ABSTRACT

Integrating forage legumes with maize has the potential to restore soil fertility and increase grain yield among smallholder farming systems. A study was conducted over two cropping seasons to determine the effect of intercropping maize with forage legumes on soil fertility restoration, weed biomass and maize yield. Treatments involved: four cropping systems (sole maize, maize-velvet bean, maize-silverleaf, maize-cowpeas) and four fertiliser regimes (no fertiliser, 150 kg ha⁻¹ of compound D fertiliser (7% N: 14% P₂O₅: 7% K₂O) + 150 kg ha⁻¹ ammonium nitrate (34.5% N), 100 kg ha⁻¹ single super phosphate (SSP, 17.5% P₂O₅) and 200 kg ha⁻¹ SSP). Maize-velvet bean intercropping reduced weed biomass by 80% relative to sole maize and maize-silverleaf intercropping. Maize-cowpea and maize-velvet bean intercropping reduced maize grain yield by 25.9% and 64.7%, respectively, compared to sole maize and maize-silverleaf intercropping. In 2017/2018, maize-silverleaf intercropping increased resin-extractable P₂O₅ by 60.1% compared to other cropping systems while the three fertiliser treatments increased the levels of this nutrient by 41.9–100%. The results of this study show that intercropping maize with silverleaf has the potential to restore soil fertility and control weeds, without reducing maize grain yield.

摘要

将饲草豆类与玉米相结合有可能恢复土壤肥力并提高小农耕作系统的粮食产量。在两个种植季节进行了一项研究，以确定玉米与牧草豆类间作对土壤肥力恢复、杂草生物量和玉米产量的影响。涉及的处理：四种种植系统（单一玉米、玉米-天鹅绒豆、玉米-银叶、玉米-豇豆）和四种肥料方案（无肥料，150 kg ha ^-1复合 D 肥料（7% N：14% P ₂ O ₅ : 7% K ₂ O) + 150 kg ha ^-1硝酸铵 (34.5% N), 100 kg ha ^-1单一过磷酸钙 (SSP, 17.5% P ₂ O ₅) 和 200 kg ha ^-1 SSP)。相对于单一玉米和玉米-银叶间作，玉米-天鹅绒间作减少了 80% 的杂草生物量。与单种玉米和玉米-银叶间作相比，玉米-豇豆和玉米-绒豆间作使玉米产量分别降低了 25.9% 和 64.7%。在 2017/2018 年，与其他种植系统相比，玉米-银叶间作使树脂可提取 P ₂ O ₅增加了 60.1%，而三种施肥处理使这种养分的含量增加了 41.9-100%。这项研究的结果表明，玉米与银叶间作具有恢复土壤肥力和控制杂草的潜力，而不会降低玉米产量。