UPSC Prelims 2020 Q80: Environment & Ecology – Sustainable Agriculture & Forestry
- (a) 1 and 2 only
- (b) 2 only
- (c) 1 and 3 only
- (d) 1, 2 and 3
Answer: (d) 1, 2 and 3
Explanation
Biochar in Farming: Applications & Benefits
| Statement | Claim | Verdict | Detail |
|---|---|---|---|
| 1 | Used in vertical farming growing medium | TRUE | Biochar serves as soil amendment in vertical farm substrates. Improves aeration + water retention. |
| 2 | Promotes nitrogen-fixing microorganisms | TRUE | Biochar's porous structure supports beneficial microbes (Rhizobium, Azospirillum). Enhances nutrient cycling. |
| 3 | Enables longer water retention | TRUE | Biochar is highly porous (large surface area). Water-holding capacity increases by 15-20% in growing medium. |
All three statements are correct. Answer: (d) 1, 2 and 3.
Answer: (d) 1, 2 and 3.
Why each option is right or wrong
- (a) Incorrect. Incomplete - statements 2 and 3 also correct.
- (b) Incorrect. Statements 1 and 3 also correct.
- (c) Incorrect. Statement 2 is also correct.
- (d) CORRECT. All three statements about biochar's agricultural benefits are true.
Key point
Biochar science: Charcoal from biomass pyrolysis (250-1000°C, no oxygen). Carbon-rich, stable, microbe-friendly. Improves soil + sequesters carbon (climate mitigation).
Remember
Biochar in farming can be: (1) used as part of growing medium in vertical farming (correct), (2) promotes nitrogen-fixing microorganism growth through its porous structure (correct), (3) enables the growing medium to retain water longer (correct). All three benefits are scientifically documented.
Common mistakes
- Confusing biochar with compost. Biochar is inert carbon; compost is nutrient-rich organic matter. Both beneficial but different.
- Underestimating microbial colonization. Biochar's porosity (>1000 m^2/g surface area) is ideal for microbial habitat.
- Missing carbon sequestration benefit - biochar can store carbon for 100+ years.
Exam tip
Biochar market: Growing interest (carbon credits, soil health). Cost ~$500-2000/tonne. Used in horticulture, cannabis farming, regenerative agriculture. India pilot programs in progress.
Sources
- IBI (International Biochar Initiative) - Biochar Research
- Journal of Environmental Management - Biochar Effects