The ground we walk on is swirling with life. It is home to plants and small burrowing animals like ants, moles, and earthworms, and countless microscopic creatures. Along with mushrooms, these microorganisms help to decompose dead animals and plants and turn them into humus, a natural fertilizer that enriches the soil. Natural forces like wind and water break down surrounding rock, and add pebbles and minerals to the soil. Last but not least, the soil contains water and air, which plants and animals need to survive. Without soft, moist, nourishing soil, plants could not grow. Our atmosphere would be unbreathable without green plants, which release oxygen into the air that we breathe. In short, our rocky continents would be almost lifeless if Earth’s crust were not partly covered in soil.
It can take more than a century for water, wind, and microscopic creatures to produce a layer of soil less than 0.5 inch (1 cm) thick. It only takes a few years of bad soil management by humans, however, to destroy it completely. Chemical products such as pesticides, as well as industrial wastes, harm organisms in the soil. Growing the same plants year after year uses up important minerals in the soil. Cutting down all the trees in a forest also damages the soil, which becomes more exposed to wind and rain. Without the roots of the trees to hold it in place, the soil is easily carried away. Human beings often have the power to preserve or destroy the soil covering our planet.
The earthworm is an animal that contributes a great deal to the health of the soil. Digging tunnels at a speed of 12 in. (30 cm) per minute, the earthworm distributes nutritious elements, while its tunnels allow water to penetrate and air to circulate underground. And that’s not all! Each day the earthworm eats three times its weight in soil. Then, it digests the soil and produces a waste that is very nourishing to plants. In fact, in some places, the soil’s surface consists mainly of worm poop!
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