Which bacteria fix atmospheric nitrogen whilethey are free - living in the soil ?

Aquatic fern which is an excellent biofertilizer

Consider the following statements about organic farming

$I.$ Organic farming promotes the use of crop rotations and cover crops and encourages balanced host/predator relationships

$II.$ Integrated pest and weed management and soil conservation systems are valuable tools on an organic farm

$III.$ Organic farming protects the environment, minimize soil degradation and erosion and decrease pollution

Which of the statements given above are correct?

Azotobacter and Bacillus polymyxa are

Which of the following is free living aerobic and nonphotosynthetic nitrogen fixing bacterium

Leghaemoglobin occurs in