soil and crops
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Soil is formed by the breaking down of rocks by the action of wind, water, and climate, a process called weathering.

Soil Profile

A vertical section through different layers (called horizons) of the soil is called its profile.

Each layer differs in feel (texture), color, depth, and chemical composition.

  1. Topsoil/ A-Horizon
  • The uppermost horizon.
  • Generally dark in color as it is rich in humus (rotting dead matter) and minerals.
  • Humus makes it fertile and provides nutrients to growing plants.
  • Generally soft, porous and can retain more water.
  • Provides shelter for many small living organisms.
  • The roots of small plants are embedded entirely in topsoil.

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2. Middle Layer/ B-Horizon

  • Generally harder and more compact.
  • Has a lesser amount of humus but more of minerals.

3. C-Horizon

  • Made up of small lumps of rocks with cracks and crevices.
  • Below is the bedrock, which is hard and difficult to dig.

Soil Types

It is classified on the basis of the proportion of particles of various sizes.

  1. Sandy soil
  • When it contains a greater proportion of big particles.
  • Sand is well-aerated as sand particles are quite large. The spaces between them are filled with air.
  • Water can drain quickly through the spaces between the sand particles. So, sandy soils tend to be light, well aerated and rather dry.

2. Clayey Soil

  • The proportion of fine particles is relatively higher.
  • Clayey soil particles have lesser spaces between them so they have less air.
  • They are heavy as they hold more water than the sandy soils.
  • Clayey soil is used to make pots, toys, and statues.

3. Loamy Soil

  • The amount of large and fine particles is about the same.
  • Best topsoil for growing plants.
  • It is a mixture of sand, clay and another type of soil particle known as silt.
  • Silt occurs as a deposit in riverbeds.
  • The size of the silt particles is between those of sand and clay.
  • The loamy soil also has humus in it. It has the right water holding capacity for the growth of plants.

Properties of Soil

  • Percolation rate of water is different in different types of soil.
  • It is highest in the sandy and least in the clayey.

Soil and crops

  • Clayey and loamy soils are both suitable for growing cereals like wheat, and gram. Such soils are good at retaining water.
  • For paddy, soils rich in clay and organic matter and having a good capacity to retain water are ideal.
  • For lentils (masoor) and other pulses, loam, which drain water easily, are required.
  • For cotton, sandy-loam or loam, which drain water easily and can hold plenty of air, are more suitable.
  • Crops such as wheat are grown in the fine clayey because they are rich in humus and are very fertile.

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Soil Erosion

  • The removal of land surface by water, wind or ice is known as erosion.
  • Plant roots firmly bind the soil. In the absence of plants, it becomes loose. So it can be moved by wind and flowing water.
  • Erosion is more severe in areas of little or no surface vegetation, such as desert or bare lands.
  • So, cutting of trees and deforestation should be prevented and effort should be made to increase the green areas.

Source: NCERT Image : pexels

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