Project Area Of ​​the Jinsha River Basin (grass) The Introduction Of Grass Seed To Soil And Water Conservation Mechanism And Effectiveness Studies

Through the project of converting cultivated land to forest and grass,it was evident that the ecological environment had been improved obviously and the economic and ecological benefits were achieved remarkably in the Jinguan Town,Yongsheng County. In order to determine the soil and water conservation mechanisms and effects of three types of introduced grasses, Pennisetum clandestinum Hochst. ex Chiov. cv. Whittet, Setaria sphacelata Stapf cv. Narok and Trifolium semipilosum cv. Safari, to ascertain whether these introduced grasses increased the economic incomes of farmers, this study adopted the simulating studies indoors and field, through comparative study of five different utilization types : three introduced grass lands , cultivated land and bare land , studied soil and water conservation mechanisms and effects and economic benefits of introduced grasses systematically in the area of returning cultivated land to forest and grass in the Jinsha River Basin of Yunnan Province.Through one-year research , the main conclusions as follows:(1)The capability of water conservation of stem leaf and litterfall of introduced grasses was closely related to biomass per unit area , and followed the linear correlation . The more the biomass was , the stronger the capability of water conservation was . The capability of water conservation decreased from Whittet, Setaria sphacelata Stapf cv. Narok to Pennisetum clandestinum Hochst. ex Chiov. cv. Whittet to Trifolium semipilosum cv. Safari.(2)Through the root exudation , root death , soil fixation of root network and the fine roots crossing each other , introduced grasses improved the soil physical and chemical properties : the introduced grasses reduced soil bulk density , enhanced soil porosity ; increased soil natural water content, capillary water content and saturated water content, enhanced the soil water-retaining capacity ; decreased soil sand grain content; increased the soil organism matter ,enhanced soil fertility ; increased initial...