WHAT IS CLAYEY SOIL - TYPES AND ADVANTAGES

What Is Clayey Soil

Clay is a 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. Clays develop plasticity when wet, due to a molecular film off water surrounding the clay particles, but become hard, brittle and non-plastic upon drying or firing. These soils are made of over 25 percent of clay. Most of the clay minerals are white or light in colour but natural clay show a variety of colours such as reddish or brownish because of the presence of small amount of iron oxide.

Formation Of Clayey Soil

Clays and clay minerals occur under a fairly limited range of geologic conditions. The environments of formation include soil horizons, continental and marine sediments, geothermal fields, volcanic deposits, and weathering rock formations. Most clay minerals are commonly form when rocks are in contact with air, water or steam and are also form locally from hydrothermal activity. The clay minerals are formed by the acidic weathering of feldspar rich rock such as granite in hot climates tends to produce kaolin.

Types Of Clayey Soil According To Its Percentage

1. Silt Soil     0 - 10 % Clay
2. Clay Soil 10 - 25 % Clay
3. Clay Soil 25 - 40 % Clay 
4. Clay Soil 40% Clay

Advantages Of Clayey Soil

• It is very fertile.
• It retains water and nutrients.

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.