Table 2.

Showing various inoculants' contributions to the amount of biological N₂ fixation.

S. No.	State	Aerobic/anaerobic	Bacteria	Crop	Amount of N2 fixed Kg/ha/year	Reference(s)
1.	Free living	Aerobic	Azotobacter		10–20	[2]
			Azotobacter	Dry land crops	20–25	[4]
		Anaerobic	Clostridia		2–5
		Facultative	Klebsiella		5–10
2.	Symbiotic	Legumes	Rhizobia		50–500	[2]
			Rhizobium strains	Groundnut, soybean	50–200	[4]
		Non-legumes	Azospirillum		5–20
			Acetobacter		150
			Anabaena	rice	600	[41,50]
3.	Blue green algae		Anabaena		20–25	[2]
			Azolla		70–100
			Azolla	rice	30–100	[4]