水氮互作对冬小麦水肥利用效率与经济效益的影响

Effects of Irrigation and Nitrogen Interaction on Water and Fertilizer Use Efficiency and Economic Benefits of Winter Wheat

摘要:

为探索冬小麦最佳的水肥管理制度，采用田间试验方法，在低水I1（60%ETc，300.0mm）、中水I2(75%ETc，370.0mm)、高水I3(ETc，495.0mm）3种灌溉下，设置低氮N1（180.0kg/hm2）、中氮N2（255.0kg/hm2）、高氮N3（330.0kg/hm2）3种施氮水平，测定不同生育期小麦土壤含水率、地上干物质累积量与最终产量指标，并计算农田耗水量、水分利用效率、氮肥偏生产力、经济效益等指标，分析水肥耦合对各指标的影响。结果表明，灌溉量对农田耗水量影响显著，农田耗水量随灌溉定额的增加而增加；适当的水肥配比可获得较高的地上干物质累积量、产量和经济效益，过量的水肥投入并不会使产量和经济效益持续增加；产量、水分利用效率、氮肥偏生产力、经济效益与灌溉量、施氮量的相关性显著，建立了各指标与灌溉量、施氮量的二次回归方程，计算得到各指标最大值对应的水氮量分别为410.0mm、260.0kg/hm2，370.0mm、260.0kg/hm2，410.0mm、180.0kg/hm2，400.0mm、250.0kg/hm2；通过回归与空间分析得出，灌溉量为359.8~428.9mm (72.6%ETc~87.5%ETc)、氮肥量为225.4~280.9kg/hm2时，冬小麦产量、水分利用效率和经济效益可同时达到最大值的95%以上。本研究可为研究区及其他环境相似地区的水肥制度优化与管理提供参考。

关键词:冬小麦;水氮互作;耗水量;产量;水肥利用效率;经济效益

Abstract:

To find out the optimized water and fertilizer management, field experiments were conducted to investigate the coupling effects of different amounts of water and fertilizers on water consumption, dry matter accumulation on the ground, wheat yield, water use efficiency, nitrogen partial fertilizer productivity as well as economic benefits. Experiments included three levels of irrigation, i.e. 60%ETc (I1, 300.0mm), 75%ETc(I2, 370.0mm) and ETc (I3, 495.0mm), and three levels of nitrogen, i.e. 180.0kg/hm2 (N1), 255.0kg/hm2 (N2) and 330.0kg/hm2 (N3). The irrigation had a significant effect on the water consumption, and water consumption was increased with the increase of irrigation quota. Only appropriate water and fertilizer ratio can obtain higher dry matter accumulation on the ground, yield and economic benefits, and excessive water and fertilizer input would not increase sustainable output and income. Yield, water use efficiency, nitrogen partial fertilizer productivity and economic benefits had significant correlation with water and fertilizer. The quadratic regression equations of each index and water and fertilizer were established and the corresponding water and fertilizer amount of the maximum value of each index was 410.0mm, 260.0kg/hm2, 370.0mm, 260.0kg/hm2, 410.0mm, 180.0kg/hm2, 400.0mm, 250.0kg/hm2, respectively. By regression and spatial analysis, it was concluded that the yield, water use efficiency and economic benefits reached no less than 95% of their maximum values simultaneously when the irrigation quantity was 359.8~428.9mm (72.6%ETc~87.5%ETc) and the nitrogen application was 225.4~280.9kg/hm2, which can provide a scientific basis for irrigation and fertilization optimization in study area and other regions with similar environments.

Key words:winter wheat;water and nitrogen interaction;water consumption;yield;water and fertilizer utilization efficiency;economic benefits