What is the use of biochar in farming ? 1. Biochar can be used as a part of the growing medium in vertical farming. 2. When biochar is a part of the growing medium, it promotes the growth of nitrogen-fixing microorganisms. 3. When biochar is a part of the growing medium, it enables the growing medium to retain water for longer time. Which of the statements given above is/are correct ?
- (a) 1 and 2 only
- (b) 2 only
- (c) 1 and 3 only
- (d) 1, 2 and 3 ✓ UPSC's answer
Why the answer is (d)
• Biochar is charcoal made by heating biomass without oxygen (pyrolysis) and added to soil or growing media.
• Its porous structure holds water and nutrients, so media containing biochar retain moisture longer (statement 3) and it can form part of soilless growing media in vertical farms (statement 1).
• Biochar's pores shelter beneficial microbes, including nitrogen-fixing bacteria, and improve their growth (statement 2).
• It also sequesters carbon for centuries, making it a climate-smart amendment.
• Hence 1, 2 and 3, option (d).
Why the other options are wrong
- (a) 1 and 2 only
- Statement 3 on water retention is also correct.
- (b) 2 only
- Statements 1 and 3 are also correct.
- (c) 1 and 3 only
- Statement 2 on nitrogen-fixing microbes is also correct.
Asked in the GS Paper I of the UPSC Civil Services Preliminary Examination 2020, held on 4 October 2020. Question and answer key: Union Public Service Commission. Explanation: UPSC Answer Check.