Tropical forage legumes provide large nitrogen benefits to maize except when fodder is removed

摘要: Integration of tropical forage legumes into cropping systems may improve subsequent crop nitrogen (N) supply, but removal legume biomass for is likely to diminish these benefits. This study aimed determine: (i) under irrigated conditions, the potential N inputs that can be provided by different a cereal crop; and (ii) residual benefits once fodder had been removed. Available soil mineral following lablab (Lablab purpureus), centro (Centrosema pascuorum), butterfly pea (Clitoria ternatea) burgundy bean (Macroptilium bracteatum) grain soybean (Glycine max) was compared with maize (Zea mays) control when retained or cut removed (phase 1). An oat (Avena sativa) cover then grown ensure consistent soil-water across treatments 2), followed 3) in which uptake, production yield were among phase 1 treatments. To determine N-fertiliser equivalence values yields, rates fertiliser (0–150 kg urea-N/ha) applied 3. Retained pea, increased 3 unfertilised 6–8 t/ha uptake 95–200 kg N/ha previous crop, contributing equivalent 100–150 kg urea-N/ha. When removed, did not increase significantly. rather than accumulated an additional 80–132 kg N/ha. After removal, only (equivalent 33 kg urea-N/ha). Burgundy either The found range could contribute large amounts crops, potentially tripling yield. However, greatly diminished little benefit crop. Given trade-offs between retaining removing biomass, quantification livestock grazing greater provide alternative achieving dual N–fodder