Question: How are you able to see how much water is in the soil

Asaf Shnel answered on 2 Nov 2020:

If you want to now how much water is in the soil you can take a sample of soil.
Weigh it, that gives you the weight of the wet soil.
Then you dry it in an oven for 48 hours at 105 degrees Celsius. In this way the soil will be completely dry. You weigh the dry soil.
If you subtract the weight of the dry soil from the weight of the wet soil you will end up with the weight of the water that was in the soil before it was dried.

weight of wet soil – weight of dry soil = weight of water

One gram of water is equal to one milliliter or one cubic centimeter of water. If you also know the volume of your sample of soil than you can calculate the how much space in that soil is filled with water.

For example, if after drying the soil and subtracting the dry weight from the initial weight you ended up with 25 grams of water which is equal to 25 milliliters of water. And lets say your sample of soil is 100 milliliters, then you now know that 1/4 or 25% of your soil sample was filled with water.