The following are importance or Roles of soil organic matter:
- Organic Matter creates a granular condition of soil which maintains favorable condition of aeration and permeability.
- Water holding capacity of soil is increased and surface runoff, erosion etc., are reduced as there is good infiltration due to the addition of organic matter.
- Surface mulching with coarse organic matter lowers wind erosion and lowers soil temperatures in the summer and keeps the soil warmer in winter.
- organic matter serves as a source of energy for the microbes and as a reservoir of nutrients that are essential for plant growth and also hormones, antibiotics.
- Fresh organic matter supplies food for earthworms, ants and rodents and makes soil P readily available in acid soils.
- Organic acids released from decomposing organic matter help to reduce alkalinity in soils; organic acids along with released CO2 dissolve minerals and make them more available.
- Humus (a highly decomposed organic matter) provides a storehouse for the exchangeable and available cations.
- It acts as a buffering agent which checks rapid chemical changes in pH and soil reaction.