地膜玉米免耕轮作春小麦水氮生产力对灌水施氮水平的响应

针对绿洲灌区春小麦生产中水氮消耗量大、连作普遍问题,2015-2018年,在河西走廊甘肃农业大学绿洲试验站进行田间试验,设两种耕作措施(玉米茬免耕一膜两年用,NT;玉米茬传统翻耕,CT)、两种灌水水平(2400m^3·hm^-2,传统水平,I2;1920m^3·hm^-2,传统灌水减量20%,I1)和三种施氮水平(225kg·hm^-2,传统施氮,N3;180kg·hm^-2,减量20%施氮,N2;135kg·hm^-2,减量40%施氮,N1),分析了不同处理下春小麦籽粒产量、灌溉水生产力和氮肥偏生产力特征。结果表明,与CT、I2相比,NT和I1均能提高春小麦的籽粒产量、灌溉水生产力和氮肥偏生产力;与N3相比,N2的氮肥偏生产力提高11.6%~30.4%,籽粒产量和灌溉水生产力在2016、2017年均无显著变化,在2018年分别降低10.7%和10.4%;N1的籽粒产量降低6.1%~23.5%,灌溉水生产力和氮肥偏生产力分别增加6.1%~23.0%和27.6%~56.5%。在所有处理中,NTI1N2和NTI2N3处理的籽粒产量三年中均较高,二者间差异不显著,但NTI1N2处理灌溉水生产力和氮肥偏生产力较NTI2N3处理分别提高7.6%~20.4%和16.5%~30.4%;NTI1N2处理的籽粒产量、灌溉水生产力和氮肥偏生产力较CTI2N3处理分别提高3.8%~22.0%、19.7%~40.8%和29.7%~52.5%。综上所述,在西北绿洲灌区以覆膜玉米为前茬,免耕穴播小麦,配套施氮180kg·hm^-2、生育期灌水1920m^3·hm^-2的种植方式是适用于小麦节约水氮的高效生产模式。

Response of Water and Nitrogen Productivity to Irrigation and Nitrogen Application Level of Spring Wheat under No-Tillage and Rotation with Plastic Film Maize

In oasis irrigation region, the greater water and nitrogen consumption, and succession cropping are the tough issues in wheat production. Therefore, this study investigated the response of productivity and yield performance of spring wheat in different water and nitrogen levels,which was in a rotation system with the no-tillage plastic film mulching maize.The objective of this research was to provide practical basis for establishing a cost-saving wheat production system. Field experiment was carried out from 2015 to 2018 in the Hexi oasis experimental station of Gansu Agricultural University. There were two tillage patterns, including no tillage with two-year plastic film mulching maize(NT), and conventional tillage(CT); two irrigation levels, including 2 400 m·hm^-2, the conventional level(I2) and 1 920 m·hm^-2, the 20% reduction(I1); and three nitrogen rates, i.e. 225 kg·hm^-2, the traditional nitrogen rate(N3),180 kg·hm^-2,20%reduction(N2), and 135 kg·hm^-2, 40%reduction(N1). We mainly investigated the grain yield, irrigation water productivity and nitrogen partial factor productivity. The results showed that compared to CT,I2 and N1,both NT and I1 increased grain yield, irrigation water productivity and nitrogen partial factor productivity. For nitrogen rates, N2 was different from N1.N2 only enhanced nitrogen partial factor productivity by 11.6%- 30.4%, whereas, nitrogen rates had no significant effects on grain yield and irrigation water productivity in 2016 and 2017. In 2018, the grain yield and irrigation water productivity of N2 treatment was decreased by 10.7% and 10.4%, compared to N3.In contrast, N1 decreased the grain yield(by 6.1%-23.5%) and improved irrigation water productivity(6.1%-23.0%)and nitrogen partial factor productivity(27.6%-56.5%). Under all treatments,there are no significant difference on grain yield between NTI1N2 and NTI2N3, while NTI1N2 increased it by 3.8%-22.0%,compared to CTI2N3. In addition, NTI1N2 increased the water productivity by 7.6%-20.4%,compared to NTI2N3, and by 19.7%-40.8% compared to CTI2N3. Similarly, NTI1N2 increased the nitrogen partial factor productivity by 16.5%-30.4% and 29.7%-52.5%, compared to NTI2N3 and CTI2N3,respectively.Therefore, the planting mode of two-year plastic film mulching maize as the former stubble, no-tillage pointing sowing wheat combined with irrigation level at 1 920 m·hm^-2at the growth stage and nitrogen rate at 180 kg·hm^-2, could provide a feasible basis for developing a resources-investment reduced and high-efficient wheat production modein northwestern oasis irrigation region.