Plant nutrient aspects of mulching in alley cropping trials as affected by micro-climatological factors of the semi-arid areas of Machakos District, Kenya.

Abstract

E:·:periments en plant nutrient status and yield of maize in relatien to ITulch nutrient compositien were cenducted at I<atumani, in Machakosfrom 1987 to 1989. In all the seasc:ns apart from the Short Rains of 1988, ~<atLunanicomposite B was SCW"1. During the SR'88 Hybrid 511 was mistakenly planted. Cassia siamea had been grCWlas the tree species forming the hedges. Eetween the hedges, 3 maize ro.vs were SCW"1 parallel to the hedges. The hedges were lopped periodically at a height of 50 cm and the loppings full y incorporated into the soil within the hedges (alleys) before the beginning of each seasc:n. In the control plots, each hedge rc:wwas replaced by a rc:wof maize and therefore no nLllch was incorporated in the control plots. I\lltrient analysis maize grains and (grains) in g/rc:w for Cassia siamea m:::nitored. was performed for Cassia loppings, maize leaves, maize stovers for nutrient analysis. Maize yield and weed biomass were also assessed. Decompositien loppings using standard litter bags was also The resul ts indicated that incorporation of nLllch increased the nutrient cencentratiens of maize leaves, grains, and stovers as revealed by higher levels of nutrient cencentratiens in the treated plots relative to the controls. Although there was a relatively higher yield in the treated plots as compared to the centrals en I=€rrc:w basis, the differences were not significant. The v..eedbiomass in the treated plots was more than in the control plots. Decompositien e>:periments indicated that appro>:imately 70-901. of Cassia nLllch dry matter COLlldbe lost within &:"..) days.