Farmers' adaptive effort to soil erosion and land productivity decline: The case of the Uluguru Mountains, Tanzania

摘要

In 1940 agricultural experts reported that soil erosion in the Uluguru mountains was so serious that the area's agriculture would not be able to support its population in a year's time even if soil erosion were completely controlled. Yet, demographic data and the growth in commercial vegetable production since the 1960s all suggest farmers in the Uluguru Mountains have survived, contrary to the prediction of "experts" in 1940. This study examines farmers' adaptive effort in response to soil erosion and land productivity decline in the western Uluguru mountains of Tanzania.;Data were collected through unstructured interviews with 30 farmers and 3 Extension Agents; personal observations of farming practices; and interview schedules administered to a random sample of 406 heads of households from the mountainous Mgeta area in western Uluguru mountains and the nearby flatland area of Mlali.;The following findings resulted from the study: farmers in Mgeta have evolved a farming system with both structural and biological soil conservation effect while farmers in Mlali have not; the evolved farmers' practice is aimed at increasing production rather than conserving soil; farmers in both Mgeta and Mlali use fertilizer and pesticides in response to declining productivity resulting from falling soil fertility and pest attacks; farmers in Mgeta are more aware and have deeper understanding of the problem of soil erosion than those in Mlali; contrary to theories of human adaptation, data do not support the notion of rationality in adaptation; farm-structural, socio-psychological, and personal variables that have been used to explain adoption of innovations account for only 11% of the variation in the use of farmer generated soil conservation practices but 40% of the variation in the use of research generated innovative farming practices; farm size has a negative effect on use of farmer generated conservation practices; ownership of assets positively affect use of farmer generated conservation practices; positive attitude towards commercialization has a negative effect on use of farmer generated conservation practices but a positive effect on use of research generated innovative farming practices; positive attitude towards conservation has a positive effect on use of farmer generated conservation practices; use of farmer generated conservation practices and research generated innovative farming practices are negatively related.