麦玉两熟秸秆长期全量还田模式下氮肥对冬小麦生长发育、产量及品质的影响

为了探讨小麦-玉米两熟区长期秸秆还田模式下氮肥的适宜用量，采取秸秆不还田、秸秆全量还田为主因素，氮肥用量（设0、90、180、270、360 kg/hm2 5 个水平）为辅因素的裂区试验设计，研究了麦玉两熟秸秆长期还田配施氮肥对冬小麦生长发育、产量及品质的影响。研究结果表明：同一氮肥水平秸秆还田处理能够增大叶面积，增强光合作用，提高叶绿素含量及地上干物质量，增加产量。随施氮量的增加，叶绿素呈增长趋势，但叶面积、地上干物质量、穗数、穗粒数及产量均呈先增后减的趋势。蛋白质及湿面筋含量随施氮量增加而提高。过量施用氮肥(270、360 kg/hm2)，产生盐害，会抑制小麦生长，导致减产。秸秆还田配施180 kg/hm2氮肥处理能明显促进冬小麦的生长发育，提高产量和品质。经模拟分析，秸秆全量还田模式下小麦最高产量的推荐施氮肥量为216.11 kg/hm2。

Wheat-corn Cropping System with Long-term Total Straw Returning: Effects of Nitrogen Application on Growth, Yield and Quality of Winter Wheat

To determine the optimum nitrogen amount in a wheat-corn cropping system with long-term straw returning, a split plot experiment was carried out, non-straw returning and total straw returning were used as the main factor, nitrogen amounts (0, 90, 180, 270 and 360 kg N/hm2) were used as cofactors. The effect of long-term straw returning combining with nitrogen fertilizer application on the growth, yield and quality of winter wheat in a wheat-corn cropping system was studied. Results showed that, at the same nitrogen amount, straw returning increased foliar area, photosynthetic rate, chlorophyll contents, ground dry matter amount and yield of the wheat. As nitrogen amount increasing, chlorophyll content generally increased, but the leaf area, ground dry matter amount, the number of spikes and spike grains and yield increased initially and then decreased. The contents of protein and wet gluten were enhanced along with the increasing nitrogen amount. 270 and 360 kg N/hm2 treatments caused salt damage and reduced the yield of wheat. Straw returning plus the application of 180 kg N/hm2 promoted the growth, yield and quality of winter wheat. The simulation analysis indicated that the optimum nitrogen amount was 216.11 kg/hm2 under the total straw returning model.