Effectiveness of “PREP-PAC” Soil Fertility Replenishment Product on Performance of the Diversified Maize–Legume Intercrops in Western Kenya

Abstract

Western Kenya region is densely populated, with population densities ranging from 500 to 1200 persons/km2. This has resulted in reduced land sizes, continuous cropping, high rates of soil nutrient depletion, and food insecurity. PREP-PAC was tested on a small-scale farm in western Kenya for three continuous seasons. Seven legume varieties were intercropped with maize (Zea mays) using MBILI intercropping system. The treatments were in a 7×2 factorial arrangement in a randomized complete block design, with each treatment replicated four times. PREP-PAC application contributed to a significant increase (p < 0.01) in soil available P and soil pH, with a maximum increase in soil-available P of 8.20 in maize–yellow gram intercrop and pH increase of 0.72 in maize–dolichos bean obtained in 2004 LR. A significant positive change (p < 0.01) in maize grain yields across all intercrops was also recorded, with a maximum change in yield of 2616 kg/ha obtained from maize–bambara nut intercrop in 2004 LR. A positive change in increase in legume grain yield was obtained for most legumes, with beans giving a maximum significant increase (p < 0.01) of 658 kg/ha in 2004 SR. Economic analysis indicated a significant increase (p < 0.01) in improved farm income. Maize–yellow grams gave the highest net profit of 89,506.70 Ksh/ha/year and maize–cowpeas gave the lowest net profit of −19,403.20 Ksh/ha/year. This study therefore concluded that intercropping yellow grams, soybeans, beans, groundnuts, and bambara nuts with maize was profitable and is recommended for adoption toward nutrient replenishment and food security in western Kenya.