供氮水平和有机无机配施对夏玉米氮利用效率的影响

通过大田试验研究了不同氮素水平下有机无机肥料配施对夏玉米氮利用效率的影响。结果表明，氮素肥料的各去向受施氮量影响较大，施氮量越大，表观残留量、淋溶损失量、气态损失量均增加。表观利用率在施氮低于200 kg/hm2时，表现为增加，高于200 kg/hm2时，则表现为减少。配施有机肥比例越大，表观利用率、表观淋溶损失率越小，表观残留率则越大。气态损失率在有机无机配施条件下最小。淋溶损失是氮素肥料的主要损失途径。综合考虑，氮肥表观利用量、表观残留量和淋溶损失量，以纯氮施入量200 kg/hm2，75%的N由有机肥提供、25%的N由尿素提供的处理为较理想的氮素施用水平和配比组合。

Effects of Nitrogen Fertilizer Rate and Combined Application of Organic Manure and Chemical Fertilizer on Yield in Summer Maize and on Nitrogen Utilization Efficiency

A field experiment was carried out to study the influence of combined application of organic and chemical fertilizer under different nitrogen levels on yield in Summer Maize and on nitrogen utilization efficiency.The results showed that:the impact of nitrogen application rate on the directions of nitrogen fertilizers was great.The more of nitrogen application rate,the number of the apparent residue rate,leaching loss and gaseous loss all were increaser.When nitrogen fertilizer rate under the level of 200 kg...