水分和氮肥运筹对小麦氮素吸收分配的影响

试验结果表明，两种灌溉方法下各处理之间的产量不存在显著差异，与两水处理相比，四水处理公顷穗数提高，但拔节水导致千粒重极显著降低。四水条件下小麦的氮素吸收量高于两水条件下的相应氮肥处理，而氮素生理效率降低。灌四水使氮素在小麦营养器官中的分配比例提高，两水灌溉更有利于氮素向子粒转运。各营养器官对子粒氮的贡献率依次为叶片＞茎秆＝颖壳＞叶鞘＞根系，其中叶片的氮素转移量最高，两水灌溉制度下，常规施肥量适宜于部分基施、部分于拔节期追施，而省肥用量可以考虑全部基施。

Effects of Water and Nitrogen Application on Nitrogen Uptake and Distribution in Wheat

The results of experiments showed the yield of all treatments had no significant differences.The ear per ha increased under 4 time irrigation,but grain weight per 1 000 decreased seriously.The wheat irrigated 2 time absorbed more N than that under 4 time irrigation which had the same N application,yet NPE decreased.With more water supply,the N distributed in vegetative organs was more than that in grain.After anthesis the N proportions transferred from various vegetable organs to the grains were ordered as leaf>stem=ear axis and grain husk>leaf sheath>root,among them leaf got the head of the others.Under 2 time irrigation,some N rates should be used as base N,and the others were used as dressing N.However economical nitrogen rates might all be used as base N as well.