Cost-benefit analysis of farmer-tested soil fertility replenishment technologies in Kirege location, Chuka Division, Eastern Kenya

A study was conducted in Chuka Division, eastern Kenya to assess trends in adoption of soil fertility replenishment strategies. Eighty farmers adopted the soil fertility improvement technologies during the short rains season of 2001. During the subsequent 2 seasons, 163 and 206 farmers representing an increase of 99% and 150% above the initial adopters practiced the soil fertility improvement strategies. Technologies involving use of Tithonia diversifolia and Calliandra calothrysus alone or in combination with inorganic fertilizer were readily adopted due to the high yields obtained as well as being sources offodder. During the 151 season of farmer follow-up, tithonia + Y2 of inorganic fertilizer gave the highest net benefit ofKshs. 50133 ha-' and was followed by the full rate inorganic fertilizer treatment with a net benefit of Kshs. 39568 ha-'. Tithonia treatment had the highest benefit cost ratio (BCR) of 5.4. Sole manure treatment recorded the lowest net benefit (Kshs. 4601) and hence the lowest BCR of 0.9. However, during the 2nd season, manure plus Yz rate of recommended inorganic fertilizer recorded the highest net benefit (Kshs. 41567) with a BCR of 3.7. Farmer practice involving no input had the lowest BCR of 0.2 with a net sale of Kshs. 9853. Sole tithonia treatment Traditional farming systems in Africa relied had the highest BCR (4.6) indicating greater on shifting cultivation practices to replenish benefit per unit investment. Constraints to soil fertility. According to Sanchez and the adoption of the proposed soil fertility Leakey (1997) and Vissoh et a!. (1998), this improvement strategies were identified as inadequate labour, poor yield observed from some of the technologies at the demonstration trial, inadequate organic and inorganic resources and laxity due to fear offailure. The technologies were seen to increase food production at affordable cost at the same time improving the soil quality in the area. Therefore tackling of the mentioned limitations to adoption of soil fertility technologies need priority in any effort to encourage widespread adoption. Timing application of the organic resources needs to be ensured to check on conflicts between labour requirements with other farm or domestic chores.