秸秆还田配施氮肥对土壤水肥状况和玉米产量的影响

本文主要围绕宁夏中部干旱区土壤贫瘠、肥力低下等问题开展研究.在玉米秸秆全量(9000 kg·hm^-2)还田条件下,设3种纯氮施用水平(150、300、450 kg·hm^-2),以秸秆还田不施氮肥处理为对照,研究秸秆还田配施氮肥对土壤水肥状况和玉米产量的影响,以探寻该区秸秆还田条件下氮肥的合理用量.结果表明: 在玉米生育中后期,施纯氮300和450 kg·hm^-2处理使0～100 cm 层土壤贮水量分别较对照显著提高10.1%和9.0%;施纯氮300 kg·hm^-2处理改善土壤肥力效果最优,其土壤有机质、全氮、碱解氮、有效磷、速效钾含量分别较对照提高12.8%、31.6%、11.6%、20.6%、74.2%.玉米籽粒以施纯氮300和450 kg·hm^-2处理增产效果最佳,分别较对照增产32.1%、23.7%.施纯氮300和450 kg·hm^-2处理的纯收入分别较对照提高31.8%和16.8%.在宁夏中部干旱区,秸秆还田配施适量氮肥可改善土壤水肥状况,实现玉米增产增收.试验以秸秆还田配施纯氮300 kg·hm^-2效果最为显著.

Effects of returning straw with nitrogen application on soil water and nutrient status,and yield of maize

The study focused on the problems of lean soil and low fertility in arid area of central Ningxia. To explore the optimum rate of nitrogen (N) fertilizer application under straw returning, taking the treatment with straw return and no nitrogen fertilization as control, we investigated the effects of three N application levels (150, 300, 450 kg·hm^-2) with return of total maize straw (9000 kg·hm^-2) on soil water and nutrient status and maize yield. The results showed that the soil water storage (0-100 cm) at 300 and 450 kg N·hm^-2 in middle and late growing period of maize was significantly increased by 10.1% and 9.0%. The enhancement of soil fertility was highest at 300 kg N·hm^-2, with significant increases of the contents of soil organic matter, total N, alkali-hydrolyzable-N, available P, and available K by 12.8%, 31.6%, 11.6%, 20.6% and 74.2%, respectively. The enhancement of maize grain yield was highest at 300 and 450 kg N·hm^-2, with the value being 32.1% and 23.7%, respectively. The net income at 300 and 450 kg·hm^-2 N was significantly increased by 31.8% and 16.8%, respectively. Our results showed that straw returning plus proper quantity of N fertilizer could improve soil water and fertilizer status and enhance maize yield and net income in arid area of central Ningxia. The treatment of straw returning with 300 kg·hm^-2 N was the best one.