不同水分和氮肥水平对冬小麦吸收肥料氮的影响

THE FATE OF FERTILIZER NITROGEN IN WINTER WHEAT UNDER DIFFERENT WATER AND NITROGEN LEVELS

田间微区条件下用15N研究了不同水分和氮肥水平对冬小麦氮素吸收及化肥氮的去向。结果表明 ,4次灌水省肥处理的全氮吸收量高于节水省肥处理 ,节水常规施肥量处理的全氮吸收量高于省肥处理 ,但小麦籽粒氮素收获指数降低。 4次灌水处理的肥料氮损失率提高 ,氮肥当季利用率和土壤残留率均低于 2次灌水的相应氮肥处理。同一水分条件下 ,常规施肥量处理的氮肥当季利用率和土壤残留率低于省肥处理 ,损失率提高。等量氮肥不同施肥方法间的比较 ,全部基施处理的损失率下降 。

N uptake and the fate of fertilizer N were studied in the field under different water and nitrogen levels with 15 N technique.Results showed that (1)the total N uptake of economical N treatment under saving irrigation was higher than that under conventional irrigation.Under saving irrigation the total N uptake of conventional N was higher than that of economical N treatment,yet the NHI decreased;(2)compared with saving irrigation,the N loss of conventional irrigation increased and NUE and soil residue decreased.On the same water condition the NUE and soil residue of conventional N treatment was lower than that of economical treatment,and N loss increased;(3)for the same fertilizer amount,the loss of N applied all as basal fertilizer is lower than that of part as basal and part as top dressing treatment.