Investigating Living Soil Components
Earth ecoSTEM Kit Materials Used: Trowels
ENGAGE - Students Observe This Phenomenon
EXPLORE a Kit-Supported Learning Experience
Working in teams of four, students will use their trowels to dig 4” deep samples from various locations and spread the soil out on white paper or cloth to identify components. (Do not use potting soil, which has no living organisms). Lenses and jars will help students see insects. Bacteria can be seen microscopically. Return soil to holes afterwards; wash hands!
Given a variety of ingredients, students should be able to design and make an edible soil model and explain that soil is composed of mineral content (broken bits of rocks or ‘parent material’), organic content (living organisms and dead / decomposing matter), water and air. Decomposing things include rotting leaves. Living organisms include various animals and the “FBI”: Fungi (underground part called mycorrhizae), Bacteria, and Insects in various stages (macroinvertebrates).
Fungi, Bacteria, Invertebrates:
Students can find a plant with mycorrhizae, dig it up, cut the roots, and grow a “trap culture” of the soil fungi for 4 months and then “inoculate” other plants to extend their root systems. They can observe these microscopic images of soil bacteria. They can observe insects and other soil macroinvertebrates.
Students can build a Berlese Funnel to make soil macroin-vertebrates emerge from a soil sample. Follow the direction or make this into an engineering design challenge.
Students may propose solutions to mineral soils and carry out a project such as adding mulch to increase soil organisms.