Types of Soil 3 rd Grade Layers of
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Types of Soil 3 rd Grade
Layers of Soil is a very important resource. ◦ Soil is what plants grow in. ◦ Some animals live in soil. Soil is a mixture of many different things. ◦ Soil is made up of: water Air Humus tiny pieces of rock.
Humus is the part of soil that is made up of parts of dead plants and animals. ◦ Example: When a tree loses a leaf, the leaf falls to the ground. As the leaf breaks down into smaller parts, it becomes humus. ◦ The soil close to the surface has a lot of humus.
Soil Layers
Top Soil The top layer is called topsoil. Topsoil has a lot of humus. Many small animals, such as ants and earthworms, live in topsoil. Topsoil particles are dark and small.
Subsoil The layer underneath topsoil is called subsoil. Subsoil does not have a lot of humus, but it does have small rocks in it. Subsoil particles are larger and lighter in color than topsoil particles.
Bedrock If you dig deep enough into soil, you will reach solid rock. This solid rock is called bedrock. Most small rocks in soil come from the bedrock underneath it.
Different Types of Soil In the United States alone there are more than 70, 000 types of soil. ◦ Different colors ◦ Hold more or less water ◦ Size of rocks found in them ◦ Different minerals make different soils
Sand Soil with grains of rock that you can see with your eyes alone Sand is made up of small grains of worndown rock. It has few nutrients. Sand doesn’t hold water well.
Silt Soil with grains of rock that are too small to be seen with your eyes alone. Silt is composed (made up of) very small broken pieces of rock. Its particles are larger than clay and smaller than sand.
Clay Soil with very tiny grains of rock Clay contains small particles of soil that hold water well and provides nutrients.
Loam Soil that is a mixture of humus, sand, silt, and clay Best type of soil for growing fruits and vegetables in.
Importance of Soil Bricks, pottery, and other items are made from clay soil. Many animals would have no where to live without soil. Plants would not be able to grow without soil.