Contributions of Short Duration Legume Fallow to Maize (Zea mays L.) Varieties Under Different Nitrogen Levels in a Semi-Arid Environment

Aims: To evaluate the contributions of short duration legume fallow to maize (Zea mays L.) varieties under different nitrogen levels in a semi-arid environment of Nigeria. Study Design: Split-plot design. Place and Duration: This study was carried out at the Research Farm of the Institute for Agricultural Research, Ahmadu Bello University, Zaria, Nigeria, during rainy seasons of 2005, 2006 and 2007. Methodology: The treatments consisted of two maize varieties (SAMMAZ 12 and SAMMAZ 27) and five rates of nitrogen (0, 30, 60, 90 and 120kg N ha-1) in the main plots, while three green manure crops (Lablab (Lablab purpureus), Mucuna (Mucuna pruriens) and Soybean (Glycine max (L.) Merrill)) and a weedy fallow were accommodated in the sub-plots. The treatments were laid out in a split-plot design with three replications. The green manure crops were incorporated at 49 days (7weeks) after planting. After 3 days of incorporation, maize seeds were planted. Results: SAMMAZ 12 and SAMMAZ 27 were similar on grain yield and most of the yield components studied. Nitrogen fertilization significantly increased yield components and grain yield. In combined mean, application of 30, 60, 90 and 120 kg N ha-1 gave 81.4, 127.2, 151.6 and 165.5% increases in maize grain yield over zero N treatment, respectively. Increasing N rate beyond 90 kg N ha-1 did not significantly increased maize grain yield. Incorporation of mucuna, lablab and soybean significantly increased yield components and grain yield. In combined mean, incorporation of mucuna, lablab and soybean gave 68.8, 73.7 and 59.4% increases in maize grain yield over weedy fallow, respectively. Conclusion: Although, application of nitrogen gave marked increases in maize grain yield as did green manure, however, incorporation of short duration legume, which is environmentally friendly and a soil improver, will be a better option for sustainable maize production in northern Guinea Savanna of Nigeria