Which formula is used to calculate soil moisture content?

The formula for calculating soil moisture content is based on the difference between the wet weight of the soil and its oven-dry weight. The correct formula is derived from the understanding that soil moisture content is essentially the amount of water that was present in the soil when it was wet compared to the weight of the dry soil.

In the correct formula, the numerator represents the water content, which is the difference between the wet weight and the oven-dry weight. This difference indicates how much water was present in the soil sample before drying. Then, this value is divided by the oven-dry weight to give a ratio that reflects the soil moisture content relative to the dry soil, making it a useful assessment for understanding how much moisture exists in a soil sample.

The multiplication by 100 in the formula converts the ratio into a percentage, which is a common way to express soil moisture content, allowing for easier interpretation.

The other options either use the wrong relationship between the weights or calculate a value that does not align with the standard approach for determining soil moisture content. Understanding the basis of these calculations is crucial in soil science and helps in the effective management of nutrients and moisture in agricultural practices.