Background Information
Soil is often viewed as the skin of the earth -- a remarkable living and breathing natural resource!
Iowa is home to some of the best soils in the world -- our landscape was historically covered with a vast tallgrass prairie, which over thousands of years led to the formation of some of the richest, most fertile soil in the world. Countless microorganisms reside down in soil and the immense root system of prairie plants. This rich soil was created through years of the repetitive prairie lifecycle. An abundance of plant material was produced each growing season. In the fall, as the foliage on the plants died and the prairie became dry, the landscape became very susceptible to fires. For the prairie, however, these fires proved beneficial and necessary to the ecosystem’s continued existence. Fire helped to decompose the thick, dead foliage, returning nutrients to the soil and clearing the way for new plant growth to emerge in the spring. The fires also continued to keep trees located only near bodies of water. Unlike prairie plants, whose deep, well-established root system allowed the plant to survive and thrive after burns, small seedling trees were eliminated. Reduction of tree growth was important to the continuance of the prairie ecosystem’s need for many hours of direct sunlight.
While our landscape looks much different today, soils still sustain life, providing the foundation for growing plants that serve as food, feed, fiber, and fuel, all while filtering and purifying water resources. However, soil is being lost much faster than it can be replenished! Conservation practices that help to hold the soil in place and build up organic matter are of utmost importance.
Vocabulary
Soil: The layer of earth in which plants grow
Organic Matter: The remains of plants and animals
Humus: Decayed organic matter in the soil
Organisms: Living things
Trophic Level: Organisms that share the same function in the food chain
Consumer: An organism that eats other living things
Producer: An organism that produces its own energy
Decomposer: An organism that breaks down (decomposes) organic matter
Fungi: Spore-producing organisms that feed on organic matter
Residue: Dead or decaying plant material
Bacteria: Microscopic single-celled organisms that aid in digestion, aid in decay of living things, and can cause disease
Books
How We Use Soil by Carol Ballard
Sand and Soil: Earths’ Building Blocks by Sharon Katz Cooper
Videos
A Culture of Conservation Video Series (and Enhanced Learning Activities)
Building A Culture of Conservation: Iowan to Iowan
Don’t Call it Dirt: A Passion for Soil
The Work of Our Hands
Reclaiming Stewardship
Land Formation in Iowa (4-minute Video Animation)
What’s In Your Water?
The Farm (Video and Activity)
Additional Activities
Soil Explorations
SOS (Saving Our Soil)
Prairies, Wetlands and Croplands: Keys to the Future Lie in the Past
Recommended activity on p.4: Soil Comparisons