The Spatial Distribution Pattern Of Soil Properties And Vegetation In The Pisha Sandstone Area Of Inner Mongolia

Soil is a heterogeneous variant formed by the parent material under the combined action of external uncertain factors such as physics,chemistry,biology,etc.The complex formation process of soil is the main reason for the spatial variation of soil properties,and there are certain differences in the spatial distribution of soil properties.The Pisha sandstone has a low degree of diagenesis.It meets water like mud and meets aeolian sand.This feature makes the area’s soil erosion violent and the ecological environment is fragile.Analyzing and mastering the spatial variability of soil properties in the Pisha area plays a key role in regional soil nutrient management and rational use of land.Therefore,this article is based on the traditional field sampling and laboratory analysis.According to statistics and geostatistics,the soil properties and vegetation variation characteristics are analyzed in the Pisha sandstone covered soil area in Inner Mongolia.The main results are as follows:(1)According to the soil nutrient classification standard,soil organic matter,total nitrogen and ammonia nitrogen were in the fifth grade and low level.The average contents of soil total phosphorus,available phosphorus and available potassium were 0.45 g/kg,7.10 mg/kg and 82.98 mg/kg,respectively,the nutrient content is relatively low.From the point of view of the coefficient of variation,the coefficient of variation of soil bulk density is 0.09,which is a weak variation intensity,indicating that the soil bulk density is relatively uniform in space.The soil water content and mechanical composition are all of moderate variability.The coefficients of variation of organic matter,total nitrogen,and total phosphorus were 0.43,0.65,and0.43,respectively,and available phosphorus,ammonia nitrogen,and available potassium were 0.52,0.40,and 0.44,respectively,all of which were moderate intensities of variation,indicating significant differences in soil properties.(2)For different slope positions,the soil structure and vegetation characteristics under and on the top of the slope are relatively good.In different slope directions,the physical and chemical properties of the soil on the shady slope and the vegetation status are obviously better than those of other parts.The physical properties of the soil did not change significantly in slope position and aspect.Soil organic matter,total nitrogen,and total phosphorus have extremely significant differences in different slope positions(P < 0.01),but the available nutrients did not produce a stable law in different slope positions.(3)In different sections,the soil water content,organic matter,and soil total phosphorus tend to accumulate from the ditch head to the ditch mouth.The soil water content,organic matter,and soil total phosphorus levels at the ditch mouth and downstream are significantly greater than those in the ditch head and upstream,and the ditch mouth and downstream The soil particle composition is dominated by sand and clay particles,and the soil composition is relatively good.Comprehensively speaking,the soil properties and vegetation characteristics at the mouth of the ditch and downstream are relatively better than other locations.The analysis of variance showed that the influence of the section on the physical properties of the soil was not obvious,but the chemical properties of the soil in different sections were significantly different(P < 0.05).(4)According to the analysis of the structural factors of the spatial variation of soil physical and chemical properties,the basal ratio of the deep soil sand is 5.8 %,less than 25 %,which indicates that the soil sand has a strong spatial correlation,deep soil sand is mainly controlled by soil parent material,topography,climate and other structural factors.Soil water content,clay,organic matter,total phosphorus,0-10 cm total nitrogen and available potassium were 25-75 %,which had medium spatial correlation,indicating that they were affected by both structural and random factors.The soil bulk density,silt,available phosphorus,ammonia nitrogen,10-20 cm total nitrogen and available potassium were all more than 75 %,and the spatial correlation was weak,to a steady state of development.(5)The spatial interpolation distribution map shows that the soil properties and vegetation are mainly distributed in strips and patches.Soil bulk density and sand are larger in the south than in the north.Clay and organic matter are distributed in regular strips and increase from the north to the south.Soil slit,total nitrogen,total phosphorus,and available potassium are mainly distributed in patches,Soil available phosphorus and ammonia nitrogen are distributed in strips,and the overall range of changes is large.The vegetation types and vegetation coverage change irregularly and have no obvious characteristics.The research results will help to better understand the local soil conditions and provide an important scientific basis for soil improvement and ecological restoration in the Pisha sandstone area.