Students take to the schoolyard with trowels in hand. Several weeks later, they are familiar with sampling techniques and soil components, weathering and erosion, minerals and nutrients, and more. Students separate soil into particle layers and classify soil types according to estimated proportions. Once they understand what soil is, they find out how it is made by modeling weathering by plants and water. Next, students observe how earthworms mix and enrich soil. They discover that nutrient-rich soil helps plants grow, and plants, in turn, help soil resist erosion. Grass gardens, pollution detectors, worm farms, and erosion models offer strong hands-on experiences.
In the Delta Science Reader Soil Science, students read about the composition and characteristics of different types of soil. They learn about the effects of weathering and erosion in producing and changing soil. They find out about ways that people both harm and protect this vital natural resource. Students also read about soil scientists and their work. Finally, students learn how earthworms keep soils rich and productive.