Research On Windbreak And Sand-fixation Efficiency Of Pennisetum Giganteum

In this paper,the stubble Pennisetum giganteum on Ulan Buh desert as the research object,the wind speed,sand flow structure,ground surface erosion,soil physical properties and vegetation restoration between sand bars for different specifications of Pennisetum giganteum sand-barrier were continuous observed.A control of adjacent shifting sand area.The results show that:(1)The effect of sand-barrier on the windbreak and the sand-barrier height and line spacing is directly related to the Pennisetum giganteum sand-barrier.The same height of stubble sand-barrier,the more line number,the smaller belt distance had better protection effect.The wind speed and surface transport sand amount between bars always less than the control of the adjacent shifting sand.Transport sand amount between sand bars mainly centralized on less than 15 cm.The surface of 0-5cm had strong hinder ability for sand flow.2015 set of high 30 cm sand-barrier,line 1m and 2m respectively after nine bands and ten bands below the sand wind speed.And the wind erosion of the ground soil was effectively reduced by the stubble sand-barrier,and the 2m and high 30 cm sand-barrier were 50.79%.(2)After setting Pennisetum giganteum sand-barrier the soil moisture content in the depth 0-20 cm range of the surface layer was increased,the soil bulk density is reduced,the total porosity increases,the soil grain size becomes smaller,the medium sand and fine sand are the main,and the sorting is good.With the set time increased between the sand-barrier plant species,frequency,cover was increased.Setting up Pennisetum giganteum sand-barrier 3 years later,shrub appearing between sand bars,the surrounding bare perennial herb appeared.(3)The setting of sand barrier should ensure ecological benefit and economic Benefit.The Pennisetum giganteum sand barrier in 30 cm height and 2 m row space is optional in arid area.It can cut down the wind speed below sand lifting after ninth belt.