Soil erosion and shifting agriculture

Thumbnail Image
Journal Title
Journal ISSN
Volume Title
Subsistence farmers are exploiting 5 to 6 billion hectares of land in the tropics. In tropical Africa, shifting cultivation is practiced on some 3.5 billion hectares and about 250 million people live on this hand-to-mouth agriculture. It is estimated that in Africa, between the Sahara and the Republic of South Africa, the amount of land cultivated in any one year is 4 to 5 percent of the potential cultivable land. Generally, it requires 15 hectares of land to support one person with shifting cultivation. At its face value, it is indeed an unproductive system of land use. One of the most important features of shifting cultivation is heavy reliance on nature, rather than on means involving the use of modern technology and human efforts to restore soil productivity. This system of agriculture can therefore, work only if the-ratio of land to people is high.One of the most limiting factors in replacing the shifting cultivation with a more productive and permanently viable system of. land use is the soil erosion. Soil erosion implies not only the physical removal of the surface soil, but also the deterioration in soil physical properties resulting in a low productivity. The failure of agricultural workers, farmers and government officials alike, to comprehend the significance of soil erosion has brought about not only the widespread distribution of shallow, badly eroded and unproductive soils in the tropics, but also the encroachment on the forest by savannah vegetation. The objective of this report is to discuss the factors responsible for widespread problems of soil erosion in the tropics, the magnitude of soil erosion under shifting cultivation and the use of cultural practices to control soil erosion under the proposed system of intensive cultivation,, Most of the examples of * International Institute of Tropical Agriculture, Ibadan. Niceria research results are from experiments conducted at the International Institute of Tropical Agriculture (IITA) and thus may be assumed valid under similar conditions elsewhere in the tropics.
Available in print form, East Africana Collection, Dr .Wilbert Changula Library( EAF FOS F78F3_11)
Shifting Cultivation
Lal, Rattan.1973).Soil erosion and shifting agriculture