To study this transformation as it happens, the 4th and 5th standard children took up a project - building up a miniature earthworm habitat.
Materials required : A glass or plastic jar, gravel, sand, garden soil, compost or humus, chopped leaves and hay, black paper, tape, rubber bands, earthworms and water.
1. Fill the jar with gravel (3 cm), garden soil (2 cm), sand (3 cm), compost or humus (3 cm) and again sand (1 cm), one over the other. Spray each layer with water as you fill up. It should keep the different layers moist. Any excess water will get collected in the bottom layer.
2. Now put a top layer of chopped leaves, hay and dead plant leaves to a height of 2 cms and sprinkle some water.
3. Add 3 or 4 earthworms.
4. Cut a sheet of black paper in circular shape and cover the top of the jar. Fix it with the tape. Make some pin holes in the lid for air circulation. Cover the sides of the bottle with a black sheet of paper and a few rubber bands.
5. Every day take out the black paper and the lid and observe carefully. Don't forget to sprinkle some water before covering with black paper.
6. Study for 8 to 10 days. Write down your observations everyday.
You will look for :
1. Any visible trails of earthworm movement.
2. The movement of the earthworms through different layers mixing them up - this leads to aeration.
3. Decomposition of the dead matter, turning it into rich compost.
4. The worms eat the soil and vegetable matter and then pass them out.
Things to know :
Earthworms render the soil very rich. They help in distributing nutrients evenly throughout the soil. They mix the soil as they push their way through the soil. They eat decaying matter near the surface of the soil and excrete in deeper layers. An acre of soil may have as many as a million earthworms.
- Arunkumar G.N.