Simulated Experiment on Effects of Soil Clay Particle Content on Soil Water Holding Capacity

This research studied the quantitative effects of sand content on soil water-holding capacity by compounding different texture of soil.The results showed that:(1) Sand content had a great effect on soil water holding capacity.Soil water holding capacity was decreased with the increase of sand content.The parameters of Gardner soil water characteristic curve model A(stand for water holding capacity) and Van Genuchten model(stand for saturated water content) went down with the increase of sand content.(2) Soil sand content had a great effect on specific water capacity.The specific water capacity of experimental soils decreased with the increase of sand content at any water suction level.(3) The saturated water content of experimental soils had liner relationship with sand content.Field capacity and wilting coefficient both have right segment of down opening quadratic parabola relationship with sand content.(4) Available water and resistant available water content of experimental soils decreased with sand increasing.Both of them have right segment of down opening quadratic parabola relationship with sand content.Quickly available water have right segment of up opening quadratic parabola relationship with sand content.