To explore the dynamic process of soil moisture under different mulching techniques in karst areas

an experimental research of soil moisture dynamic changes was carried out in Huajiang typical karst valley area of Guizhou Province from March to May

2009.The results show that under the controlled condition

the evaporation of soil moisture closely related with the way and area ratio of covering.The magnitude of changes in soil moisture over time was bare land>thin-film semi-covered land>gravel throughout land>litter throughout land>thin-film throughout land.The relationship between soil moisture contents and time was best fitted by third degree polynomial equations.Soil firmness

soil porosity

soil bulk

density

and soil permeability differed significantly under different coverings.Although the water-holding capacity of the soil under thin-film throughout treatment was the highest

its permeability and porosity was fairly low.The soil under the gravel throughout has the highest infiltration rate and firmness