Food Production Trends. Sub-Saharan Africa has fared very poorly in food production over the last three decades. While the annual rate of population growth has averaged some 3 percent, that of food production has been 1.9 percent, leading to a steady fall in per caput food production (Fig.1). This in turn has led to a rapid rise in commercial food imports and food aid, which have registered annual growth rates of 4 percent and 7 percent respectively. But in spite of these food inflows, food intake per person is currently estimated at around 87 percent of requirement, implying growing chronic under-nutrition. The situation generally looks set to get worse, given the poor balance of payments position and crushing debt burden of most sub-Saharan countries, exacerbated by a sharp rise in grain prices on the world market and dwindling global food aid availabilities.
Fig.1 also shows the high degree of inter-annual fluctuation of food production in the region, a characteristic reflecting reliance on highly variable and erratic rainfall. These unpredictable swings give rise to situations whereby a country may need to import large quantities of food in one year, straining port and storage facilities, and may end up with exportable surpluses in another year without assured markets. Furthermore, because of the risks they engender, these swings discourage small farmers from adopting cash-based innovations to increase food production. Clearly, rational planning at both household and national level is extremely difficult under these circumstances.
To make matters even worse, there is the problem of recurrent severe droughts which precipitate large-scale sub-regional food emergencies, such as those of 1972/73, 1983/84, 1992/93 and 1994/95. Others, less severe and more localized, have occurred over the years.
Land Availability. The "land surplus" model of agricultural development advocated for sub-Saharan Africa by farm management economists during the '60s and '70s, and even today by some, has increasingly become irrelevant. According to this model, increased food production should be sought through measures to expand cultivated area rather than attempting to maximize yields per unit area. While the situation does vary from country to country, Fig.1 clearly shows that over the past three decades, under increasing population pressure, available land per person is falling rapidly, and this means that fallow periods, the traditional resting time for land to recuperate its fertility, have been shortened. And in the absence of increased use of fertilizer (see below), the result is fast declining soil productivity. Furthermore, crop cultivation is rapidly spilling into marginal and fragile lands, where yields are not only very low but unsustainable, and the risk of irreversible damage to the environment very high. Clearly, there is an urgent need to intensify food production in the region that will require improved crop water availability, substantially enhanced and balanced fertilizer applications in conjunction with rapid introduction of fertilizer responsive foodcrop varieties.
Use of Improved Technology. In general, food production in sub-Saharan Africa remains a subsistence activity, with family labour, land and low-yielding seeds as sole inputs; improved, yield-enhancing technologies (improved seed, fertilizer, pesticides, etc.) are scarcely used. During 1993, the rate of fertilizer consumption in sub-Saharan Africa was 11 kg/hectare compared to 129 kg/hectare in Asia and 67 kg/hectare in Latin America (Fig.2).
Use of Irrigation. In spite of the highly variable and in many cases insufficient rainfall, and the high incidence of droughts, food production in sub-Saharan Africa is almost entirely rainfed. In 1993, irrigated land as a percentage of total cultivated area was estimated at 5 percent for sub-Saharan Africa, 37 percent for Asia and 14 percent for Latin America (Fig.3). Moreover, 68 percent of the little irrigated land in the region was concentrated in three countries, namely Sudan (31 percent), Madagascar (17 percent) and South Africa (20 percent). At the same time, irrigation potential in sub-Saharan Africa is estimated at around 33 million hectares, of which only about 16 percent is currently being utilized.
Crop Yields. For the period 1993-95, cereal yield (including rice in milled equivalent) in sub-Saharan Africa was 41 percent of Asian yield and 44 percent of Latin American yield. On the other hand, trials by researchers on farmers fields in many sub-Saharan countries have revealed the existence of a very large gap between farmers yields and the achievable potential.
The need for a significant expansion of irrigation in sub-Saharan Africa is very urgent. Compelling reasons include the overwhelming reliance on highly variable, erratic rainfall, frequent severe droughts, rising population pressure accompanied by declining farm size, falling soil productivity and land degradation, and the existence of substantial, untapped irrigation potential. Irrigation expansion will contribute to increased food production and enhanced food security through (a) increased productivity of resources, and (b) stabilization of production.
Increasing productivity. Food production in sub-Saharan Africa generally follows a rainfall-determined seasonal pattern, with all production activities confined to no more than 6 to 8 months, the remaining months of the year being the so-called "off-season". By assuring year-round availability of water, production can be intensified through double or multiple cropping, thus raising resource productivity and total production. Research studies have found that, other things being equal, yields on irrigated land in sub-Saharan Africa average 3.5 times those from rainfed land. This has tremendous implications. Currently, irrigation potential in the sub-region is estimated at 33 million hectares, of which only 16 percent or 5.3 million hectares are being utilized, leaving 27.7 million hectares unutilized. While the realization of the full potential would be constrained by economic and technical factors, a tapping of even 10 percent of the potential could lead to full substitution of cereal imports.
Moreover, by applying supplementary irrigation to rainfed crops, the water stress caused by short, dry spells during the growing season can be minimized, thus substantially raising rainfed production as well.
Secondly, apart from its basic function of meeting crop water requirements, irrigation increases the impact of other yield-enhancing technologies, particularly of fertilizer applications.
Stabilizing production. As already indicated, food production in sub-Saharan Africa is subject to substantial inter-seasonal, rainfall-induced fluctuations, as well as to recurrent droughts. Improved water control would make food production more stable from year to year, thus enhancing household and national food security, and enabling improved decision-making.
Moreover, at the farmer's level, irrigation would reduce the financial risk of applying fertilizer inputs and thus stimulate their greater use. There is no doubt that such risks have contributed to the abysmally low level of fertilizer use in sub-Saharan Africa. A recent study in Senegal found that while total fertilizer consumption fell sharply between 1980/81 and 1987/88 following the reduction in subsidies associated with structural adjustment, the remaining use of fertilizer was mostly on irrigated rice and vegetables and cotton - i.e. either where there was water control (rice and vegetables) or where subsidies remained (cotton). This risk-reducing aspect of irrigation is extremely important in the promotion of improved production technologies in sub-Saharan Africa.
Notwithstanding some disappointing experiences with irrigation projects in the past, a recent World Bank study has revealed that about 75 percent of all sub-Saharan African irrigation projects studied achieved or exceeded the expected economic rate of return. Regarding the generally high capital costs of irrigation projects in the region, the study concludes that with adequate planning and careful design, costs should be no higher in sub-Saharan Africa than elsewhere.
Nevertheless, while all possible irrigation options should be considered, there is now general agreement that, because of the limited experience with irrigation, shortage of skills, and scarcity of investment capital, sub-Saharan Africa should give first priority to the development of small-scale, technically simple and low-cost irrigation systems. While by no means problem-free, such systems have proved to be more successful where tried, being less costly and easier to operate and maintain.
The strategy for the development of small-scale irrigation may, inter alia, embrace the following vital elements.
Chronic food insecurity is a serious problem facing sub-Saharan Africa today and all indications are that it would worsen in the coming years, unless drastic action is taken now. The problem is manifested most vividly by the trend decline in food production per caput and the growing number of the chronically undernourished. The insidious factors include: mounting population pressure, growing land scarcity, declining soil fertility and increasing land degradation, very low use of improved production technology, and the highly variable and erratic rainfall on which sub-Saharan Africa overwhelmingly depends for its food production. In addition, chronic shortages of foreign exchange, sharply rising grain prices on world markets, tightening global cereal supplies and dwindling food aid resources are combining to severely limit food imports which in the past helped sub-Saharan Africa to reduce its food gap. All these factors clearly call for urgent and drastic action to avert an impending catastrophe.
But the region has the capacity, given political will and adequate external support, to meet its future food needs. One fundamental fact must be fully recognized that the required large and sustained increase in food production will not come about under the prevailing low-input, rainfed farming systems; intensification has become an urgent necessity, requiring vigorous promotion of improved production technologies and expanded use of irrigation. The two will need to go hand in hand. Over the past two decades or so, research systems have produced improved plant cultivars of major food crops and associated improved cultural practices which, if adopted by farmers, can make a big impact on food production. At the same time, on a country by country basis, considerable irrigation potential remains untapped. Irrigation expansion will increase productivity and total food output, stabilize production, and promote the use of improved production technologies by reducing production risks. It is entirely possible to reverse the production trends and safeguard the food security of the increasing population of the region.