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Topic Biofertilizers
Asked 4 times across 3 UPSC exams over 30 years (1994–2024), peaking in 2013.
Key insights
- Most tested in CSE — 2 of 4 PYQs
- Most asked in 2013
- Recurs across 4 years (1994–2024)
How it travelled across exams
First appearance in each exam — the same idea, reframed.
CSE 1994 → GEO 2023 → CISF 2024
How the concept evolved
Long-running — most appearances (2 of 4) predate 2016, and it still returns.
Sample questions
You've seen the pattern — here are a few of the actual PYQs.
CISF2024
Rhizobium is a
- A biopesticide
- B biofertilizer ✓
- C bioherbicide
- D mycoherbicide
✓ Correct answer: (B)
Agriculture › Soils & Inputs
GEO2023
Duckweed or Azolla is used as a/an
- A pesticide
- B biofertilizer ✓
- C arsenic indicator
- D antiseptic
✓ Correct answer: (B)
Science & Technology › Biology & Health
CSE2013
Consider the following organisms
- Agaricus
- Nostoc
- Spirogyra
Which of the above is/are used as biofertilizer/biofertilizers?
- A 1 and 2
- B 2 only ✓
- C 2 and 3
- D 3 only
✓ Correct answer: (B)
Agriculture › Soils & Inputs
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