Stratification of soil profile moisture and its influence factors in typical karst stone hillslope

ObjectiveStratification of soil profile moisture and the relationship between soil profile moisture and soil physicochemical properties of karst stone hillslope were studied with the purpose of providing a scientific basis for rocky de-sertification treatment, water and soil erosion and karst hydrological processes in karst areas of southern China. MethodTypical karst stone hillslope soil profile was used as sample. Stratified sampling integrated with statistical analysis method was applied to study vertical distribution characteristics and its influencing factors,and to analyze stratification of soil profile moisture. ResultThere was obvious difference in soil profile moisture content of karst stone hillslope. It ranged from 34.66% to 47.10%,with the mean value of 38.15%. The maximum value of soil mass moisture was at the depth of 35 cm. Co-rrelation analysis results showed a significant positive correlation between soil mass moisture content and organic matter content(P<0.05, the same below). There was significant negative correlation between soil mass moisture content and pH. The correlation between it and median diameter was insignificant(P>0.05). Organic matter affected soil moisture content through improving soil aggregate structure. The variations of soil mass moisture content and soil physicochemical properties exhibited a distinctive stratification which could be divided into topsoil layer(from surface to the depth of 35 cm),transition layer(depth 35-85 cm) and stable layer(depth 85-115 cm). ConclusionSoil profile moisture in karst stone area has obvious stratification, which is a combined results of soil property,structure characteristics,root activities,water movement,chemi-cal eluviation and bedrock interface. In particular, effects of root activities in depth of 20-40 cm and bedrock interface on soil profile moisture should be paid more attention to.