Effects of Straw Management and Nitrogen Rates on Soil Quality and Grain Protein of Two Barley (Hordeum vulgare L.) Cultivars under Dryland Conditions

A 2-years (2007-2009) field study was carried out at the college of Agriculture, Shiraz University, to evaluate the influence of crop residues management and nitrogen (N) rates on soil quality and barley grain protein under dryland conditions. The experiment was conducted as strip split plot with four replications. Horizontal plots were three crop residues rates (0, 750 and 1500 kg ha-1), vertical plots consisted of two barley cultivars (CVs) (Afzal and Reyhan), and sub-plots were three N rates (0, 40, and 80 kg N ha-1). The Results of ANOVA showed that there were significant differences for year effects and Y×C×N for total N grain and protein percentage. When the crop residues were completely added (100%), N rates should be added according to residues rates. Increasing crop residue level increased soil organic carbon. Crop residue application had no effect on grain protein percentage. There were no significant differences between two cultivars for Crop residue application. High N increased grain protein percentage significantly.