作物N、P、K含量对于平衡施肥的诊断意义

Diagnosis of balanced fertilization by N,P,K contents in grain and straw of wheat and maize

利用在河南封丘潮土进行的长期肥料试验,以NPK处理为参照,分析肥料N、P、K不同配比处理的小麦、玉米子粒和秸秆中N、P、K含量变化。结果表明,小麦和玉米子粒或秸秆中N、P、K含量或比值可以很好地反映提供给小麦和玉米的N、P、K养分是否均衡。因此,通过作物收获物养分含量和比值及其产量分析,有可能为施肥是否满足作物对养分的均衡需求提供一个诊断标准,为下一季同一作物的施肥提供依据。文章还提出了制定相对参照标准的可能途径。

A key issue to raise nutrient utilization efficiency and to mitigate environmental impact of fertilization is to balance the supplies of nutrients for crop growth. Techniques for balanced fertilization have been well developed, for instance, soil testing and plant analyses. The aims of balanced fertilization are not only to balance nutrient input into and output from soil, but also to balance nutrient supplies for crop growth. However, indicators have not been developed to diagnose whether supplied nutrients are balanced or not for crop growth. We analyzed the N, P, K contents in grain and straw of wheat and maize harvested from a long-term fertilizer experiment located at the Fengqiu Ecological Experimental Station, Chinese Academy of Sciences. The results showed that the contents of N, P, and K in grain and straw of wheat and maize well reflected the balance status of N, P, and K supplies. Thus the analyses of nutrient contents would be able to diagnose whether the fertilization was balanced or not and to recommend fertilizer application rates and ratios of N, P, and K for the next same crop. The method for establishing relative criteria was also proposed.