Bacteria in soil convert atmospheric nitrogen into a form usable by plants, and more bacteria mean healthier soil. Given these facts, what allows soil to convert atmospheric nitrogen into a usable form by plants among the following options:
- hydrogen and oxygen
 - diseased soil
 - peachleaf willow
 - bacteria-free soil
 - healthier soil
 - nutrients
 - virus filled soil
 - Cooking


 

     healthier soil    