Ampact of Different Nitrogen Application on Nitrogen Movement and Gaseous Loss of Winter Wheat Fields

The impact of different nitrogen application on nitrogen movement of winter wheat fields and gaseous loss.By the methods of field micro-plot experiment with four nitrogen treatment: N75,N150,N225 and N300,15N tracer technique and closed micro-area chamber intermittent ventilation,sealed and static chamber in situ field to monitor nitrogen movement and gaseous loss of winter wheat fields.The yield of winter wheat and aboveground N uptake were increased with the nitrogen,except when the amount of nitrogen is higher than 150 kg/hm2,yield become falling,the N uptake proportion of aboveground turn from the main soil nitrogen into nitrogen-based fertilizers.The soil nitrogen residues of N75,N150,N225,and N300 of 0-100 cm were 32.6,26.8,34.7,40.6 kg/hm2.The winter wheat field emissions of ammonia volatilization from soil increase with the amount of nitrogen,the emissions were from 6.03 kg/hm2 to 13.26 kg/hm2 and accounted for 5.4%～11.4% of the amount of nitrogen.The nitrogen losses caused on the emissions of N2O by the ratio of 0.08%～0.28%,centralized in the period of wheat seedlings.The winter wheat seasonal crops absorption,residues and losses of fertilizer nitrogen were respectively 37.2%～50.2%,26.7%～40.6%,17.4%～22.2%,and increased with the amount of nitrogen.In the present the appropriate amount of nitrogen is 150 kg/hm2,in the level,the yield and the nitrogen utilization of crop both were the highest,yet,the residual of soil nitrogen was the lowest,the gaseous losses of nitrogen fertilizer higher than 75 kg/hm2 treatment,but the difference was not significant(p0.05).Hence,the control was a key measure to increase nitrogen fertilizer efficiency.