Effect of residue retention strategies on maize productivity in Zimbabwe

Abstract

Most smallholder farmers in Zimbabwe rely on rainfall for crop production. However, the changes in the climate results in erratic rainfall patterns which makes most farmers to be food insecure. Efforts have been made to improve agronomic practices through no till practices and retention of crop residues in the field. However, most farmers practice conventional tillage for land preparation, weed management, incorporating manure and sowing crops. This study aimed at investigating the effects of tillage practices and crop residue retention strategies on maize production in Zimbabwe. The study involved an experiment laid out as a randomised complete block design with two main treatments (no till and conventional tillage) and four sub-treatments (no residues, 3t ha-1 maize residues, 3t ha-1 pigeon pea residues and 6 t ha-1 maize crop residues). Data collected included water infiltration, soil macrofauna, leaf chlorophyll content, maize biomass and grain yield. The results show that crop residue retention strategies have a significant effect (p <0.05) on water infiltration and soil macrofauna. Tillage systems had a significant effect (p <0.05) on leaf chlorophyll content and grain yields. Water infiltration was also influenced by soil types which were distinct at the study sites. The delayed gratification which occurs in no till systems results in low maize grain and stover??? yield at the beginning of adopting no till systems. However, improvement in water infiltration and soil macrofauna helps improve maize productivity in the long term thus improving food security in smallholder farms. Small holder farmers should practice no till farming and retain crop residues in their fields to improve maize productivity in the face of climate change. Keywords: rainfed, smallholder farmers, infiltration, chlorophyll, yield