Abstract: To explore the effects of different nitrogen application rates on oats under sandy loam soil conditions,and to provide reference for the management of oat fertilizer in oats in Horqin Sandy Land,we tested oat (Avena sativa L.) plant height,aboveground biomass,underground biomass,total biomass,and root/shoot ratio,stem/leaf ratio,leaf contribution rate,stem contribution rate,root contribution rate and spike contribution rate under different Nitrogen fertilizer application levels. The results showed that the oat plant height,aboveground biomass,total biomass with the increase of nitrogen showed a trend of decrease after the first increase,they reached the highest values in N3 (375 kg·hm^-2),respectively:90.6 cm,1878.6 g·m^-2,2 341.2 g·m^-2;There are different fertilization gradients between leaf contribution rate,spike contribution rate,root contribution rate,stem/leaf ratio and root/shoot ratio,but there was no significant differences in stem contribution rate;with the increase of fertilizer application rate,leaf contribution rate and spike contribution rate increased first and then decreased,which suggested the best nitrogen fertilizer for oats is 375 kg·hm^-2,the range of nitrogen application ranged from 300~450 kg·hm^-2in Horqin sandy land.

Key words: Avena sativa L., Biomass, Plant height, Contribution rate, Nitrogen fertilizer

摘要： 在科尔沁沙地研究不同施氮条件下燕麦（Avena sativa L.）株高、地上生物量、地下生物量、总生物量，以及根冠比、茎叶比、叶片贡献率、茎秆贡献率、根系贡献率和穗贡献率等相关指标，探讨沙壤土条件下不同施氮量对燕麦的影响，为科尔沁沙地燕麦氮肥管理提供参考。结果表明：燕麦株高、地上生物量、总生物量随着施氮量增加呈现先增加后降低的变化趋势，均在N3（375 kg·hm^-2）达到最高值，值分别为：90.6 cm，1 878.6 g·m^-2，2 341.2 g·m^-2；不同施肥梯度之间叶片贡献率、穗贡献率、根系贡献率、茎叶比、根冠比均表现出一定差异，而茎秆贡献率差异不显著；其中，随着施肥量的增加，叶片贡献率和穗贡献率均呈现先增加后降低的变化趋势；建议本试验条件下，燕麦最佳追施氮肥量375 kg·hm^-2，追施氮肥范围300~450 kg·hm^-2之间。

关键词: 燕麦, 生物量, 株高, 贡献率, 氮肥