施氮量对旱地小麦氮素吸收转运和土壤硝态氮含量的影响

【目的】在黄淮冬麦区，研究施氮量对旱地小麦氮素利用规律的影响，为该区旱地小麦合理的氮肥运筹提供理论依据。【方法】于2009-2010和2010-2011两个小麦生长季，在大田条件下设置6个施氮量处理（0、90、120、150、180和210 kg•hm-2），研究施氮量对旱地小麦氮素吸收转运和土壤硝态氮含量的影响。【结果】在150 kg•hm-2及以下的处理增加施氮量，小麦各生育时期植株氮素积累量、成熟期籽粒氮素积累量、开花前吸收氮素向籽粒的转运量和开花后氮素吸收量显著增加；在150 kg•hm-2基础上增加施氮量，小麦各生育时期植株氮素积累量、开花前吸收氮素向籽粒的转运量和开花后氮素吸收量与150 kg•hm-2处理无显著差异，成熟期籽粒氮素积累量及分配比例降低，营养器官氮素积累量及分配比例升高。施氮量为180 kg•hm-2和210 kg•hm-2，成熟期0-140 cm土层土壤硝态氮含量显著高于150 kg•hm-2处理，深层土壤硝态氮含量增加。施氮150 kg•hm-2处理小麦籽粒产量最高，氮素利用效率和氮肥生产效率较高。【结论】本试验条件下，施氮量为150 kg•hm-2，是兼顾产量和氮肥利用效率的适宜施氮量。

Effects of Nitrogen Fertilizer Application Rate on Nitrogen Absorption,Translocation and Nitrate Nitrogen Content in Soil of Dryland Wheat

【Objective】The objective of this experiment was to study the effects of nitrogen fertilizer application rate on the nitrogen utilization regulation in Yellow and Huaihe River valleys, and to provide a scientific basis for rational nitrogen application in this area.【Method】The experiment was conducted to determine the effects of nitrogen fertilizer application rate on nitrogen absorption, translocation and nitrate nitrogen content in soil of dryland wheat by using six nitrogen levels of 0 (control), 90 kg•hm-2, 120 kg•hm-2, 150 kg•hm-2, 180 kg•hm-2, and 210 kg•hm-2, respectively, under field conditions in 2009-2010 and 2010-2011 wheat growing seasons. 【Result】 The results showed that nitrogen accumulation amount at various growth stages, nitrogen accumulation amount in grain at maturity, N translocation amount from absorbed N before anthesis to grain and nitrogen absorption amount after anthesis were significantly increased as nitrogen fertilizer application rate was lower than 150 kg•hm-2. As nitrogen fertilizer application rate was increased based on 150 kg•hm-2, nitrogen accumulation amount at various growth stages, N translocation amount from absorbed N before anthesis to grain and nitrogen absorption amount after anthesis had no significant difference with those of nitrogen fertilizer application rate 150 kg•hm-2, nitrogen accumulation amount in grain and its ratio were decreased whereas nitrogen accumulation amount in vegetative organs and its ratio were increased. When nitrogen fertilizer application rate was increased to 180 kg•hm-2 and 210 kg•hm-2, the nitrate nitrogen contents in 0-140 cm soil layers at maturity were significantly higher than those of 150 kg•hm-2, and the nitrate nitrogen content at deeper soil layers were also increased. Nitrogen fertilizer application rate of 150 kg•hm-2 treatment gained the highest grain yield, as well as relatively high nitrogen use efficiency and nitrogen productive efficiency.【Conclusion】N application at 150 kg•hm-2 was considered to be optimum under the experimental conditions.