Class | Extremely high | High | Moderate to high | Low to moderate | Low | Extremely low |
Organic matter | >40 | 30 - 40 | 20 - 30 | 10 - 20 | 6 - 10 | <6 |
Total nitrogen | >2 | 1.5 - 2 | 1 - 1.5 | 0.75 - 1 | 0.5 - 0.75 | <0.5 |