Which organisms are used to increase thesoil fertility ?

Assertion : Nitrogen-fixing enzyme in legume root nodules function at low oxygen concentration.

Reason : Low oxygen concentration is provided by leghaemoglobin.

Organic farming includes

$I.$ use of biofertilisers and biopesticides

$II.$ crop rotation

$III.$ locally developed pest resistant varieties

Choose the correct option

A nitrogen fixing bacterium that forms a loose assocation with the roots of crop plants is

$VAM $ is important for

Biofertilizers