Which of the following are used as nitro-genous biofertilizers?
- Azola
- Blue Green Algae
- Alfalfa
- Nitrolin Select the correct answer from the codes given below:
Verified Answer
A. 1, 2 and 3
B. 1, 2 and 4
C. 2, and 4 only
D. 2, 3 and 4
Explanation:
Azolla (a fern hosting nitrogen-fixing cyanobacteria) and Blue Green Algae (Cyanobacteria) are well-known nitrogenous biofertilizers. Alfalfa is a leguminous plant that fixes nitrogen, but it is a crop itself, not typically applied as a biofertilizer product. 'Nitrolin' is not a standard term for a biofertilizer, but assuming it refers to a nitrogen-fixing agent or product, then 1, 2, and 4 would be the most plausible combination among the given options.