Primary Study Of The Soil And Water Conversation Effect And Ecosystem Effect About Feeding Grass

This experiment researched relative effects in two different terrains, one of that was the Soil and water conversation study about Grass on slope. Establishing the regulation which grass obstructed runoffs and sediments in different stages of grass growth and analyzing important influence factorizations, including slope, rainfall intensity, degree of cover, by proceeding experiment about Soil and water conversation grass on slope of eight degree and fifteen degree. The other was the study of yield and soil physics and chemistry kinds effects. According to the native economy Developments, we choosed the leaving farmland which had been low but unsteady level in native yield to study grass's adaptability, growth and the influence of the soil physics and chemistry kind. The results showed that:(1)The amount of runoffs and bedloads is a joint result of rain,soil,plants and terrain, along with the growth of herding grass, the function of cumulating water and protecting soil would produce quickly. The output of runoffs and sediments were more, when the slope was more heavy, rainfall intensity was stronger, degree of cover was lower. In whole growth process of grasses, the result of cumulating water and protecting soil was 8° Medicago sativa L. >8° Astragalus adsurgens Pall. >8° weed >8° check naked slope > 15° Medicago sativa L. >15° Astragalus adsurgens Pall. >15° weed >15° check naked slope.(2) On the leaving farmland, by surviving the seedling out rate, the feeding grass surviving rate, reviving rate, growth speed, tillering numbers, cluster measurement, degree of cover, root measurement, root Weight, fresh grass yield and hay yield, and so on, four kinds of feeding grasses which were Medicago sativa L., Dactylis glomerata L., Cichorium intybus L. , Astragalus adsurgens Pall., were confirmed that can adapt the native ecosystem term and acquire good economic benefits in that year ; Bromus inermis Leyss. growed slowly in the first year, but Behaved well in the next year; Silpniumperfoliatum L. Behaved badly by now, and had to observe if it can succeed in the indraught.(3) On the leaving farmland, by contrasting and analyzing the soil water content, we made a conclusion that different feeding grasses consumed the soil water content differently, the mount from large to small was Dactylis glomerata L.> Astragalus adsurgens Pall. >weed> Bromus inermis Leyss.> Medicago sativa L. > Silpniumperfoliatum L. > Cichorium intybus L.; To the pH analysis of Variance, we got mostly feeding grasses make the soil pH lower; By the analysis of Variance about soil organic matter,, whole N, valid N, valid P, valid K, we concluded that in the process of feeding grasses' growth, feeding grasses consumed the soil fertility, among them, soil organic matter, whole N, valid N consumed more, valid P, valid K less. Because of short time, we have not study if soil fertility could come back or advance after withered and defoliation and part of herding grass returned to the soil and decomposed.