And, after a pouring rain, they enjoy the simple pleasure of splashing through mud puddles. Using simple tests, students learn to identify sand, clay, and humus in soil. They also study how water affects different kinds of soil. Through long-term experiments, they explore how roots and plants grow in various soils and how, with the help of worms, old plants decompose and become part of soil. Then, applying what they have learned, they investigate their own local soil.
Students begin by discussing what they already know about soil and what they want to find out.
After learning the difference between predictions and observations, they predict what a sample of garden soil might contain. Examining the sample with a hand lens reveals particles of different sizes, along with bits of plants and tiny animals. This sets the stage for Lesson 2, when students create compost bags using garden soil, plant matter, and redworms. For the next five weeks they watch what happens as dead plants decay in soil. Lessons 3 through 7 introduce students to sand, clay, and humus, three of the basic components in soil.