How is soil water content measured?
Soil water content can be measured either directly by collecting a soil sample, weighing, drying, and reweighing the soil sample, or by using one of several types of equipment which indirectly measure the amount of soil water present. Soil water content most commonly is expressed as percent water in the soil by weight, percent water in the soil by volume, or inches equivalent depth of water per specified depth of soil. Other units such as inches of water per inch of soil also are used. By determining the equivalent depth of water for each layer or horizon of soil, the total water in the soil profile can be estimated by adding all the values for the profile together (South Dakota Cooperative Extension Service) Water content by weight is determined by dividing the weight of water in a soil sample by the dry weight of that same soil sample. This ratio is then converted to percent by multiplying the ratio by 100%. Water content by volume is obtained by multiplying the water content of a so
