Chapter 30. E.W. Russell. 1972. The impact of technical developments on soils in East Africa. Pages 567-576.

Keywords: misuse of chemical fertilizers has resulted in the acidification of soils, pesticide problems have also occurred, farmers cannot afford expensive inputs particularly under rainfed conditions as risk of crop failure is too high, humus loss from erosion is commonplace, ecological and social problems need to be solved before farmers use tractors can be justified, some soils under old rain forests whose subsoils are high in hydrated iron oxides (laterites) and are prone to erosion, soil conditions necessary for high yields, pore size of soil, structure of surface soil can be managed by farmers, the ability of a soil to supply nutrients is now under farmers’ control through the use of fertilizers, acidification can result from use of ammonium sulfate fertilizer so it this is a problem then use urea which is alkaline, some examples of agricultural developments in East Africa, a groundnut project caused ecological problems as the land to be cleared was woody vegetation and was costly and difficult, other problems were low germination, drought in some areas, low agricultural yield, viral rosette disease, and rapid growth of weeds where heavy rains caused delay in mechanized cultivation, some areas had very infertile soils, a tea-growing project in East Africa was located on problem soils where weed problems became severe, a rhizomatous grass Digitaria scalarum was especially difficult to control, coffee growing was placed in an area of low rainfall, it was recommended to cut tall coarse grass to make a mulch for weed control and for moisture conservation, problems of grazing lands