The thin layer on the surface of the earth, on which the terrestrial living beings survive, is called soil. This layer of material holds the roots of plants. These plants grow by absorbing water and required nutrients from the soil. The plants are consumed by herbivorous animals. And these animals are prey to carnivores. Therefore soil plays an essential part in the ecosystem.
There are different types of plants; they require certain nutrients and climatic conditions to survive. Likewise, plants of different types have also adapted to different types of soil, from which they gain their required nutrients.
Soil is a mixture of solid particles (i.e. salt minerals and organic compounds), air and water. The quantity of each of these and factors such as climatic conditions, kind of rock, the rate at which the rock is weathered, vegetation and quantity of wildlife present determine the type of soil.
Generally soil is classified into silt, clay, loam, sand, peat, and chalky soil, of which sand, silt and clay are the main ones. Each of these are different from each other in terms of amount of organic matter, size and amount of weathered rock in each one of them as well as its adapted climatic conditions.
SAND: This type of soil has the biggest particles. It is formed by the weathering of certain rocks for example limestone, granite, quartz and shale. The texture of this soil is gritty as the rock particles are granular and it consists of very small mineral particles. The degree of aeration and drainage depends upon the size of the particles. This type of soil is an easy choice for cultivation as it is rich in organic matter but in this case it allows more drainage than necessary and thus the plants become dehydrated in the summer season. It is obligatory to water it at regular intervals during the spring season, because during spring sandy soil heats very fast. However a break should be given during the winter and rainy season, as during these seasons it regains the moisture and nutrients. The quick drainage of sandy soil is at times profitable for plants as it does not let water remain in the roots of the plants long enough to cause decay.
SILT: It is granular but unlike sandy soil it has more nutrients and offers better drainage. When silt is dry it has a smooth texture and looks like dark sand. It is considered one of the most fertile soils; it is formulated of minerals like quartz and fine organic particles. It is not only found in nature as soil but also as suspended sediment in water. It becomes compact at times because of the reason that it contains a lot of moisture.
CLAY: Clay soil is formed after years of rock weathering and is found naturally, often as sedimentary deposits. The drainage is poor due to less air space and finely grained particles. Due to poor drainage this type of soil can sometimes e harmful for the plants, as it causes water logging which harms the plant roots. To cultivate this soil, fertilizers should be added.
LOAM: It is considered to be the perfect soil for cultivation. To a certain extent it is a mixture of sand, silt and clay. The texture is gritty. The drainage is well even when this type of soil regains water very easily. Loam is of various kinds, from fertile to very muddy to thick sod.
PEAT: Peaty soil is generally found in wet and marshy areas and is basically formed by the decomposition of dead organic matter; however the amount of nutrients in this soil is fewer than most soils. It has an acidic nature. It is prone to water logging and can be a good choice for cultivation if a right amount of fertilizers, care and attention is provided.
CHALKY SOIL: Consists of a large number of stones and is alkaline in nature. Fertility of chalky soil depends upon the depth of the soil upon a bed of chalk. This soil is very dry and even blocks nutritional elements for plants like iron and magnesium. Therefore it is poor choice for cultivation especially in summers.