Detailed Explanation:

Answer: Option 1 — 1, 2 and 3 only

Eco-friendly agricultural practices minimize environmental harm while maintaining productivity. Crop diversification, legume intensification, and precision irrigation using tensiometers all qualify as sustainable practices in the Indian context, whereas vertical farming's high energy demands make it unsuitable.

✅ Statement 1 – Correct: Crop diversification enhances soil health, increases biodiversity, breaks pest cycles, and reduces chemical pesticide dependence.
✅ Statement 2 – Correct: Legume intensification naturally enriches soil through nitrogen fixation via Rhizobium bacteria, reducing synthetic fertilizer requirements.
✅ Statement 3 – Correct: Tensiometers measure soil moisture tension, enabling precision irrigation that conserves water and prevents nutrient leaching from over-watering.
❌ Statement 4 – Incorrect: Vertical farming in India is not eco-friendly due to its heavy reliance on artificial lighting and climate control systems powered predominantly by fossil fuel-based electricity, creating a large carbon footprint.

📝 Short Notes: Eco-Friendly Agricultural Practices

• Crop Diversification: Growing multiple crop species in rotation or together; improves soil fertility, pest control, and resilience to climate variability.
• Legume Intensification: Increased cultivation of pulses/legumes (e.g., lentils, chickpeas) that fix atmospheric nitrogen naturally, reducing chemical fertilizer use.
• Precision Irrigation: Use of tools like tensiometers, drip irrigation, and soil moisture sensors to optimize water use and prevent wastage.
• Organic Farming: Avoids synthetic chemicals; uses compost, green manure, and biopesticides.
• Agroforestry: Integrating trees with crops/livestock; enhances carbon sequestration and biodiversity.
• Conservation Tillage: Minimal soil disturbance practices like zero-tillage that preserve soil structure and organic matter.
• Integrated Pest Management (IPM): Combines biological, cultural, and mechanical pest control methods to minimize pesticide use.
• Green Manuring: Growing and plowing back green crops (like Sesbania, Dhaincha) to enrich soil organic content.