Nitrogen Use and Protein Yield of Two Maize Cultivars in Cohesive Tropical Soil

One major challenge to developing sustainable family farms in tropical regions is increasing nitrogen use efficiency. The aim of this study was to evaluate the combined effects of leguminous residues of low-and high-quality on nitrogen uptake, as well as on content of protein of a Quality Protein Maize (QPM) and of a hybrid maize in a tropical sandy loam soil. The experimental design consisted of randomized blocks with four replicates in a 6 × 2 factorial and six treatments- Gliricidia + Clitoria (GC); Gliricidia + Acacia (GA); Leucaena + Gliricidia (LG); Leucaena + Clitoria (LC); Leucaena + Acacia (LA) and a control without legumes (C). A sub-plot was constructed, sowing in each plot two maize cultivars, opened pollination QPM BR 473 and hybrid Ag 7088. We conclude that the combined use of leguminous residues applied on the soil surface might increase the uptake of nitrogen, the protein contents of maize and the grain yield. In bare soil prone to cohesion, the use of synthetic N is not feasible for both maize yield and for protein yield compared with use of covered soil. The results also showed that the effects of leguminous residue quality on N uptake may differ from year to year due to variation in water stress days.