RBSE Class 7 Science Notes Chapter 9 Soil

These comprehensive RBSE Class 7 Science Notes Chapter 9 Soil will give a brief overview of all the concepts.

RBSE Class 7 Science Chapter 9 Notes Soil

→ Soil is important for life on the earth.

→ The soil is formed by the breaking down of rocks by the action of wind, water and climate. This process is called weathering.

→ The nature of any soil depends upon the rocks from which it has been formed and the type of vegetation that grows in it.

→ A vertical section through different layers of the soil is called the soil profile. Each layer differs in feel (texture), colour depth and chemical composition. These layers are referred to as horizons.

→ The mixture of rock particles and humus is called the soil.

→ The soil is classified on the basis of the proportion of particles of various sizes. Different types of soil are : sandy, clayey, loamy and silt.

→ Percolation rate(mL/min) = \(\frac{\text { amount of water }(\mathrm{mL})}{\text { percolation time }(\mathrm{min})}\)

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

→ Soil is affected by wind, rainfall, temperature, light and humidity. These are some important, climatic factors which affect the soil profile and bring changes in the soil structure.

→ Soil holds water in it, which is railed soil moisture. The rapacity of a soil to hold water is important for various crops.