Detailed Explanation:

Answer: Option 4 — 1, 2 and 3

System of Rice Intensification (SRI) is a climate-smart agricultural practice that optimizes resource use through alternate wetting and drying (AWD) of rice fields. This method significantly reduces seed, water, and energy requirements while minimizing methane emissions from paddy fields.

✅ Statement 1 – Correct: SRI requires only 5-8 kg/ha of seeds compared to 60-80 kg/ha in traditional methods, as single younger seedlings are planted with wider spacing.

✅ Statement 2 – Correct: Alternate Wetting and Drying (AWD) prevents continuous flooding, reducing anaerobic conditions that produce methane through methanogenic bacteria, cutting emissions by 30-40%.

✅ Statement 3 – Correct: SRI reduces water requirement by 30-50% through controlled irrigation, directly lowering electricity/fuel consumption for pumping groundwater.

📝 Short Notes: System of Rice Intensification (SRI)

• Origin: Developed in Madagascar in the 1980s by Fr. Henri de Laulanié; promoted globally for sustainable rice cultivation.
• Key Principles: Early, quick, and healthy plant establishment; reduced plant density; improved soil conditions with organic matter; reduced and controlled water application.
• Planting Method: Single seedlings (8-12 days old) transplanted with wide spacing (25×25 cm), unlike traditional clumps of 3-4 seedlings.
• Water Management: Alternate Wetting and Drying (AWD) instead of continuous flooding; fields kept moist but not submerged, saving 25-50% water.
• Environmental Benefits: 30-40% reduction in methane emissions; lower water pollution; reduced energy consumption; enhanced soil health and biodiversity.
• Yield & Economics: 20-50% higher yields with 80-90% less seed requirement; reduces input costs while improving grain quality and farmer income.
• Challenges: Labor-intensive initially; requires knowledge and training; not suitable for all soil types; needs good water control infrastructure.