Smallholder farming in many parts of Kenya is mainly constrained by declining soil fertility. The use of inorganic fertilizers is limited by their high costs and erratic availability. Incorporating green manure legumes into the cropping systems can be a cheaper alternative of alleviating soil infertility and soil erosion. However, a major problem with the use of soil-improving legumes is the lack of species suited to the different agro-ecological zones and soil types of Kenya. In 1994 a Legume Screening Network was formed primarily to identify promising species for the different regions in Kenya. About forty species were screened in eleven sites spread across the country. Identification of promising species was based on biomass production, nodulation and nitrogen fixation, ground cover, pests and disease resistance. The effects of planting and harvesting dates on the species were evaluated. Two years of results identified promising green manure legumes and they included Lablab purpureus cv Rongai, Mucuna pruriens, Vicia dasycarpa, Vicia benghalensis, Crotalaria juncea and Crotalaria ochreleuca. Planting at the onset of rains was associated with lower levels of pest infestation and disease incidence. The best harvesting date was the one that gave species a longer growing period. The selected herbaceous legume species are being evaluated under local farming systems with active farmer participation for inclusion in smallholder farming systems.

English

9906|AGRIS 9902|R98-99ANALY

Jose Juan Caballero

CIMMYT Publications Collection