Effects of Wheat and Canola Residues Management and Tillage Methods on Maize Yield and some Soil Properties

To study the effects of wheat and canola residue management and tillage methods on maize yield and some soil properties, two separate experiments were carried out over three years (2009-2011) in Experimental Research Station of Orzoiyeh in Kerman, Iran. In each experiment randomized complete block design arranged in a split plot was used with four replications. Tillage methods (conventional and minimum tillage) were compared in the main plots and crop residue (residue rentention, residue removal and residue burning) were compared in the sub plots. In maize planted under canola bed, in conventional tillage, grain yield (14.4%) and plant height (7%) was more than minimum tillage. In maize planted under wheat bed, grain yield of maize was higher in conventinal tillage in the first and second years, but there was not any significant difference between two tillage methods in the third year. In comparison between wheat residue treatments, residues retention had the highest maize grain yield. The moisture content stored in the soil was highest in treatment of minimum tillage along with residue retention of wheat. In both experiments, residue rentention increased significantly soil organic matter and residue burning increased soil phosphorus and potassium. Grain protein of maize was higher in minimum tillage than conventional tillage, but crop residue management has not significant effect on grain protein content. Based on the results of this study, residue retention in soil can be recommended, but to determine minimum tillage positive effects in soil, long term experiments should carried out.