What is organic matter
This is the non mineral portion of soil solids from decayed and partially decayed plant and animal residues.
It is composed of
- Pigments e.t.c
Organic matter is grouped into three main components,.
Litter: This includes relatively un decomposed dead parts of plants and animals and their wastes that have just been deposited on the soil surface.
Residues: These include the dead parts of plants and animals which are actively decomposing.
Humus: This is the well decomposed and stable organic matter. It is the final product of organic matter decomposition.
Importance of organic matter in the soil
It provides food and shelter for soil living organisms.
It is a source of plant nutrients.
It buffers the soil pH i.e. controls pH.
It improves the soil structure by binding soil particle together.
It increases the soil CEC
It reduces soil erosion because it holds soil particles together more firmly.
Provides attachment sites for attachment of mineral ions.
The organic acids released during the process of organic mater break down help in weathering
It contains hormones and vitamins that stimulate plant growth e.g auxins.
It improves air movement and water percolation because it improves the soil structure.