Layers of soil

A science topic about soil.

1. SOIL

2. WHAT IS SOIL? Soils are complex mixtures of minerals, water, air, organic matter, and countless organisms that are the decaying remains of once-living things. It forms at the surface of land – it is the “skin of the earth.” Soil is capable of supporting plant life and is vital to life on earth.

3. SOIL TYPES

4. SOIL TYPES There are different types of soil on the planet, as every soil has different compositions of minerals and organics, and every soil has been formed in different ways. There are four basic types of soil. These are sand, clay, silt, and loam.

5. SAND Sand is used to provide bulk, strength, and other properties to construction materials like asphalt and concrete. It is also used as a decorative material in landscaping. Specific types of sand are used in the manufacture of glass and as a molding material for metal casting.

6. CLAY Clay soil has incredibly small particles. This means that clay has very little air spaces, allowing almost no drainage. This is the reason why clay soil becomes very sticky and heavy when wet. Clay soil can be bad for growing some plants. Water cannot escape clay soil when it is wet, causing the plant roots to rot.

7. CLAY Clay soil has been used for construction since ancient times. It can be sun-dried or fired to make adobe bricks and then be used to assemble a house. Clay is used in ceramics, turning it into pots, vases, pipes, and other useful objects. It is also used in making sculptures or antique jars, which are usually expensive when bought.

8. SILT Silt is one of the most fertile of the many types of soil, with rich nutrients and good drainage. It is slightly smaller in size than sandy soil, but otherwise is very similar in composition. Silt soil is generally quite dark in color , and is excellent for planting almost any plant.

9. LOAM Loam soil is actually made up of different soil types, with varying amounts of clay, silt, and sand mixed together. Loam holds water well because of the heavy grittiness given from the sand. It also has exceptional drainage so that the water do not build up too much and is also nutrient-rich. Loamy soil is the ideal soil for gardening.

10. Soil covers much of the land on  Earth . It is made up of minerals (rock, sand, clay, silt), air, water, and organic material (matter from dead plants and animals). Soil provides a substrate for plants (roots anchor in soil) , a source of food for plants, and a home for many animals (insects, spiders, centipedes, worms, burrowing animals, bacteria, and many others).

11. Soil Horizons (layers) Soil is made up of distinct horizontal layers; these layers are called horizons . They range from rich, organic upper layers (humus and topsoil) to underlying rocky layers (subsoil, and bedrock).

12. ORGANIC The organic layer (also called the humus layer ) is a thick layer of plant remains such as leaves and twigs.

13. TOPSOIL Topsoil is considered the "A" horizon. It is a fairly thin layer (5 to 10 inches thick) composed of organic matter and minerals. This layer is the primary layer where plants and organisms live. The topsoil has sand and clay but is mostly made up of loam.

14. SUBSOIL Subsoil is considered the "B" horizon. This layer is made primarily of clay, iron, and organic matter. Its color is usually light because there is more sand and clay in this layer. The roots of most trees grow downward into the subsoil. .

15. BEDROCKS The bottom layer is several feet below the surface. The bedrock is made up of a large solid mass of rock. Plants and animals cannot live in this layer. This layer is a source of materials for constructing buildings and making roads and bridges. .

16. HOW DO PEOPLE USE SOIL?

17. AGRICULTURE Soil has vital nutrients for plants. As a result, it is used in agriculture to nourish plants. The roots of a plant receive nutrients from the soil to help it grow.

18. BUILDINGS Soil is an important part of the building process. Soil compaction, which increases the density of the soil, is done as part of the building process. The purpose of the compaction is to improve the load support. If not done, structural failure can result. Soil can also be used as building materials such as adobe and red bricks.

19. POTTERY Clay soil is used in making ceramics, or pottery. When water is added to clay soil, it can be used to create the ceramics. Once formed, you can leave it to dry and it will retain its shape. Any type of ceramic can be created with the clay soil, such as a vase, bowl, cup or sculpture.

20. MEDICINE Soil is commonly used in antibiotics. Microbes created in the soil are harmful to bacteria, which is why soil is used in medicine. Medicines created by soil include skin ointments, tuberculosis drugs and anti-tumor drugs.

21. BEAUTY PRODUCTS Some beauty products are made with soil. Commonly used beauty products where used soil is used in the production include blush and foundation. Soil rich in clay can also be used in facial masks and toothpastes.

22. CARE AND CONCERN FOR SOIL

23. CARE AND CONCERN FOR SOIL Chemicals like oil, detergent and acid affect the minerals in soil that help plants grow. Polluted soil affects the health of plants; it can even make plants die.

24. SOIL EROSION Soil erosion is a gradual process of movement and transport of the upper layer of soil (topsoil) by different agents – particularly water, wind, and mass movement – causing its deterioration in the long term.

25. SOIL EROSION Planting many trees and plants may prevent this from happening especially when there are heavy rains. Sweeping the garbage carefully from the ground would also prevent the topsoil from being eroded.