3. How does the presence of humus
affect soil?
4. Why are dams called multi-purpose
projects?
5. What do you mean by rainwater
harvesting?
6. Why is it important to conserve our
mineral resources?
7. What is soil erosion? How does it
Hou can it he nrevented?
Answers
Explanation:
1Humus significantly affects the bulk density of soil and contributes to its retention of moisture and nutrients. ... Humus has many nutrients that improve the health of soil, nitrogen being the most important. The ratio of carbon to nitrogen (C:N) of humus is 10:1.
Answer:
3. Some experts think humus makes soil more fertile. Others say humus helps prevent disease in plants and food crops. When humus is in soil, the soil will crumble. Air and water move easily through the loose soil, and oxygen can reach the roots of plants.
4. Dams are called multi-purpose projects because:1 Earlier they were built to impound rivers and rainwater could be used later for irrigation. ... 3 Thus they are called multi-purpose projects.
5. Definition. Rain water harvesting is a technique of collection and storage of rain water in surface (storage tanks) or sub surface aquifer before it is lost as surface runoff.
6. Conservation of mineral resources is essential because they are a country's valuable possession. ... Minerals should be used in a planned and sustainable manner. Technology should be upgraded to allow the use of low-grade ore at low costs. Recycling of metals also results in the conservation of mineral resources.
7. Planting Vegetation as ground cover: Farmers plant trees and grass to cover and bind the soil. Plants prevent wind and water erosion by covering the soil and binding the soil with their roots. The best choice of plants to prevent soil erosion are herbs, wild flowers and small trees.