Enhancing Maize Productivity With Infield Rainwater Harvesting Techniques and Cattle Manure in Semi-Arid Areas of Zimbabwe

Abstract

Soil fertility and moisture management can be sustainable ways to improve crop production in low rainfall areas. The aim of this study was to evaluate the effects of infield rainwater harvesting and cattle manure on maize yield, rainwater use efficiency, agronomic efficiency, and the value–cost ratio. The experiment used a split plot design with three in situ rainwater harvesting (IRWH) techniques (planting pits, infiltration pits, and conventional tillage (as a control)) as the main treatment factor and cattle manure as the sub-plot factor at four levels (0, 2.5, 5, and 10 t ha−1). The interactive effects of IRWH, cattle manure, and season were significant among all parameters measured (p<0.05). The highest maize grain yield (3990 kg ha−1) was obtained from the planting pits with 10 t ha−1 cattle manure in the 2022/23 cropping season. Maize stover yield increased with an increase in cattle manure, with the highest yield of 6450 t ha−1 at 10 t ha−1 cattle manure. Rainwater use efficiency was significantly (p<0.05) increased by an average of 2.5 kg ha−1 mm−1 from 0 to 2.5 t ha−1. Agronomic use efficiency significantly decreased with the increasing application rate of cattle manure (p<0.05). The interaction of planting pits and 2.5 t ha−1 cattle manure had the highest cost ratio of 6.66 in the 2022/23 season. The interaction between planting pits and 10 t ha−1 cattle manure resulted in higher maize yields and rainwater use efficiency. However, it is recommended that smallholder farmers use planting pits and 2.5 t ha−1 cattle manure to obtain higher yield increments and high profits in high-risk climates.