Soil Composition

Composition

1. Forms 5% of the total volume of soil.
2. Made up of plant and animal remains (humus) resulting from decomposition.

Importance of humus

1. Improves soil structure and water retention capacity.
2. Limits leaching and accelerates soil formation.
3. Stores and supplies essential nutrients to plants (nitrogen, phosphorus, potassium, calcium).
4. Helps regulate soil temperature and pH.
5. Living microorganisms aid in decomposition.

Composition

1. Forms 45% of the total volume of soil.
2. Made up of minerals from the parent rock.
3. Minerals include:

• Silicon, iron, calcium, magnesium, copper, lead, nitrogen, phosphorus, sulfur, manganese, zinc, potassium, vanadium.

Importance

1. Minerals provide essential nutrients for plant growth.

Composition

1. Forms 25% of the total volume of soil.
2. Derived primarily from rainfall through infiltration and throughflow.

Importance of water

1. Regulates soil temperature.
2. Helps in the solution and transfer of nutrients within the soil.
3. Excessive water can lead to the leaching of mineral nutrients.
4. Controls chemical processes like weathering and mechanical weathering.

Composition

1. Forms 25% of the total volume of soil.
2. Consists of gases from the soil atmosphere, providing oxygen for plants and soil organisms' metabolism.
3. Helps in the removal of carbon dioxide and other gases.