Moisture-retaining and transmissibility properties of soil profiles with different architectures in dolomite karst areas

In karst areas， soil is generally shallow and discontinuous， where unevenly distributed soil beds and bedrock in soil profiles with different architectures. Whether their moisture-retaining and transmissibility properties are variable remains unclear. To address this issue， the BEST single-ring infiltrometer method was employed to investigate such soil profiles in a dolomite karst area， namely， deep soil profile （DS）， shallow soil profile （SS） and soil-rock mixture profile （SR）， respectively. The results show that the hydraulic properties above mentioned of these profiles are different， which are mainly affected by soil particle component and profile architecture features. The surface soil of three kinds of soil profiles have high water conductivity， among which surface Ks of the soil-rock mixture profile（SR） is the highest， up to 244.1 mm?h-1， while the surface Ks of shallow soil profile（SS） is only 56.8 mm?h-1. For deep soil profile （DS）， the soil is clayey and of low water conductivity but of high water holding capacity except for surface soil and regolith layers. Due to the impact of underlying bedrock， shallow soil profile（SS） shows low water conductivity and high water holding capacity as a whole. In the soil-rock mixture profile （SR）， loose soil beds have both good water conductivity and holding capacity， while the rock layer has relatively poor water conductivity but better water holding capacity. In the soil’s effective water content， the SR is the highest， while DS and SS are relatively lower due to the clayey soils. The results of this study could provide scientific guidance for the selection of vegetation restoration sites in karst areas.