state the factors affecting soil formation ?
Answers
• The Parent Rock: The original rock from which soil is formed by the process of weathering is known as the parent rock. For example, the black soil of India is derived from the lava rock.
• The Topography: Topographical variations, such as mountains, plateaus and plains affect the thickness of a soil cover. In mountainous regions, on the steep slopes, the top layer of soil is shallow and thin. On the other hand, at gentle slopes, the soil cover is thick and deep. Soil cover is always thick in plains. For example, the northern plains of India have thick soil cover as compared to the Himalayas. Even within mountains, river valleys have thick soil cover
• The Climate: Climatic factors, like temperature and rainfall, affect the soll formation. In the areas of high rainfall and extreme temperature, rocks are easily weathered. In Rajasthan, due to extreme difference in day and night temperatures, rocks expand and contract, which results in quick formation of the soil. In regions of heavy rainfall, soluble rock material easily gets dissolved and washed away by the running water. Thus, it affects the soil formation.
•The Vegetation Cover: At times, plants grow in the cracks existing in a rock. With time, roots of these plants start penetrating in the cracks and make them wider. As a result, cracks disintegrate into smaller pieces and help in the soil formation. Remains of dead or decomposed plants and animals provide humus to the soil, which enriches the fertility of the soil. The soil of densely forested area is generally very rich in humus content.
• Time: Time gives maturity to the soil. Although, soil is a renewable resource, yet it takes thousands of years to develop a very thin layer of soil on the earth's surface. For example, the Nile delta and delta formed by the Ganga and Brahmaputra rivers have very deep and fertile soil.