Spatial variation of soil water content under drying and wetting cycle in karst area of Guilin

Objective In this study,spatial variation of soil water content under drying and wetting cycle in karst area of Guilin was investigated to provide theoretical reference for solutions to soil and water loss and crop drought resistance in the area.Method Three plots cultivated with soybean,pear trees and sugarcane were investigated to analyze the spatial variation of soil water content in upper soil layer(0-6 cm) under alternate drying and wetting conditions,and the variation of soil spatial distribution under different land use patterns was studied by geostatistical method.Result The difference in soil texture among the three plots was not significant(P>0.05).Pear tree plot presented the lowest soil bulk density,but the greatest soil organic matter content and total porosity.The soil water content of these three plots during wet stage was nearly 2-3 times of the soil water content during dry stage.During the whole drying and wetting cycle,soil water contents of the three plots were pear tree plot>sugarcane plot>soybean plot.The proportion of spatial distribution of soil water content was 37.18%-95.99%,presenting a medium-high spatial correlation.It referred that the spatial distribution of plots was stable within a certain range.However,as different land use patterns resulted in certain variation,the variation intensity depended on tillage method or management mode.ConclusionThe soil in karst area of Guilin has the capacity to maintain stability of spatial distribution in soil water content which can be weakened by human factors such as tillage method and irrigation to a certain extent.