Impact of mineral concentration on capillary water rise in sandy soil

This article summarizes results of the experiment on capillary water rise in sandy soil with different combinations of grain sizes and mineral concentrations (1g.L^-1, 30 g.L^-1, 100 g.L^-1 and 250 g.L^-1). Tests show that: in coarse sandy soil, capillary water height has positive correlation with mineral concentration and the capillary water height from solution of mineral concentration of 250 g.L^-1 is evidently lower than those of other three solutions with mineral concentrations of 1 g.L^-1, 30 g.L^-1 and 100 g.L^-1 in the same time period; in fine sandy soil, capillary water height at the late stage of observation presents a descending sequence of 1 g.L^-1, 250 g.L^-1, 100 g.L^-1 and 30 g.L^-1 for the solution groups; in silty soil, capillary water height of the solution with mineral concentration of 30 g.L^-1 is obviously higher than those of the other three solution groups. It is also found that: with higher mineral concentrations, density of the solutions impacts on gravity potential of capillary water and evaporative crystallization in the capillary tubes impacts on the matrix potential of capillary water, and the process of capillary water rise is impacted by these two factors in combination.