What is Soil?

Soil is a naturally occurring, loose, organic, or inorganic material that lies on bedrock created by rock weathering. Soils are formed by different particles like gravel, rock, sand, silt, clay loam, and humus. Soil classification helps select the best soil for the proposed application. The knowledge of soil is essential in construction to choose the proper foundation types and designs. In this article, we will go through the types of soil in detail.

Types Of Soil

The major types of soils are as follows: 

  • Sand
  • Clay
  • Silt
  • Loam

1. Sand

Sand is the most widely used construction material. Sand is made up of rock and hard mineral particles, such as silicon dioxide, which is created by the interaction of silicon with oxygen. 

Sand is generally made up of silicate and granular silicate rock particles. It is the largest form of soil particle, with each particle visible to the naked eye. Large sand particles help aerate the soil, improve drainage in dense soil, and increase the growth of plants.

Physical Properties Of Sandy Soil

Coarse sand has particle sizes ranging from 2 mm to 4.75 mm, medium sand ranges from 0.425 mm to 2 mm, and fine sand ranges from 0.075 mm to 0.425 mm. The texture of sand can be gritty, smooth, or polished.

Sandy soil is likely nutrient-deficient, bright, warm, and dry. This type of soil has a lot of sand and very little clay, also known as light soil. This dirt drains water quickly.

Uses of Sandy Soil

• Sand is used to create a road base that serves as a protection layer for roadways.

• Sandy soil is nutrient-rich and dry, allowing it to drain quickly. As a result, this soil was used to grow shrubs as well as plant and harvest crops.

• This soil is utilized as a foundation for muddy land.

• Sand is used for glass manufacturing.

• Sandy soil is used to reduce water velocity. This soil percolates, causing the water table to increase.

2. Silt

Silt soil is a loose sedimentary material composed of tiny rock particles that form naturally. It is a light, moisture-retaining soil with a high fertility value. Silt particles are usually medium in size, so they drain easily and retain moisture efficiently.

Physical Properties Of Silt Soil

The silt particle size of silt soil ranges from 0.002 mm to 0.075 mm. This soil is nutrient-rich, making it ideal for gardening. Due to its fineness, it is non-plastic or has limited plasticity.

Also, because of its fineness, when the soil gets wet, it creates smooth mud that is easy to mold into balls or other shapes, and when silt soil becomes extremely moist, it smoothly combines with water to form fine, runny puddles of mud. This soil may hold more water than sand due to its fineness and smoothness.

Uses of Silt Soil

• This soil is more fertile than other soil types, making it appropriate for growing crops.

• Similar to sand, silt is used to fill lava pits.

3. Clay

Clay soil is made up of very microscopic particles. Clay is excellent for storage and resists moisture and air penetration. While clay is moist, it is highly sticky and heavy, but it becomes hard like concrete when it dries.


Because of the particles’ small size and tendency to clump together, only a tiny amount of air can pass through their gaps. As a result, clay soil holds water well and resists moisture and air penetration. Clay is the densest and heaviest type of soil, and it does not drain well or allow roots to spread out.

Physical Properties Of Clay Soil

Clay soil is made up of microscopic and sub-microscopic particles that form due to the chemical breakdown of rocks. It is a cohesive fine-grained soil. When soil particles are wet or dry, they stick together quickly and transform into a sticky or gluey texture.

Clay soils contain a lot of water because of the gaps between the clay particles. When soil comes to contact with water, it expands and contracts. Clay particles are flat, thin compared to sand particles.

Clay soil is weak and highly compressible, with substantial volumetric fluctuations. However, this type of soil has been explored and is continuously being studied because of its extraordinary flexibility, permeability, bearing capacity, and settlement qualities.

Uses of Clay Soil

• Organic clay is very compressible and has a high dry strength, so it is utilized in the building as mud mortar.

• Clay is used in agriculture to grow fruit trees and decorative plants. These plants may thrive independently because clay soils have a high moisture content.

• When mixed with water, clay can be molded into any shape, making it helpful for making household items. 

• Clay is also used in medicine. According to the study, clay soil includes minerals with antibacterial properties that can efficiently eradicate antibiotic-resistant bacterial infections.

• Clay serves as a base for pavers and other hardscape elements. They are also used for landscape borders, beds, and paths.

4. Loam

Loam is a mixture of clay, sand, and silt. The properties of these three varied textures benefit water retention, air movement, drainage, and fertility. Loam soil is fertile, easy to deal with, and has good drainage.

They might be sandy or clay loam, depending on their primary composition. This soil retains moisture and minerals, making it more appropriate for cultivation. In addition, loam soil contains higher calcium and pH levels.

Loam soils are ideal for growing plants since they contain a mixture of sand, silt, and clay and have favorable properties. In addition, this type of soil does not dry out in the summer.

Physical Properties Of Loam Soil

Loam soil comprises 50%sand, 30% clay & 20% silt. When loam soil dries up, it becomes black and crumbly to the touch. Loam soils are rich in nutrients and moisture. As a result, loam soil has improved air and water infiltration and drainage.

Uses of Loam Soil

• Because of its nutrient content, this soil is ideal for gardening and agriculture.

• An interior wall can be added to the construction project to help regulate air humidity.