Relationship Between Soil Physical And Chemical Properties And Water Transport Of Typical Plantations In Loess Hilly Region Of Inner Mongolia

To study the relationship between soil physical and chemical properties and water transport of Typical plantations in the Loess Hilly Region of Inner Mongolia,so as to provide reference for the construction of water conservation forest,vegetation restoration and reasonable forest planting in the loess hilly region.This paper takes the soil under Pinus tabuliformis,Populus davidii,Caragana korshinskii,Pinus tabuliformis ×Populus davidii,Pinus tabuliformis×Caragana korshinskii,Populus davidii×Caragana korshinskii as the research object and grassland as the control,the ring knife was used for multi-point sampling to determine the soil physical and chemical properties and evaluate the soil quality.The single ring soil column method was used to observe the law of soil water movement,and the linear regression analysis was carried out between the characteristics of water movement and the soil physical and chemical properties.The main conclusions are as follows:1.There are significant differences in soil physical and chemical properties of the six plantations in the study area,among which the difference in surface soil properties is the largest,which decreases with the depth of soil layer.Compared with grassland,different plantations have obvious effects on soil quality improvement,and the soil quality of mixed forest is better than that of single pure forest.The soil quality index is Pinus tabuliformis ×Populus davidii(0.7314),Populus davidii×Caragana korshinskii(0.5831),Pinus tabuliformis×Caragana korshinskii(0.5641),Populus davidii(0.4921),Pinus tabuliformis,Caragana korshinskii(0.3878),grassland(0.3847).2.The permeability of different man-made forests is evaluated by the stable infiltration rate,cumulative infiltration amount and the advance rate of wetting front.The water storage capacity of different man-made forests is evaluated by the water storage capacity of forest land,the maximum water content in the infiltration process and the field water holding capacity after infiltration.The six kinds of Typical plantations in the study area are represented by Pinus tabuliformis ×Populus davidii > Populus davidii > Populus davidii × Caragana korshinskii > Pinus tabulaeformis > Pinus tabuliformis×Caragana korshinskii > Caragana korshinskii > grassland.3.Under the water heads of 5mm,10 mm and 20 mm,the greater the water head,the greater the initial infiltration rate and the advance rate of wetting front of surface soil,and the surface water content will increase in a certain range,resulting in the increase of cumulative infiltration in the early stage.The difference between 5mm head and10 mm head is small,and the difference between 20 mm head and 5mm and 10 mm head is large.However,the water head will not affect the stable infiltration rate and the whole cumulative infiltration of soil.4.According to regression analysis and correlation analysis,soil bulk density,capillary porosity,noncapillary porosity and organic matter content are the main reasons affecting soil water transport in different artificial forests in the study area.Among them,soil bulk density has a significant negative correlation with the infiltration rate and soil water content in the process of water transport,while capillary porosity,noncapillary porosity and organic matter content have a significant positive correlation with water transport.