紫云英在我区引种获得成功后,推广发展很快,年种植80万亩左右,深受群众欢迎。以往在提高紫云英鲜草产量的施肥措施中对磷肥施用较为重视,至于是否需要追施氮肥,用量多少,追施时间及增产机制不甚明了。本文主要研究追施氮肥对提高紫云英产草量的有关效应及其对根瘤固氮的影响,为生产应用提供措施与依据。 After the introduction of Swire in our region was successful, the promotion of rapid development, planting about 800000 acres, welcomed by the masses. In the past to improve the yield of fresh milk vetch applied fertilization measures more emphasis on the application of phosphate fertilizer, as to whether the need for topdressing nitrogen fertilizer, dosage, chase time and yield mechanism is not clear. In this paper, we mainly study the effects of topdressing nitrogen fertilizer on increasing the yield of Astragalus sinicus and its effect on nitrogen fixation of nodules, and provide measures and basis for production and application.