水氮量对小麦／玉米间作土壤硝态氮累积和水氮利用效率的影响

Effects of nitrogen fertilizer application and irrigationlevel on soil nitrate nitrogen accumulation and water and nitrogen use efficiency for wheat/maize intercropping

为了提高氮肥和水分利用效率,该文在甘肃河西灌区试验地点,采用田间小区试验,研究了不同氮水平(0、225、450kg/hm2)和灌水量(750、1125、1500m3/hm2)对小麦/玉米间作土壤硝态氮累积和水氮利用效率的影响。结果表明,不同氮肥和灌水量对小麦带土壤硝态氮含量和累积量影响较小,对玉米带影响显著。随氮肥用量增加,玉米带土壤硝态氮含量和累积量增加,随灌水量和氮肥用量增加,0～60cm土壤硝态氮相对累积量增加,60～140cm土层降低。氮肥当季利用率、氮肥生产率、氮肥产投比都是以225kg/hm2氮水平较高,但不同灌水量差别不大。WUE(水分利用效率)以W750N225最高,W1500N0最低,随灌水量增加WUE降低。

In order to improve nitrogen and water use efficiency, effects of nitrogen fertilizer application and irrigation level on soil nitrate nitrogen accumulation and water and nitrogen use efficiency for wheat/maize intercropping were conducted in Hexi corridor of Gansu Province with three nitrogen rates （0, 225 and 450 kg/hm^2 ） and three irrigation levels （750, 1125, 1500 m^3/hm^2）. The results showed that irrigation level and nitrogen rate affected little on nitrate nitrogen accumulation of wheat strip, yet significantly affected maize strip. With the increase of nitrogen rate, nitrate nitrogen accumulation of maize strip increased .With the increase of irrigation level and nitrogen rate, relative nitrate nitrogen of soil in 0-60 layer increased, and that of soil in 60-140 cm decreased. Apparent nitrogen utilization rate by plant, nitrogen production rate and the ratio of output to input were the biggest at 225 kg/hm^2 of nitrogen rate, but there was no significance among different irrigation levels. Water use efficiency was the highest at W750N225, and lowest at W1500N0. With the increase of irrigation level, water use efficiency decreased.