A variety of techniques are available for direct measurement of soil water content and most of them are based on the fact that water is removed from a sample by evaporation, leaching, or chemical reaction, with the amount of water removed being determined. One of the most common methods of soil water content determination is gravimetric method with oven drying. This method involves weighing a moist sample, oven drying it at 105°C for 24-48 h, reweighing, and calculating the mass of water lost as a percentage of the mass of the dried soil.
Click here to download a video notes sheet before watching the following video.
Calculations for Gravimetric Water Content
Results are usually reported as % soil water on a dry-mass basis. When reporting the results, you need to specify the conditions under which the determination has been carried out s (e.g., dried at 105°C for 24-48 hours).