Abstract: The root/shoot ratio,stem/leaf ratio,root contribution rate,stem contribution rate,leaf contribution rate and panicle contribution rate of oat under different planting densities were measured and calculated to explore the effects of planting density on plant height,biomass and material distribution of oat in Horqin sandy land,which provided a reference for the determination of reasonable planting density of oat in Horqin sandy land. The results showed that the plant height of oat increased gradually with the increase of planting density. Under the condition of 4.5 million·hm^-2,the plant height was the highest,92.06 cm;above ground biomass,the underground biomass and total biomass increased with the increase of density. The highest values occurred under the condition of 3.5 million·hm^-2 strains and were 2 277.32 g·m^-2,578.47 g·m^-2 and 3 022.46 g·m^-2,respectively. The root-to-shoot ratio and stem-leaf ratio of 3 million·hm^-2 plants were higher than other density treatments. There was no significant difference in stem-to-leaf ratio between the density treatments,and the root-shoot ratio of 3 million·hm^-2 plants was significantly higher than other density treatments. There was no significant difference in leaf contribution rate and culm contribution rate among the density treatments,but the root contribution rate under the condition of 3 million·hm^-2 plants was significantly greater. The content of soluble sugar and starch in roots,stems and leaves reached the maximum under the condition of 3.5 million·hm^-2,and the content of crude fat and crude protein in leaves decreased gradually with the increase of density. The maximum values were 16.02% and 5.66% respectively. Therefore,it is suggested that the planting density of oat in Horqin Sandy Land should be 3.5 millon·hm^-2.

Key words: Avena sativa, Density, Output, Material distribution, Horqin sandy land

摘要： 通过对不同种植密度条件下燕麦株高、根、茎、叶、穗生物量测定，计算根冠比、茎叶比、根系贡献率、茎秆贡献率、叶片贡献率、穗贡献率等相关指标，探讨种植密度对沙地燕麦株高、生物量和物质分配规律的影响，为科尔沁沙地燕麦合理种植密度的确定提供参考。结果表明：燕麦株高随着种植密度增加呈现逐渐增加的变化趋势，450万株·hm^-2条件下株高最高，其值为92.06 cm；地上生物量、地下生物量和总生物量均随密度增加呈现先升高后降低的变化趋势，最高值均出现在350万株·hm^-2条件下，分别为2 277.32 g·m^-2，578.47 g·m^-2，3 022.46 g·m^-2；300万株·hm^-2条件下根冠比和茎叶比均高于其他密度条件下，其中密度处理之间茎叶比差异不显著，300万株·hm^-2条件下根冠比显著高于其它密度处理；叶片贡献率和茎秆贡献率各密度处理之间没有显著差异，300万株·hm^-2条件下根系贡献率显著高于400万株·hm^-2，根茎叶中可溶性糖、淀粉含量在350万株·hm^-2条件下达到最大值，叶片中粗脂肪、粗蛋白含量随密度增加呈逐渐降低的变化趋势，最大值分别为16.02%，5.66%。因此，综合考虑，以饲用为主要目的建议科尔沁沙地燕麦种植密度350万株·hm^-2。

关键词: 燕麦, 密度, 产量, 物质分配, 科尔沁沙地