Agriculture and Environment: UPSC Previous Year Questions (Environment and Ecology)

Explanation

Terrestrial Carbon sequestration is the process through which carbon dioxide from the atmosphere is absorbed by trees and plants through photosynthesis and stored as carbon in soil and biomass. Option 3 is correct: Zero Tillage is the process where the crop seed will be sown through drillers without prior land preparation and distributed in the soil where previous crop stubbles are present. Zero tillage not only reduces the cost of cultivation it also reduces the soil erosion, crop duration, irrigation requirement and weed effect which is better than tillage. Zero tillage is environmentally safe because it helps in reducing greenhouse effect through carbon sequestration. Options 1 and 2 are incorrect:

Contour bundling involves the construction of banks along the contours. Terracing and contour bunding divide the hill slope into numerous small slopes, check the flow of water, promote absorption of water by soil and save soil from erosion. Retaining walls of terraces control the flow of water and help in reducing soil erosion. Relay Cropping is the process of growing one crop, then planting another crop (usually a cover crop) in the same field before harvesting the first. This helps avoid competition between the main crop and the intercrop. It also uses the field for a longer time, since the cover crop usually continues to grow after the main crop is harvested.