不同施氮量对滴灌春小麦生长及氮素吸收规律研究

Effects of Different Nitrogen Applications on the Growth and Nitrogen Absorption of Spring Wheat under Drip Irrigation

[目的]研究不同施氮量对滴灌春小麦干物质、氮素积累及产量的影响,探索滴灌春小麦的氮素吸收利用规律,为生产中氮肥的合理施用提供依据.[方法]以新春6号为材料,通过田间小区试验,设置4个施氮处理0、225、300、375 kg/hm^2,分别用N0、N1、N3N3表示.[结果]滴灌春小麦干物质、氮素快速积累时间分别在出苗后30～61和25 ～55 d,且干物质与氮素的最大积累及最大积累速率随着施氮量的增加呈现出先增加后降低的趋势.随着施氮量的增加,籽粒氮素含量呈现出先增加后降低的趋势,氮素向籽粒的分配比例呈现出下降趋势.小麦产量和氮肥当季利用率随着旋氮量的增加也呈现出同样的趋势,产量以N2最高,达到7 619.86kg/hm^2,比N0增产40.96％.[结论]合理的施氮量和施氮时期是小麦实现优质高产高效的重要举措,在滴灌春小麦出苗后25-55 d这段时期需保证水肥充足供应.通过一元二次多项式拟合,施氮量为329.02 kg/hm^2时理论产量达到最高.

[ Objective]The project aims to study effects of different nitrogen applications on accumulation of dry matter and nitrogen, yield of spring wheat under drip irrigation, which would result in the law of nitrogen absorption of spring wheat under drip irrigation. [ Method ] Through a field plot experiment of 4 nitrogen levels（No： 0 kg/hm^2,N1：225 kg/hm^2, N2：300 kg/hm^2 and N3：375 kg/hm^2） with cultivar Xinchun 6, the test was carried out at the experiment station. [ Result ] The result showed that dry matter and nitrogen absorption dynamic could be fitted by Logistic equation, accelerated accumulation period of spring wheat dry matter and N, uptake was at 30 -61 d, 25 -55 d after seedlings emergence, respectively. With the increase of N dosage, the maximum acceleration rates of dry matter and N showed a Quadratic curve at all N levels. The seed nitrogen and the ratio of nitrogen to the grain distribution were gradually increased and then decreased with the increasing amount of the N - fertilization increasing. With the increase of N dosage, the yield and N utilization efficiency displayed the same trend. Applied nitrogen fertilizer could significantly improve crop yields by 32.83%, 40.96% and 36.73% for N1 , N2 and rq3 treatments compared with No, respectively. [ Conclusion] A reasonable amount of nitrogen and nitrogen period was the important measure to realize efficient high quality and high yield of wheat. The spring wheat under drip irrigation needs to ensure adequate water and fertilizer supply at 25 - 55 d after seedlings emergence. The quadratic polynomial in one element fitted results between yield and nitrogen application rate gen application rate was 329.02 kg/hm^2. showed that the highest yield could be obtained when nitrogen application rate was 329.02 kg/hm^2.