轮耕秸秆还田促进冬小麦干物质积累提高水氮利用效率

通过田间定位试验,探究了不同耕作措施及秸秆还田对2015-2017年2个生长季冬小麦物质积累、氮素积累及水氮利用效率的影响。采用2因素裂区试验设计,主区为秸秆还田(S)和秸秆不还田(NS);副区分别为深耕(DT)、轮耕(RT)和免耕(NT)处理。结果表明:S处理较NS处理显著增加冬小麦旗叶SPAD和光合速率,提高成熟期植株生物量,但产量增加不显著。RT处理于2015-2016年和2016-2017年较DT处理分别显著增产4.88%和9.05%,2016-2017年较NT处理显著增产3.64%。秸秆还田和耕作方式交互作用显著影响冬小麦产量,S+RT处理2015-2016年和2016-2017年较NS+DT处理分别显著提高8.68%和16.98%。S处理显著增加植株氮素积累量和水分利用效率;RT处理显著提高冬小麦水分利用效率,增加冬小麦氮素积累量、籽粒氮素积累量、氮素转运及其利用效率。2015-2016年和2016-2017年RT处理水分利用效率较NT处理分别提高8.45%和8.92%,2015-2016年较DT处理提高5.24%;2016-2017年RT处理氮肥偏生产力较NT和DT处理分别显著提高3.68%和9.16%;氮素籽粒生产效率较NT和DT处理分别显著提高10.60%和4.78%。S+RT处理花后SPAD下降幅度最小,花期和成熟期均具有较高的光合速率,产量、水分利用效率和氮肥偏生产力与NS+DT和S+DT相比分别平均提高了12.58%,8.53%,7.95%和4.11%,19.79%,11.44%。因此,秸秆还田配合轮耕措施是黄淮海南部较为适宜的节水省肥型冬小麦耕作栽培措施。

Rotational Tillage with Straw Returning Increased Dry Matter Accumulation and Utilization Efficiency of Water and Nitrogen in Winter Wheat

The field experiment has been conducted to investigate the effects of different tillage practices and straw treatments on dry matter accumulation, nitrogen accumulation, and water, nitrogen use efficiency of winter wheat in 2015-2017. The split-plot experiment design was adopted. The main plot was straw returning (S) and no straw returning (NS). The sub-plot was deep tillage (DT), rotation tillage (RT) and no tillage (NT). The results showed that, compared with NS treatment, S treatment significantly increased flag leaf SPAD, photosynthetic rate and aboveground biomass in mature stage of winter wheat, while the yield of winter wheat was not significantly increased. The yield of winter wheat was significantly influenced by tillage practices. Yield of RT was significantly higher than that of DT for 4.88% and 9.05% in 2015-2016 and 2016-2017 respectively, and it was significantly higher than that of NT for 3.64% in 2016-2017. Significant interaction existed between straw returning and tillage practices. Yield of S+RT was significantly higher than that of NS+DT for 8.68% and 16.98% in 2015-2016 and 2016-2017 respectively. Compared with NS treatment, S treatment significantly increased aboveground N accumulation and water use efficiency of winter wheat. RT treatment significantly increased water use efficiency, aboveground N accumulation, kernel N accumulation, nutritional organs N operation rate and N grain production efficiency. Water use efficiency of RT was significantly higher than that of NT for 8.45% and 8.92% in 2015-2016 and 2016-2017 respectively, and it was higher than that of DT for 5.24% in 2015-2016. The partial productivity of N fertilizer in RT was higher than in NT and DT for 3.68% and 9.16% respectively, and N grain production efficiency of RT was significantly higher than that of NT and DT for 10.60% and 4.78%. There was a small decline in SPAD after anthesis, higher photosynthesis rater in anthesis and mature stage of winter wheat existed in S+RT treatment, that yield, water use efficiency, N partial productivity were significantly higher than those of NS+DT and S+DT treatments for 12.58% and 8.53%, 7.95% and 4.11%, 19.79% and 11.44% respectively. Therefore, the treatment of straw returning with rotational tillage was suitable for Huang-Huai-Hai Plain as a water and N saving cultivation practice.