容重对土壤水分蓄持能力影响模拟试验研究

通过人工改变土壤颗粒级配,并设置不同容重水平,测定土壤水分特征参数,研究了容重对土壤水分蓄持能力的定量影响。结果表明:(1)容重对土壤水分特征曲线、比水容量有较大影响,试验土壤各吸力段水分蓄持能力均随容重增大递减,比水容量也随容重增大递减。(2)容重对试验土壤饱和含水量、田间持水量、凋萎系数有较大影响,此3个水分参数均随容重增大递减。饱和含水量与容重呈幂函数负相关关系,田间持水量及凋萎系数均与容重呈指数负相关关系。(3)容重对试验土壤有效水、易效水、迟效水含量有较大影响,此3水分参数均随容重增大递减,分别与容重呈指数、幂函数、对数负相关关系。

Simulated experiment on effects of soil bulk density on soil water holding capacity

Effects of soil bulk density on soil water-holding capacity were explored through simulated experiments designed to have soils different in soil texture by artificially altering composition of soil particle fractions. (1) Water holding capacity and specific water capacity of the experimental soils decreased along with increasing soil bulk density. (2) Soil saturated water content, field moisture capacity and wilting coefficient showed the same trend, and negative correlation of power, exponent and exponential function, respectively, with soil bulk density. (3)Soil available water, readily available water and slowly available water contents were also significantly affected. The three water parameters decreased along with increasing soil bulk density, too, showing negative correlation of exponential, power and logarithmic function, respectively, with soil bulk density.