Bacteria in soil convert atmospheric nitrogen into a form usable by plants.
More bacteria mean healthier soil.
Healthier soil allows soil to convert atmospheric nitrogen into a usable form by plants.
What allows soil to convert atmospheric nitrogen into a usable form by plants?
  - hydrogen and oxygen
  - diseased soil
  - peachleaf willow
  - bacteria-free soil
  - healthier soil
  - nutrients
  - virus filled soil
  - Cooking