Which of the following is pair of biofertilizers?[2001]a)Azolla and BGAb)Nostoc and legumesc)Rhizobium and grassesd)Salmonella and E. coliCorrect answer is option 'A'. Can you explain this answer?

Question

Answer

Azolla and BGA are biofertilizers so option a is correct

Answer

Biofertilizers are the suspension of microorganism which mainly increases the growth of the plants.These secrete the growth promoting substances.The microorganisms in biofertilizers restore the soil's natural nutrient cycle and build soil organic matter. Biofertilizers such as Rhizobium,Azobacter,Azospirilium,and blue-green algae(BGA)are used.Anabaena in association with water fern azolla.Contributes nitrogen up to 60kg/ha/season and also enriches soil with organic matter so, the correct answer is option 'A'.

Answer

Azola is a aquatic pteridophytes that grow in mainly rice fields and increases the production
while BGA has special structure call heterocysts (non photosynthetic site thick walled structure)help in nitrogen fixation
so they both are called biofertilizer.
thanks

Answer

Pair of Biofertilizers:

A. Azolla and BGA:
- Azolla is a floating aquatic fern that belongs to the family Salviniaceae.
- It is known for its nitrogen-fixing ability, as it forms a symbiotic relationship with a blue-green alga called Anabaena azollae.
- This alga fixes atmospheric nitrogen and provides it to the fern, which in turn utilizes it for its growth and development.
- Azolla is commonly used as a biofertilizer in rice cultivation because it enhances soil fertility by fixing atmospheric nitrogen and releasing it into the soil.
- The nitrogen fixed by Azolla can be utilized by the rice plants, resulting in increased crop productivity.

B. Nostoc and legumes:
- Nostoc is a genus of cyanobacteria, commonly known as blue-green algae.
- It forms symbiotic associations with the roots of leguminous plants, such as soybeans, peas, and clover.
- The relationship between Nostoc and legumes is mutualistic, where Nostoc provides fixed nitrogen to the plant, and in return, the plant provides carbohydrates and a suitable environment for the growth of Nostoc.
- This process is known as nitrogen fixation, and it plays a crucial role in improving soil fertility and plant nutrition.
- Legumes are often used as biofertilizers in agriculture due to their ability to fix atmospheric nitrogen and enhance the growth of other crops.

C. Rhizobium and grasses:
- Rhizobium is a genus of bacteria that forms a symbiotic relationship with the roots of legumes, not grasses.
- These bacteria infect the root nodules of legumes and convert atmospheric nitrogen into a usable form for the plants.
- Grasses, on the other hand, typically form associations with arbuscular mycorrhizal fungi for nutrient uptake but do not have a symbiotic relationship with Rhizobium.

D. Salmonella and E. coli:
- Salmonella and E. coli are not biofertilizers, but rather pathogenic bacteria that can cause diseases in humans and animals.
- They are not associated with nitrogen fixation or enhancing soil fertility.

Therefore, the correct pair of biofertilizers among the given options is option A, Azolla and BGA.

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