Which practice helps maintain soil fertility and structure?

• A. Mulching
• B. Irrigation
• C. Crop rotation
• D. Pest control

Answer: (C)

Rotating crops directly supports soil health by varying nutrient use and residue input, which helps keep the soil fertile and its structure (tilth) stable. Different plants draw on different nutrients and leave behind different kinds of organic matter. Legumes, for example, add usable nitrogen through their symbiotic bacteria, boosting nitrogen availability for subsequent crops. A mix of deep- and shallow-rooted plants creates a network of roots that aerates the soil, improves porosity, and reduces compaction, which enhances water movement and root growth. With diverse residues returning to the soil, organic matter content increases over time, strengthening soil structure and stability.

Mulching can protect and gradually improve soil organic matter and moisture, but it doesn’t directly manage nutrient balance and root penetration in the same way. Irrigation supplies water but doesn’t add nutrients or change soil structure. Pest control helps protect yields but doesn’t inherently build soil fertility or improve soil structure.