氮利用率和氮转化率评价氮肥肥效比较研究

基于生态平衡施肥理论和通用施肥模型,以河南省小麦氮肥肥效试验数据为例,分别求算长期定位试验、普通田间试验、示踪试验三种情况下的肥料氮利用率和氮转化率,并进行评价,结果表明:①长期定位试验氮利用率和氮转化率都比较稳定;普通田间试验在最佳施氮情况下,氮利用率和氮转化率均与长期定位试验结果接近,但不同普通田间试验之间氮利用率变幅较大;示踪试验的氮利用率或氮转化率不能作为评价肥效和指导施肥的科学依据;②氮利用率低估了氮肥肥效;不考虑外源氮时则高估了氮肥肥效;使用氮转化率和外源氮是科学评价氮肥肥效的方法;③具体施肥实践时,可以不考虑外源氮而直接使用氮相对转化率评价肥效和指导施肥;参照长期定位试验的最佳施氮量,即使在不测定土壤氮的情况下也可以使用氮转化率半定量地指导施肥。

Comparative research of evaluation nitrogen fertilizer efficiency between nitrogen use efficiency and fertilizer yield method

Fertilizer use efficiency and N fertilizer yield were calculated and valued in long-term fertilizer experiment,common fertilizer experiment and tracing experiment using data of wheat N fertilizer efficiency experiment in Henan Province based on the ecological balanced fertilization theory and universal model.Results showed that: ① N use efficiency and N fertilizer yield were stable in long-term fertilizer experiment;N use efficiency and N fertilizer yield in common fertilizer experiment were similar with that in long-term fertilizer experiment under optimum fertilization in common fertilizer experiment,but N use efficiency varied a lot under different experiments in common fertilizer experiment;N use efficiency or fertilizer yield coming from tracing experiment can not be scientific base of evaluating fertilizer efficiency and guiding fertilization;② N use efficiency underestimated N fertilizer efficiency and overestimated N fertilizer efficiency under no considering external N;using N fertilizer yield and external N was the method of scientific evaluation N fertilizer efficiency;③ using N fertilizer relative conversion to evaluate fertilizer efficiency and guide fertilization not considering external N when concrete practicing fertilization;guidance fertilization semi-quantitatively can be realized by referencing optimum nitrogen application rate of long-term experiment even without determining soil N using N fertilizer yield.