Studies on the Moisture Characteristic Curve and the Water Absorption Character of Soil.

Soil can be regarded as a source and a storage of water in soil-plant-atmosphere continum (SPAC).To make clear the characteristics of moisture retention of the soil in relation to other soil properties is part of the basic work of water dynamic analysis in SPAC.In this study, water retention characteristic curves and other soil properties were measured for 50 samples representing 5 different kinds of soil from the northeastern region of China.From the results, a new empirical equation for moisture characteristic curve was proposed.The parameters of the equation had physical meaning and could be estimated by the percentage of micro-aggregate and the organic matter content in the soil, and the geometric mean of soil particle size.Furthermore, an equation to describe the rate of soil water absorption was also proposed.Parameters in the equation depended upon the specific surface a'rea of the soil, the organic matter content in the soil and the percentage of soil particles less than 0.01 mm.