Know About Soil

Soil is formed from decayed vegetable matter (dead leaves and plants), mineral grains, and larger pieces of rock. Creatures, such as earthworms, help the decomposition process by mixing the soil. The process by which rocks are often broken down into smaller pieces is called weathering . Chemical weathering occurs when minerals are dissolved by water. Some minerals break down or dissolve quickly. Others, such as quartz, are not dissolved but stay behind in the soil as stones. The action of burrowing animals, animals, insects, and growing plants is called physical weathering. Attrition (grinding down) is another kind of physical weathering and it occurs when wind-blown particles rub against each other. This kind of weathering occurs mainly in dry areas, such as deserts. You can see how attrition works simply by shaking some sugar cubes together in a glass jar.

ON THE HORIZON
Soil occurs in layers, called horizons. There are four main horizons. The top horizon (also known as topsoil) is a layer of fine particles that supports the roots of plants and trees. The next two layers, beneath the topsoil, have larger soil particles. The bottom layer is partly solid rock.

WORMERY

You need :
1) Large and small plastic bottles.
2) Scissors
3) Funnel
4) Gloves
5) Damp soil
6) Sand
7) Six worms
8) Rotting leaves
9) Black paper
10) Sticky tape

WHAT IS IN SOIL?

You will need :
1) Gloves
2)Trowel
3) Soil
4) Sieve
5) Paper
6) Magnifying glass
7) Notebook, pen.

BIG OR SMALL?

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