| Average | Median | StDev | Rel Error vs. FeAlO | Average | Median | StDev | % Error vs. FeAlO |
| RFA (mg P/kg soil) | (%) | ICP (mg P/kg soil) | (%) | ||||
FeAlO | 58.2 | 31.9 | 103.6 | - | 74.7 | 39.4 | 137.2 | - |
H3A-3 | 58.1 | 32.6 | 104.3 | −0.2% | 69.4* | 38.7 | 130.9 | −7% |
M3 | 142.4* | 84.8* | 315.4 | 145% | 155.9* | 96.6* | 330.9 | 109% |
Water | 10.8* | 23.4* | 31.9 | −81% | 14.9* | 6.8* | 42.4 | −44% |