Detailed Explanation:

Carbon sequestration is the process of capturing and storing atmospheric CO₂ in soil organic matter, helping mitigate climate change.

✅ Contour bunding: Prevents soil erosion on slopes, retains organic matter and moisture, enhancing carbon storage in soil.

✅ Relay cropping: Maintains continuous soil cover by sowing second crop before first harvest, reduces soil disturbance, increases biomass return and carbon sequestration.

✅ Zero tillage: Eliminates soil disturbance, preserves soil structure, increases organic matter retention and microbial activity, significantly enhances carbon storage.

All three practices contribute to carbon sequestration in soil.