Which of the following can fix atmospheric nitrogen while free living in the soil ?  (A) Azospirillum  (B) Azotobacter  (C) Both (A) & (B)  (D) Rhizobium
Which of the following can fix atmospheric nitrogen while free living in the soil ?  (A) Azospirillum  (B) Azotobacter  (C) Both (A) & (B)  (D) Rhizobium

Answer: (C) Both (A) & (B)

Explanation: Bacteria such as Azotobacter and Azospirillum fix nitrogen from the atmosphere while free-living in soil, enriching the nitrogen content of the soil.