Kenya Agricultural Research Institute Legume Research Project Participatory Technology 2000

Abstract

Declining soil fertility is a major constraint facing resource poor maize farmers. A Participatory Rural Appraisal (PRA) carried out in 1994 showed that most farmers get less than 2.0 t maize grain ha·1 compared to on-station researcher yield of about 9.0 t ha· 1 • Farmers attributed the low yields to declining soil fertility caused by continuous cropping, crop residue burning, soil erosion and inadequate use of organic and inorganic fertilisers partly because of high costs of inorganic fertilisers. In response, a study was initiated during 1995 short rains (SR) to address the problem of low maize yields. The objectives of the trial were to test the effect of combinations of organic and inorganic fertilisers on maize yield, and determine low cost and affordable fertiliser recommendation. Seven treatments were tested in a randomised complete block design replicated on 23 farms with farmers serving as replicates. The treatments were: (1) control (no fertiliser applied), (2) 5 t compost manure ha·1 (3) 10 t compost manure ha·1 (4) 5 t compost manure + 30 kg P20S + 30 kg N ha· 1 , (5) 10 t compost manure + 30 kg PzOs + 30 kg N ha·1 , (6) 10 t compost manure + 15 kg PzOs + 15 kg N ha·1 and (7) 60 kg P20S + 60 kg N ha·l. Results obtained during the three and half year period indicated that use of 10 t compost manure in combination with 30 kg PzOs + 30 kg N ha- I or 15 kg PzOs + 15 kg N ha·1 improved soil fertility and had the highest maize yields. These fertiliser combinations were promising low cost options to the recommended rate of inorganic fertiliser for maize production. Farmers also preferred these treatments.