密度及覆盖方式对直播当归农艺性状和产量的影响

通过覆盖方式和密度对直播当归农艺性状和产量的影响研究，结果表明，采用麦草覆盖对直播当归农艺性状和产量的促进效应显著大于覆盖柴胡秆和覆盖地膜的效应；当归地上部鲜干重、单株叶数、根粗、根长、单根鲜干重随密度增加而降低，低密度44.4万株/hm2下直播当归生物量最高；覆盖方式和密度对当归生长有显著互作效应，覆盖麦草方式与低密度44.4万株/hm2配合时直播当归单根鲜重14.70 g、干重4.73 g、产量6690 kg/hm2，均为最高。

Effects of Density and Mulching Method on Agronomic Characters and Yield of Angelica sinensis Direct Seeding

The effects of mulching method and plant density on agronomic characters and yield of Angelica sinensis direct seeding was studied . The densities were 30 000 plants/hm2, 38 000 plants/hm2 and 53 000 plants/hm2 . The split plot design was adopted in the experiment . The results showed that promoting effects of mulching straw of wheat after seeding were significant on the agronomic characters and yield of Angelica sinensis. The root diameter, root length, root fresh weight and dry weight were increased whith densities decreased . The biomasses of Angelica sinensis were the highest by 444 000 plants/hm2 applied . The conclusion was that mulching straw of wheat combined with 444 000 plants/hm2 were must applied after Angelica Sinensis direct seeding to obtain high root fresh weight, dry weight and yield, and they were 14.70 g, 4.73 g and 6 690 kg/hm2.