Evaluation of Nitrogen Use efficiency and Wheat Yield under Fertilizer Management and crop rotation

Crop rotation is an annual succession of crops grown on the same land. Good crop rotation is a systematic succession of the different classes of farm crops. Crop rotation should be done in such a way to give large yields and provide the farm at the least expense of labor and fertilizes the soil. Pulses in crop rotations can improve the productivity of subsequent crops due to increased soil available N and other agronomic benefits. However, the magnitude of this effect can vary with environmental conditions, agricultural management practices and legume genotypes. Also, Legume plants can promote C storage by enhancing the formation and stabilization of soil aggregates that protect soil organic C from mineralization. In order to Evaluation of Nitrogen Use efficiency and Wheat Growth and Yield under Fertilizer Management and Pre-Cropping with crops an experiment was conducted.

A factorial experiment was designed based on randomized complete blocks with three replications and implemented on a sandy clay soil during 2012-13 and 2013-14 growing seasons, at the Agricultural Research Station, Faculty of Agriculture, University of Bu-Ali Sina, Hamedan, Iran. The first factor consisted of chickpea and corn (forage) and the second factor was urea fertilizer levels of 0, 40, 80, 120, 160 and 200 kg/ha. Harvest operation was done on July, 2013 and 2014. SAS procedures and programs were used for analysis of variance (ANOVA) calculations.

The results showed that about all of the evaluated properties of wheat affected by pre-cropping and nitrogen fertilizer treatments. But, none of the wheat traits do not affect by pre-cropping × nitrogen fertilizer. The highest biological yield (1486 g m-2), grain yield (675 g m-2) and protein percentage (13.70%) were observed in chickpea pre-cropping treatment. Chickpea pre-cropping treatment increased wheat biological yield and grain yield and protein percentage about 17, 21 and 18 percent in comparison to corn pre-cropping treatment. Pay attention to the improved physicochemical conditions of the soil after cropping legumes such as chickpea, it is normal to improve the growth and yield characteristics of the next crop (in this study, wheat). Among the nitrogen fertilizer levels the lowest wheat biological yield and grain yield and protein percentage (about 1102 and 417 g m-2 and 11.06%, respectively) was achieved at 0 kg ha-1 N fertilizer consumption. Also, the highest wheat biological yield and grain yield and protein percentage (about 1544 and 775 g m-2 and 13.24%, respectively) was observed at 200 kg ha-1 N fertilizer consumption, but it had not significant difference with 160 kg/ha treatment. One of the most well-known effects of nitrogen fertilizers is to increase the crops properties of growth and yield. The highest nitrogen use efficiency was observed at chickpea pre-cropping and lowest level of fertilizer application. In this study, wheat growth and yield characteristics such as plant height, chlorophyll index, grain yield components, biological and grain yield, harvest index, and percentage of grain protein increased due to urea application.

It seems that in the wheat farming, legumes pre-cropping such as chickpea pre-cropping is a good solution to reduce the use of nitrogen fertilizers and to contribute to environmental health. Also, attention to optimum fertilizer levels and non-overuse of fertilizers will contribute to agricultural sustainability.