Assessing the adoption potential of improved fallows in eastern Zambia

Declining soil fertility is a key problem faced by farmers in eastern Zambia. This chapter assesses farmers' experiences of testing improved tree fallows in participatory on-farm trials to increase soil fertility. It also highlights the development of an adaptive research and dissemination network of institutions and farmer groups for testing and disseminating improved fallows. Sesbania sesban and Tephrosia vogelii performed well, but Cajanus cajan was discontinued because it was browsed heavily by livestock. The economic analysis compared a 2-year improved fallow, followed by maize cropped for 3 years, with fertilized and unfertilized continuously cropped maize. Over a 5-year period, farmers used 11% less labour on the improved fallow plot than on unfertilized maize, but harvested 83% more maize. Improved fallows had higher returns to land and to labour than continuously cropped unfertilized maize; returns compared to fertilized maize were mixed. Farmer interest is strong, as the number of farmers planting improved fallows has increased from under 20 in 1993-94 to roughly 10000 in 2000. Key elements contributing to the progress made thus far include: (1) effective diagnosis of farmers' problems and screening of potential solutions; (2) farmer participation in the early stages of testing of improved fallows; (3) testing of a range of management options by farmers and researchers, and encouraging farmers to innovate; and (4) development of an adaptive research and dissemination network