农田水位与施氮对拔节孕穗期受涝后冬小麦的调控效应

Regulation Effects of Farmland Water Level and Nitrogen Application on Winter Wheat after Waterlogging at Jointing and Booting Stage

摘要:

为探明拔节孕穗期受涝后农田水位与施氮对冬小麦生长、产量、籽粒品质、水氮利用及氮磷负荷的调控效应，于2020—2021年在南京市江宁区开展测坑种植试验。以冬小麦品种“扬麦25”为试验材料，在冬小麦拔节孕穗期受涝后设置高、中、低3个农田水位（即受涝1d后农田水位3d内降至-40、-60、-80cm）和低、中、高3个施氮量（160、190、220kg/hm2），以不受涝且常规施氮190kg/hm2处理作为对照。结果表明，涝渍条件下，冬小麦株高、干物质量、产量、水分利用效率、籽粒粗蛋白含量、籽粒赖氨酸含量均随农田水位的降低和施氮量的增加而逐渐增大，氮肥偏生产力随农田水位的降低和施氮量的减小而逐渐增大，总氮、总磷等污染物负荷随着农田水位的降低而逐渐增大。与对照处理相比，试验设计农田水位下，增施氮肥（220kg/hm2）可以缓解涝渍对冬小麦植株的不良影响，促进冬小麦干物质量和产量分别增加4.76%~23.81%、2.75%~9.19%；中、高农田水位下氮肥减施（160kg/hm2）导致冬小麦分别减产2.20%和14.00%，水分利用效率分别下降4.55%和9.74%；低农田水位可以降低因氮肥减施导致的减产效应，使得冬小麦产量和氮肥偏生产力分别提高3.98%、23.49%。农田水位越高，其控水期间综合涝渍程度越大，对应产量越低。此外，短期内涝对提高籽粒粗蛋白含量具有积极效应，与对照处理相比，各处理对应粗蛋白含量提高11.50%~20.21%。综上，以高产、高效、减污、提质为目标，建议冬小麦拔节孕穗期5cm水层受涝1d后，农田水位3d内降至-80cm，施氮量为220kg/hm2。研究结果可为中国南方以及类似易涝易渍农业区冬小麦种植及涝渍灾害修复提供理论依据。

Abstract:

The planting experiment was conducted from 2020 to 2021 in the lysimeters at Jiangning District of Nanjing City to investigate the effects of farmland water level and nitrogen fertilization regulations on winter wheat growth, yield, grain quality, water and nitrogen utilization, nitrogen and phosphorus load after the winter wheat suffered from waterlogging during the jointing and booting stage. Winter wheat variety “Yangmai 25” was chosen as the experimental material, after the winter wheat suffered from waterlogging during the jointing and booting stage, three high, middle and low farmland water level (the farmland water level down to -40cm, -60cm, -80cm in 3 days after the 1 day waterlogging) and three low, middle and high nitrogen application rates (160kg/hm2, 190kg/hm2, 220kg/hm2), as well as a control group with non-waterlogging and the nitrogen of 190kg/hm2 were set in the experiment. The results indicated that the winter wheat plant height, aboveground dry matter, yield, water use efficiency,grain crude protein content and grain lysine content were gradually increased with the decrease of farmland water level and nitrogen application rate. Partial factor productivity of nitrogen was increased gradually with the decrease of farmland water level, while decreased with the increase of nitrogen application rate. The total nitrogen, total phosphorus, and other pollutant loads were increased gradually with the decrease of farmland water level. Compared with the control treatment, the increase of nitrogen fertilizer (220kg/hm2) could alleviate the effect of waterlogging stress, and promote the increase of winter wheat aboveground dry matter and yield by 4.76%~23.81% and 2.75%~9.19%, respectively. The reduction of nitrogen fertilizer (160kg/hm2) made the winter wheat yield at the medium and high farmland water level decreased by 2.20 % and 14.00%, respectively, and the corresponding water use efficiency was decreased by 4.55% and 9.74%, respectively. The low farmland water level could decrease the yield reduction effect due to the nitrogen reduction, which increased the yield and nitrogen partial factor productivity of winter wheat by 3.98% and 23.49%, respectively.The higher the farmland water level was, the greater the comprehensive waterlogging degree during the water control period was, and the lower the yield was.In addition, short-term waterlogging had a positive effect on increasing the crude protein content of grains, as the crude protein content of each treatment was increased by 11.50%~20.21% compared with that of the control treatment. Aiming at high yield, high efficiency, pollution reduction and quality improvement,it was recommended that the farmland water level should be lowered to -80cm in 3 days after the winter wheat suffered from waterlogging with 5cm water layer for 1day at winter wheat jointing and booting stage, and the nitrogen application rate should be 220kg/hm2. The research results can provide a theoretical basis for the winter wheat planting and waterlogging disasters restoration in southern China and similar waterloggingprone agricultural areas.