More production, less erosion: a Kenyan case history

Erosion is one of the most common causes of declining soil fertility and productivity in ACP countries and farmers often avoid anti-erosion measures because of the labour required. One exception is the successful soil and water conservation strategy being implemented by farmers of the Machakos district in Kenya. Machakos farmers adopted bench-terracing as long ago as 1948, when soldiers resuming from service in the British army experimented with techniques that they had seen in India. Though bench-terracing is laborious, because it requires dug soil to be thrown uphill, farmers have found that manuring is more effective on terraced land, since it is not washed off. Manuring also helps to improve water infiltration and therefore bench terraces are more effective for water conservation. Machakos farmers have found that manuring and terracing are the two most effective ways of maintaining and even improving soil productivity and, despite relatively low rainfall in the area, they are able to grow traditional food crops and vegetable crops for sale in Nairobi. Historically the Machakos district was prone to drought and food shortages. In the 1930s there were despairing reports on the eroded grazing land and arable fields and food shirtages were experienced in fourteen out of twenty years 1942 and 1962. The first attempts to combat erosion and conserve moisture were through the compulsory digging of contour ditches, narrow based terracing where soil is thrown downhill. The initiative failed due to lack of farmer commitment, and even resistance, to the imposed contour construction. It was 20 years later, when farmers could see the value of benchterracing for themselves, that voluntary effort transformed the communiity. By 1978, most of the arable land in the older settled areas had been terraced. However, population growth forced resource-poor farmers into newer areas. These farmers were provided with toois and training for leaders of farmers groups by the Swedish International Development Agency (SIDA), the European Community-supported Machakos Integrated Development Programme (MIDP) and the local Catholic Diocese. By 1990 most of the land that needed terracing had been terraced. The full story is told in More people, less erosion: environmental recovery in Kenya by Tiffen, Mortimore and Gichuki. published by Wiley, Chichester, UK.Erosion is one of the most common causes of declining soil fertility and productivity in ACP countries and farmers often avoid anti-erosion measures because of the labour required. One exception is the successful soil and water conservation..