Multiple choice

A simple technology has been developed in India for plant breeders and farmers to use two plants as biofertilizers for growing rice. The two biofertilizers are

  1. azotobacter and rhizobium

  2. chlorella and spirulina

  3. azolla and nitrogen-fixing blue-green algae

  4. riccia and marchantia
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Azolla is a small water fern that forms symbiotic relationships with nitrogen-fixing cyanobacteria (Anabaena). Blue-green algae (cyanobacteria) are free-living nitrogen fixers. Together, these two biofertilizers are used in rice cultivation in India to reduce nitrogen fertilizer requirements. Azolla is grown in rice paddies and then incorporated into the soil. Neither azotobacter nor rhizobium are used in this system (rhizobium requires legume hosts).

Keep practicing — related questions