Question

Compare the top three horizons of soil and write short descriptions on each horizon.​

Answer 1

Answer:

Formation of Soil

The soil has taken thousands of years to form. Soil formation takes place in the following ways:

Big rocks break down into smaller rocks by continuous action of wind and rain. It takes many years for these rocks to break down into smaller rocks.

Rocks are mainly broken by two types of weathering- physical weathering and chemical weathering. A number of natural force, called agents, work to break down the parent rock into tiny particles of soil. These agents include wind, water, the sun’s heat, and plants and animals.

These pieces get further broken down to form sand and silt and, ultimately, into finer particles and the process continues. This process is very slow. It takes thousands of years to form a just 1cm layer of soil. These fine particles form the top layer of the soil.

Answer 2

A-horizon=the uppermost horizon is generally dark in colour as it is rich in humus and minerals.this provides shelter for many living organisms such as worms,rodents,moles and beetles.the roofs of small plants are embedded entirely in the topsoil.



B horizon=The next layer has a lesser amount of humus but more minerals.this layer is generally harder and more compact and is called the B-horizon or the middle layer


C horizon=the third layer is the c-horizon,which is made up of small lumps of rocks with cracks. And crevices.


Bedrock=this layer is the bedrock,which is the last layer and difficult to dig with a spade