Taking the typical lime soil in Karst area as the research object

the indoor one-dimensional fixed head method was used to simulate the soil column. Four activated carbon concentrations (0

0.005

0.01 and 0.02 g/g)

two mixed application methods (0-10

10-20 cm) and three layered application methods (6-8

10-12 and 16-18 cm) were used as variables. To observe the dynamic process of soil wetting front movement and cumulative infiltration

the linear relationship and van Genuchten empirical formula were used to simulate the movement of wetting front and the empirical formula of water characteristic curve

respectively

and the mass water contents of different soil layers were measured to study the effect of activated carbon powder on soil infiltration process. The results showed that:(1) In the same infiltration time

compared with other experimental groups

the higher concentration (0.02 g/g) and the shallow application mode (0-10 and 6-8 cm) were better in slowing down the moving speed of soil column wetting front. (2) At the early stage (t<80 min)

the inhibition degree of infiltration by activated carbon powder was positively correlated with its concentration

but the high concentration of carbon powder could slow down the movement rate of wetting front at the same time. Therefore

the final infiltration amount (t<340 min) was less affected by its concentration

and affected by the physical and chemical properties of activated carbon powder. The slope increased at the later stage of layered laying infiltration. (3) The simulation of soil infiltration parameters by van Genuchten empirical formula and RETC software showed that the concentration of activated carbon powder was positively correlated with the ability of soil to absorb water

and it was negatively correlated with soil water release capacity. (4) Activated carbon powder increased soil field water holding capacity and wilting coefficient

and the higher the concentration of activated carbon powder

the greater the field water holding capacity. (5) Under the condition of layer application

the activated carbon powder could increase the mass water content of the soil layer

but had little effect on the water content of other deep soil layers.