What is conservation agriculture?
Conservation agriculture (CA) aims to produce high crop yields while reducing production costs, maintaining the soil fertility and conserving water. It is a way to achieve sustainable agriculture and improve livelihoods.
Conservation agriculture has three basic principles:
To gain the full benefit of conservation agriculture, all three principles have to be applied at the same time. This ideal is not possible everywhere, but farmers should try to go into that direction as far as possible.
History of conservation agriculture
In the 1930s, soil erosion in the United States reached crisis proportions. The problem was particularly severe in the Midwest, where millions of tons of topsoil were blown away by the wind or washed into rivers, in what came to be known as the 'Great Dust Bowl'. Supported by the government, American farmers started abandoning their traditional practice of ploughing. Instead, they left the crop residues on the soil surface, and planted the next crop directly into the stubble. Faced with similar problems, farmers in South America also took up conservation agriculture. They sowed cover crops to protect the soil, and rotated crops in order to maintain soil fertility. Because of the benefits, knowledge passed quickly from farmer to farmer.
By the year 2000, conservation agriculture was practised on about 60 million hectares of land worldwide, mainly in North and South America. Government support has been important: in some states in Brazil, conservation agriculture is official policy. In Central America, Costa Rica's Ministry of Agriculture has a Department for Conservation Agriculture. Conservation agriculture is used to cultivate over half the crop land in Paraguay, about one-third of the land in Argentina, one-third in Brazil, and one-sixth in the United States.
The many South American conservation agriculturists are well organized in local and national farmers' associations. They are supported by institutions from North and South America and have links with international agencies such as FAO, GTZ and the World Bank. This support is essential to help farmers to adopt quickly new approaches and technologies that many see as a radical change in the way they farm.