Study On Cultivation And Selection Of Wheat-bran-substrate Mobile Lawn And Its Soil And Water Conservation Effects

Our country is one of the countries with the most serious soil and water loss. Great numbers of excavation activities in social development and construction lead to serious perturbation and damage, and result in large amount of secondary bare land and soil and water loss. Lawn construction as one of the effective approach of vegetation protection serves well in rapidly restoring function of vegetation community in districts around roads. However, for the soil-less-substrate lawn approach, the grass species is less selective and the soil and water conservation function is ineffective, these limit the practical application of this new approach to slope protection. The study used the wheat bran as the main raw material of the soil-less cultivation lawn substrate, decomposed the wheat bran by using the present prescription to generate bran substrate, measured its basic physical and chemical properties and determined its suitability in using as the substrate of soil-less cultivation lawn. This work chose five kinds of grass species and nine kinds of fertilized processing method in lawn cultivation, and evaluated its advantages and disadvantages to analyze its selectivity. Artificial simulated rainfall experiment was implemented to measure the soil and water conservation effect of the lawn.l. The wheat bran has good physical and chemical properties with PH value of6.4, bulk density of0.31and0.73g/cm3for dry and wet condition respectively and bulk porosity of67.1%, and is considered as a comparatively better lawn cultivation substrate and suitable to soil-less lawn cultivation.2. Perennial ryegrass and festuca are the most optimal species among five lawn grass species in cultivation under same fertilizing and seeding quantity conditions, considering from the properties in density, coverage, stem height, chlorophyll content and root length; kentucky bluegrass is the second; trifolium repens and alfalfa are the lost. Considering from the properties of root-shoot ratio and root activity, trifolium repens and alfalfa are better than kentucky bluegrass, perennial ryegrass and festuca.3. In general, the five lawn grass species show better properties in density, coverage, stem height, chlorophyll content, root length, root-shoot ratio and root activity, in the conditions of composite fertilizing (with active fertilizer5g/m2and slow-release fertilizer5g/m2) and individually fertilizing (5g/m2,10g/m215g/m2). All the properties show the worst performance in the condition of individually fertilizing.4. According to specialized quality assessment for the soil and water effect of lawn, this study concludes that among the five lawn grass species used in wheat bran substrate cultivation, perennial ryegrass and festuca should be firstly considered; kentucky bluegrass secondly; trifolium repens and alfalfa thirdly.5. Using perennial ryegrass bran as experimental material, initial infiltration rate and stability infiltration rate increase as lawn coverage and the rainfall intensity increase, for different conditions in coverage rate (33%,55%,80%) and rainfall intensity (0.5mm/min,1.0mm/min,1.5mm/min) and slope degree (5°,10°,15°,20°,25°,30°). The lawn coverage and rainfall intensity significantly influence runoff and sediment. For a certain degree of the rainfall intensity, runoff generation time postpones and runoff generation content decrease as the lawn coverage increases, and both of them increase as the rainfall intensity increases. Compared with bare land, the lawn can increase infiltration capacity and reduce production flow, and the wheat bran lawn can decrease sediment with at least90percentages.