Science fun-Retaining the Right Amount

Farmers carefully choose which crops to plant where, and what type of soil to plant them in. Today we practiced our metric measuring skills in an experiment to learn about water retention in different types of soil.

First we added 160 mL water to 250 mL clay, sand, and potting soil, each in their own foam cup. Each cup had 10 small holes in the bottom to allow for drainage. After 2 minutes we recorded how much water drained from each.

Using the information we gathered, our next objective was to make a mixture of soil that had a water retention of 50%. We formulated a hypothesis that contained the amounts of each soil we would use. We then poured 160 mL over our cup containing 250 mL of our mixtures, and timed it for 2 minutes.

              

We learned that sand drained the fastest, clay drained the slowest, and we discussed what kind of mixtures we would need for different plants water retention needs.