Dead level contour technical design parameters required for sustainable crop production in semiarid areas of Zimbabwe
Smallholder farmers in sub-Saharan Africa are increasingly exposed to risks such as erratic rainfall, prolonged dry spells, and frequent droughts that threaten sustainable crop production. This study assessed the effectiveness of dead level contours with innovations (DLC INN), dead level contours with infiltration pits (DLC INFIL), dead level contours with open channels (DLC OPEN) and standard graded contours (SGCs) in harvesting and storing water in the channel, improving crop conditions during the critical stages of maize growth on different soil textural groups in the Zvishavane District of Zimbabwe. The DLC INFIL, DLC OPEN and DLC INN outperformed the SGC under medium- and heavy-textured soils, with yields ranging between 1.7 and 2.36 t/ha compared to 0.9 t/ha for the SGC. For light textured soils, the DLC INN had the highest maize yield, averaging 0.8 t/ha. On heavy textured soils using DLC INN, DLC INFIL and DLC OPEN, smallholder farmers may use a spacing interval of 24–27 m. On medium textured soils, DLC INN and DLC INFIL can be used at a spacing interval of 18–21 m and 12 to 15 m with DLC OPEN. On light textured soils, farmers are advised to invest in DLC INN only, using a spacing interval of 12–15 m.