Effects of soil clay content on soil water-holding capacity by simulated experiments

Quantitative effects of clay content on soil water-holding capacity were studied by compounding different texture of soil.The results showed that: 1) Soil clay content has a great effect on water-holding capacity.Soil water-holding capacity strengthened with the increase of clay content.The parameters of Gardner and van Genuchten soil water characteristic curve models went up with the increase of clay content.2) Soil clay content has a great effect on specific water capacity.The specific water capacity of experimental soils strengthened with the increase of clay content at any water suction level.3) The saturated water content and field capacity of experimental soils have exponential and logarithmic function relationship with clay content.And the relationship between the wilting coefficient and clay content is exponential function.4) while the clay content increase,available water and resistant available water content of experimental soils firstly increase and then decrease,and peak at the stage of soil clay content was 35.9% and 35.8%,respectively.There is no significant correlation between quickly available water and clay content.The results provides the theoretical basis for the further study on soil water-holding mechanism.