Basics of Soils and it's functions

To know about the natures of our soils, first we should know 

• What is soil?

• What are the functions of soils in our ecosystem?

Soil can be defined in many ways. But first we all should know what Kellog says.

According to Kellog, "The soil is a collection of natural bodies occupying a portion of the earth crust that supports the plant growth which have properties due to integrated effect of climate and vegetation acting upon parent material as conditioned by relief over a period of time."

Now, what does N.C. Brady say?

According to N.C. Brady, "A soil may be defined as a dynamic natural body on the surface of the earth in which plants grow, composed of minerals and organic materials and living forms."

Now, if we simply think what soil is, it can be said that "soil is considered as a natural habitats for plants and other living organisms."

There are two main branches of soil science.

What are they?

1. Pedology: It deals with the soil formation, soil genesis, soil classification and description of soil properties.
2. Edaphology: It is the study of soil in relation to growth, nutrition and yields of crops or plants.

Now, It is time to know the functions of soils in our ecosystem.

In any ecosystem, soils play five vital roles:

1.  First, soil supports the growth of plants.
2.  Second, soil properties are the principal factor that control the fate of water in the hydrologic system. Water loss, purification, utilization, contamination all are affected by soil.
3.   Third, soils function as nature's recycling system.
4.  Fourth, Soil is habitat for organisms.
5.  Finally, Our soil is also an engineering medium.

How soil supports plant growth?

Soils is a medium for plant root and it supplies nutrient elements that are essential to the entire plant.

Besides it provides Physical support, Air, Water, Temperature, Protection from toxins.

How soil regulates water supplies?

Soil can regulate the drainage, flow and storage of water and solutes, which includes nitrogen, phosphorus, pesticides, and other nutrients and compounds dissolved in the water. With proper functioning, soil partitions water for groundwater recharge and for use by plants and soil animals.

How soil acts as nature's recycling system?

Soils have the capacity to assimilate great quantities of organic waste, turning it into beneficial humus, converting the mineral nutrients in the wastes to forms that can be utilized by the plants and animals. Also soils return the carbon to the atmosphere as carbon dioxide, where it again becomes a part of plant photosynthesis. Some soils can accumulate large amount of carbon as soil organic matter thus having a major impact on global changes.

How soil is a habitat for organisms?

There are billions of organisms live in soils. They can be predators, parasites, producers etc.

How is it possible for organisms to live and interact in such a small space in soil? It is possible because there is tremendous range of niches and habitats in even a uniform appearing soil. The pore spaces that are filled with water can be an ideal habitat for diatoms, roundworms etc. And when pores are filled with moist air, it can be a good habitat for other organisms that can live in aerobic environment.

How soil is an engineering medium?

To have a good and stable foundation we must have a stable and good soil. Every foundations are built on soils. Soil properties such as bearing strength, compressibility, shear strength are much more variable and difficult to predict for soils than for manufactured building materials.

Without these there are many other functions of soil such as carbon sequestration, flood regulation, climate regulation, provision of foods, fibers and fuels etc.

We can clearly understand the functions from the following picture