Correct Option
The correct option is A-4, B-2, C-3, D-1
Explanation
Soil conservation refers to the prevention of soil loss from erosion or reduced fertility caused by over usage, acidification, salinization, or other chemical soil contamination. The methods listed in the question are specific techniques used to protect the topsoil from the erosive forces of wind and water.
Detailed Analysis
- A. Mulching (Matches 4): Mulching involves covering the bare ground between plants with a layer of organic matter like straw. This helps to retain soil moisture, regulate temperature, and prevent soil erosion by reducing the direct impact of rain.
- B. Contour Barriers (Matches 2): Stones, grass, and soil are used to build barriers along the contours of a slope. Trenches are dug in front of the barriers to collect water, which reduces the speed of runoff and allows water to percolate into the soil.
- C. Rock Dam (Matches 3): Rocks are piled up across a drainage path to slow down the flow of water. This prevents the formation of gullies and further soil loss by reducing the kinetic energy of the flowing water.
- D. Intercropping (Matches 1): Different crops are grown in alternate rows and are sown at different times to protect the soil from rain wash. This ensures that the field is not left entirely bare at any point, reducing surface runoff.
Key Takeaway
Soil Conservation Methods: Mulching focuses on moisture retention; Contour Barriers and Rock Dams focus on slowing water runoff; Intercropping focuses on maintaining soil cover to prevent rain wash.