Characteristics Of Soil Water Infiltration And Its Influencing Factors In Patchy Vegetation Areas In The Desert-oasis Transition Zone

In arid areas,soil moisture is the main factor restricting the restoration and growth of vegetation,and one of the key factors affecting the growth and development of desert sand-fixing plants and their ecological benefits.The desert-oasis transition zone in the northern part of Linze County is a sensitive zone for the struggle between desertification and oasis.Regional atmospheric rainfall maintains the growth and development of various sand-fixing plants in the transition zone.The number of sand-fixing plants is scarce due to lack of water.However,sand-fixing plants can play an important role in maintaining the stability of the oasis ecosystem.Therefore,this article selects the soils of three different sand-fixing plant root zones in the patchy vegetation zone of the northern Linze County as the research object,and uses the double ring knife method to determine the soil moisture infiltration characteristics of different sand-fixing plant root zones.A comparative analysis of the differences in the soil water infiltration performance of the root zones of different sand-fixing plants was carried out;SPSS software was used to analyze the correlation between the soil moisture infiltration characteristic indexes and the physical and chemical properties of the soil in the root zones of different sand-fixing plants;the roots of different sand-fixing plants were analyzed.Perform linear regression analysis on the physical and chemical properties of the soil in the area and the measured soil moisture infiltration characteristics;and further screen out the main environmental factors that affect the soil moisture infiltration in the root zone of different sand-fixing plants through principal component analysis and path analysis.Three soil moisture infiltration models are used to fit the soil moisture infiltration process in the root zone of different sand-fixing plants,and the fitting results of different infiltration models are compared and analyzed.The results of this study can more accurately explain the characteristics of soil water infiltration in the root zone of three different sand-fixing plants and their influencing factors,and provide a scientific basis for restoring the growth and development of sand-fixing plants in arid areas.The main conclusions are as follows:（1）The soil water infiltration process in the root zone of the three sand-fixing plants in the study area can be roughly divided into three stages,that is,the infiltration stage when the infiltration rate drops sharply（0～10 min）,and the decline in infiltration rate slows down and tends to in the stable leakage stage（10～60 min）and the infiltration rate basically stable infiltration stage（60～120 min）.（2）The soil moisture infiltration rate in the root zone of Haloxylon ammodendron is between 1.871～10.056 mm·min^-1,and the soil moisture infiltration rate in the root zone of Calligonum mongolicum is between 1.411～9.056 mm·min^-1,The soil moisture infiltration rate in the root zone of Nitraria sphaerocarpa is between 0.710～7.455 mm·min^-1.The soil water infiltration performance in the root zone of different sand-fixing plants is as follows:Haloxylon ammodendron>Calligonum mongolicum>Nitraria sphaerocarpa.（3）On the whole,there are significant differences in the soil water infiltration characteristics of the root zones of the three sand-fixing plants at different soil depths.The soil water infiltration characteristics of the root zone of the three sand-fixing plants all decreased with the increase of soil depth.The soil water infiltration characteristics of the root zones of the three sand-fixing plants were the largest in July and the smallest in October.（4）The fitting result of the Kostiakov model is 0.902,the fitting result of the Horton model is 0.987,and the fitting result of the Philip model is 0.973.All three infiltration models can describe the three types of sand fixation well.The soil moisture infiltration process of plants in different months and different soil depths.From the accuracy of the fitting results for comparison,Horton model>Philip model>Kostiakov model.（5）There is a significant correlation between the soil physical and chemical properties of the root zones of different sand-fixing plants in the study area and the characteristics of soil water infiltration.The negative correlation between the soil moisture infiltration characteristics and bulk density of Jujube and Sophora japonicus is extremely significant.The negative correlation between the soil water infiltration characteristics of Haloxylon ammodendron and Shaguaia jujube and the initial water content is extremely significant.The positive correlation between the soil water infiltration characteristics of the three sand-fixing plants and the total porosity is extremely significant.The positive correlation between the soil water infiltration characteristics of Haloxylon ammodendron and Sophora japonicus and the capillary porosity is extremely significant,and the positive correlation between the soil water infiltration characteristics of Shaguai jujube and the capillary porosity is significant.The positive correlation between the soil water infiltration characteristics of the three sand-fixing plants and the organic matter content is extremely significant.（6）The principal component analysis of the soil water infiltration performance of three sand-fixing plants shows that the cumulative contribution rate of the principal components summarized by environmental factors is greater than 85%,indicating that the general principal components can explain the impact of environmental factors on the soil in the root zone of sand-fixing plants.The influence of moisture infiltration performance.Soil bulk density,initial moisture content,total porosity,organic matter content and coarse sand content are the main factors affecting soil water infiltration in this area.Other factors can also affect soil water infiltration directly or indirectly.