Composition of Soil

The composition of soil is mentioned below:

• Soil is composed of 3 things: Inorganic components (minerals), organic components, water, and air.
• In reality, the percentage of the four components varies tremendously, but on a broad basis the composition is 45% minerals, 20-30% air, and 5% organic matter.
• Water and air are present in spaces between the soil particles but there is variation in the ratio of pores filled by air and water.
• The ratio may vary seasonally, weekly, or even daily.

Inorganic Components of Soil

They are derived from rocks and minerals. 50% of the total mass of the soil is inorganic minerals. The inorganic components are important as:

• They are responsible for soil mass and volume.
• They provide nutrients important for plant growth.
• They supply materials for the formation of other minerals also.

Organic Components of Soil

The percentage of organic matter in the soil is <5%.

• It largely determines soil productivity, as provides food for microorganisms, and other nutrients to the plants and supplies more oxygen to the plant roots.
• The physical properties of soil are also altered by chemical reactions such as ion exchange.
• The decomposition of plants nutrient and animal matter results in the building of organics into the soil.
• It is an important component of soil as it holds soil particles together and stabilizes them and reduce the risk of erosion, improves the ability of soil to transfer air and water.
• Major organic compounds in the soil are fats, waxes, saccharides, and nitrogen.

Water and Air in the soil

Mineral soil consists of 20-30% of water and only half of it is available to plants.

• It acts as a medium for the transport of essential plant nutrients from soil to roots and to the farthest reaches of the plant leaf structure.
• Soil water is part of the global hydrological cycle, which shows how water that falls as precipitation returns to the atmosphere through transpiration and evaporation.

Soil is the loose material that covers the Earth’s surface in most parts of the world. It gives plants the nutrients they need to grow and plants give people and animals food to live. Soil also provides building materials, homes for animals, and things we use every day. More than just dirt, soil is a valuable natural resource that serves as the basis for life as we know it on Earth. Rocks, decaying plants and animals, air, and water all makeup soil. By the process of weathering big rocks break down into smaller and smaller pieces eventually, becoming part of soil.