Environmental and nutritional effects on yield and nitrogen efficiency of chickpea (Cicer arietinumL.) in a warm and semi-arid climate of Iran

To move toward the principles of ecological agriculture in the direction investigating environmental and nutritional effects on yield and nitrogen efficiency of chickpea (Cicer arietinumL.), a field experiment was conducted on the experimental farm of Gonbad Kavous University, Iran; during the growing seasons of 2016 and 2017. The experimental layout was based on a factorial randomized complete block design with three replications and three factors. Three factors were Nitrogen (N) at four rates (0, 20, 40 and 60 kg N ha(-1)), two planting date (early January and early February) and twoMesorhizobiumbiological fertilizer levels (inoculation withMesorhizobiumand no-inoculation). Maximum seed yield, N agronomic efficiency, N utilization efficiency and N use efficiency were obtained from early January. The highest protein percent in seeds and N percent in straw were obtained from early February. Although, protein percent of seed, N percent of residues and seed yield increased with N rate, the N agronomic efficiency and N use efficiency decreased. The inoculation withMesorhizobiumhad positive effects on yield and N use efficiency but had negative effect on N agronomic efficiency. The effect of biofertilizer levels was different at each planting date for seed protein percent in 2016.