

The above policy provisions in the Lagos Plan do not specifically mention Integrated Crop/Livestock (ICL) strategy in the development of improved farming systems, but various aspects of the Plan such as alternative energy sources and mechanization of agriculture, achievement of self-sufficiency in cereals and livestock, integrated development of areas freed from tsetse flies and the recent interest of governments and the World Bank in integrated rural development have direct and indirect ICL implications. It is the role of scientists in various disciplines to design and conduct research and studies which confirm the beneficial effects of ICL. Priority should be given to the development of appropriate technologies and production systems which can be used by the producer on his farm, priorities which will require political commitment through sound policies and allocation of scarce but needed resources.

Impediments to Integration

Constraints to increased agricultural production by small farmers are the same that impede agricultural development and adoption of integrated crop and livestock production strategy. Many of these impediments are related to the same factors which differentiate various farming systems and have been discussed in detail by Flinn et al. (1974), Ryan and Thompson (1979), Okigbo (1981) and ILCA (1980).

Physio-chemical Factors

The most important physio-chemical constraints to increased crop and livestock production are related to climatic and other environmental factors.

While there is no danger from low temperatures, high temperatures in the surface soil or in the atmosphere close to the ground of 45°C or above, especially when associated with low humidity, can cause serious stresses that are detrimental to plant and animal life. High temperatures are injurious to seedlings and may have adverse effects on rhizobia and nitrogen fixation. They make vegetation very dry increasing the severity of burning and the spread of fires. High temperatures cause rapid decomposition of soil organic matter with adverse effects on soil texture, nutrient retention properties and the colloidal complex of the soil and increase the rate of evapotranspiration which renders light rains ineffective, causes severe losses from dams and reservoirs and, in irrigated soils, triggers off salinity problems. Uniformly high day and night temperatures contribute to low yields as a result of relatively high losses due to respiration. High temperature associated with high humidity has adverse effects on human work performance and contributes to the poor performance of temperate animal breeds in the tropics.

Tropical rainfall is characterized by high intensity, especially close to the beginning and end of the wet season, which increases the erosion hazard on land where the soil has become exposed by forest clearing and tillage. A very serious and frequent cause of famine in the Sahel is the erratic nature of the rain and unpredictable cycles of drought. In the humid tropics, especially above latitudes 6–7°N, and further inland, one or two weeks of drought may occur after planting. Drought stress is a major cause of crop failure and with high temperatures results in marked yield reduction. Related to rainfall is the constant cloud cover in the humid tropics which reduces photosynthesis and thus productivity. Insufficient sunshine in the humid tropics results in reduced response of crops like maize to fertilizers and is one reason why maize production is becoming increasingly important in the savannah areas, provided that moisture is not limiting. Another aspect of the light factor is photoperiodicity to which some traditional short-day plants are sensitive. The short-day sorghums take longer to mature resulting in high culm yields which provide structural materials for fencing and other purposes. As a result dwarf photoperiod-insensitive improved sorghum varieties may not be accepted by farmers.

Other physio-chemical conditions are related to soils which are highly weathered, acid and of low inherent fertility. These soils are not only fragile but in areas of Guinea, Liberia and Sierra Leone are subject to laterization; under continuous cultivation these soils develop multiple nutrient deficiencies and toxicities, but regular liming may also cause nutrient imbalance and toxicities. The infertility of tropical soils and climatic constraints contribute to the low nutritive value and poor quality of forage. Although the highly weathered soils of the tropics possess good physical characteristics for arable farming, it is these same properties which render them more erodible. Further, the adverse environmental conditions in tropical soils which make large areas marginal for plant growth require large quantities of fertilizers, which may not be economic, to sustain high yields.

Biological Constraints

Biological constraints are related to the favourable conditions that high temperatures have on pests, diseases and parasites. The extent of the adverse environmental problems (weeds, insects, locusts, trypanosomiasis, etc.) which constrain agricultural production, and various health hazards that affect agricultural development in the tropics have been discussed by Kamark (1976). Human diseases and parasites that affect settlement patterns and productivity include malaria, sleeping sickness, river blindness, onchocerciasis, filariasis, bilharzia (schistosomiasis), meningitis, etc., have rendered parts of the Middle Belt uninhabited and unutilized. There are also animal diseases like trypanosomiasis, rinderpest, foot and mouth disease, theileriasis, East Coast fever,dermatophilosis (streptothricosis) and parasites in both humid and arid areas which make livestock production hazardous. Serious diseases and pests of crops include Swollen Shoot of cocoa, maize rust (Puccinia polysoria), cassava mosaic, cassava bacterial blight (Xanthomonas manihotis), cassava mealybug (Phenacoccus manihoti), green spider mite (Mononychellus tanajoa), sweet potato weevil (Cyles puncticollis), maize streak virus, etc. Weeds cause serious losses in the tropics and rampant weed growth is one reason why farmers practise shifting cultivation. As a result the breeding for resistance to pests and diseases and adaptation to environmental stresses are key objectives in plant and animal improvement.

Technological Problems

Despite the relative antiquity of indigenous agricultural production systems in West Africa, the developing countries of Africa have not yet developed the long-term scientific tradition and quality of research necessary to maintain satisfactory growth in technology and its transfer to produce rapid agricultural and economic development. At the time of independence there were, for example, interterritorial research organizations for most major cash crops and food crops but all have been closed down. The exodus of expatriate staff after independence, except for countries like Ivory Coast, weakened the research effort and retarded progress. There is still a shortage of trained manpower. Wherever research has been carried out it has given priority to specialized individual commodity production systems and the solution of problem along separate lines. As a result the complex food production systems which require an interdisciplinary approach have been neglected. Research on food crops did not benefit from local knowledge of traditional farming systems or from the socio-economic environment within which they operate until farming systems research programmes were started at the international and some national agricultural research centres. It is only by using an integrated approach to research and understanding the various interacting components of crop and livestock subsystems that effective priorities and programmes can be identified to establish the potential and limits of ICL production systems. The lack of this orientation has resulted in the unsuccessful attempts to transfer successful technologies from temperate countries and to establish large-scale mechanized farms in the tropics. Thus lack of understanding of the traditional farming systems in Nigeria, in particular the role of livestock, led to over-emphasis on the improvement of indigenous trypanotolerant cattle for milk production and the abandonment, until recently, of the work with these valuable breeds. Lack of knowledge of the role of small animals in traditional production systems led to a wrong strategy in poultry improvement for small farmers which advocated intensive production systems which could only be adopted by the affluent, mainly because there was no economic technology to produce maize and concentrates locally.

Socio-economic Problems

Several socio-economic constraints bedevil agricultural development and some of these have hampered exploitation of the existing potential and benefits of ICL. These include:

  1. Lack of the basic statistical data and knowledge of the socio-economic background, the environment, the resources and the management capacities within traditional production systems which can be used as a basis for planning, identifying constraints and priorities and the selection of strategies in research and development in agriculture.
  2. Rapid population growth which, in addition to associated socioeconomic pressures, has outmoded the traditional farming systems to the extent that their underlying scientific base and the economic viability cannot now be understood and appreciated.
  3. The complexity of traditional agricultural production systems, the competition between subsystems and nonfarm components, and the farmers’ interest in diversification and the reduction of risk through the achievement of reasonable but sustained yields rather than maximization of the production of one or two commodities.
  4. Land tenure and associated problems of fragmentation of holdings, small farm size, the problems of economies of scale and their effects on the profitability and acceptance of certain technologies like communal land ownership which, although eliminating landlessness, deterred investment in land improvement.
  5. Continuing reliance on simple farm tools and manual labour which accentuates the drudgery of farm work. (Nevertheless, there are limitations in mechanization using animals in areas of high incidence of trypanosomiasis or tractors which most farms cannot afford to buy, maintain, hire or fully utilize.)
  6. Shortage of labour at seasonal peaks of demand due to division of labour between the sexes, relatively low return to agricultural work, rural-urban migration and education for children. As a result farming is left to old men and women with low productivity. Despite this there is a marked underemployment during certain times in the year.
  7. Lack of capital and credit for the purchase of inputs, including draught animals in areas where they can be used, associated with the relatively high cost of fertilizers, pesticides and equipment.
  8. Poor extension services and the inappropriateness of new technologies resulting in a very wide gap between experiment station yields and those on farmers’ fields.
  9. Conflicting ideologies about development and insufficient understanding of the socio-economic parameters which control the extent and nature of government involvement in production.
  10. Poor marketing and pricing policies for agricultural products which reduce the incentives that are needed to motivate increased agricultural production. Related to this is the shortage of infrastructure which is required to allow farmers access to inputs, services and markets.
  11. Poor communication among technicians, policy-makers and politicians which results in deficient policy formulation and inadequate allocation of the resources required to achieve national priorities.
  12. Inadequate coordination between research and development policies and lack of integrated programmed which take into account the common resources and environmental endowments of ECOWAS countries.

Related Research

Farming Systems Research

The most significant development in agricultural research within the last two decades has been the formation of international agricultural research centres and the incorporation of Farming Systems Research (FSR) into research programmes. The purpose of FSR is the study of the farmers’ environment as well as the various integrated components of the prevailing farming systems. An understanding of the farming systems enables them to be evaluated, modified and redesigned to fit the needs of the farmer. FSR adopts a multidisciplinary approach to research that gives priority to:

  1. Baseline data collection and analysis of farming systems based largely on collection, collation and evaluation of secondary data which is then updated and made more complete by special surveys.
  2. The study of existing farming systems, farmers’ objectives, resources, decision-making processes, input/output relationships, sources of income and constraints to increasing productivity.
  3. The analysis and understanding of the workings of the individual components of the systems and the constraints faced by the farmer constitute the basis for determining research priorities and strategies. This ensures that proposed new technologies and system components are relevant to the farmers’ needs and circumstances and have a high probability of adoption.
  4. Experiment station testing and analysis of new technologies based on the results of items 1 & 2.
  5. On-farm testing of promising technologies, the evaluation and monitoring of technology adoption and wherever possible, the introduction of necessary modifications, and the identification of the farm level constraints which are responsible for the yield gap between experiment station and the farmers’ fields; this also enhances feed-back to on-station research. On-farm research also facilitates the identification of the various off-farm, infrastructural and policy constraints which interact to determine the success of a farm enterprise.

FSR, because of its multidisciplinary nature and detailed study of the farmers’ environment, has made agriculturalists aware of the importance of anthropological, sociological, geographical and economic literature which describes aspects of traditional farming systems ranging from the initial hunting and gathering stage to shifting cultivation and pastoralism, through various intensities of cultivation down to the numerous development projects aimed at modernizing agriculture in the tropics.

Other significant developments include economic assessment of traditional and other farming systems, farmers’ decision-making processes, resource utilization and the comparative performance of various systems. There has been an upsurge in the study of livestock and small ruminant production systems in the tropics. Of major importance are the activities, conferences and reports of the Winrock International Livestock Research and Training Centre, the Bellagio Conference on Integrated Crop and Animal Production (McDowell and Hildebrand, 1980) and the research programmes of the International Livestock Centre for Africa (ILCA) and the International Laboratory for Research on Animal Diseases (ILRAD). These two livestock research centres complement the work of 11 other stations coordinated by the Consultative Group on International Agricultural Research (CGIAR) most of which are giving priority to food crop improvement and the development of more efficient systems for their production.

Socio-economic Studies

FSR gives priority to socio-economic studies of farming systems, which define the characteristics of various farming systems and constraints to their improvement. Work on production economics has demonstrated why certain technologies fail to be adopted by farmers; at ILCA it was shown that some maize varieties were not accepted because they were not suitable for eating green; in other situations local preference is for white maize instead of yellow. Economic studies have also demonstrated the profitability of different technologies or production systems. Norman et al. (1982) indicated the extent to which valley bottom or lowland (fadama) plots give higher returns than upland areas. Most of the lowland areas of hydromorphic soils in West Africa are unexploited. Related to these are multidisciplinary studies of integrated development of small watersheds which will be discussed in greater detail.

Current Crop-Based Farming Systems Research with Implications for ICL

The results of FSR that are pertinent to the design and development of improved cropping systems in West Africa include:

  1. Intercropping which has been demonstrated to give higher stable yields especially at low input levels than sole cropping. It results in more efficient use of resources and involves more uniform distribution of labour throughout the year.
  2. Intercropping involves a wide range of crop species and different varieties of each species that differ in time of maturity and other characteristics which allow the farmer greater flexibility in management and utilization of resources.
  3. The practice of intercropping satisfies the objective of attaining diversification of production for subsistence on small farms, minimizing risks of failure, and producing some commodities for sale.

    In some situations intercropping minimizes losses from pests and diseases and provides better cover for the soil which reduces erosion.

  4. Considerable progress has been made in the identification of compatible mixtures of crops such as maize/cassava, plantain/ cocoyam, yam/maize and sweet potato/pigeon peas for the humid and subhumid tropics and sorghum/millet, maize/sorghum, sorghum/ groundnuts and sorghum/cowpeas for the savannah areas.
  5. Some progress has been made in developing rotations for humid and arid areas. At ILCA, in Ibadan, it has been shown that a viable rotation involving intercropping is maize/cassava followed by cowpeas alone or intercropped with chillies or tomato. It was also shown that cowpea is a better crop than soybean in rotation with maize since it leaves more residual nitrogen in the soil.
  6. Soil fertility studies have shown that for sustained yields fertilizer application is imperative but fertilizer application is not often profitable during the first year after fallow. Some application of organic manure is not only beneficial but may enhance the effects of fertilizers.
  7. A start has been made to study potential fodder species, pasture establishment and herbage productivity (ILCA, 1979a). In addition to the collection of data on grass and legume fodder species, ILCA has identified promising forage and browse plants for use in agrosilvicultural systems in the humid trops.

Recent Developments at ILCA and Cooperating Institutions

The CGIAR centres are giving priority to quantitative and qualitative improvement of major food crops in developing countries in addition to the development of more efficient farming systems for their production by small farmers. The crop improvement programmes are giving priority to increased yield, better nutritional quality and other characteristics but especially resistance to disease and pests, tolerance to environmental stresses and adaptation to various production systems. Emphasis is being given to integrated pest management and various ways of reducing the costs of inputs. Areas of FSR in which significant progress has been made include land development and subsequent cropping patterns, zero tillage, live mulch, alley cropping with leguminous shrubs and evaluation of browse in agrosilvipastoral systems. These are summarized below:

Land Development

Probably the most crucial problem in the development of a permanent food production system for sustained yields is the development of appropriate techniques for land clearing, land preparation and subsequent soil management. In the humid tropics sustained agricultural production is possible when (i) chemical nutrients removed by crops or otherwise lost during cultivation are replenished; (ii) soil physical conditions are maintained at a favourable level by ensuring that adequate levels of soil organic matter are present; (iii) soil is kept constantly covered and erosion effectively controlled; (iv) soil acidity, nutrient deficiencies and toxic constituents are corrected, and (v) build-up of pests, diseases and weeds are prevented (Greenland, 1975). In West Africa bringing new land into cultivation remains the most widespread method of increasing food production. Clearing new land is now expensive as a result of labour shortage, and many governments are resorting to mechanical clearing for large-scale farms and the use of hired tractor units for cultivation on small farms, although most of the mechanized largescale farms in the tropics have failed because of poor land development and subsequent soil management during cropping. At ILCA priority has been given to the study of the physical, chemical and biological characteristics of the more important soils of the humid and subhumid areas of Africa to provide a basis for evaluating their capabilities under cultivation and different management systems. An evaluation of various manual, mechanical and chemical land clearing techniques has shown that clearing methods and soil management must be suited to the crops to be grown. Soil disturbance during clearing was found to cause serious erosion losses and irreversible soil degradation; manual clearing produced the least adverse effects but was slow and expensive. Chemical methods applied by spraying, ringing or trunk injection with selected chemicals such as 2-4-D or Tordon have been shown to be suitable for pasture establishment, but a shear blade with V-shaped cutting edge proved to be the most appropriate mechanical method of clearing for arable crops. It was economical and, when followed by zero tillage, erosion rates were lower and yields higher than with conventional tillage. With good plant residue management and control of weeds with herbicides, the soil is protected and there is no need for terracing or other expensive soil conservation measures on average slopes. Results obtained in land development studies by ILCA are presented in Table 12 and Figure 13. The no-tillage technique requires that crop residues should be left on the surface. Although it has worked on Alfisols at ILCA, tillage studies at Ougadougou in Upper Volta in the Sahel have shown that tillage is necessary and that tied ridging which conserves moisture increased yields by over 13 percent.

Cover Crops, Organic and Live Mulches

Crop and weed residues are important in reducing erosion and enhancing adequate levels of soil organic matter and water infiltration in the no-tillage system. Experiments by ILCA on degraded soils have shown that soil rejuvenation can be achieved by 1–2 years of leguminous cover which is then killed using a herbicide and followed by no-tillage cropping.

Fig. 13 Comparison of various lengths of fallow in relation to cultivation periods in African farming systems (adapted from Grove & Klein, 1979) in comparison with recent attempts to eliminate long term fallows and achieve intensification through alley cropping.

CULTIVATION PERIODFALLOW PERIOD
Fig. 13

Experiments with industrial waste mulches such as sawdust, rice husks, rice straw and legume husks also indicate that these agricultural by products, which are often burnt or thrown away, can be put to good use.

Interest in living mulch is related to the fact that, although 40–70 percent of the farmer’s time in the tropics is spent on weeding, hand or mechanized weeding destroys soil surface structure and exposes it to erosion. Moreover herbicides are expensive and hazardous. Experiments at ILCA in which maize has been grown in living leguminous cover have shown that wild groundnut (Arachis repens), Centrosema pubescens, a forage legume, and the wild Wing Bean (Psophocarpus palustris) are promising (Table 13). The results also show that the live mulch added nitrogen and organic matter to the soil while reducing weed growth. The live mulch technique is suited to high rainfall areas where competition with the crop for water is low. It also facilitates cropping of steep slopes without terracing or bunding.

TABLE 13

MEAN GRAIN AND ROOT YIELDS FOR INTERCROPPED MAIZE AND CASSAVA IN RELATION TO LEGUMINOUS COVER AND TILLAGE PRACTICE

Legume CoverMaizeCassavaTreatmentMaize Dry GrainCassava Fresh Roots
Psophocarpus5 05424 047No-Tillage4 04326 027
Centrosema 4 91422 206Conventional Tillage4 43126 813
Calapo3 81728 519No Fertilizer3 88225 497
Stylosanthes3 22827 088With Fertilizer4 59227 343

Source: IITA, Ibadan.

Alley Cropping with Leguminous Shrubs and Browse Plants (Figure 13)

Leguminous cover crops, even when they have been shown to be economically viable and suitable, are not popular with farmers. They fix nitrogen but are not as effective in nutrient cycling in fallows as deep rooted shrubs like Leucaena leucocephala, Gliricidia sepiumand Acacia barteri. Experiments have shown thatLeucaena leucocephala can be grown in rows (alleys) 4m apart and maize, yams, cassava or cowpeas can be planted between. The Leucaena is periodically pruned and the twigs used as mulch returning nutrients to the soil while protecting the soil and preventing shading of the crop. The Leucaena can be pruned at about 2m and the stems used as stakes for viney crops such as yams; the prunings supply fuelwood.

A cooperative study involves grazing browse plants such as Leucaena, Gliricidia and Ficus spp in alley cropping systems with small ruminants. Preliminary results indicate that this system constitutes an effective way of integrating crops and livestock in a permanent production system.

Socio-Economic Studies of Animal Production Related to Arable Farmers

Sleeper (1978) conducted an economic analysis of breeding and cattle fattening to stratify livestock production in West Africa. This called for planned agricultural land use in which the arid zone is used for extensive grazing, the semi-arid areas are used for extensive production of adapted crops, while the subhumid areas are used for intensive fodder and pasture production; cattle should be fattened near terminal markets or export abattoirs. He showed that (i) under the current scheme bovine traction would not substantially increase farm income; (ii) adoption of small feeding units could substantially increase cash income; (iii) bovine traction will not draw a substantial number of cattle from rangelands as envisaged, and (iv) bovine traction and small unit feeding can increase meat supply. Eddy (1979) conducted a linear programming study of mixed farming among the bush Tuaregs of Niger and showed that farmers in the unfavourable terrain have developed a system of integrated cattle and goat rearing with grain production to minimize the risk posed by drought and fluctuating grain prices on the edge of the pastoral zone between the rainfed agricultural zone and the desert. The Tuaregs, who used to plant millet prior to migrating north with the rains, have been forced by competition with Hausa cultivators and Fulani herders to settle and grow millet, sorghum, cowpeas, and spices in the rains, and tomatoes and onions under irrigation in the dry season. Delgado (1978) investigated mixed farming in the Tenkodogo area of Upper Volta, using bovine traction, which was aimed at providing the farmer with milk, meat, a cash income and manure for increasing crop yields. It was found that the smallholders had difficulty in controlling animals in unfenced fields, and that seasonal labour conflicts occurred between the requirements for stock and for sorghum and millet harvesting. He recommended that policy should be directed toward improving the traditional system in which the sedentary Mossi cattle owners entrusted animals to the Fulani herders. Ware (1979) reported that droughts between 1966 and 1973 forced nomadic Fulani herders in the Diourbol area of Senegal to change to mixed farming by having their older sons grow food crops (millet and sorghum) while the women fattened animals and reared poultry. He noted that the Wolof mixed farmers had developed an east/west pattern of grazing fields in such a way that millet, sorghum, cowpeas, tomatoes, etc. are grown on the western half of a field in a given season: in the next season this area is grazed while the eastern half is cropped. Kline et al. (1969) studied problems of mechanization in tropical Africa and found cattle herders were more reluctant to become farmers that arable farmers were to adopt animal traction. They reported trypanosomiasis and feeding to be problems in maintaining oxen and that the oxplough could be used only for planting and cultivation. These studies of animal production in association with crop production must be taken into account in designing ICL projects, planning, research and training.


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Welcome to Pan Africa Agro Farming system

Here we will study, learn and understand the native and modern farming systems and methods used in west Africa…

We will also enlighten you on some easy and cheaper animal rearing /breeding and feeding techiques… And easier planting and farming methods…There will be provision to comnect and talk to expets and proffessional in these fields.

THE PROGRESSION FROM ARABLE CROPPING TO INTEGRATED CROP AND LIVESTOCK PRODUCTION

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Current Agricultural Production Systems in West Africa

The existing agricultural or farming systems in different ecological zones of West Africa are designed to produce subsistence food, cash sales and materials for local or industrial use. There is no generally accepted classification of farming systems in tropical Africa, but for convenience a classification which is based on intensity of cultivation and/or animal rearing is presented in Table 11. The various production systems are grouped under (i) traditional and transitional systems, and (ii) modern systems and their local adaptations.

Traditional and Transitional Agricultural Systems

The majority of the farming systems of West Africa belong to this group which range from the extensive (shifting cultivation and nomadic herding) to more permanent and specialized types of farming (compound farms and terrace farming). Shifting cultivation is an extensive agricultural production system in which a cultivation phase on ‘slash-and-burn’ cleared land alternates with a fallow period (Okigbo, 1982). The clearing is done using axes or matchetes and usually only herbaceous plants, saplings and undergrowth are cut. When dry the cut material is burned and the cleared area is planted on the flat or on mounds with crops like yams, rice, sorghum, millet, maize and cassava depending on the ecological zone. The land is cultivated for one to four years after which it returns to fallow. The regrowth of natural vegetation rejuvenates the soil through nutrient cycling, addition of litter and suppression of weeds. The cultivation phase alternates with a much longer fallow phase, ideally 10–20 years. Marked variation in the relative lengths of cultivation and fallow periods have been reported by Nye and Greenland (1960) and Ruthenberg (1974).

In classical shifting cultivation, the homestead of the farmer is relocated near the cultivated fields after each cultivation phase. In practice the situation varies from where the farmer may never return to the same piece of land to situations where cultivation is repeated on the same plots. This cultivation system is ecologically viable in frontier situations where population density is low and fallow periods are long enough to restore soil fertility. Shifting cultivation in the classical sense has all but disappeared in West Africa and Morgan (1980) reported it to be restricted to parts of Ivory Coast and small areas between Nigeria and Cameroon (Figure 10). Nomadic herding is the extensive animal rearing counterpart of shifting cultivation in the savannah and more arid areas is discussed separately.

Fig. 10

Fig. 10 WEST AFRICA: MAIN AGRICULTURAL OR FARMING SYSTEMS.

Pastoralism and sabel fringe cultivation
Shifting cultivation
Rotational woody bush fallow
Rotational bush/grass land fallow
Permanent cultivation
Floodland cultivation
Mixed farming

TABLE 11

CLASSIFICATION OF FARMING SYSTEMS IN AFRICA1
(Okigbo & Greenland, 1977)

A. Traditional and Transitional B. Modern Farming Systems and
Systems their Local Adaptations
1. (a) Nomadic Herding 1. Mixed Farming
(b) Shifting Cultivation (Phase I), L 10*
2. Livestock Ranching
2. Bush fallowing or Land Rotation Shifting Cultivation (Phase II) L = 5 – 10
3. Intensive Livestock Production (Poultry, Pigs, Dairying)
3. Rudimentary Sedentary Agriculture. Shifting Cultivation (Phase III) L = 2 – 4
4. Large Scale Farms and Plantations
4. Compound Farming and Intensive Subsistence Agriculture. Shifting Cultivation (Phase IV) L 2 (a) Large scale food and arable crop farms based on natural rainfall.
(b) Irrigation projects involving crop production.
5. (a) Terrace Farming: L = 1 – 2 (c) Large scale tree crop plantations.
(b) Floodland agriculture L ≤ 1
5. Specialized Horticulture
(a) Market gardening.
(b) Truck gardening and fruit plantations.
(c) Commercial fruit and vegetable production for processing.

1 Adapted from Whittlesey, 1936; Morgan and Pugh, 1969; Floyd, 1979; Laut, 1971; Benneh, 1972; Greenland, 1974.

*

where C = Cropping period
F = Fallow period
L = Land use factor

Shifting cultivation has been replaced by more intensive farming systems as the result of increasing population pressure and the shortening of the fallow period. The intensity of cultivation can be measured using the Land Use Factor (L) of Allan (1965) where:

where
C = number of years of cultivation
F = number of years of fallow

Greenland (1974) reported that intensification of cultivation (Table 11) passes through the following phases:

System Intensity of Cultivation
Phase I – Shifting cultivation L = 10
Phase II – Recurrent cultivation L = 3 – 10

(a) Long-term
(b) Middle-term
(c) Short-term

L = 7 – 10
L = 5 – 7
L = 3 – 5

Phase III – Semi-permanent cultivation L = 2.5 – 3
Phase IV – Permanent cultivation L = 2

The intensification of production in the farming systems shown in Table 11 can be assessed by relating their L values to those above. Based on the foregoing, the traditional and transitional West African farming systems in which crops are grown and some animals reared are characterized as follows:

Objectives

Originally farming in West Africa was subsistence orientated. During the colonial era trade in spices, forest products and later cash crops led to increased cash cropping and with increasing industrialization, the production of export orientated raw materials (palm oil, palm kernels, groundnuts, rubber, cotton, etc.). With increasing domestic industrialization many of these raw materials can be sold locally. With increasing urbanization and mobility, the market economy has become well established in West Africa, particularly the need by farmers for money to purchase goods, services and farm inputs which can only be obtained through sales of farm produce. By products of farming (manure, fuel wood, etc.) can also be used. Therefore the objectives of traditional farmers are various and, although food crops still have priority, some commodities are produced specifically for sale.

Spatial Arrangement and Structure

Traditional West African farming systems consist of several fields in more or less concentric circles round a compound or homestead-garden. (Figures 11 and 12). The homestead-garden is under intensive, permanent production and contains a mix of perennial and annual crops grown in a complex agroecosystem. In the tropical rain forest zone this may attain a multistoried structure approaching that of the tropical rain forest (Plates 2 and 3). In the savannah, it is not so complex owing to lower rainfall but the diversity index usually exceeds that of the surrounding woodland. Fertility is maintained by applying household refuse, crop residues and animal manure. The fields are located at varying distances from the homestead and have fallow periods which increase with increasing distance from the homestead (Plate 4).

In areas where population densities are low, L values on the farthest fields can exceed 10. Where population densities are high, as in southeastern Nigeria or Kano, L values are much lower than 10. Most fields outside the homestead-garden contain useful semi-wild or indigenous trees; these include the oil palm (Elaeisguineensis), the oil bean (Pentaclethra macrophylla) and the African mango (Irvingia gabonensis) in the rain forest zone, and the shea butter (Butyrospermum paradoxum), locust bean (Parkia spp), Acacia albida andBalanites aegyptiaca in the savannah. Fields near the intensively cultivated homestead-garden are generally impoverished and under short periods of fallow (L = 1 – 3) because they are constantly being cropped or grazed with no manure or fertilizer application. More distant fields are more fertile mainly because the period of fallow is longer. There is a tendency for these fields to carry crops which are grown for sale or those which are more easily harvested.

There are specialized cropping systems that take advantage of topographical or microenvironmental variations which occur within the farm. The homestead-garden is usually sited in a dry, upland situation, but nearby may be lowland or valley bottoms (called fadamain the savannah areas of Nigeria or boliland in Sierra Leone) (Plate 5) where rice, vegetables, yams, sugar cane, bananas, taro, etc. may be grown depending on the ecological zone. Crops which require high levels of fertility or greater care like yams, vegetables and cocoyam in the forest zone or tobacco and vegetables in the savannah, are grown nearest to the homestead. The homestead-garden system includes varying numbers of small ruminants, pigs and poultry; cattle, donkeys, camels and horses are kept in tsetse-free savannah areas. Livestock are a feature of the homestead and adjacent areas and they graze on fallows and residues on the harvested fields.

The different production systems compete for labour and resources and to maximize these, different crops or varieties of a crop are grown in the different fields. With distance from the homestead, fishing, hunting and some food gathering increase in importance. This concentric field system is sometimes called ‘land zoning’ (Grove and Klein, 1979), or the ‘ring system of cultivation’ (Ruthenberg, 1980; and Norman, et al., 1982).

Fig. 11 SIMPLIFIED MODEL OF SPATIAL ORGANIZATION OF FIELDS AND FARMING SYSTEMS IN TROPICAL AFRICA. (Adapted from Grove & Klein 1979)

Fig. 11

NOTE: Specialised field on land use systems include valley bottoms, terraces, termite mounds etc.

Fig. 12 Schematic diagram of compound farms in relation to associated fields systems in traditional farming systems of the humid tropics of West Africa.

Fig. 12
PLATE 2

PLATE 2 – Compound or homestead-garden in the Humid Zone, Nigeria

PLATE 3

PLATE 3 – Compound or homestead-garden and adjacent plot in the Subhumid Zone, Nigeria

PLATE 4

PLATE 4 – Distant open cultivated field in the Humid Zone, Nigeria

PLATE 5

PLATE 5 – Distant cultivated lowland fadama in the Subhumid Zone, Nigeria. Note bananas, maize and beds of onions in foreground

Farms and Production Methods

Farm sizes are small, generally less than 2 ha, but farms in the savannah are larger than those in the forest zone; in Nigeria in 1965, 82 percent of the farms were less than 2 ha.

Tools are simple and hand operated. There is very limited mechanization although since the early 1930s use of animal power for cultivation, planting and transportation on the farm has been increasing in areas free from tsetse. Use of tractors and tractor-drawn implements is increasing but is of no general significance.

Land is almost always universally cleared by manual cutting and burning. Thereafter there is little or no tillage and crops are grown on the flat, or on mounds or ridges which are manually constructed. Weeding is usually carried out manually. There is increasing mechanical land clearing as a result of the high cost of labour.

West African agriculture is characterized by a division of labour between the sexes, with women specializing is some operations and the men in others. There is often acute shortage of labour on farms due largely to seasonal demand peaks for farm operations and division of labour between sexes and age groups. Shortage of labour is aggravated by rural-urban migration, children attending schools and competition from the non-agricultural sector.

Apart from organic and animal manures very little use is made of chemical fertilizers. Physical and cultural methods are used to control pests and diseases although pesticides are used on some cash crops (e.g. cocoa).

Traditional farming systems are designed by the timing of operations, species grown and resource manipulation to make best use of the prevailing rainfall regime. Although there is some traditional use of water to supplement crop growth very limited use is made of irrigation. It has been estimated that West Africa is currently using less than 10 percent of its irrigation potential.

Many believe that shifting cultivation and nomadic herding are the dominant farming systems in West Africa but, according to Morgan and Pugh (1969), Gleave and White (1972) and Grove and Klein (1979), true shifting cultivation has almost disappeared apart from isolated areas. It has been replaced by the farming systems listed in Table 11.

Crops are usually grown as mixtures, relay intercrops or associated sequences. Crop rotations and sole crops are rare apart from rice and to some extent cash crops like groundnuts, cotton and sugar cane; the more a crop is grown for sale the greater the likelihood of its being grown in pure culture.

While productivity per unit of energy may be high, yields per unit of area are low in traditional farming systems. There is not only a wide gap between attainable yields on farms as compared to experimental stations but also as compared to average and recorded yields in other parts of the world.

Traditional and transitorial farming systems in West Africa are complex and not only involve several species of crop but often include livestock. Although crop production is not a component of nomadic herding there are many examples of complementary and symbiotic interrelationships between farmers and herders (Ruthenberg, 1980; Dyson-Hudson (1972) and Norman,et al., 1982).

Traditional farmers, their wives and farm family members in rural areas usually engage in many paid non-farm activities. Earnings from these activities significantly contribute to family income.

Changes in Traditional Farming Systems

Farming systems in West Africa have reacted to changing circumstances. Changes have resulted from (i) introduction of Asian and New World Crops; (ii) population expansion; (iii) European colonization of Africa and the need for spices and agricultural raw materials for industry; (iv) improved means of transportation and communication; (v) expansion of cassava production into marginal areas where other crops often fail, and (vi) introduction of mechanization into farming and adoption of new techniques. Modern farming systems and their local adaptations, as listed in Table 11, often exist side by side with traditional systems.

Progression towards Integrated Crop and Livestock Production Systems

The first system of crop production which replaced hunting and gathering was shifting cultivation. In West Africa, as elsewhere, it was an efficient and reliable production system in situations where population density was low. As population density increased, however, fallow periods became shorter and more intensive and semi-sedentary agricultural production systems replaced shifting cultivation. Sedentary agriculture involved settlement in villages and communities in which the homestead became a permanent feature associated with a homestead-garden. The outlying fields associated with each homestead were subjected to different periods of cropping but, when population became very dense, these fields were permanently cropped. It would appear that in almost all parts of the world traditional farming systems centred around a homestead-garden where livestock were kept. The various stages in the evolution of farming systems in which crop production constitutes an integral component are shown in Table 12. Continued intensification of production often resulted in more specialized production systems which required more inputs, more capital, specialized practices and new tools and technology. Animals rarely feature in the specialized crop production systems, except where mixed farming is possible, but Lagemann (1977) showed that animal populations increase with increasing human population density. The animal component of the traditional farms plays a crucial role in the maintenance of soil fertility, without which the permanent farming system used on the homestead-garden and adjacent areas would be impossible. Livestock provide meat and other animal products, form a savings account, utilize household waste and fulfil social and cultural obligations. In almost all the ecological zones of West Africa livestock make a significant contribution to farm income.

Interactions between Cultivators and Herders

According to Monod (1975) “no nomad can exist for long without contact with sedentary peoples.” Monod also observed that even the Tuareg nomads of the Sahara maintain contact with oasis dwellers. Contact with sedentary cultivators makes it possible for pastoralists to obtain food (grains, legumes and vegetables) and sometimes water, fodder, grazing land or even cash for part-time work on their farms. Pastoralists are individuals of distinct ethnic groups and in West Africa they consist of (i) Fulani (or Fulbe) who rear cattle and sheep in the Sudan/Sahel, savannah extends from Senegal to parts of Ethiopia; (ii) Tuaregs with herds of cattle and camels who sometimes live in oases in Mali and Niger; (iii) the Toubou who rear cattle and camels and who may also live in oases in Mali and Niger; (iv) Moors in the Sahara comprising a northern group that keeps herds of camels and a southern one rearing cattle and camels, and (v) Shuwa Arab cattle herders near Lake Chad.

It is common practice for herders to arrange with arable farmers to graze stubbles or crop residues from harvested fields, in return for animal manure. It is also the common practice for farmers like the Hausa, the Mossi or Mende to arrange with the pastoralists to look after their livestock and sometimes graze them during the dry season in distant pastures. Arable farmers, on the other hand, obtain animal products (milk, cheese, leather goods), animal transportation and manure from the pastoralists. The importance of manure in maintaining soil fertility in the absence of fertilizer cannot be overemphasized. Even when cattle owned by arable farmers are grazed by herders, a kind of mixed farming is being practised in which, according to Monod (1975), the herders facilitate the combination of crop production and animal production rather than integrating them.

TABLE 12

CHANGES IN CROPPING SYSTEMS IN RELATION TO THE INTENSIFICATION
OF CULTIVATION AND INTEGRATION OF ANIMAL AND CROP PRODUCTION

Stages in Evolution of Crop Based
Farming Systems
Remarks and Extent of Livestock
Association
Per-humid to Sub-humid Tropics
1. Collecting, hunting and fishing No permanent settlement, some camping places. No cultivation, no rearing of stock
2. Shifting cultivation Homesteads moved as fields shift. Cultivation practised. Some animals especially the dog may be kept. Hunting and fishing still substantial. Has almost disappeared or confined to small areas.
3. Recurrent cultivation, bush fallow land rotation Homesteads permanent and associated with fields and temporary huts in new plots. Fields shift or rotate may be in secondary forest, bush, thicket, woodland or grassland fallow. Homestead or compound garden present with some livestock and cultivated trees and shrubs. Protected or semi-cultivated trees and shrubs present in fields.
4. Permanent cultivation

(i) lowlands

(a) uplands

– compound gardens
– planted short-term fallows and rotations

(b) lowlying areas

– wet rice cultivation
– flood plains cultivation
– valley bottoms and ‘fadamas’

(ii) highland areas

(a) terrace farming
(b) mixed farming

Most widespread permanent farming system. Arable crops, spices, tree crops, etc. and livestock present (cattle mainly in savannah zona). In areas of high population density or confined sites, southeastern Nigeria or Kano close settled zone. Rice zone – Sierra Leone, Senegal, Mali Inland Niger delta decrue and crue systems. Very common in the savannah; animals present in 4 (i) in association with farmers compound.

In defensive positions in highland areas – mountains in Togo, Mandara mountains, and Maku in southeastern Nigeria. Livestock usually present. Mixed farming practised by sedentary Fulani in Futh and Mambilia plateau in Adamawa. Monod (1975) reported expansíon of cattle rearing among horticulture people, e.g. Hausa, Kanuri, Borgu, Waja, Kilka, Kaka and Mambila.

5. Specialized Cash Cropping

(a) Smallholder tree crop plantations
(b) Smallholder arable crops

These cropping systems grow cash crops such as cocoa, groundnuts or cotton almost in pure culture in rotation with other crops.
6. Non-agricultural work Livestock may graze residues of arable crops after harvest but may not belong to the farmer. Some peoples whose ancestors were cultivators often move to other professions and some farmers engage in multiple occupations.

Based on Ruthenberg (1980), Monod (1975) White and Ybeave (197) Gallais and Sidikou (1978)

When this relationship does not exist the herders may plant a crop of millet before migrating north during the rains, which will be harvested when they return during the dry season. Arable farming peoples like the Kanuri, Hausa, Borgu, Waja, Kibba, Chamba, Kaka and Mambilla often rear cattle and other animals and produce their own manure. With the rapid changes now taking place ethnic groups which were traditionally arable farmers are ready to acquire cattle and pastoralists are increasing their arable farming.

Relevant National Policies

In almost all countries of West Africa national policies in agricultural development have changed very little with respect to integration of crop production and livestock rearing. There has, however, been a shift of emphasis since independence. During the colonial era, priority was given to research, extension, marketing and infrastructural development that enhanced production of cash or export crops to the detriment of the major staples. Since independence many African countries have experienced rising food import bills at a time when they are already having balance of payment problems with high petroleum prices and/or the result of adverse effects of drought. Consequently, emphasis has been shifted from cash crops to food crops. Although during the colonial era higher priority was given to crops than to livestock, considerable efforts were made to control major livestock diseases like rinderpest, bovine pleuropneumonia, trypanosomiasis, East Coast fever, anthrax, contagious abortion and parasites such as helminths and ticks. The alarming losses caused by these pests and diseases reached such a magnitude that greater emphasis was given to veterinary services than to the equally important animal husbandry practices and nutrition. Veterinarians dominated policy concerned with animal production and, even when many of these diseases had been brought under control, low productivity attributable to nutrition and husbandry remained neglected. Sometimes animal breeding and production were grouped into a separate Ministry while crop production, which should include forage and pasture crops, belonged to the Ministry of Agriculture. Thus integration of crop husbandry with livestock production was as difficult as integration of veterinary services with animal husbandry, even though animal health and husbandry were very closely related. Various aspects of agricultural development policies and trends in West Africa were reviewed by a number of authorities including Hance (1958 & 1975), FAO (1961 & 1966), Stenning (1969), Dumont (1966), Wells (1974), etc.

Close to, and following, independence a Society for Rural Development (SONADER) was founded in Benin (then Dahomey) and a similar one (SODEPALM) in Ivory Coast for the production of oil palms. Since independence many agricultural production projects involving government corporations, parastatals, state farms and farm settlement schemes have been implemented; most have been unsuccessful. Very few of these projects were aimed at the smallholder who produced most of the food crops and also some of the cash crops. During the last decade, however, special projects aimed at increased food crop production have been launched and include the Operation Feed Yourself (OFY) in Ghana, The National Accelerated Food Production Programme (NAFPP) in Nigeria which was followed by the Operation Feed the Nation (OFN) and, in 1979, the Green Revolution Programme. Of these the most successful was the NAFPP which aimed at making Nigeria self-sufficient in the production of basic staples (rice, maize, sorghum, millet, cassava and wheat) by (i) encouraging farmers to use fertilizers through a 75 percent subsidy; (ii) improved seed; (iii) construction of agro-service centres for input distribution, processing, storage and purchase of produce, and (iv) provision of loans to farmers. It also involved minikit trials which provided the farmers with the opportunity of becoming involved in on-farm trials and evaluation of technology thereby significantly speeding up adoption and feed-back to research. The programme, however, suffered from shortage of small farmer credit and being followed too closely by OFN and the Green Revolution Programme.

There are currently policy guidelines which could act as an umbrella under which effective integrated crop and livestock strategies could be employed in the development of improved alternatives to traditional agricultural production systems. The current Lagos Plan of Action (OAU, 1981) to which all Economy Community of West African States (ECOWAS) countries, as members of OAU, are signatories, provides such policy guidelines. Pertinent provisions of the Plan which accepts ICL research and development strategies as components of a planned national and integrated natural resources management and utilization programme are:

  1. Self-reliance and self-sustainment in economic growth and development.
  2. Putting science and technology at the service of African development.
  3. Achievement of self-sufficiency in food production and supply.
  4. Preservation, protection and improvement of the environment.
  5. Reduction of reliance on export raw materials and priority to development and growth based on Africa’s considerable resources within a coordinated strategy.
  6. Achievement of self-sufficiency in cereals, livestock and fish products.
  7. Realistic agrarian reform as the basis for improved agricultural production.
  8. Enhanced utilization of water for irrigation based on existing and new irrigation schemes.
  9. Integrated development of areas freed from the tsetse fly and improvement of trypanotolerant breeds of cattle.
  10. Intensification of programmes to integrate woodlots and trees in land use and agricultural practices at village level.
  11. Priority in research and development to be given to:
    • increased production of plants and animals through improved husbandry techniques;
    • assessment and development of natural resources;
    • alternative energy sources including use of draught animals, biogas, etc.;
    • maintenance of the carrying capacity of arid lands and soil conservation;
    • incorporation of agri-silviculture practices into shifting cultivation.

The above policy provisions in the Lagos Plan do not specifically mention Integrated Crop/Livestock (ICL) strategy in the development of improved farming systems, but various aspects of the Plan such as alternative energy sources and mechanization of agriculture, achievement of self-sufficiency in cereals and livestock, integrated development of areas freed from tsetse flies and the recent interest of governments and the World Bank in integrated rural development have direct and indirect ICL implications. It is the role of scientists in various disciplines to design and conduct research and studies which confirm the beneficial effects of ICL. Priority should be given to the development of appropriate technologies and production systems which can be used by the producer on his farm, priorities which will require political commitment through sound policies and allocation of scarce but needed resources.

Impediments to Integration

Constraints to increased agricultural production by small farmers are the same that impede agricultural development and adoption of integrated crop and livestock production strategy. Many of these impediments are related to the same factors which differentiate various farming systems and have been discussed in detail by Flinn et al. (1974), Ryan and Thompson (1979), Okigbo (1981) and ILCA (1980).

Physio-chemical Factors

The most important physio-chemical constraints to increased crop and livestock production are related to climatic and other environmental factors.

While there is no danger from low temperatures, high temperatures in the surface soil or in the atmosphere close to the ground of 45°C or above, especially when associated with low humidity, can cause serious stresses that are detrimental to plant and animal life. High temperatures are injurious to seedlings and may have adverse effects on rhizobia and nitrogen fixation. They make vegetation very dry increasing the severity of burning and the spread of fires. High temperatures cause rapid decomposition of soil organic matter with adverse effects on soil texture, nutrient retention properties and the colloidal complex of the soil and increase the rate of evapotranspiration which renders light rains ineffective, causes severe losses from dams and reservoirs and, in irrigated soils, triggers off salinity problems. Uniformly high day and night temperatures contribute to low yields as a result of relatively high losses due to respiration. High temperature associated with high humidity has adverse effects on human work performance and contributes to the poor performance of temperate animal breeds in the tropics.

Tropical rainfall is characterized by high intensity, especially close to the beginning and end of the wet season, which increases the erosion hazard on land where the soil has become exposed by forest clearing and tillage. A very serious and frequent cause of famine in the Sahel is the erratic nature of the rain and unpredictable cycles of drought. In the humid tropics, especially above latitudes 6–7°N, and further inland, one or two weeks of drought may occur after planting. Drought stress is a major cause of crop failure and with high temperatures results in marked yield reduction. Related to rainfall is the constant cloud cover in the humid tropics which reduces photosynthesis and thus productivity. Insufficient sunshine in the humid tropics results in reduced response of crops like maize to fertilizers and is one reason why maize production is becoming increasingly important in the savannah areas, provided that moisture is not limiting. Another aspect of the light factor is photoperiodicity to which some traditional short-day plants are sensitive. The short-day sorghums take longer to mature resulting in high culm yields which provide structural materials for fencing and other purposes. As a result dwarf photoperiod-insensitive improved sorghum varieties may not be accepted by farmers.

Other physio-chemical conditions are related to soils which are highly weathered, acid and of low inherent fertility. These soils are not only fragile but in areas of Guinea, Liberia and Sierra Leone are subject to laterization; under continuous cultivation these soils develop multiple nutrient deficiencies and toxicities, but regular liming may also cause nutrient imbalance and toxicities. The infertility of tropical soils and climatic constraints contribute to the low nutritive value and poor quality of forage. Although the highly weathered soils of the tropics possess good physical characteristics for arable farming, it is these same properties which render them more erodible. Further, the adverse environmental conditions in tropical soils which make large areas marginal for plant growth require large quantities of fertilizers, which may not be economic, to sustain high yields.

Biological Constraints

Biological constraints are related to the favourable conditions that high temperatures have on pests, diseases and parasites. The extent of the adverse environmental problems (weeds, insects, locusts, trypanosomiasis, etc.) which constrain agricultural production, and various health hazards that affect agricultural development in the tropics have been discussed by Kamark (1976). Human diseases and parasites that affect settlement patterns and productivity include malaria, sleeping sickness, river blindness, onchocerciasis, filariasis, bilharzia (schistosomiasis), meningitis, etc., have rendered parts of the Middle Belt uninhabited and unutilized. There are also animal diseases like trypanosomiasis, rinderpest, foot and mouth disease, theileriasis, East Coast fever,dermatophilosis (streptothricosis) and parasites in both humid and arid areas which make livestock production hazardous. Serious diseases and pests of crops include Swollen Shoot of cocoa, maize rust (Puccinia polysoria), cassava mosaic, cassava bacterial blight (Xanthomonas manihotis), cassava mealybug (Phenacoccus manihoti), green spider mite (Mononychellus tanajoa), sweet potato weevil (Cyles puncticollis), maize streak virus, etc. Weeds cause serious losses in the tropics and rampant weed growth is one reason why farmers practise shifting cultivation. As a result the breeding for resistance to pests and diseases and adaptation to environmental stresses are key objectives in plant and animal improvement.

Technological Problems

Despite the relative antiquity of indigenous agricultural production systems in West Africa, the developing countries of Africa have not yet developed the long-term scientific tradition and quality of research necessary to maintain satisfactory growth in technology and its transfer to produce rapid agricultural and economic development. At the time of independence there were, for example, interterritorial research organizations for most major cash crops and food crops but all have been closed down. The exodus of expatriate staff after independence, except for countries like Ivory Coast, weakened the research effort and retarded progress. There is still a shortage of trained manpower. Wherever research has been carried out it has given priority to specialized individual commodity production systems and the solution of problem along separate lines. As a result the complex food production systems which require an interdisciplinary approach have been neglected. Research on food crops did not benefit from local knowledge of traditional farming systems or from the socio-economic environment within which they operate until farming systems research programmes were started at the international and some national agricultural research centres. It is only by using an integrated approach to research and understanding the various interacting components of crop and livestock subsystems that effective priorities and programmes can be identified to establish the potential and limits of ICL production systems. The lack of this orientation has resulted in the unsuccessful attempts to transfer successful technologies from temperate countries and to establish large-scale mechanized farms in the tropics. Thus lack of understanding of the traditional farming systems in Nigeria, in particular the role of livestock, led to over-emphasis on the improvement of indigenous trypanotolerant cattle for milk production and the abandonment, until recently, of the work with these valuable breeds. Lack of knowledge of the role of small animals in traditional production systems led to a wrong strategy in poultry improvement for small farmers which advocated intensive production systems which could only be adopted by the affluent, mainly because there was no economic technology to produce maize and concentrates locally.

Socio-economic Problems

Several socio-economic constraints bedevil agricultural development and some of these have hampered exploitation of the existing potential and benefits of ICL. These include:

  1. Lack of the basic statistical data and knowledge of the socio-economic background, the environment, the resources and the management capacities within traditional production systems which can be used as a basis for planning, identifying constraints and priorities and the selection of strategies in research and development in agriculture.
  2. Rapid population growth which, in addition to associated socioeconomic pressures, has outmoded the traditional farming systems to the extent that their underlying scientific base and the economic viability cannot now be understood and appreciated.
  3. The complexity of traditional agricultural production systems, the competition between subsystems and nonfarm components, and the farmers’ interest in diversification and the reduction of risk through the achievement of reasonable but sustained yields rather than maximization of the production of one or two commodities.
  4. Land tenure and associated problems of fragmentation of holdings, small farm size, the problems of economies of scale and their effects on the profitability and acceptance of certain technologies like communal land ownership which, although eliminating landlessness, deterred investment in land improvement.
  5. Continuing reliance on simple farm tools and manual labour which accentuates the drudgery of farm work. (Nevertheless, there are limitations in mechanization using animals in areas of high incidence of trypanosomiasis or tractors which most farms cannot afford to buy, maintain, hire or fully utilize.)
  6. Shortage of labour at seasonal peaks of demand due to division of labour between the sexes, relatively low return to agricultural work, rural-urban migration and education for children. As a result farming is left to old men and women with low productivity. Despite this there is a marked underemployment during certain times in the year.
  7. Lack of capital and credit for the purchase of inputs, including draught animals in areas where they can be used, associated with the relatively high cost of fertilizers, pesticides and equipment.
  8. Poor extension services and the inappropriateness of new technologies resulting in a very wide gap between experiment station yields and those on farmers’ fields.
  9. Conflicting ideologies about development and insufficient understanding of the socio-economic parameters which control the extent and nature of government involvement in production.
  10. Poor marketing and pricing policies for agricultural products which reduce the incentives that are needed to motivate increased agricultural production. Related to this is the shortage of infrastructure which is required to allow farmers access to inputs, services and markets.
  11. Poor communication among technicians, policy-makers and politicians which results in deficient policy formulation and inadequate allocation of the resources required to achieve national priorities.
  12. Inadequate coordination between research and development policies and lack of integrated programmed which take into account the common resources and environmental endowments of ECOWAS countries.

Related Research

Farming Systems Research

The most significant development in agricultural research within the last two decades has been the formation of international agricultural research centres and the incorporation of Farming Systems Research (FSR) into research programmes. The purpose of FSR is the study of the farmers’ environment as well as the various integrated components of the prevailing farming systems. An understanding of the farming systems enables them to be evaluated, modified and redesigned to fit the needs of the farmer. FSR adopts a multidisciplinary approach to research that gives priority to:

  1. Baseline data collection and analysis of farming systems based largely on collection, collation and evaluation of secondary data which is then updated and made more complete by special surveys.
  2. The study of existing farming systems, farmers’ objectives, resources, decision-making processes, input/output relationships, sources of income and constraints to increasing productivity.
  3. The analysis and understanding of the workings of the individual components of the systems and the constraints faced by the farmer constitute the basis for determining research priorities and strategies. This ensures that proposed new technologies and system components are relevant to the farmers’ needs and circumstances and have a high probability of adoption.
  4. Experiment station testing and analysis of new technologies based on the results of items 1 & 2.
  5. On-farm testing of promising technologies, the evaluation and monitoring of technology adoption and wherever possible, the introduction of necessary modifications, and the identification of the farm level constraints which are responsible for the yield gap between experiment station and the farmers’ fields; this also enhances feed-back to on-station research. On-farm research also facilitates the identification of the various off-farm, infrastructural and policy constraints which interact to determine the success of a farm enterprise.

FSR, because of its multidisciplinary nature and detailed study of the farmers’ environment, has made agriculturalists aware of the importance of anthropological, sociological, geographical and economic literature which describes aspects of traditional farming systems ranging from the initial hunting and gathering stage to shifting cultivation and pastoralism, through various intensities of cultivation down to the numerous development projects aimed at modernizing agriculture in the tropics.

Other significant developments include economic assessment of traditional and other farming systems, farmers’ decision-making processes, resource utilization and the comparative performance of various systems. There has been an upsurge in the study of livestock and small ruminant production systems in the tropics. Of major importance are the activities, conferences and reports of the Winrock International Livestock Research and Training Centre, the Bellagio Conference on Integrated Crop and Animal Production (McDowell and Hildebrand, 1980) and the research programmes of the International Livestock Centre for Africa (ILCA) and the International Laboratory for Research on Animal Diseases (ILRAD). These two livestock research centres complement the work of 11 other stations coordinated by the Consultative Group on International Agricultural Research (CGIAR) most of which are giving priority to food crop improvement and the development of more efficient systems for their production.

Socio-economic Studies

FSR gives priority to socio-economic studies of farming systems, which define the characteristics of various farming systems and constraints to their improvement. Work on production economics has demonstrated why certain technologies fail to be adopted by farmers; at ILCA it was shown that some maize varieties were not accepted because they were not suitable for eating green; in other situations local preference is for white maize instead of yellow. Economic studies have also demonstrated the profitability of different technologies or production systems. Norman et al. (1982) indicated the extent to which valley bottom or lowland (fadama) plots give higher returns than upland areas. Most of the lowland areas of hydromorphic soils in West Africa are unexploited. Related to these are multidisciplinary studies of integrated development of small watersheds which will be discussed in greater detail.

Current Crop-Based Farming Systems Research with Implications for ICL

The results of FSR that are pertinent to the design and development of improved cropping systems in West Africa include:

  1. Intercropping which has been demonstrated to give higher stable yields especially at low input levels than sole cropping. It results in more efficient use of resources and involves more uniform distribution of labour throughout the year.
  2. Intercropping involves a wide range of crop species and different varieties of each species that differ in time of maturity and other characteristics which allow the farmer greater flexibility in management and utilization of resources.
  3. The practice of intercropping satisfies the objective of attaining diversification of production for subsistence on small farms, minimizing risks of failure, and producing some commodities for sale.
    In some situations intercropping minimizes losses from pests and diseases and provides better cover for the soil which reduces erosion.
  4. Considerable progress has been made in the identification of compatible mixtures of crops such as maize/cassava, plantain/ cocoyam, yam/maize and sweet potato/pigeon peas for the humid and subhumid tropics and sorghum/millet, maize/sorghum, sorghum/ groundnuts and sorghum/cowpeas for the savannah areas.
  5. Some progress has been made in developing rotations for humid and arid areas. At ILCA, in Ibadan, it has been shown that a viable rotation involving intercropping is maize/cassava followed by cowpeas alone or intercropped with chillies or tomato. It was also shown that cowpea is a better crop than soybean in rotation with maize since it leaves more residual nitrogen in the soil.
  6. Soil fertility studies have shown that for sustained yields fertilizer application is imperative but fertilizer application is not often profitable during the first year after fallow. Some application of organic manure is not only beneficial but may enhance the effects of fertilizers.
  7. A start has been made to study potential fodder species, pasture establishment and herbage productivity (ILCA, 1979a). In addition to the collection of data on grass and legume fodder species, ILCA has identified promising forage and browse plants for use in agrosilvicultural systems in the humid trops.

Recent Developments at ILCA and Cooperating Institutions

The CGIAR centres are giving priority to quantitative and qualitative improvement of major food crops in developing countries in addition to the development of more efficient farming systems for their production by small farmers. The crop improvement programmes are giving priority to increased yield, better nutritional quality and other characteristics but especially resistance to disease and pests, tolerance to environmental stresses and adaptation to various production systems. Emphasis is being given to integrated pest management and various ways of reducing the costs of inputs. Areas of FSR in which significant progress has been made include land development and subsequent cropping patterns, zero tillage, live mulch, alley cropping with leguminous shrubs and evaluation of browse in agrosilvipastoral systems. These are summarized below:

Land Development

Probably the most crucial problem in the development of a permanent food production system for sustained yields is the development of appropriate techniques for land clearing, land preparation and subsequent soil management. In the humid tropics sustained agricultural production is possible when (i) chemical nutrients removed by crops or otherwise lost during cultivation are replenished; (ii) soil physical conditions are maintained at a favourable level by ensuring that adequate levels of soil organic matter are present; (iii) soil is kept constantly covered and erosion effectively controlled; (iv) soil acidity, nutrient deficiencies and toxic constituents are corrected, and (v) build-up of pests, diseases and weeds are prevented (Greenland, 1975). In West Africa bringing new land into cultivation remains the most widespread method of increasing food production. Clearing new land is now expensive as a result of labour shortage, and many governments are resorting to mechanical clearing for large-scale farms and the use of hired tractor units for cultivation on small farms, although most of the mechanized largescale farms in the tropics have failed because of poor land development and subsequent soil management during cropping. At ILCA priority has been given to the study of the physical, chemical and biological characteristics of the more important soils of the humid and subhumid areas of Africa to provide a basis for evaluating their capabilities under cultivation and different management systems. An evaluation of various manual, mechanical and chemical land clearing techniques has shown that clearing methods and soil management must be suited to the crops to be grown. Soil disturbance during clearing was found to cause serious erosion losses and irreversible soil degradation; manual clearing produced the least adverse effects but was slow and expensive. Chemical methods applied by spraying, ringing or trunk injection with selected chemicals such as 2-4-D or Tordon have been shown to be suitable for pasture establishment, but a shear blade with V-shaped cutting edge proved to be the most appropriate mechanical method of clearing for arable crops. It was economical and, when followed by zero tillage, erosion rates were lower and yields higher than with conventional tillage. With good plant residue management and control of weeds with herbicides, the soil is protected and there is no need for terracing or other expensive soil conservation measures on average slopes. Results obtained in land development studies by ILCA are presented in Table 12 and Figure 13. The no-tillage technique requires that crop residues should be left on the surface. Although it has worked on Alfisols at ILCA, tillage studies at Ougadougou in Upper Volta in the Sahel have shown that tillage is necessary and that tied ridging which conserves moisture increased yields by over 13 percent.

Cover Crops, Organic and Live Mulches

Crop and weed residues are important in reducing erosion and enhancing adequate levels of soil organic matter and water infiltration in the no-tillage system. Experiments by ILCA on degraded soils have shown that soil rejuvenation can be achieved by 1–2 years of leguminous cover which is then killed using a herbicide and followed by no-tillage cropping.

Fig. 13 Comparison of various lengths of fallow in relation to cultivation periods in African farming systems (adapted from Grove & Klein, 1979) in comparison with recent attempts to eliminate long term fallows and achieve intensification through alley cropping.

CULTIVATION PERIOD FALLOW PERIOD

Fig. 13

Experiments with industrial waste mulches such as sawdust, rice husks, rice straw and legume husks also indicate that these agricultural by products, which are often burnt or thrown away, can be put to good use.

Interest in living mulch is related to the fact that, although 40–70 percent of the farmer’s time in the tropics is spent on weeding, hand or mechanized weeding destroys soil surface structure and exposes it to erosion. Moreover herbicides are expensive and hazardous. Experiments at ILCA in which maize has been grown in living leguminous cover have shown that wild groundnut (Arachis repens), Centrosema pubescens, a forage legume, and the wild Wing Bean (Psophocarpus palustris) are promising (Table 13). The results also show that the live mulch added nitrogen and organic matter to the soil while reducing weed growth. The live mulch technique is suited to high rainfall areas where competition with the crop for water is low. It also facilitates cropping of steep slopes without terracing or bunding.

TABLE 13

MEAN GRAIN AND ROOT YIELDS FOR INTERCROPPED MAIZE AND CASSAVA IN RELATION TO LEGUMINOUS COVER AND TILLAGE PRACTICE

Legume Cover Maize Cassava Treatment Maize Dry Grain Cassava Fresh Roots
Psophocarpus 5 054 24 047 No-Tillage 4 043 26 027
Centrosema 4 914 22 206 Conventional Tillage 4 431 26 813
Calapo 3 817 28 519 No Fertilizer 3 882 25 497
Stylosanthes 3 228 27 088 With Fertilizer 4 592 27 343

Source: IITA, Ibadan.

Alley Cropping with Leguminous Shrubs and Browse Plants (Figure 13)

Leguminous cover crops, even when they have been shown to be economically viable and suitable, are not popular with farmers. They fix nitrogen but are not as effective in nutrient cycling in fallows as deep rooted shrubs like Leucaena leucocephala, Gliricidia sepiumand Acacia barteri. Experiments have shown thatLeucaena leucocephala can be grown in rows (alleys) 4m apart and maize, yams, cassava or cowpeas can be planted between. The Leucaena is periodically pruned and the twigs used as mulch returning nutrients to the soil while protecting the soil and preventing shading of the crop. The Leucaena can be pruned at about 2m and the stems used as stakes for viney crops such as yams; the prunings supply fuelwood.

A cooperative study involves grazing browse plants such as Leucaena, Gliricidia and Ficus spp in alley cropping systems with small ruminants. Preliminary results indicate that this system constitutes an effective way of integrating crops and livestock in a permanent production system.

Socio-Economic Studies of Animal Production Related to Arable Farmers

Sleeper (1978) conducted an economic analysis of breeding and cattle fattening to stratify livestock production in West Africa. This called for planned agricultural land use in which the arid zone is used for extensive grazing, the semi-arid areas are used for extensive production of adapted crops, while the subhumid areas are used for intensive fodder and pasture production; cattle should be fattened near terminal markets or export abattoirs. He showed that (i) under the current scheme bovine traction would not substantially increase farm income; (ii) adoption of small feeding units could substantially increase cash income; (iii) bovine traction will not draw a substantial number of cattle from rangelands as envisaged, and (iv) bovine traction and small unit feeding can increase meat supply. Eddy (1979) conducted a linear programming study of mixed farming among the bush Tuaregs of Niger and showed that farmers in the unfavourable terrain have developed a system of integrated cattle and goat rearing with grain production to minimize the risk posed by drought and fluctuating grain prices on the edge of the pastoral zone between the rainfed agricultural zone and the desert. The Tuaregs, who used to plant millet prior to migrating north with the rains, have been forced by competition with Hausa cultivators and Fulani herders to settle and grow millet, sorghum, cowpeas, and spices in the rains, and tomatoes and onions under irrigation in the dry season. Delgado (1978) investigated mixed farming in the Tenkodogo area of Upper Volta, using bovine traction, which was aimed at providing the farmer with milk, meat, a cash income and manure for increasing crop yields. It was found that the smallholders had difficulty in controlling animals in unfenced fields, and that seasonal labour conflicts occurred between the requirements for stock and for sorghum and millet harvesting. He recommended that policy should be directed toward improving the traditional system in which the sedentary Mossi cattle owners entrusted animals to the Fulani herders. Ware (1979) reported that droughts between 1966 and 1973 forced nomadic Fulani herders in the Diourbol area of Senegal to change to mixed farming by having their older sons grow food crops (millet and sorghum) while the women fattened animals and reared poultry. He noted that the Wolof mixed farmers had developed an east/west pattern of grazing fields in such a way that millet, sorghum, cowpeas, tomatoes, etc. are grown on the western half of a field in a given season: in the next season this area is grazed while the eastern half is cropped. Kline et al. (1969) studied problems of mechanization in tropical Africa and found cattle herders were more reluctant to become farmers that arable farmers were to adopt animal traction. They reported trypanosomiasis and feeding to be problems in maintaining oxen and that the oxplough could be used only for planting and cultivation. These studies of animal production in association with crop production must be taken into account in designing ICL projects, planning, research and training.


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