滴灌水氮耦合对水氮利用及冬小麦产量的影响

Coupling effects of water-nitrogen on water and nitrogen use efficiency and yield of winter wheat under drip irrigation

以华北地区冬小麦为试验对象,参考直径20 cm标准蒸发皿的累计水面蒸发量E,通过2 a的大田试验(2012—2013),研究了大田地表滴灌条件下水氮耦合制度对作物耗水量、作物生理指标、产量、氮残留及水氮利用效率的影响.结果表明:冬小麦生育期内的耗水量、叶面积指数及产量受灌水定额的影响更为显著(P<0.05);滴灌条件下,当施氮量在120~290 kg/hm^2时,水氮耦合效应对冬小麦耗水量的影响不具有统计学意义;在滴灌灌水定额为0.80E,施氮量为140~190 kg/hm^2的水氮耦合模式下,冬小麦的产量较高,土壤硝态氮的当季残留较少,且进一步显著增加灌水定额和氮肥投入量将导致产量的明显下降;综合考虑冬小麦水氮利用效率和对地下水的潜在淋失风险,华北典型区滴灌水氮耦合的优化组合范围宜为灌水定额为0.80E,施氮量为140~190 kg/hm^2.

With reference to the cumulative 20 cm diameter pan evaporation （E）, a field experiment was conducted for 2 consecutive years （2012-2013） to study the coupling effects of water- nitrogen on water consumption, crop physiological indexes and yield of winter wheat under drip irrigation in the North China Plain. The results show that the irrigation-scheduling had significant effects （ at 0.05 level） on water consumption, LAI and wheat yield. In a nitrogen application range of 120 to 290 kg/hm^2 with drip irrigation, water - nitrogen coupling effects had no significant influence on water consumption. At 140 - 190 kg/hm^2 with irrigation level of 0. 80E under drip irrigation, the yield was higher and residual nitrate nitrogen after one season was less. Furthermore, significant increasing in irrigation level and nitrogen level would lead to significant decline in wheat yield. Referring to guarantee yield and low environmental contamination risks, an optimized water-nitrogen combination, irrigation level of 0. 80E with nitrogen application of 140 - 190 kg/hm^2, was recommended under drip irrigation in the North China area.