沿黄灌区水肥一体化条件下玉米水氮优化研究

Optimization of maize water and nitrogen under the condition of integrated water and fertilizer in the irrigation area along the Yellow River

为进一步提高黄河南岸灌区水氮利用效率,实现农田水肥深度节约的目标,于2023年在鄂尔多斯市杭锦旗吉日嘎朗图镇开展了滴灌条件水氮调控试验,研究了滴灌条件下不同水氮处理对玉米产量及水氮利用效率的影响并进行了水氮用量优化。结果表明:同一灌水条件下,中氮处理玉米产量较低氮处理增加23.3%、水分利用效率增加7.14%、氮肥偏生产力降低18.3%,较高氮处理玉米产量增加2.8%、水分利用效率增加7.7%、氮肥偏生产力增加38.1%。同一施肥条件下,中水处理玉米产量较低水处理增加37.1%、水分利用效率增加26.1%、氮肥偏生产力增加16.6%,较高水处理玉米产量增加12.8%、水分利用效率增加38.3%、氮肥偏生产力增加12.9%。建立灌水量、施氮量与玉米产量、水分利用效率、氮肥偏生产力之间的三组回归模型,通过寻优得到三组水氮区间并取交集,获得同时满足高产、高水氮利用效率的全生育期水氮总用量优化区间为1800~2046 m ^(3)·hm^(-2)与210~249.2 kg·hm^(-2)。引用以Jensen模型为基础的水氮生产函数对生育期水氮总用量优化区间进行了各生育期分配,合理分配了滴灌条件下各生育期水氮制度。研究成果可为沿黄南岸灌区玉米种植水肥管理模式和方案提供参考。

To further enhance water and nitrogen use efficiency in the irrigation areas on the southern bank of the Yellow River and achieve the goal of significant water and fertilizer conservation in farmland,an experiment on groundwater nitrogen control under drip irrigation was conducted in Garangtu Town,Hangjin Banner,Ordos City,in 2023.The study examined the effects of various water and nitrogen treatments on maize yield and water and nitrogen use efficiency under drip irrigation,with the aim of optimizing the water and nitrogen application rates.The results showed under the medium nitrogen treatment the yield of maize increased by 23.3%,the water use efficiency increased by 7.14%,and the partial productivity of nitrogen fertilizer decreased by 18.3%when compared with low nitrogen treatment.When comparing with the high nitrogen treatment,the medium nitrogen treatment,the yield of maize increased by 2.8%,and the water use efficiency increased by 7.7%,and the partial productivity of nitrogen fertilizer increased by 38.1%.Under the same fertilization condition,the yield,water use efficiency and nitrogen partial productivity of maize under middle water treatment increased by 37.1%,26.1%and 16.6%when compared with low water treatment.The yield increased by 12.8%,water use efficiency and nitrogen partial productivity increased by 38.3%and 12.9%under the higher water treatment.Three sets of regression models were established between irrigation amount,nitrogen application amount,corn yield,water use efficiency and nitrogen partial productivity.Through optimization,three sets of water and nitrogen intervals were obtained,and their intersection was taken.The optimal interval of total water and nitrogen use in the growing period was 1800~2046 m^(3)·hm^(-2)and 210~249.2 kg·hm^(-2),which both met high yield and high water and nitrogen use efficiency.The water and nitrogen production function based on Jensen model was used to allocate the optimal range of total water and nitrogen consumption in each growth period,and the water and nitrogen system in each growth period under drip irrigation was rationally allocated.The research results can provide reference for water and fertilizer management models and plans for maize planting in the irrigation area along the southern bank of the Yellow River.