Azotobacter and Azospirillum - Azotobacter uses the organic matter present in soil to fix nitrogen asymbiotically; it is capable of fixing up to 30 kg nitrogen/ha/yr. Azospirillum species occur in association with the roots of many plants of the grass family, e.g., sugarcane, jowar, wheat, bajra, etc. These bacteria are capable of fixing over 30 kg N/ha/yr. Field inoculation of crops with Azotobacter or Azospirillum is estimated to save 15-25 kg N/ha.