Which one of the following microorganisms is not used as a biofertiliser that enriches the nutrient quality of the soil?
Answer & explanation
Correct answer: option 1
The correct answer is Option (1) → Trichoderma
Biofertilisers are living organisms that make the soil richer in nutrients. The main ones are bacteria, fungi and cyanobacteria.
(1) Trichoderma — Not a biofertiliser. Trichoderma is a free-living fungus of the root area. It is a biocontrol agent, used against several fungi that cause plant diseases. It protects plants; it does not add nutrients to the soil.
(2) Azospirillum — A biofertiliser. It is a free-living bacterium in the soil that fixes atmospheric nitrogen.
(3) Azotobacter — A biofertiliser. It is another free-living soil bacterium that fixes nitrogen.
(4) Rhizobium — A biofertiliser. It lives in the root nodules of leguminous plants (symbiotic) and fixes nitrogen for the plant.
NCERT Extract:
Microbes as Biocontrol Agents – …
