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在节水灌溉的条件下,通过田间现场试验测定了冬小麦生长期田间土壤中铵氮、硝态氮含量的动态分布,分析了田间土壤中氮素的迁移转化规律,为合理施肥提供科学依据。试验结果表明,冬小麦耕层中的营养氮素含量以硝态氮为主,约占85%多,除用施肥的方法为植物生长提供一定的氮素以外,土壤本底的含量,特别是土壤中有机氮矿化后的无机氮也是植物营养氮素的一个重要来源,在节水灌溉的条件下,冬小麦生长季节硝态氮的深层渗漏微乎其微,但是冬小麦收割后根层中仍有大量的硝态氮,如不合理利用会在汛期因大量降水造成肥料的大量流失,并对地下水构成潜在的威胁。
Under the condition of water-saving irrigation, the dynamic distribution of ammonium nitrogen and nitrate nitrogen in field soil of winter wheat was measured by field experiments in field. The law of nitrogen migration and transformation in field soil was analyzed to provide scientific basis for rational fertilization. The results showed that the content of nutrient N in winter wheat plow was mainly composed of nitrate nitrogen, accounting for more than 85%. Besides the application of fertilization to provide some nitrogen for plant growth, the content of soil background, especially soil Organic nitrogen mineralized mineral nitrogen is also an important source of plant nutrient nitrogen, under the conditions of water-saving irrigation, nitrate nitrogen in the growing season of winter wheat deep leakage is minimal, but there is still a lot of post-harvest winter wheat root layer Nitrate nitrogen, if not used reasonably, will cause a large loss of fertilizer due to heavy rainfall in flood season and pose a potential threat to groundwater.