Effects Of Different N Supply Levels On The Production And Soil Nitrate Nitrogen In Annual Ryegrass Wheat

In order to explore the area of Yangzhou moist nitrogen on profile of soil migration rule, wheat and ryegrass on nitrogen absorption and utilization and the effectiveness of the crop for optimal fertilization and cropping systems and reduce the residual nitrate in the soil and to provide the theoretical basis of deep soil movement. The same of natural conditions rainfall and irrigated and supply of phosphorus and potassium on under the same conditions, with the conditions of the "Yang mai 13" wheat and annual ryegrass "Bond" as the test material. The experiment followed a completely random split-plot design, taking the N supply treatment as split-plot (with four levels of 0kg/hm²,100kg/hm², 200kg/hm², 300kg/hm²; denoting N0, N100, N200, and N300,respectively).Reac-hed NO3--N, NH4+-N, total nitrogen, water content and soil PH. The results were showed in following. 1 Effects of different N supply levels on Growth of Perennial in Lolium multiflorum Lam and wheatNitrogen had a significant effect on growth characteristics in annual ryegrass and winter wheat. Annual ryegrass tiller number increased with the nitrogen , The second cutting capacity of ryegrass tillers was significantly weaker than the first mowing. With N fertilizer rate increased, the ratio of annual ryegrass leaves gradually decreased, The plant growth height increased with the nitrogen in Wheat and Annual ryegrass, The plant height was not increased when the nitrogen rate than 200kg/hm². N increased in fresh and dry, reducing the leaf ratio, increased palatability of annual ryegrass and utilization in the annual ryegrass and wheat plants. 2 Effects of different N supply levels on grain yield and economic performance check components in annual ryegrass and winter wheatDuring the grass cutting production, plant nitrogen content, shoot dry mass and height reached the maximum value in ryegrass when N reached 200 kg/hm², N200 had the highest grain yield,about 74504 kg/hm², N300 treatments the grain yield were 70670 kg/hm². When N reached 300 kg/hm², grain yield, plant nitrogen content and other indicators had lower reduce trend in the annual ryegrass. The wheat the highest yield was to 8284.14 kg/hm² when the nitrogen application rate was 200 kg/hm².when the fertilizer was 300 kg/hm², the yield decreased slightly to 8276.63 kg/hm². Ryegrass yield and wheat was to highest output /input ratio, small investment is relativeed, the net highest income to 15618.36 yuan/hm² and 14967.34 yuan/hm², the net income was to 8981.4 yuan/hm² when nitrogen is 200kg/hm². Winter wheat grain yield is to the maximum 8284.14 kg/hm² when nitrogen reached 200 kg/hm², Under mowing twice in a year on ryegrass and the premise of the starting point of economic considerations, post-harvest cultivation of rice that of planted annual ryegrass is better than winter wheat in Yangzhou3 Effects of different N supply levels on distribution and accumulation of nitrogen content of annual ryegrass and winter wheatReached the highest levels and plant N content is 3.68% when the rate of N rate was 200 kg/hm². The annual ryegrass plant nitrogen content and other indicators to reduce When N reached 300kg/hm². The yield components significantly different N uptake increased with N supply levels of annual ryegrass. Accumulation of N in annual ryegrass also increased with increasing N supply. The accumulated of different plant parts si difference with N supply. Generally the size of the cumulative amount of the whole is plant> leaves> stems. The N content was highest in grain yield, the spike and the whole plant. With increased N supply, N distribution in different organs of wheat decreased gradually.4 Effects of different N supply levels on N use efficiency of annual ryegrass and winter wheatNitrogen supply on plant nitrogen uptake of annual ryegrass and wheat, apparent utilization, apparent use efficiency of N Fertilizer, N-physiological use efficiency, Agronomic efficiency of applied N, Crude protein yield and other indicators has a significant effect. When N supply is 200kg/hm² the apparent nitrogen utilization is the the highest, with N supply increased, the apparent efficiency lower. Nitrogen significantly increased the crude protein content of plants. N-physiological use efficiency at is lower. Grain protein content increased with the N supply. Wheat nitrogen use efficiency, soil, and agronomic efficiency of nitrogen partial productivity increased with the nitrogen decreased.5 Effects of different N supply levels on nitrate nitrogen dynamics and accumulation in annual ryegrass and winter wheatExperimental results showed that: the content of NO₃--N is highest in surface soil profiles, the treatment of basal nitrogen used before sowing nitrogen used can make different profiles nitrate accumulation increased; the high nitrogen N300, low nitrogen N100 or N0 N leached is than N200 with N a significant increase in fertilizer, Through controlled to reduce infiltration redussed loss of nitrate. I1, I2 and I5 times nitrate accumulation is higher, with nitrogen application increase, at different times in different depths of soil nitrate content is significantly different, the soil layers of different soil nitrate content during most of the increase with the amount of nitrogen increased with increasing N supply , nitrate in the range of 60¹40cm cumulative increase leaching. I1 period of 0¹40cm in nitrate accumulation reached 101.88kg/hm2¹98.14 kg/hm2, followed by the subsequent accumulation. The period of different growth N accumulation content is I1 and I2 higher, with nitrogen application increase, the growth period for nitrate accumulation highest when N300 treatment.Winter wheat and annual ryegrass is similar in different soil profile nitrate dynamics curve, except there are differences between individual changes in nitrogen treatment, The content of NO₃^--N in the 0¹40 cm soil profiles nitrate accumulation is increased with N supply. The same growth period, with increased N supply, soil nitrate content increased gradually with different profiles. In the 60¹20cm soil layer can appeared a peak level of nitrate accumulation occurs. Peak size is deside differences according to nitrogen fertilization. In general, the higher N supplied, the peak is greater of cumulative. N supply equal to or greater than 200kg/hm2 to exceed the application rate of wheat and annual ryegrass plant N uptake, It would resulted nitrate accumulated a lot in soil of different layers to form N leaching potential danger.