Soil is more than just dirt. Soil is a natural resource that provides vital nutrients for plants to grow. The amount of humus, organic material, in soil is critical to the soils quality and health. This, in turn, is a direct link to the health of the trees and vegetation growing in the soil. Humus is food for the microorganisms that play an important part in the decomposition process. Humus also helps minerals in the soil bond together so that the soil will stay moist and more minerals will be available for the growing plants. The ideal soil has a blend of sand (less dense allowing for better aeration), clay (holds water well), and humus (organic material that increases the ability of sand and clay soils to hold water and create oxygen pockets).
To provide students with the opportunity to test the amount of humus (organic material) in local soil samples.
Use the Treeture, Mud Meister, as a guide, icon or symbol to help animate and enhance your soil lesson. Mud Meister is a Soiler Spoiler, but the Treetures are always finding clever ways to turn him into a Soil Toiler who replenishes the land with healthy soil. Collect soil samples from around your school and community to see if Mud Meister has been busy adding organic materials to your soil to help it stay rich and healthy. It would be best to have a variety of samples clearly labeled with their locations: soil from an open area with very little vegetation, soil from under a tree, soil from a wetland/river area or potting soil with a high organic content. Explain that soils rich in humus, organic material, tend to be more acidic in content than soils without. This is due to the carbon dioxide (which forms an acid in water) produced by the decomposers in the soil.
Before testing your soil samples for organic content, have students make predictions for each of the soil samples and give reasons to support them. Fill each jar with 2-3 Tablespoons of a different soil sample, making sure each is clearly labeled. Add _ cup of cabbage water to each jar. If the water turns red, it means the soil has a high acidic content which, in turn, usually indicates the soil is high in organic content. If the water turns blue, the soil is more alkaline in content, which indicates the soil is lower in organic content. (This test usually indicates content of organic matter, but sometimes soils low in organic content can have some acid in them.) Line up your jars in order from the darkest reds to the purples to the blues and make your conclusions to the organic content of your soil samples.
Visit Stomper or Humus for more ideas and resources.*The Treeture characters, as learning tools, can be adapted to any grade level. For example, students in grades K-1 could utilize coloring pages, finger puppets, and collages. Stories, poems, creation of new Treeture characters, newsletters, and plays could be fun and used as mentoring projects by 5th and 6th graders for younger students. Another entertaining and educational activity is to hold a Treeture Fair. This project has been successfully implemented in several schools. Each Treeture character can be enlarged and placed on an easel on a table with an appropriate experiment or example of its tree role.
More than 4 billion tons of topsoil are lost each year through erosion by wind and water. It can take hundreds of years to regenerate just one inch of topsoil. (National Gardening Association)