关键词: 三七, 三七, 重金属, 土壤, 富集, 转运

Abstract: Farmland return for planting trees and grasses is the center of the ecological construction, and is beginning to be carried out in the western development in China. Planting trees and grasses will bring a good material condition for the western husbandry development. It was suggested that the western husbandry should greatly be developing with planting trees and grasses, building a good ecological mechanism. Their combination will increase the stability of Agricultural ecological systems , relieve the production pressure of north grasslands for quickly renewing and protecting them. Moreover, it coincides with the strategy structure adjustment of national and western agricultures, to adapt to international competition after China joins in the World Trade Organization (WTO).