Types of Soils and their Distinctive Properties

            There are many types of soils that possess different physical properties: sand, clay, silt, loam, and peat. The physical properties of soil that can be used to characterize different types of soils are color, density, structure, texture, and temperature. Soil color is primarily determined by the amount of organic matter and water content. The soil density is based on the mineral and organic makeup of the soil and its structure around the soil. In other words, it is defined as the proportion of the weight of the soil relative to the volume of its soil. Soil structure can be defined as the arrangement of the soil particles inside the soil itself. The soil texture can be defined as the proportion of soil particles that make up the overall ‘feel’ of the soil.

Soil temperature is affected by the weather, amount of water content in the soil, the color of the soil, and the depth of the soil profile. It can also be said that darker colored soils are usually warmer and can maintain higher temperatures than lighter colored soils.

Different types of soils and their distinctive properties are discussed in detail below:

Soil Types: Sand

Sand Soil

            Sandy soil has a light, pale color and is usually warm. They also tend to have low nutrients and weak water retention abilities. They have a light texture because these soils tend to have a larger proportion of sand particles compared to clay particles and clay particles are heavier than sand particles. Sandy soils contain more than 70% sand particles and less than 20% clay particles. The structure of this soil type is usually weak or underdeveloped and it may also have no structure at all.

The general texture or ‘feel’ of this soil type can be classified as a gritty or rough feeling. This type of soil is generally found in desert landscapes where there is lots of sunlight available to warm the soil. The increased availability of sunlight in desert landscapes causes this type of soil to retain less overall moisture than other soil types.

 Soil Types: Clay

Clay Soil

            Clay soil can range from yellow to red. This type of soil tends to remain wet and cold during the winter and then dry out during the summer season. Soils that are classified as clay soils contain more than 25% clay particles in their soil. They tend to have strong water retention abilities as there are spaces found between clay particles that are used to hold water. Unlike sandy soils, this type of soil is generally heavier and possesses more nutrients and water.

Clay soil tends to have a structure that is quite dense in nature as many clay particles are bonded together which makes it difficult for plants to penetrate this type of soil with their roots. Clay soil tends to have a smooth texture and is slightly sticky. This type of soil is generally found near a water source such as fresh lakes, rivers, or ponds.

Soil Types: Silt

            Silt soil tends to have a light color that is usually beige. This type of soil tends to be slippery when it is wet and feels similar to the texture of flour when it is dry. Soils that are classified as silt soils contain more than 80% of silt particles in the soil. These particles are medium-sized and are able to retain moisture from water.

The structure of silt soil is developed when sediments such as rocks and minerals are mixed with water in suspension. Similar to clay soils, this type of soil is found near water sources such as freshwater lakes, rivers, and ponds. This type of soil is also more fertile than sandy and clay soils and it is usually used to improve soil fertility in agriculture.

Soil Types: Loam

Loam Soil

Loam soil tends to have a color that is either black or brown. It remains warm during the spring season but does not dry out quickly in the summer. This type of soil’s structure is a mixture of sand, silt, and clay particles. Depending on the composition that loamy soils are made up of, they can be classified as sandy loam or clay loam soils.

This soil is able to retain water and contains a lot of nutrients which makes it an ideal soil type for gardening practices and growing shrubs. The texture of loamy soils is that they can be crumbled easily when it is dry yet feel fairly smooth. Loam soil is very commonly found in gardens because this type of soil is ideal for gardening as it is able to hold plenty of moisture and allows for enough air to reach the roots.

Soil Types: Peat

            Peat soils tend to have a color that is a mixture of an orange and yellow or brownish color. These soils tend to be warm and found in moist climatic areas. Peat soils possess a very high amount of organic content and are able to retain large amounts of moisture. The structure of this soil type is comprised of pores that are open, dead-ended, or isolated. This type of soil is made up of decomposed matter that forms over many years.

Peat Soil

Peat soil’s texture has a spongy and damp feeling when they are squeezed. This type of soil is found everywhere but they are predominantly found in temperate areas. Peat soils are usually formed in wetland areas where a large amount of water obstructs the natural flow of oxygen in soils. This type of soil is also very rarely found in gardens, lawns, or recreational areas.

A decision on top soil or the type of soil is mainly dependent upon the environment among other factors….

A Gardening series article on “Types of Soils and their Distinctive Properties” by Saad