Saturated-surface-dry

When big people work with soil, they need to measure how much water is in it. But they can’t just measure it when it’s soaking wet or all dried up, because that’s not how the soil usually is. So they use a special way to test the soil called “saturated-surface-dry”.

First, they take a little bit of soil and put it in a container. Then they add water to the container until the soil is completely wet. This is called “saturated”. It’s like when you pour water over a sponge and it gets all soggy.

Next, they take a little tool called a scraper and they use it to remove any excess water from the container. They want the top of the soil to be just a little bit wet, but not soaking wet like it was before. This is called “surface-dry”.

Finally, they weigh the container with the soil and the little bit of water left on top. That tells them how much water is in the soil when it’s at the “saturated-surface-dry” stage.

Now they know how much water is in the soil when it’s in a state that’s most like how it would be in real life, and they can use that information to make important decisions about how and when to water plants, or how much fertilizer to add to the soil.