2.1. The Evolution of West African Farming Systems
2.2. The Humid and Subhumid Tropics
2.3. Semiarid Tropics
Table 1 outlines the region's economies. Roughly 215 million people live there, of whom some 70 % are employed in agriculture. Agriculture - crops, livestock, forestry, and fisheries-provides about 40% of the regional product, varying from 23% (Senegal) to 55% (Mali). Average regional GDP is low, less than US$400 per caput, and declined in many countries from 1980 to 1992.
The main field crops are maize, sorghum, millet, rice, cassava, yam, cowpea, and groundnut. The chief tree crops are banana, plantain, coffee, cocoa, oilpalm, rubber and coconut. Cereals dominate the semiarid countries (Mauritania, Senegal, Mali, Burkina, Niger, Chad, northern Nigeria and Cameroon) while roots, tubers, and tree crops dominate the subhumid and humid (Guinea, Guinea-Bissau, Côte d'Ivoire, Ghana, Togo, Benin, and the central and southern parts of Nigeria and Cameroon). Rice and maize are grown throughout the region.
The chief problems relevant to the mandate of the IARCs in West Africa are agricultural growth with an employment content adequate to relieve poverty and alleviating the environmental degradation associated with agricultural intensification. Are the problems facing West African agriculture so different that they impose a different mandate on the CGIAR Centers from other regions?
TABLE 1: Some Characteristics of West Africa
|
Country
|
Population |
GNP |
Area |
Total cropland |
Irrigated cropland |
Agricultural growth rate |
Index of food production |
Fertilizer nutrients, used |
|
(1) |
(2) |
(3) |
(4) |
(5) |
(6) |
(7) |
(8) |
|
|
1990 |
1970/89 |
1965/90 |
|
|
||||
|
Benin |
5.0 |
360 |
11.3 |
1.8 |
0.3% |
|
112 |
1.8 |
|
Burkina Faso |
9.0 |
330 |
27.4 |
2.8 |
0.4% |
1.0 |
114 |
5.8 |
|
Cameroon |
12.0 |
960 |
47.5 |
6.7 |
0.2% |
3.0 |
89 |
4.1 |
|
Chad |
6.0 |
190 |
128.4 |
3.1 |
0.2% |
-1.0 |
85 |
1.5 |
|
Côte d'Ivoire |
12.0 |
750 |
32.2 |
3.2 |
1.3% |
1.0 |
101 |
11.3 |
|
Gambia |
|
|
|
0.2 |
6.7% |
|
|
|
|
Ghana |
15.0 |
390 |
23.9 |
2.8 |
3.0% |
-1.0 |
97 |
3.1 |
|
Guinea |
6.0 |
440 |
24.6 |
0.7 |
1.6% |
|
87 |
1.1 |
|
Mali |
9.0 |
270 |
124.0 |
3.2 |
0.8% |
2.0 |
97 |
5.4 |
|
Mauritania |
2.0 |
500 |
102.6 |
0.2 |
5.4% |
-1.0 |
85 |
11.6 |
|
Niger |
8.0 |
310 |
126.7 |
3.2 |
0.8% |
-2.0 |
71 |
0.8 |
|
Nigeria |
116.0 |
290 |
92.4 |
30.5 |
0.8% |
|
106 |
12.1 |
|
Senegal |
7.0 |
710 |
19.7 |
5.1 |
3.2% |
-1.0 |
102 |
5.5 |
|
Sierra Leone |
4.0 |
240 |
7.2 |
1.7 |
1.1% |
|
89 |
0.3 |
|
Togo |
4.0 |
410 |
5.7 |
1.4 |
0.4% |
|
88 |
8.3 |
|
Total/average |
215.0 |
0 |
773.6 |
66.3 |
1.0% |
|
99.5 |
8.0 |
|
%, Nigeria |
54.0% |
n.a. |
n.a. |
46.0% |
78.6% |
n.a. |
n.a. |
152.1% |
Notes: Full data unavailable for Guinea-Bissau, Liberia, and Gambia
(7) Index of food prod per capita, for 1988/90 (1979/81 = 100)
(8) Plant nutrient, 1989/90Sources: Columns (1)-(3),(6)-(8), World Bank, Stars Database; Columns (4)-(5) World Resources Institute Database
The basic arguments for concentrating on food production as a growth strategy are three. First, food is always a high share of the consumption of the poor, so that gains in food productivity translate into welfare gains for the poorest. Second, many poor consumers of the basic foods also produce those crops and have few alternatives for raising their incomes. Third, food output is a high share of farm output, so the latter cannot develop without improvements in the former. These arguments are quite strong in West Africa. In addition, there are economic limits to complementary strategies based on expansion of cash crops. Perennial crops in the humid zones face both rising economic and environmental costs. Cash crops except cotton and groundnut have low additional potential in the semiarid climate without irrigation, and groundnut faces competition from oil crops produced outside Africa.
The growth path of West Africa agriculture has shifted, and will do so more and more, toward intensification-mat is, to higher output per unit of land and to higher variable inputs per unit of output. Intensification is expected to induce higher costs of environmental degradation through: (i) greater soil erosion and weed infestation induced by shorter fallows; (ii) loss of organic matter from intensively cultivated soils; (iii) loss of vegetative cover from overgrazed areas; (iv) damage to water sources and wildlife from greater quantities of agrochemicals; and (v) deforestation.
We refer to three climates: the semiarid tropics, the subhumid tropics, and the humid. Ruthenberg refers to humid climates, semi-humid climates, semi-arid climates, and the tropical highlands (1980, p. xi). TAC refers to warm arid and semiarid, within which IITA distinguishes the northern Guinea Savanna or moist savanna and mid-altitude semiarid; the term semiarid tropics is used here. TAC refers to warm subhumid climates and IITA to southern Guinea Savanna, derived savanna, coastal savanna, acid woodlands, mid-altitude savanna, and volcanic areas; TAC further refers to warm humid and IITA to humid forest and mid-altitude and highland savanna and woodlands; the term subhumid tropics is used here. TAC also refers to cool climates, which do not occur in West Africa (IITA, 1992, p. 7). While the problems of these climates occur throughout tropical agriculture, they are unusually severe and widespread in West Africa.
Unproductive environment. Soils are poor, attacks of pests, diseases and parasitic weeds are aggressive and rainfall is irregular and often deficient. A long dry season reduces vegetative production. Cloud cover slows photosynthesis in wetter areas. Weeds become troublesome under continuous cultivation. Transport costs are high as a share of producer price and of variable cost, making it unprofitable to intensify with modem purchased inputs because output/input price ratios are too low. Irregular topography makes water control harder and more expensive. Heat and humidity reduce the time for work and cut the productivity of labor when it is employed.
Variable environment. Agriculture is highly variable even with so many common environmental features. IITA's characterization of 14 countries of humid and subhumid West Africa described at least 13 farming systems, distinguished by their major crops (five cereals, cassava, yam, cotton, and four perennials) and six major contrasting conditions of population density and market access (Manyong et al, 1994). ICRISAT village studies in Burkina Faso, Niger, and Mali found many discrete systems with different farm sizes, cropping patterns, types and levels of mechanization, soil fertility and weed control practices, intercropping, and productivity. Variability makes the average fixed costs of research and extension greater per unit of land because there are so many discrete sub-systems among which the costs of identifying and transferring research results are high.
Expensive irrigation. There are poor prospects for economical irrigation, though this may change somewhat in the CFA countries after the 1994 devaluation, because of physical constraints that cause irrigation investments to be expensive. Therefore, and unlike much of East Asia, India, Pakistan, and Bangladesh, irrigated farming in West Africa is likely to remain secondary because it is so costly. This implies: (i) slower adoption of modem inputs in aggregate; (ii) smaller spillovers from irrigated into rainfed areas through factor, input and product markets; (iii) isolated genesis of highly productive and homogeneous farming systems by intensification of a few crops, such as the rice-wheat systems of Asia; (iv) lesser chance of diversifying into higher-value crops; (v) remoter prospect of multiple cropping to boost total land productivity; and (vi) inability to use silt deposition from flood and irrigation waters to restore soil fertility.
Small farms. The principal farm type, a small holding of 2-3 hectares, blocks some innovations that are profitable on larger operations. Examples of such innovations include motorized arable cropping, ranching, and estate agriculture with permanent crops under intensive management. Small farms raise the cost per farmer of management, research, extension, processing and transport.
Effect of climate on livestock adaptation. Trypanosomiasis, other diseases, and the continuous heat and humidity devalue indigenous stock productivity in the wetter climates. The hot and humid climate stops the introduction of European dairy breeds. Innovations depending on those breeds, such as intensive smallholder dairying or ley farming with grasses or legumes as found in highland East Africa, are usually impossible in West Africa, thus closing one path of agricultural development.
Institutions. Public and private institutions alike are often unable to stimulate agriculture. Public extension services are poor. Some technologies that might have been more widely adopted, such as hybrid maize, lag behind their potential because of the weakness of the public extension service. Private research, extension and input supply are weak and sometimes totally absent. Attempts by comparatively powerful international seed companies to establish stable and profitable businesses have generally failed.
Given these basic features, what are the most probable expansion paths in the three climates? What should be the emphasis of the various centers with respect to profitable research directions? The most likely avenues of growth are outlined in Dumont (1957), Boserup (1965), Ruthenberg (1980), and Pingali et al (1987), among others. If IARC programs radically diverge from those paths, then either the basic theory is fundamentally wrong, circumstances have changed to render it obsolete, or the approach of the Centers is misguided.
Ruthenberg observed that "The permanent cultivation of upland in a hot, humid climate presents some of the most troublesome problems of tropical agriculture" (p. 127). The toughest problems are soil erosion and weed invasions, which occur rapidly when land clearing for farming removes the natural vegetation, and pest and disease attacks, which devastate introduced cultivars. Ruthenberg concluded that the efficient solutions to those problems are irrigated rice, intensive root crop cultivation, or permanent crop cultivation. Other alternatives, initially proposed by analogy with European farming, such as forest clearing for annual crop cultivation with heavy applications of chemical inputs, induce such soil erosion, nutrient leaching and pest or weed infestation that they quickly become unsustainable 2. An additional problem in West and Central Africa is animal trypanosomiasis which lowers the return to ruminant livestock production and prevents farmers from using mixed farming to maintain soil fertility.
2 Dumont (1957) gives a lucid and prescient account of the unhappy fate of such alternatives in the Congo soon after World War II.
Any innovative farming system that seeks to provide higher incomes than the traditional alternatives must also protect against erosion, weeds and pests. Irrigated rice is the common solution throughout Asia, but covers only small areas of humid and subhumid West Africa because of the costs of water control and soil problems. In theory, intensive root crop cultivation both covers the soil and provides a marketable surplus of the subsistence crop, while permanent crop cultivation also protects the soil and provides enough cash income to purchase subsistence. In practice, Ruthenberg concluded that irrigated rice is often uneconomic and argued that "there may be technically feasible solutions to the problems of permanent cultivation, but their economic returns are as yet still marginal" (p. 128). There is now more awareness of environment problems caused by agrochemicals, including pest resistance, thus adding additional costs.
Research in the Centers is broadly consistent with the lessons of experience with the humid zones of West Africa. Work at IITA on alley farming, improved fallows, and live mulches recognizes the necessity to maintain the vegetative cover and control weeds in a permanent cropping system. The Slash and Bum Program explicitly recognizes the linked problems of maintaining vegetative cover to protect the soil, while providing higher incomes to producers in a permanent cropping system. WARDA's program takes a careful approach to the problems of vegetative cover, weed management, and the fate of agrochemicals in this environment.
Ruthenberg was more optimistic about the semiarid tropics, because the costs of land clearing for stable field systems are lower than in the humid zones. More complete land clearing allows field cropping and pasture systems to replace shifting fallows, thereby permitting some farming practices - field mechanization, plowing, planting and cultivating in rows, mixed farming with stable animal production - that are impossible where it is wetter. He argued that the growth paths for the semiarid tropics are irrigated agriculture, ley farming, large-scale ranching, or more intensive upland cropping with shorter fallows. Irrigated agriculture and ley farming are usually not economic. Large-scale ranching is both uneconomic and technically infeasible while being socially impossible because it would deprive small farmers and ranchers of their land rights. Hence, more intensive upland farming and livestock production are the feasible expansion paths, necessarily accompanied by shorter fallows associated with rising population pressure.
Research in the Centers is consistent with this concept. ICRISAT seeks to develop stable cereal-legume production systems with higher yields. Work at IITA, ICRISAT and ICRAF on agroforestry supports both more intensive cereal and legume cultivation with trees. WARDA assists irrigated rice research in the Sahel. Inconsistent initiatives - mainly large-scale ranching - have not been supported by the IARCs. Other inappropriate work - strict monocropping, overreliance on chemical crop protection in lieu of biological control - has not been very consequential in the IARCs' work.
