Table 9. The ultimate source of essential plant nutrients is from air, water and the geosphere. The ultimate source of nitrogen in soil is from nitrogen fixation. Once nitrogen is fixed into organic matter, nitrogen mineralization from organic matter becomes the primary source of nitrogen for plant growth. Atmospheric deposition can be a large source of sulfur for many forest systems.
| Macronutrients | Micronutrients |
|---|
| From air and water | From geosphere | From geosphere |
|---|
| carbon | phosphorus | iron |
| hydrogen | potassium | manganese |
| oxygen | calcium | boron |
| nitrogen | magnesium | molybdenum |
| sulfur | copper |
| | zinc |
| | chlorine |
| | cobalt |