| Project Name | Duration (years) | # of Samples (n) | Description of sampling method. | Outliers Removed |
| Humic Hope | 2 | 449 | 15’ radius around GPS points | 16 |
| Experiment.com | 3 | 40 | 60’ × 100’ plot composites | 0 |
| 2013 CIG | 4 | 13 | Zone composites by soil series | 0 |