NEET BIOLOGY

Detailed explanation-1: -The topsoil layer is a mixture of sand, silt, clay and broken down organic matter, called humus. Humus is rich, highly decomposed organic matter mostly made from dead plants, crunched-up leaves, dead insects and twigs.

Detailed explanation-2: -Topsoil: Topsoil is often referred to as the organic layer. In this layer, plants grow and animals live on top of the soil. The plants keep the soil cool and from drying out. It also has decomposers that recycle the dead plants and animals.

Detailed explanation-3: -The O horizon is typically at the top of the soil structure and is made up of mostly organic matter. This organic matter is vital to the growth of crops and other plants because it holds nutrients such as carbon, phosphorus, nitrogen and sulfur.

Detailed explanation-4: -Topsoil is the upper layer of soil. It has the highest concentration of organic matter and microorganisms and is where most of the Earth’s biological soil activity occurs.

Detailed explanation-5: -The topsoil has the highest concentration of organic matter, nutrients and is where most of the soil’s biological activity occurs. Soil that is not protected by residue or living cover is subject to erosion.