减氮结合不同覆盖对冬小麦产量、水氮利用及根系的影响

Effect of Nitrogen Reduction Combined with Different Cover Measures on Yield,Utilization of Water and Nitrogen and Root of Winter Wheat

【目的】研究减氮结合不同覆盖措施对黄土高原旱地冬小麦的保水增产效应,探索旱地冬小麦在减氮结合不同覆盖模式下的高产、高效与环境友好型的栽培施肥技术。【方法】于2014-2016年在陕西省永寿县进行田间试验,研究减氮结合不同覆盖措施对冬小麦产量、水氮利用效率和根系的影响。【结果】在150 kg·hm^(-2)施氮条件下,与农户减氮相比,垄覆沟播氮肥生理效率在第1年增加12%,耗水量在第2年显著增加7%;全膜穴播产量、播前贮水量和氮肥生理效率在第1年分别增加15%、15%和16%,在第2年分别增加12%、10%和35%;秸秆覆盖产量和播前贮水量在第1年分别增加9%和16%,水分利用效率和地上部吸氮量在第2年分别增加12%和17%。垄覆沟播和全膜穴播总根长在第1年分别减少35%、26%;秸秆覆盖总根干重、总根长在第1年分别减少63%、43%;第2年分别减少41%和17%。【结论】农户减氮相比农户模式冬小麦产量、水氮利用及根系生长均无显著影响。在150 kg·hm^(-2)施氮条件下,与农户减氮相比,垄覆沟播提高了氮肥生理效率和耗水量;全膜穴播显著提高冬小麦产量、播前贮水量和水分利用效率,同时能够提高对氮素的吸收和利用效率;秸秆覆盖显著提高播前贮水量和水分利用效率,进而提高冬小麦产量;垄覆沟播、全膜穴播和秸秆覆盖均显著降低冬小麦总根干重和总根长。因此,减氮结合覆盖是实现旱地冬小麦增产增效的重要措施。

【Objective】The effects of nitrogen reduction combined with different mulching methods on water-saving and yield-increasing of winter wheat were studied in dry land of Loess Plateau,to explore dry land winter wheat yielding under reduced nitrogen binding overlay mode,efficient and environmentally friendly cultivation fertilization techniques. 【Methods】A field test was conducted in Yongshou county Shaanxi province in 2014-2016 years,to determine the effects of nitrogen reduction and different mulching methods on winter wheat yield,water use efficiency and root growth. 【Result】Under the nitrogen application rate of 150 kg·hm^（-2）,compared with the household nitrogen reduction,the physiological efficiency of nitrogen fertilizer of ridge mulching and furrow sowing increased by 12 % in the first year,water consumption increased by 7 % in second year. The yield and water storage before sowing and physiological efficiency of nitrogen fertilizer of whole film mulching increased by 15 %,15 % and 16 % in the first year,while increasing by 12 %,10 % and 35 % in second year. The yield and water storage before sowing of straw mulching increased by 9 % and 16 % in the first year,water use efficiency and above-ground nitrogen uptake increased by 12 % and 17 % in the second year respectively. The total root length of ridge mulching and furrow sowing and whole film mulching decreased 35 % and 26 % in the first year. The total dry weight and total root length of straw mulching decreased 63% and 43 % in the first year,while decreasing by 41 %,10 % and 17 % in second year. 【Conclusion】Compared with the farmer model,there was no significant effect of nitrogen reduction on yield,water use and root growth of winter wheat compared with farmer model. Under the nitrogen application rate of 150 kg/hm^2. Compared with the farmer nitrogen reduction,the ridge mulching and furrow sowing increased the nitrogen fertilizer physiological efficiency and water consumption. The whole film mulching significantly increased winter wheat yield,water storage and water use efficiency,and the nitrogen absorption and utilization efficiency can be improved. Straw mulching significantly increased water storage and water use efficiency before sowing,thereby increasing winter wheat yield. Reducing total root dry weight and total root length of winter wheat by ridge mulching and furrow sowing,whole film mulching and straw mulching. Therefore,the nitrogen reduction combined with different cover measures is an important measure to achieve efficiency of dry land winter wheat yield.