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３年小麦／玉米带田定位试验研究明确了①每公顷总量分别为４５０、９００和１３５０ｋｇＮ的氮肥第１年一次性施用和分年施用的增产效果，每公顷４５０ｋｇ左右Ｎ为带田适宜施氮量；②一次性施用氮肥后的残效、影响残效大小及持续性的主要因素是氮肥用量及土壤保肥性；③不同用量及不同分配方式氮肥的当年利用率比累积利用率低５．７％～２．０％，评价氮肥利用率的高低时，应将残效考虑在内；④等量氮肥分年施用与一次性施用相比，增产效果及氮肥利用率高得多
3 years of wheat / corn belt field positioning test clear ① the total amount per hectare of 450,900 and 1350kgN nitrogen fertilizer in the first year of single-time application and annual application of about 450kg per hectare N is appropriate Nitrogen content; ② After a one-time application of nitrogen fertilizers, the main factors that affect the residual size and sustainability are the amount of nitrogen fertilizer and soil fertility conservation; ③ The utilization of nitrogen fertilizer in different dosage and different ways of allocation is lower than the cumulative utilization rate of 5.7 % ~ 2.0%. When assessing the level of nitrogen use efficiency, the residual effect should be taken into account. ④ The annual yield increase and nitrogen use efficiency of the same amount of nitrogen fertilizer are much higher than that of one-time application