Grain maize yield improvement using Tephrosia vogelii and Tithonia diversifolia biomass at Maseno, Kenya

Abstract

This study aimed at assessing the response of maize crop to application of Tephrosia vogelii and Tithonia diversifolia biomass obtained six month-old fallows. The biomass were chopped into 5-cm long pieces and incorporated in the soil one week before planting maize. The natural fallow biomass was used as a control. These organic inputs were supplied with 20 kg phosphorus (P) /ha to attain P recommended rates. Shrub aboveground and litterfall biomass incorporation significantly (p=0.05) increased maize yield. Plots where above ground biomass was removed produced lower maize yield compared to those where the aboveground biomass was retained. Addition of 20 kg P/ha to soil together with the biomass increased maize yield by 40%. P in form of organic materials was insufficient to meet plant nutritional requirement. Residual effect of the biomass was low on the second and third subsequent crops. This may be due to the high rate of nutrient release during the biomass decomposition, the high crop nutrient uptake and also the nutrient losses through soil chemical and physical processes