Biological components of the soil

• In addition to physical components the soil also has biological components as well
• These include living plants, animals and dead organic matter
• Some of these active and useful organisms found in the soil are microscopic
• These are known as micro-organisms
• They include bacteria and fungi
• These micro-organisms break down dead animals and plants
• During this decay/decomposition process nutrients are released into the soil
• These nutrients include mineral salts such as phosphates and nitrates as well as are mineral elements required in plant growth and development
• If there is high organic content in the soil the soil is called fertile
• It will support healthy plant growth
• The biological component of the soil play important roles in the life of the soil and the whole ecosystem
• The fertility of the soil is improved by the action of micro-organisms on dead organic matter in the soil
• The organic matter is broken down slowly to become part of the soil in the form of humus
• The organic matter itself and the action of the micro-organisms improve the aeration of the soil
• Worms and insects make burrows in the soil which allows air to penetrate more easily
• The soil particles are also held together by the organic content which improves the texture of the soil
• The particles are held together much more loosely with air spaces
• This makes the soil lighter and easier to cultivate
• Loamy soils are said to have a god crumb structure which makes them suited to agricultural activities

To access more topics go to the Combined Science Notes page.