DIFFERENT TYPES OF SOIL

Types Of Soil

The term soil refers to the upper layer of earth crust in which plants grow. It consists of weathered rock, organic matter, air space and water. In civil engineering soil can be defined as a naturally occurring loose/uncemented /weakly cemented/unconsolidated mineral particle, organic or inorganic in character, lying over the bed rock which is formed by weathering of rock.

Types Of Soil

1. Sand
2. Silt
3. Clay
4. Loam

1. Sand

This is the first type of soil. It consists of particle of weathered rock such as silicon dioxide. Sandy soil has the largest particles where each particle can be seen from naked eyes. The large particle size increases soil aeration, improves drainage in tight soils. 

The particle size of course sand ranges from 2 - 4.75 mm, medium sand ranges from 0.425 - 2 mm. The biggest particle size of the sand gives wet or dry sandy soil a grainy texture when you rub between your finger.

2. Silt Soil

Silt is granular material of size between sand and clay, whose mineral origin is quartz and feldspar. Silt may occur as a soil or as sediment mixed in suspension with water and soil in a body of water such as river. Silt has a moderate specific area with a typically non-sticky, plastic feel. Silt is easily transported by moving currents and it is mainly found near the river, lake and other water bodies. The silt soil is more fertile compared to the other types of soil.

3. Clay Soil

Clay is a type of fine-grained natural soil material containing clay minerals. Clay particles are the finest of all the soil particle measuring less than 0.002 mm in size. It consists of microscopic particles derived from the chemical decomposition of rocks.The particle in this soil are tightly packed together with each other with very little or no airspace. Clay is a fine grained cohesive soil but become hard, brittle and non-plastic upon drying of firing. Most pure clay minerals are white or light coloured but natural clay show a variety of colours from impurities such as a reddish or brownish colour from small amounts of iron oxide.

4. Loam Soil

Loam is a soil composed of sand, silt and clay. These soil are fertile, easy to work  and provide good drainage. Loam is considered ideal for gardening and agricultural uses because it retains nutrients and retain water while still allowing excess water to drain away. Apart from this, it also has higher calcium and pH levels because of its inorganic origins.