运用同位素^(15)N研究冬小麦不同时期追施尿素的效果及氮肥的利用率

Use the Isotope ^(15)N to Study the Effect of Urea Application as Top Dressing at Different Growth Stage of Winter Wheat and the Nitrogen Fertilizer Efficiency

本文运用同位素15N,对冬小麦不同追肥时期的效果 ,氮肥的利用率 ,氮素在秸杆、籽粒中的分配、土壤残留、挥发损失进行了研究。结果表明 :拔节期追肥一次 ,再加上追施穗肥一次效果最好 ;前期追肥 ,秸杆对 N的利用率高 ,籽粒对 N的利用率低 ;后期追肥 ,籽粒对 N的利用率高 ,秸杆对 N的利用率低 ;前后期结合追肥比一次追肥土壤氮素残留量高 ,损失较少。

The study of urea dressing with isotope 15N at different growth stages of winter wheat was conducted at Jizhou City.That of N use efficiency,N distribution in straw and seeds,N remin in soil and N volatilization loss was studied.The results showed:There was high N use efficiency with twice urea dressing for winter wheat,once at shooting stage,another at filling stage.The straw had higher N use effciency with urea dressing at shooting stage.And the seeds had higher N use efficiency with urea dressing at filling stage.N remained more in soil and loss less with urea dressing twice than once.