Nitrogen uptake and utilization efficiency and the productivity of wheat in double cropping system under different rates of nitrogen

摘要

This research was carried out under the temperate climate condition of Ilam province, Iran, during 2011-2013 growing seasons to determine the suitable crop rotation for enhancing the nitrogen (N) uptake, utilization, and N use efficiency of wheat. Treatments were arranged in a split plot based on RCBD with four replications. The main plots were 6 pre-sowing plant treatments (control, Perko PVH, Buko, Clover, Oilseed radish and combination of three plants Ramtil, Phasilia, clover), and sub-plots were allocated to four levels of nitrogen fertilizer (Zero, fertilizer recommendation, 50% lower and 50% higher than the recommended fertilizer). Results showed that nitrogen use efficiency (NUE), nitrogen uptake efficiency (NUpE), nitrogen utilization efficiency (NUtE) and Nitrogen efficiency ratio(NER) in wheat were significantly affected by crop rotation and nitrogen fertilizer and their interaction. The lowest and highest NUEwere in oilseed radish-wheat and fallow-wheat rotation, respectively. The highest and lowest NUtE were observed in oilseed radish-wheat and fallow-wheat rotation, respectively. Perko-Wheat rotation with the consumption of nitrogen based on fertilizer recommendation for wheat due to economic performance and high nitrogen uptake and use efficiency, were evaluated better than any other rotation