Agriculture and the environment: Two often opposing forces which must work together
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CTA. 1989. Agriculture and the environment: Two often opposing forces which must work together. Spore 23. CTA, Wageningen, The Netherlands.
Permanent link to this item: http://hdl.handle.net/10568/45124
Throughout Africa the population is ever growing. Because of this the age-old shifting methods of farming are under pressure to give way to continuous and intensive cultivation, and the environment is suffering more and more as a consequence. But...
Throughout Africa the population is ever growing. Because of this the age-old shifting methods of farming are under pressure to give way to continuous and intensive cultivation, and the environment is suffering more and more as a consequence. But the only way to stabilize and even raise the level of agricultural production is better stewardship of the continent's natural resources. For a long time countries in both North and South have striven for increased production. Now as a result the North produces so much it cannot get rid of its surpluses, while in the South agriculture is unable to keep up with growth of population. In Africa yields have not risen in 30 years, food production per capita has fallen by 20%, and farmers can no longer feed a population which now doubles every 24 years. This has brought about a shift in the emphasis of development programmes. Although increased production remains the priority in developing countries, present necessity must no longer be allowed to jeopardize future needs. The World Commission on the Environment and Development, better known as the Brundtland Report made it perfectly clear that from now on development must be lasting or sustainable, and economic progress must be match ed by the management of resources. Now 'quality' and 'sustainable' rather than increased production are the watchwords; to attain this there has to be an improvement in the husbandry of agricultural 'capital' - water, soil, flora and fauna. For some while drought was seen as solely responsible for the damage to the environment, but now there is a growing recognition that errors in development policies have often accelerated the process of degradation. However, neither drought not errors in policies fully explain the poor performance of African farmers' and smallscale farming systems must also come under scrutiny. The predominant migratory agriculture of centuries is no longer appropriate. The unprecedented population growth of the last 30 years has forced farmers to cultivate the land almost without break, but they have still kept their nomad mentality - taking more from the soil than it can make up without help. When the balance between man and nature is tipped, both ecology and economy suffer. The destruction of the environment is the most glaring example of this, and the signs are well known: the decline of the forests in wet zones, the disappearance of trees in the Sahel, the increasing scarcity of grazing land, erosion, and the reduced fertility of the land. The catalogue of man's mistakes combined with the whims of nature and their effect on the environment is a long one. Traditional agriculture eats away at available land Traditional agricultural systems grew up where land was in abundant supply, and there was no need to impose limits on its use. Each patch of land cleared would be productive for five to ten years in the savannah lands and less in the forests, and was farmed 'to death'. To become fertile again the land needed ten - even 30 - years' rest, but the population explosion has progressively whittled down this interval. Once the population density rises above 30 to 50 per square kilometre the fallow period decreases in proportion and eventually disappears altogether. In the Maradi department of Niger the speed of this process has been measured. In Magami village 30 years ago only 25% of the land was under cultivation. In 1974 this proportion had risen to 53%. As a result of this rise, by 1990, no land will remain uncultivated. When the harvest is insufficient farmers are forced to increase the area cultivated, but they do not always give their fields enough care and attention - whether from lack of time, cash, or labour. Marginal land, often far from the village, and usually only good for grazing is put under the plough. Because this soil is extremely fragile and easily exhausted, yields drop steadily. Other small farmers prefer to move to as yet unsettled areas where the agriculture they practise is the most extensive possible, and they do not give a thought to land care. This 'pillaging' of the land also does not last long. The migration in the Sahel from north to south in turn accentuates the pressure on humid zones. Indeed, because of either population growth or because of the rigours of the climate, there are now few regions in Africa where there is sufficient fertile land remaining to be exploited. In forest regions, which require even more time for the soil to regenerate, perennial plantations and the proximity of towns and main roads have limited the areas under cultivation. Here, peasant farmers no longer move their villages round in search of land to clear: cocoa or coffee planters have to stay close to their plots in order to look after their trees and the fallow period of the food crop fields becomes shorter and shorter. Soon the forest cannot be pushed back any further, the land is worked to death and loses its fertility. The most obvious result of this over-exploitation is severe erosion. When the grassy or woody vegetation does not have time to grow again the top layer of soil is left bare, and the wind and rain soon remove it The highlands of mountainous or plateau regions, which usually support a large population, are particularly at risk. In the Ethiopian mountains, where 70% of the country's population and nearly 80 million head of cattle live, the trees have virtually disappeared. Each year nearly 2000 tonnes of soil per square kilometre are eroded away. This sort of damage is now seen not only in dry areas but in those where rainfall is more significant, such as Fouta Djallon in Guinea, and in the Rwanda or Burundi hills. Trees hold the key to fertility Trees are of paramount importance. Lloyd Timberlake writes in his book 'Africa in crisis - the causes, the cures of environmental bankruptcy', that once the trees have gone essential products become more and more scarce, the landscape becomes prone to erosion by wind and water, and the fertility of the soil diminishes. Without a tree cover, bare soil is easily eroded. In the savannahs of the Sahel and in the Horn of Africa the increasing scarcity of the forests, or indeed of any trees, is the most obvious sign of the destruction of the environment. Trees put back nourishment into the soil through leaf mould, their roots draw up water and nutrients from depth and also bind and stabilize the soil. Trees are also as necessary to the rural population itself as they are to the regeneration of farmland, since they provide fuel wood, dietary supplements, medicines, and fodder for cattle. Unfortunately, all too often trees are seen as a nuisance and they are cut down to make way for crops. Thoughtless tree clearance and over-use of heavy machines have sometimes brought about catastrophic results, especially in forest regions where fragile soil can no longer withstand the effect of heavy rain. Other factors have speeded up the disappearance of trees; the growing need for fuelwood, bushfires, the ever-increasing numbers of cattle allowed to wander, all extend the areas of deforestation. In the Sahel it is estimated that each inhabitant needs around one hectare of wooded savannah and at present the amount of wood cut for fuel exceeds the rate of natural regeneration by 30%. On the Mossi plateau, in the Vatenga in Burkina Faso and near large towns, the devastating effects of these practices on agricultural land have been demonstrated more than once Restoring the land to fertility The cumulative effect of these pressures (drought, wholesale exploitation of land, over-use of wood and pastureland) on fragile ecosystems have resulted in lower yields and has transformed once-fertile land into unworkable areas now lost to agriculture. Farmers, however, do not stand idly by and watch this happening. In areas where high population density has forced them into continuous cultivation of the land, the first steps towards husbanding the land and intensifying production have been taken at the same time. But this is always a last resort once the economic necessities of this agricultural revolution is made clear. As long as extensive cultivation, which is also less labour intensive, can keep them fed, they will see no point in changing. The disappearance of fallow means that land has to be managed more comprehensively and production has to be maintained if not increased within the same amount of space. In Rwanda, where there are now more than 250 people per square kilometre, farmers learned long ago to make the best possible use of land which is both scarce and fragile: there are trees in the fields - fruit trees, crop and fodder trees, windbreaks - and these provide extra income In the Sahel some farmers have started to bring back their land to full fertility. In the Mopti region where land is seriously damaged, one peasant farmer planted 3000 eucalyptus per four hectares. These acted both as windbreaks and marked out the field boundaries, protected his crops and produced poles which sell well. He also planted fruit trees (guavas and tamarinds) for a cash income. On his millet plots acacia albida was allowed to regenerate naturally, and he obtained yields far higher than those of his neighbours. The environment does not have to be 'protected' to the extent of being treated as a nature reserve, but it does have to be nursed back to better health and farmed with care so the next generation will receive a richer inheritance than that which their fathers inherited. Development and environment must go hand-in-hand. Soil fertility must be restored by putting back the elements it loses after each harvest if agricultural production is to become more intensive. The judicious use of inorganic fertilizers is one way of doing this, if peasent farmers can get hold of them: the state needs the foreign currency, the farmer has to have credit, distribution systems must exist, adequate training must be given, and market prices must justify them. Organic fertilizers - spreading compost or, where possible, manure - are more economic and suit the pocket of the African farmer much better. They also improve the soil structure and enrich it. In 1986 Burkina Faso launched a national campaign to get one compost-heap for each rural family.In Rwanda each smallholding must have not only a compost-heap for household waste, but each farmer is obliged to have a manure heap as well.To make this intensification programme work cultivation must be concentrated on the best land, and the poorer lands must be given over to pasture and woods. Vegetable and crop production must not therefore be seen as something apart from other rural activities.Better husbandry of all the land farmed by villagers contributes to a better standard of living all round. One way of improving fertility is to link crop-growing and cattle-rearing more closely. Improved pasturage and increased forage crops are important factors in agricultural production if cattle-rearing is well managed. Agroforestry, which combines crop-growing, tree-planting, and sometimes stock-rearing, is another good alternative. In wet zones alley-cropping between rows of quick-growing nitrogen fixing shrubs (for example, Leucaena) enriches the soil and produces both fuelwood and forage.These species can also be planted in the short-term fallow lands in order to speed up the process of refertilization. Traditional ways of preserving the numerous useful but little-known trees, and of aiding their regeneration can produce interesting results. Good husbandry must not stop at village level; it must also be on a national scale.The protection of irrigation basins, the construction of dykes, and anti-erosion cordons help conserve the soil and allow the water table to refill.The storage of water permits irrigation, which is vital for increasing and diversifying production.Each individual ecosystem requires specific solutions peculiar to it, but none of these solutions can be adopted in isolation without taking the others into account.The environment must be seen as one entity, and any change will have repercussions right across the board. Agronomic research, which has often neglected environmental issues, has a major part to play in this new 'agricultural revolution' by studying new techniques which will be kinder to the environment.The value of the long-standing and much-vaunted monoculture, promoted by development projects which sought short-term economic viability, is now in doubt. Multi-crop and rotation systems which allow better use to be made of the soil's resources, are now encouraged. Research is also currently in hand on varieties which make fewer demands on the ecology, and which do not require heavy applications of fertilizer or pesticides. Other techniques are being tested, such as direct sowing through a protective mulch, which avoids damage to fragile soil, and which has been successful in Brazil. To Brah Mahamane, executive secretary of CILSS (Comite Inter-Etats de Luttecontre la Secheresse au Sahel / Inter-State Anti Drought Committee for the Sahel), the challenge is clear: 'Necessity is the mother of invention, so let us pick up this gauntlet and start taking charge of events. Safeguarding the environment is now one of the underlying aims of society. Man and the earth he lives on are our resources, and we must make better use of them.This means we must stop thinking we have all the time and the space in the world.' BIBLIOGRAPHY L. Lloyd Timberlake - 'Africa in Crisis the causes, the cures of environmental bankruptcy' Earthscan 1985. OCDE-CILSS - Le Sahel face aux futurs -1988 CMED - Notre avenir 2 tous - CHIRON -1988 FAO - Transformation de la culture itinerante en Afrique - Etude FAO forets - 1984