soil-moisture content The ratio of the volume of contained water in a soil compared with the entire soil volume. When a soil is fully saturated, water will drain easily into the underlying unsaturated rock. When such drainage stops, the soil still retains capillary moisture and is said to contain its field-capacity moisture content. Further drying of the soil (e.g. by evaporation) creates a soil-moisture deficit, which is the amount of water which must be added to the soil to restore it to field capacity, measured as a depth of precipitation.

soil-moisture content The ratio of the volume of contained water in a soil compared with the entire soil volume. When a soil is fully saturated, water will drain easily into the underlying unsaturated rock. When such drainage stops, the soil still retains capillary moisture and is said to contain its field-capacity moisture content. Further drying of the soil (e.g. by evaporation) creates a soil-moisture deficit, which is the amount of water which must be added to the soil to restore it to field capacity, measured as a depth of precipitation.