| County, State | Date of Initial Sampling | Treatment | Cover Crop Year† | 2018 Cash Crop | Fall 2018/Summer 2019 | Fall 2019/Summer 2020 | |||
| Cover Crop | Cash Crop | Cover Crop | Cash Crop | ||||||
| St. Francis, AR | December 2019 | No-cover crop | - | Cotton | - | Cotton | - | Cotton | |
| Cover crop | 2018 | Cotton | Cereal rye | Cotton | Cereal rye | Cotton | |||
| Clay, AR | October 2019 | No-cover crop | - | Corn | - | Cotton | - | Cotton | |
| Cover crop | 2018 | Cotton | Cereal rye | Cotton | Cereal rye | Cotton | |||
| Shelby, TN | May 2020 | No-cover crop | - | Cotton | - | Cotton | - | Cotton | |
| Cover crop | 2019 | Cotton | - | Cotton | Cereal rye | Cotton | |||
| Cross, AR | December 2019 | No-cover crop | - | Corn | - | Soybean | - | Corn | |
| Cover crop | 2015 | Corn | Cereal rye Black oats Crimson clover Austrian winter pea | Soybean | Cereal rye Black oats Crimson clover Austrian winter pea | Corn | |||
| Greene, AR | November 2019 | No-cover crop | - | Soybean | - | Soybean | - | Soybean | |
| Cover crop | 2018 | Soybean | Cereal rye Black oats Crimson clover | Soybean | Cereal rye Black oats Crimson clover | Soybean | |||