Science ( soil )

Science ( soil )

What is soil?

Soil is the loose upper layer of the Earth's surface where plants grow. Soil consists of a mix of organic material (decayed plants and animals) and broken bits of rocks and minerals.

Properties of Soil

Soil is often described using several characteristics including texture, structure, density, temperature, color, consistency, and porosity. One of the most important properties of soil is the texture. Texture is a measure of whether the soil is more like sand, silt, or clay. The more like sand a soil is the less water it can hold. On the other hand, the more like clay a soil is, the more water it can hold.

Types of soil

Soil is classified into four types:

Sandy soil. Silt Soil. Clay Soil. Loamy Soil.

Sandy Soil

The first type of soil is sand. It consists of small particles of weathered rock. Sandy soils are one of the poorest types of soil for growing plants because it has very low nutrients and poor water holding capacity, which makes it hard for the plant’s roots to absorb water. This type of soil is very good for the drainage system. Sandy soil is usually formed by the breakdown or fragmentation of rocks like granite, limestone and quartz.

Sandy soil is easily blown away by wind.To prevent this sandy must be kept wet.

Clay Soil

Clay is the smallest particle amongst the other two types of soil. The particles in this soil are tightly packed together with each other with very little or no airspace. This soil has very good water storage qualities and makes it hard for moisture and air to penetrate into it. It is very sticky to the touch when wet, but smooth when dried. Clay is the densest and heaviest type of soil which does not drain well or provide space for plant roots to flourish.

Loamy Soil

Loam is the another type of soil. It is a combination of sand, silt and clay such that the beneficial properties from each is included. For instance, it has the ability to retain moisture and nutrients; hence, it is more suitable for farming. This soil is also referred to as an agricultural soil as it includes an equal amount of all three types of soil materials being sandy, clay, and silt and it also happens to have humus. Apart from these, it also has higher calcium and is quite dark in colour.

Silt Soil

ilt, which is known to have much smaller particles compared to sandy soil and is made up of rock and other mineral particles, which are smaller than sand and larger than clay. It is the smooth and fine quality of the soil that holds water better than sand. Silt is easily transported by moving currents and it is mainly found near the river, lake and other water bodies.

Erosion

Erosion is the wearing away of soil by forces such as water, wind, and ice.

What causes erosion?

The three main forces that cause erosion are water, wind, and ice.

Weathering

Weathering is the breaking down of rocks,  and their minerals through , waters, or living things.

Layers of soil.

Soil is made up of layers. The layers rest on solid rock, called bedrock. A layer of broken rock rests on the bedrock. Some of this rock may have gone into forming the soil above. The soil above the broken rock is called subsoil. Subsoil contains mostly minerals and a small amount of humus. Only the deepest plant roots reach the subsoil. The top layer is called topsoil. Topsoil contains a lot of humus. It is the layer where plants grow.

Water in the soil

There is a over a thousand times more water in the ground than is in all the world's rivers and lakes. These waters are held undergound in aquifers.

These underground aquifers are filled whenever it rains.

THE End.