Influence of basin‐based conservation agriculture on selected soil quality parameters under smallholder farming inZimbabwe

Abstract

AbstractThe research was carried out to determine the effect of basin‐based conservation agriculture (CA) on selected soil quality parameters. Paired plots (0.01 ha) ofCAand conventional tillage based on the animal‐drawn mouldboard plough (CONV) were established between 2004 and 2007 on farm fields on soils with either low (12–18% – sandy loams and sandy clay loams) or high clay levels (>18–46% – sandy clays and clays) as part of an ongoing project promotingCAin six districts in the smallholder farming areas of Zimbabwe. We hypothesized thatCAwould improve soil organic carbon (SOC), bulk density, aggregate stability, soil moisture retention and infiltration rate. Soil samples forSOCand aggregate stability were taken from 0 to 15 cm depth and for bulk density and soil moisture retention from 0 to 5, 5 to 10 and 10 to 15 cm depths in 2011 from maize plots. LargerSOCcontents,SOCstocks and improved aggregate stability, decreased bulk density, increased pore volume and moisture retention were observed inCAtreatments. Results were consistent with the hypothesis, and we conclude thatCAimproves soil quality under smallholder farming. Benefits were, however, greater in high clay soils, which is relevant to the targeting of practices on smallholder farming areas of sub‐Saharan Africa.