The climatic conditions like wind, rainfall, humidity, amount of available sunlight, etc determine the type and soil profile of a particular region.

Percolation rate is a measure of the water retention capacity of a soil sample. It is measured as:

Percolation rate (mL/min) = $\frac{\text{Amount of water (mL)}}{\text{Percolation time (mins)}}$

The different types of particles and substances present in soil lead to the formation of different vertical layers. This is called soil profile. Each individual layer has different properties and texture.

Humus is the lightest layer of soil profile and floats on top of water. It is composed of dead and decomposing remains of animals and plants. It helps increase the quality of soil by adding nutrients to it. It makes the soil more suitable for plant growth.

$\bullet$ Clay soil is the type of soil that is composed of fine particles. Hence, it has very few air spaces. Unlike sandy soil, it will not flow out of the hand if we hold it in our fist. 
$\bullet$ Sand particles are quite large. They cannot fit close together, so there are large spaces between them. These spaces are filled with air. So, it has highest air spaces bewteen its particles.
$\bullet$ Loamy soils have particle size in between those of sandy and clayey soils. So, it has air spaces between those of sandy and clayey soil.
$\bullet$ The rotting dead matter in the soil is called humus.

Cotton and pulses grow well in sandy loams found in Maharashtra, Gujarat and Karnataka. Rice and jute need clay soils and clayey loams to grow.

Soil on earth comes from rocks. The dynamic natural elements like wind, flowing rivers, change in seasons, etc are responsible for the erosion of rocks and the formation of soil.

Sandy soil is characterized by large-sized particles, loosely packed together which flow easily.

Clayey soil is composed of fine particles which have very few air gaps and the particles are tightly packed together.

Loamy soil is a mixture of sandy and clayey soil, along with some percentage of silt.