Effect of Canola (Brassica napus L.) Residue Management and Nitrogen Fertilizer on Wheat (Triticumaestivum L) Yield and Some Soil Properties

In order to evaluate the effect of nitrogen (N) and canola residuals on yield and improve the physical and chemical properties of soil in wheat-canola rotation, a split block experiment was carried out in a randomized complete block design (RCBD) with three replications for four years (2010-2014) at Chahartakhte Agricultural Research Station in Shahrekord. The treatments consisted of three rates of N (N1:0, N2:25, N3:50 kg N.ha-1) in the main plots and four rates of canola residues (M1: complete removal of plant residues from plots, M2: Turning and removal of residues with plow, M3: incorporating residues with surface soil by means of discs and M4: first incorporating residues with disks and then turning into the soil with plow) in the subplots. The analysis of variance results revealed that the effect of year was significant on biological and seed yield and weight of 1000 seeds. The maximum of these parameters was obtained in the second year. The effect of N was significant on biological and seed yields, protein percentage, leaf N, and weight of 1000 seeds. The maxima of these parameters were, respectively, 10061 and 3975 kg ha-1, 19%, 2.9%, and 38.7 gr and were obtained in N2 treatment. Different managements of residue showed a significant effect on biological and seed yield, harvest index, soil organic carbon, and weight of 1000 seeds. The maximum values of these parameters were, respectively, 10441 and 4186 kg ha-1, 4.36%, 0.77%, and 38.7 gr and obtained in M2. The interaction effect of N and residues was significant on seed yield and weight of 1000 seeds. The maximum of the studied parameters was obtained in the N2M2 treatment. Considering the experimental results, the N2M2 treatment was suggested for wheat in Shahrekord region and regions with the same soil and climate condition.