We're going to find out how fast soil absorbs water. Of course, some soils absorb faster than others. You can tell that when you water your yard, if there are different types of soil and/or different degrees of compaction. You will see the water "pool" in some places, and run off in other places, while some soils will absorb the water immediately. Here's how we will test soils for the rate of absorption:

Tie a piece of cloth over one end of each of several lamp chimneys. (Any transparent cylinder with both ends open will suffice.)

Fill each cylinder three-fourths full with a different type of soil (sandy, loamy, fine gravel, clay). There can even be some mixtures of different types of soil. That would be more like the real world. Further, we could even compact some soil more than that of another cylinder of the same type, to see what a difference it would cause in the absorption rate.

Place the cylinders in a flat pan of water, and note the type of soil in which the water rises the highest or fastest.

Make some judgments about the types of soil and their ability to absorb water. Rates of absorption can be determined by timing the absorption for 1 minute and measuring the height of the water in each cylinder. The relationship of height to time will provide the absorption rate (e.g., 1 inch in 30 seconds).

Make some judgments, also, about the reasons that some soils are better for certain crops than others. What kind of soil is present in the desert? What grows there? What kinds of animals live there? Think about how the type of soil present in different areas affects our own lives.