Agriculture's Effect on the Environment

Increased farm productivity and agricultural growth, with concomitant increases in food availability and incomes, help the environment now and over the long run. Sustainably intensifying production on currently cultivated land will reduce pressure on poor farmers to push onto fragile margin land and to rely on labor-intensive gathering strategies off-farm in the biodiversity-rich commons.

More specifically, poor farmers who cannot produce enough food on their land practice "extensification," extending cropping onto marginal land and the commons (forests, wetlands, bushlands, hillsides). This degrades fragile soils, setting up a cycle of further impoverishment - a vicious circle. Research carried out by Michigan State University (MSU) in Rwanda shows that farmers have been pushing down fragile hillsides, creating erosion.

Poor households also rely on the products of the commons for survival. There, the poor gather every stick that can pass for fuelwood and there they overstock livestock to insure their livelihoods. Richer households draw on the commons too, pursuing livestock husbandry on wild lands or harvesting trees. Often, these activities have an even greater absolute effect because this economic group usually has larger herds and better tools to harvest wild products - chain saws and guns, not just machetes.

But in many places the days of extensification are ending as open areas available to expand farming disappear. Many poor farmers in these areas turn to "labor-led intensification," farming more on the same land.

They reduce fallow periods, plant seeds more densely, push the land harder. Yet, few can afford to offset this mining of the soil by applying fertilizer and manure to protect soil fertility and prevent soil exhaustion.

Extracting more without giving more back is one of the most important environmental issues in Africa, and at the core of the agricultural crisis. International Resources Group (IRG) analyses in the Sahel, conducted with the Center for Agrobiological Research in the Netherlands, found that current production is being maintained by progressively depleting soil nutrients. MSU research with the Senegalese Agricultural Research Institute shows that in Senegal, increasing peanut seeding density without applying manure and fertilizer is rapidly leading to soil exhaustion.

In Africa, agricultural pollution is not at all the problem that it is in some parts of Asia or in North America or Europe. Fertilizer, pesticide, and even manure use is extremely low in Africa. Even a 10-fold increase in use would not create serious chemical-runoff problems. On the contrary, the big problem is using too little fertilizer and manure, which undermines sustainable intensification and forces farmers to seek new lands to clear. For this reason, not intensifying agriculture will undermine farmlands and the commons in the medium-to-long run, and will mean that food needs go unmet. Low-input agriculture, which typically allows growth of 1 percent a year, cannot meet demand growing at 3-4 percent a year. The land frontier is closing, making intensification a critical agricultural and environmental goal.

Cropping intensification need not be the enemy of the environment, however. Intensification can be accomplished in a way that meets food and fiber supply goals and helps the environment on-farm and off. In "capitalled intensification," farmers crop more intensively but offset harmful effects on soil fertility by enhancing the soil with fertilizer, manure, or compost and by protecting it with bunds, terraces, and windbreaks. This approach checks degradation and can enhance the on-farm environment.

Evidence indicates that intensifying farmland use can also protect the commons. Derek Tribe of the Crawford Fund for International Agricultural Research speculates that had there been no Green Revolution in India, 44 million hectares of land currently under forest would now be plowed and farmed.