Which one of the following organisms can serve as a biofertilizer for rice crop?
- ABlue-green algaeCorrect
- BRhizobium sp
- CMycorrhizal fungi
- DAzotobacter sp
Explanation
The correct answer is A because Blue green algae, also known as cyanobacteria, have the unique ability to fix atmospheric nitrogen in waterlogged conditions, which are typical for rice cultivation. These organisms, specifically genera like Anabaena and Nostoc, form a symbiotic relationship with the water fern Azolla or exist freely in the paddy fields, significantly enhancing soil fertility and crop yield.
In contrast, Rhizobium is primarily associated with leguminous crops, Azotobacter is used for dryland crops like wheat or maize, and Mycorrhizal fungi mainly assist in phosphorus absorption rather than primary nitrogen fixation for rice. Therefore, Blue green algae is the most suitable biofertilizer specifically for the rice ecosystem.
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