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氮肥利用率是关系到施肥、农产品生产和环境保护的重要指标,计算氮肥利用率的差减法与示踪法都存在有待进一步研究的问题,计算的氮肥利用率结果都偏低。分别总结了差减法和示踪法测定氮肥利用率的应用及计算方法,示踪法能够研究氮肥在土壤中的转化及移动问题,但是测定的氮肥利用率仅仅是15N的吸收利用率,是氮肥利用率的一个部分,不能代表氮肥的吸收利用率。详细论述了差减法计算氮肥利用率结果偏低的原因,还对已有的改进方法作了介绍和评述,提出了进一步改进的原则。
Nitrogen use efficiency is an important index that is related to fertilization, agricultural production and environmental protection. There are some problems that need to be further studied to calculate the difference of nitrogen use efficiency and tracer method. The calculated results of nitrogen use efficiency are low. The applications and calculation methods of difference and tracer methods to determine nitrogen use efficiency are summarized respectively. Tracer method can study the conversion and movement of nitrogen fertilizers in soils. However, the measured nitrogen use efficiency is only 15N, A part of utilization, can not represent the absorption and utilization of nitrogen fertilizer. The reasons for the low yield of nitrogen fertilizer calculated by the subtraction method are discussed in detail. The existing methods of improvement are introduced and reviewed, and the principle of further improvement is put forward.