秸秆还田及施氮量对冬小麦产量及氮素利用效率的影响

Effects of Straw Returning and Nitrogen Application Rate on Grain Yield and Nitrogen Use Efficiency of Winter Wheat

为研究秸秆还田和施氮量对冬小麦花后旗叶SPAD值、干物质积累、氮效率及产量的影响,以冬小麦济麦22(JM22)为材料,于2015—2016年通过田间定位试验测定冬小麦产量及氮效率。试验采用裂区设计,主区为秸秆处理:秸秆还田(S1)与无秸秆还田(S0);副区为氮肥处理:设置施氮水平分别为0(N1)、180kg/hm^2(N2)、240 kg/hm^2(N3)、300 kg/hm^2(N4),基追比例均为1∶1。结果表明,秸秆还田显著提高冬小麦花后旗叶SPAD值,同一时期SPAD值随施氮量的增加而增加。与单施氮肥相比较,秸秆还田配施氮肥提高了花后干物质积累比例,增幅为0.24%~6.75%,增加施肥量有利于冬小麦全生育期干物质积累总量的提高。秸秆还田配施适量氮肥显著提高了冬小麦氮效率,增加了穗粒数及千粒重最终达到提高产量的目的。

In order to investigate the effects of straw returning and nitrogen application rate on the SPAD value of flag leaf after flowering,dry matter accumulation,nitrogen efficiency and yield of winter wheat variety Jimai 22（ JM22）,the field experiment was conducted in 2015 to 2016,and the wheat yield and nitrogen efficiency were determined. The split block design was adopted in this study. The main plot was straw treatment including straw returning（ S1） and no straw returning（ S0）. The subplot was nitrogen fertilizer treatment including four nitrogen fertilization rates of 0（ N1）,180 kg/hm^2（ N2）,240 kg/hm^2（ N3） and 300 kg/hm^2（ N4） with the ratio of base to dress of 1∶ 1. The results indicated that straw returning obviously improved the SPAD value of flag leaf after flowering,and it increased with the increase of nitrogen application rate at the same period. Compared with the single nitrogen treatment,straw returning significantly increased the proportion of dry matter accumulation after anthesis with the increase amplitude of 0. 24% ^ 6. 75%. Boosting the nitrogen application rate was contribute to the improvement of dry matter accumulation during the whole growing period. In short,straw returning with a moderate amount of nitrogen fertilizer was beneficial to improve the nitrogen efficiency,kernels per spike and thousand seed weight of winter wheat,thereby improve the grain yield.