ICSE Class 6 Answered
ii. Paedogenesis: In this phase of soil formation, soil gets enriched with minerals and humus by the action of detritivores and arthropods. The addition of organic matter is the final stage in the soil formation.
3. Soil erosion refers to the wearing away of a field's topsoil by the forces of water and wind leading to desertification
Factors of soil erosion are:
- Deforestation: The roots of the trees hold the soil together. So indiscriminate felling of the trees leads to soil erosion by running water and wind.
- Floods and torrential rains: Floods and rains result in soil erosion especially when the land is devoid of any trees or vegetation cover.
- Overgrazing of land: Grazing of animals may lead to the removal of grass cover, which may result in soil erosion.
4.
Deforestation |
Afforestation |
Destruction of trees in the forest area and converting large area of land as a habitat for human beings |
Planting of trees in barren lands to increase the area under forests |
Leads to increased carbon dioxide levels and global warming |
Helps in maintaining balance in nature |
5. Major sources of soil pollution are:
i. Industrial wastes
ii. Agricultural practices
iii. Biological agents
iv. Mining
v. Radioactive pollutants
vi. Urban wastes