Soil is a natural resource broadly defined as the loose top layer of earth made up of disintegrated rock, humus, and inorganic and organic materials. Soil is usually formed when rocks break up into smaller pieces under the action of various natural forces like wind, water, gravity, the reaction of salts etc. Conversely, soil hardens to form rocks, but this is a prolonged process. Various soil types are classified based on texture, proportions and different forms of organic and mineral materials.
The smallest soil particles are called clay. Slightly bigger particles are called silt, and large, coarse particles are called sand. Soil consisting of mostly sand, as in deserts, is called sandy soil, while soil made up of mostly clay is called clayey soil. Loam soil, consisting of silt, sand and clay particles, is considered the best for the growth of plants. This kind of soil is also usually rich in humus, which provides nutrients to plants.
There are mainly three basic types of soils. These are sandy soil, clayey soil and loam soil. The differences in the compositions of these three types of soil and their properties are discussed below:
Clayey soil contains mainly clay (having very small particles with very small spaces). It has hardly any sand or silt in it. Clayey soil also contains very little humus. Due to its small and tightly packed particles, clayey soil has a high water-holding capacity. Clayey soil is heavier than sandy soil because it can hold more water. The smallness of particles of clayey soil is also a disadvantage. This is because the water drains out very slowly through clayey soil leading to water-logging of soil and damaging the crop plants. Moreover, due to the smallness of its pores, clayey soil types cannot trap enough air for the roots of the plants. Clayey soil is compact and sticky, ploughing a clayey soil is quite difficult.
Clayey soil types are, however, rich in minerals which are good for the growth of plants. Clayey soil is more fertile than sandy soil. By adding sand and humus (manure) to clayey soil, it can become more fertile. Sand will help clayey soil drain better, while humus will supply the necessary plant nutrients. Clayey soil has a lot of stickiness. As a result of this clayey soil is used to make pots (like matkas and surahis, etc.), bricks, toys and statues. Clayey soil is the best soil for making pots, bricks, toys and statues.
Sandy soil is mostly made up of sand (having large particles with large spaces). It has hardly any clay or silt in it. Sandy soil contains very little humus. Sandy soil is found in desert areas. Large particles with large spaces between them describe sandy soil. Sandy soil has the drawback of not being able to hold much water because water drains quickly through the large crevices between its particles. So, sandy soil dries out quickly, which is not good for plants.
However, sandy soil provides good aeration (air) to the plant roots and can be ploughed very easily. Sandy soil is light. It tends to blow away if left bare. Sandy soil is not as fertile as other soil types. Adding humus in the form of manure to a sandy soil can increase its fertility. Humus improves sandy soil’s water-holding capacity while also providing essential plant nutrients. The dirt in sandy areas is not sticky. As a result, it cannot be used to construct pots (like matkas and surahis, etc.), bricks, toys and statues.
Loam soil is a mixture of sand, clay, silt and humus in the right proportions. Loam soil is a mixture of large and small rock particles which impart the desired properties. For example, it has the right water-holding capacity for the growth of plants. Excess water can also be simply drained through it. Soils of this kind also have adequate air spaces between their particles to hold sufficient air needed by plant roots. Therefore, it can also be ploughed easily. It is also to be noted that it contains a sufficient amount of humus. So, loam soil has all the necessary nutrients for the growth of plants. Loam soil is the most fertile soil. Loam soil is the finest soil for growing crops. Loam soil is also known as ‘loamy soil’.
We have looked at the classification of soil types based on the relative proportions of rock particles of various sizes from the above discussion.
|Property||Sandy soil||Clayey soil||Loam soil|
|1. Main constituent||Large-sized sand particles||Smaller-sized clay particles||Clay, sand and silt present in the right proportions|
|2. Space between particles||Quite large||Quite less||Sufficient|
|3. Presence of air||Well-aerated||Not well-aerated||Can hold sufficient air|
|4. Water-holding capacity||It cannot hold much water||Can hold much water||Right water-holding capacity|
|5. Nutrients||Cannot hold nutrients||Can hold nutrients||Can hold nutrients|
|6. Ploughing||Easy to plough||Difficult to plough||Easy to plough|
Source for this article : Soil Types: Chart, Classification, Uses & Examples – Embibe