Question 88 from UPSC CSE 2020 - ENVIRONME NT

Question

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 a longer time.
Which of the statements given above is/are correct?

IASCODEX · Accepted Answer

Correct Option: D. 1, 2, and 3

Strategy: *   Focus on biochar's core properties and uses to evaluate the statements.
*   **Statement 1:** Biochar's structure suits modern farming techniques like vertical farming substrates.
*   **Statement 2:** Its micro-porous surface supports nitrogen-fixing microorganisms.
*   **Statement 3:** Biochar's porosity enables significant water retention.
*   All statements are factually accurate and align with known biochar capabilities.

Key Info: Biochar is a carbon-rich material created by pyrolyzing organic biomass (such as crop residues, wood chips, or manure) under an oxygen-limited environment. It is widely researched and used in agriculture for several reasons:

*   **As a growing medium:** Its stable structure and high porosity make biochar suitable for soilless substrates in hydroponics and vertical farming. It improves aeration, nutrient retention, and acts as a renewable component in horticultural growing media.
*   **Promotion of nitrogen-fixing microorganisms:** Biochar's large surface area provides a favorable habitat for beneficial microorganisms, including those that fix atmospheric nitrogen (e.g., Rhizobia in legumes). Studies show biochar-amended soils support higher microbial activity, increased nitrogen fixation, improved soil fertility, boosted plant productivity, and reduced N2O emissions.
*   **Water retention:** Biochar's porous nature increases soil's ability to retain water, minimizing drought stress and supporting plant growth during low rainfall or irregular irrigation. This property enhances plant-available water, reduces nutrient leaching, and improves overall soil health.

Biochar also sequesters stable carbon, mitigating greenhouse gas emissions. Its benefits in sustainable agriculture are recognized in both field soil applications and controlled-environment agriculture, such as vertical and urban farming. Regulatory and research institutions, such as ICAR and FAO, promote biochar for soil improvement and climate resilience.

IASCODEX · Answer

Option A: 1 and 2 only

IASCODEX · Answer

Option B: 2 only

IASCODEX · Answer

Option C: 1 and 3 only