The Study Of Spatial Variety On Soil Physicochemical Properties Of In Alpine Grassland Areas Of Eastern Qilian Mountains

Alpine grassland ecosystem has great ecological and ecological value for soil and water conservation,biodiversity conservation and ecological balance.The alpine meadow has a wide area and abundant vegetation types.Because of its unique environment,its special ecological environment has been created.The differences of soil physical and chemical properties should be paid attention to in the region of Alpine grass based on micro environment.At present,there are few studies on soil physical and chemical properties of alpine grassland micro topography,most of them are concentrated in hilly area and loess plateau area.In order to explore the effects of micro topography on the physical and chemical properties of soil in alpine grassland,the soil physical and chemical properties of different soil layers,different slope directions and different slopes are compared and analyzed.The following conclusions are drawn:1.Change law of soil physical propertiesWith the increase of soil depth,the volume of soil volume and soil water content all changed greatly,and as the elevation increased,all of them decreased first and then became larger.In the soil layer of 0-10 cm,the size of soil bulk density gradually decreases with elevation.In the 10-30 cm soil layer,the size of soil bulk density varies with the elevation,and the soil water stability aggregate of>5 mm and 0.5¹mm is decreasing with the elevation of altitude,1² mm,2⁵ mm grain grade soil The soil water stability aggregates tend to decrease first and then increase with the elevation,and the 0.25⁰.5 mm soil water stability aggregate level increases with the increase of altitude.It shows that the trend of soil water content in the sample plots at the slope position in the sunny slope is about the upper slope>lower break>middle slope position,but the trend of soil water content in the sample plots at the slope position of the shady slope is about the downslope>upper break>middle slope position,the shade slope>the sunny slope position.2.Change law of soil chemical propertiesWith increasing the depth of soil layer,the content of total N and NH₄-N decreases in Terrace.The content of soil total N is the trend of“V”and NH₄-N decreases in different position of North-facing Slope.In different position of South-facing Slope.the content of soil total N decreases,but soil content of NH₄-N is the trend that increases and decreases after;With increasing the depth of soil layer,The content of soil Organic Carbon decreases in all micro topography.With increasing the depth of soil layer,soil content of hydrolyzable nitrogen will decrease in T、MS、MN micro topography.The content of Hydrolyzable N firstly decreases and increases after in the micro topography of BS and BN.And the content of Hydrolyzable N firstly increases and decreases after in the micro topography of TS and TN.The slope position change about Total N、Hydrolyzable N and OC content in soil layer is Bottom Slope>Top Slope>Middle Slope.However,the content of NH₄-N is the trend that firstly decreases and increases after.So,the micro topography change positively impacts the soil content of OC and N3.The relationship between physical and chemical properties of soil0-10 cm soil ammonium nitrogen has a very significant correlation with soil bulk density and soil water content.0-10 cm soil hydrolysate nitrogen has a significant correlation with soil total nitrogen,0-10 cm,The soil total nitrogen content and soil organic carbon content showed a very significant correlation.In the 0-30 cm soil layer,soil water content and soil volume water content showed a very significant correlation.0-20 cm soil layer,soil bulk density and soil volume water content showed a very significant correlation,10-20 cm soil layer,soil total nitrogen and soil bulk density,Soil moisture content has a very significant correlation.The size of soil water content affects the size of soil volumetric water content.The relationship between soil organic carbon and total nitrogen is very close.The relationship between soil total nitrogen and soil hydrolytic nitrogen is very close,and the relationship between soil bulk density and soil water content is very close.