Soil is a natural resource that can be categorized into different soil types, each with distinct characteristics that provide growing benefits and limitations. Identifying the type of soil you require for a project is paramount to support the healthy growth of plant life.

Soil can be categorized into sand, clay, silt, peat, chalk and loam types of soil based on the dominating size of the particles within a soil.

Sandy soil : Sandy Soil is light, warm, dry and tend to be acidic and low in nutrients. Sandy soils are often known as light soils due to their high proportion of sand and little clay (clay weighs more than sand). These soils have quick water drainage and are easy to work with. They are quicker to warm up in spring than clay soils but tend to dry out in summer and suffer from low nutrients that are washed away by rain. The addition of organic matter can help give plants an additional boost of nutrients by improving the nutrient and water holding capacity of the soil.

Clay Soil: Clay Soil is a heavy soil type that benefits from high nutrients. Clay soils remain wet and cold in winter and dry out in summer.These soils are made of over 25 percent clay, and because of the spaces found between clay particles, clay soils hold a high amount of water. Because these soils drain slowly and take longer to warm up in summer, combined with drying out and cracking in summer, they can often test gardeners.

Silt Soil: Silt Soil is a light and moisture retentive soil type with a high fertility rating. As silt soils compromise of medium sized particles they are well drained and hold moisture well. As the particles are fine, they can be easily compacted and are prone to washing away with rain. By adding organic matter, the silt particles can be bound into more stable clumps.

Peat Soil: Peat soil is high in organic matter and retains a large amount of moisture. This type of soil is very rarely found in a garden and often imported into a garden to provide an optimum soil base for planting.

Chalk Soil: Chalk soil can be either light or heavy but always highly alkaline due to the calcium carbonate or lime within its structure. As these soils are alkaline they will not support the growth of ericaceous plants that require acidic soils to grow. If a chalky soil shows signs of visible white lumps then they can’t be acidified and gardeners should be resigned to only choose plants that prefer an alkaline soil.

Loam Soil: Loam soil is a mixture of sand, silt and clay that are combined to avoid the negative effects of each type. These soils are fertile, easy to work with and provide good drainage. Depending on their predominant composition they can be either sandy or clay loam. As the soils are a perfect balance of soil particles, they are considered to be a gardeners best friend, but still benefit from topping up with additional organic matter.

The removal of soil by running water and wind is called Soil Erosion. Soil forming process and erosional process of running water and wind are continuous.
Different types of erosion caused by water are:
Sheet erosion
Hill erosion
Gully erosion
Stream bank erosion
Shore erosion, and
Slip erosion

Wind erosion is significant in desert and semi-desert regions. In some regions, the top soil is blown away by wind in dry season. Soil in deserts also gets washed away by running water in wet season.
1.Topography
2.Nature of rainfall
3.Nature of soil, and
4.Human factor

Soil is an essential natural resource that supports a majority of plant and animal life on the earth. It is a renewable resource.

The loss of soil cover due to natural agents like wind and running water is called soil erosion. The roots of plants and trees keep the soil moist and hold the soil particles together. Humans destroy vegetation cover by deforestation, overgrazing, construction and mining activities.

Without vegetation cover, soil becomes dry and loose, and gets easily eroded. Defective farming methods, like ploughing up and down a slope, increase the speed of water flowing down the slope increase the rate of soil erosion.

Running water carves deep channels through clayey soils, called gully erosion, which converts the land into bad-land making it unsuitable for cultivation.

When flowing water washes away the entire sheet of top soil in a region, it is called sheet erosion. Wind erosion occurs generally in areas of little or no vegetation. It happens in places that receive scanty rainfall.

Conservation of Soil

The prevention of soil erosion is called soil conservation Following methods are normally adopted for conserving soil:

• Afforestation: The best way to conserve soil is to increase area under forests. Indiscriminate felling of trees should be stopped and efforts should be made to plant trees in new areas. A minimum area of forest land for the whole country that is considered healthy for soil and water conservation is between 20 to 25 per cent but it was raised to 33 per cent in the second five year plan; the proportion being 20 per cent for the plains and 60 per cent for hilly and mountainous regions.

• Checking Overgrazing:  Overgrazing of forests and grass lands by animals, especially by goats and sheep, should be properly checked. Separate grazing grounds should be earmarked and fodder crops should be grown in larger quantities. Animals freely move about in the fields for grazing and spoil the soil by their hoofs which leads to soil erosion. This should be avoided.

• Constructing Dams:  Much of the soil erosion by river floods can be avoided by constructing dams across the rivers. This checks the speed of water and saves soil from erosion.

• Changing Agricultural Practices: We can save lot of our valuable soil by bringing about certain changes in our agricultural practices.