Soil fertility management of maize-legume intercrops: comparing best bet options in western Kenya

The second season to FURP and MBILI. Overall crop yields were 2.38 t maize and 0.24 t legume ha-1 in the first season and 0.98 t maize and 0.17 t legumes ha-1 in the second season. In terms of total crop yield (t ha'lyr-l), PREP (4.40) MBILI (4.29) FURP (4.21) farmers's bet (4.05) compost (3.66) LpRF (3.05) no inputs (2.79) CgRF (2.42) where "LSDo.05 = 0.62. The return ratio (total crop value/total costs) resulted in the order MBILI (2.21) no inputs (1.84) compost (1.72) LpRF (1.67) CgRF (1.63) FURP (1.54) PREP (1.51) farmers's bet (1.42) where LSDo.05 = 0.20. Anticipated residual benefits of some treatments, particularly PREP, LpRF and CgIF, are not expected to materialize until the on-going growing season (March to August 2003). These findings demonstrate that recommendations producing greater yield are not necessarily profitable, and that farmers' reluctance to adopt many of these practices may be justified in terms of their poor economic returns. Many researchers refer to the "basket of options" as a means of assisting rural poor to improve their food security and wellbeing, and direct their efforts toward contributing to those "best bets". In Western Kenya, that basket contains several soil fertility management practices targeted to smallholders' maize-legume enterprise, but these recommendations have often been developed in isolation of one another. The Best Bet Network of six NGOs was formed in Western Kenya to independently test several soil fertility management practices in 140 farmer-managed trials during 2002. These options included; no inputs as a baseline condition costing US KSh 14030 ha"yr-', mineral fertilizers, FURP receiving 66 kg Nand 20 kg P ha-1 as DAP, urea and CAN costing KSh 22630),fortified compost at 2 t ha-' (KSh 17070), the PREP nutrient replenishment package containing 35 kg N and 100 kg P ha-1 (KSh 26820), the MBILI legume intercrop rotation receiving 31 kg N and 20 kg P ha-1 (KSh 22080), a relay fallow with Lablabpurpureus (LpRF, KSh 16615), a short-term improved fallow using Crotolaria grahamiana (CgIF, KSh 14980), Soil fertility management is widely regarded and a "farmer's bet" comprising local land as the key to successful maize-based food management strategies (average cost KSh production in smallhold farming systems in 23645). All trials were planted with western Kenya (Sanchez et ai., 1997;recommended maize hybrids at 44400 plants Smaling et aI., 1997). The soil is unable to ha-' and beans or groundnuts at 88800 plants supply sufficient mineral nutrients to maize ha". Soil inputs were applied or fallows legume intercrops because of low inherent established during the first cropping season soil fertility (see Kenya Soil Survey, 1982), and only N side dressing was applied during nutrient depletion