浅埋滴灌水氮运筹对春玉米产量及水分利用效率的影响

采用二因素二次饱和D-最优设计，于2016-2017年在辽西半干旱区移动遮雨棚内进行了水氮精量控制试验，设灌溉量和施氮量2个因素，灌溉量分别设145.4、271.7、348.2、436.2 mm 4个水平，施氮量分别设0、84.6、136.1、195.0 kg·hm^-2 4个水平，共6个处理。试验分析了水氮交互作用对春玉米产量和水分利用效率的影响，建立了产量回归模型。研究结果表明：浅埋滴灌条件下，灌溉量在145.4~350.5 mm时，春玉米产量随灌溉量的增加而增高至11 005.60 kg·hm^-2；灌溉量在350.5~436.2 mm时，产量随灌溉量的增加而降低至10 730.09 kg·hm^-2；施氮量在0~146.9 kg·hm^-2时，产量随施氮量的增加而增高至10 983.19 kg·hm^-2，施氮量在146.9~195.0 kg·hm^-2时，产量随施氮量的增加而降低至10 862.39 kg·hm^-2。灌溉量因素的影响大于施氮量，水氮之间有明显的正向交互效应，当灌溉量为373.1 mm，施氮量为165.6 kg·hm^-2时产量最高。作物耗水量在拔节-抽雄期和灌浆-收获期较大，分别为115.64、127.50 mm；水分利用效率随灌溉量的增加呈逐渐降低趋势，降低幅度达到52.21%，随着施氮量的增加则呈先升高后降低趋势，增幅为14.73%~20.08%；其中处理6（灌溉量348.2 mm，施氮量195.0 kg·hm^-2)最利于水分利用效率的提高。综合产量和水分利用效率两方面的因素，初步建立了春玉米浅埋滴灌水氮施用优化模式，参数组合为灌溉量348.2 mm、施氮量165.6 kg·hm^-2。

Effects of water and nitrogen management on yield and water use efficiency of spring maize under shallow-buried drip irrigation

A two-factor quadratic saturation D-optimum design was used to carry out water and nitrogen precisely controlled experiment in a mobile shelter in semi-arid area of western Liaoning Province during 2016 to 2017. There were two factors, irrigation and nitrogen (N) applications. The irrigation rates were 145.4, 271.7, 348.2 and 436.2 mm, and the nitrogen application rates were 0, 84.6, 136.1 and 195.0 kg·hm^-2, respectively, and there were totally 6 treatments. The effects of water and N interaction on yield and water use efficiency were analyzed and a regression model for yield was established. The results showed that the yield of spring maize increased to 11 005.60 kg·hm^-2 with the increase in water when the irrigation quantity was between 145.4~350.5 mm, and it decreased to 10 730.09 kg·hm^-2 with the increase of water when the irrigation quantity was 350.5~436.2 mm. When the amount of nitrogen was 0 to 146.9 kg·hm^-2, the yield increased to 10 983.19 kg·hm^-2 with the increase in N application. When the amount of N was 146.9 to 195.0 kg·hm^-2, the yield reduced to 10 862.39 kg·hm^-2 with the increase in N application. The effect of irrigation was greater than that of N application, there was an obvious positive interaction effect between the two factors, when the irrigation was 373.1 mm and the N application was 165.6 kg·hm^-2, the yield reached the highest. Crop water consumptions were greater in the jointing-tasseling and the filling-harvesting periods, which were 115.64 mm and 127.50 mm, respectively. Water use efficiency decreased with the increase in irrigation, and decreased up to 52.21%. However, water use efficiency increased first and then decreased with the increase in N application, and it increased in 14.73%~20.08%. Treatment 6 (irrigation volume 348.2 mm, N application 195.0 kg·hm^-2) was most conducive to the improvement of water use efficiency. Based on the results of both yield and water use efficiency, the suitable water-N application pattern for shallow-buried drip irrigation of spring maize was established and the optimum parameters of irrigation amount was 348.2 mm and N application rate was 165.6 kg·hm^-2.