Effect Of Sabaigrass Cultivation On Water And Soil Conservation And Its Mechanism In Purple Soil

The water and soil erosion is the most serious problem of purple soilarea. In order to solve this problem, we find a kind of herbages plant-Sabaigrass(Eulaliopsis binata) which not only can accommodate the badly environment of purple soil but also have excellent water and soil conservation effect and good economic benefit. This study adopt quantitative and qualitative methods, through comparative study of four different utilization types: Sabaigrass treatment, grass tree solid plating treatment (planting Sabaigrass under fruit trees treatment), bare land treatment, natural wild grassland treatment, study water and soil conservation effect, soil water condition, soil constructors condition, soil fertility condition and soil surface temperature, then evaluated the water and soil conservation effect of plating Sabaigrass in purple soil bare sloping field and probed into water and soil conservation mechanism. The main results are as follows:1. The water and soil conservation effect of plating Sabaigrass in purple soil bare sloping field is excellent.Four runoff fields were set in this study. The standard of the fields is 20m X 5m and the slope is 10 degree. The soil erosion and runoff of each treatment was observed in each rainfall. The results show that the water and soil erosion of Sabaigrass treatment and grass tree solid plating treatment was markedly reduced. The soil fertility erosion, soil surface runoff, soil erosion was reduced too. At the same time the change range of soil erosion in different precipitation and precipitation intensity was weakened. Moreover the soil erosion resulted from soil runoff was reduced.2. The structure of purple soil is meliorated by Sabaigrass.When contrast to bare land treatment and natural wild grassland treatment we knew that Sabaigrass treatment and grass tree solid plating treatment reduced soil bulk density, enhanced soil capillary porosity, non-capillary porosity and porosity ratio, decreased soil sand grain content, enhanced soil clay grain and silt grain content so as to reduced the dispersal degreeof soil, improved the aggregate capacity of soil, increased the amount of soil aggregate structure, meliorated the water permeability of soil, accelerated the form of good soil structure. As a result it enhanced the water-retaining and fertility-retaining capacity, strengthened the anti-scour and anti-erosion ability.3. Sabaigrass can meliorated the little entironment of purple soil bare slope fieldThe results show that Sabaigrass treatment and grass tree solid plating treatment can reduce N(nitrogen), P(phosphorus) and K(Potassium) erosion, increase soil nutrition element content, it also increase soil water content and soil pondage, decrease soil water evaporation, strengthen the anti-drought ability. Moreover it decrease soil surface temperature in summer, reduce temperature variety range so as to decrease soil water evaporation and construct a suitable exist condition for soil life, accelerate the activity of life-form in soil, promote the recover of vegetation and the rebuild of ecosystem.