冬小麦拔节期追肥与土壤湿度的生物效应

Biological effect of soil moisture and N fertilization on winter wheat at jointing stage

以冬小麦为试验材料,利用盆栽试验研究了拔节期不同土壤水分条件下不同施氮处理对其叶片光合速率、硝酸还原酶、根系长度及数目、根冠比、养分吸收及籽粒产量的影响。结果表明,在干旱条件下,不论施肥与否,适当增加土壤湿度均能改善小麦的生长状况,增加产量。在低水条件下,增加施肥量不能相应增加产量;在中、高水情况下,基肥结合拔节期追施氮肥可以促进冬小麦生长,使其籽粒产量显著提高;氮肥一次施用的效果不如基肥加拔节期追肥处理。在中水条件下,2/3氮肥基施,1/3氮肥拔节期追施是干旱地区冬小麦较佳的水肥耦合模式。

In this experiment, winter wheat was used to study the effects o f manners of applying nitrogen fertilizer on photosynthesis, activity of nitrate r eductase, morphology of seedlings, biomass yield, grain yield and some other related traits under different water conditions. The results showed that water was the restrictive factor of winter wheat, and it affected all the traits mentioned above by different degrees. The traits of wheat were improved by increasing soil moisture and applying N fertilizer. Under low soil moistare (40 %), the yield was not raised by increasing N application; Under medium moisture, it was optimal to use twothird of N as basal fertilizer and onethird of it as top dressing at jointing stage.