Question

write the name of microorganisms used as biofertilizer.3marks​

Answer 1

Explanation:

Several microorganisms are commonly used as biofertilizers including nitrogen-fixing soil bacteria (Azotobacter, Rhizobium), nitrogen-fixing cyanobacteria (Anabaena), phosphate-solubilizing bacteria (Pseudomonas sp.), and AM fungi.

Answer 2

Answer

Rhizobium: They form root nodules in leguminous plants and fix the atmospheric nitrogen into an organic form. Rhizobium also has no negative effect on soil quality and improves the quality, nutrient content, and growth of the plant.

Azotobacter: These are free-living nitrogen fixers found in all types of upland crops. These not only fix nitrogen but also provide certain antibiotics and growth substances to the plant.

Azospirillum: Unlike Azotobacter, these can be used in wetland areas. They are found inside the roots of the plant (non-free-living) where they fix the atmospheric nitrogen.

Blue-green algae: These are free-living nitrogen-fixing Cyanobacteria that are present only in wet and marshy lands. However, they do not survive in acidic soil.

Mycorrhiza: It is a symbiotic association between the fungi and the roots of a plant. The mycorrhizal fungi play an important role in binding the soil together and improves the activity of the microbes. The fungi draw water and nutrients from the soil thereby increasing the plant productivity. It also helps the plant to survive under various environmental stresses.