| Cover crop species | Cu rate (mg kg−1) | Average | |||
| 0 | 5 | 10 | 20 | ||
| 1. Crotalaria (Smooth crotalaria) | 17.37ab | 27.34abc | 29.63bc | 25.66abc | 25.00bc |
| 2. Crotalaria (Showy Crotalaria) | 19.91ab | 25.36bc | 20.61c | 30.53ab | 24.10bc |
| 3. Calopogonio (Calapo) | 18.40ab | 18.56c | 15.49c | 20.44bc | 18.22cd |
| 4. Pueraria (Tropical Kudzu) | 23.28ab | 44.17a | 43.38ab | 18.74bc | 32.39b |
| 5. Pigeonpea (black) | 40.91a | 36.24ab | 50.12a | 38.38a | 41.41a |
| 6. Lablab | 21.29ab | 18.31c | 19.15c | 27.88ab | 21.65cd |
| 7. Black velvet bean | 29.42ab | 24.64bc | 23.86bc | 26.43ab | 26.09bc |
| 8. Gray velvet bean (Bengal bean) | 34.05ab | 22.96bc | 20.61c | 21.85bc | 24.86bc |
| 9 Jack bean | 15.49b | 12.36c | 12.64c | 11.63c | 13.03d |
| Average | 24.45a | 25.55a | 26.16a | 24.61a | 25.19 |
| F-Test | |||||
| Copper rate (Cu) | ** | ||||
| Cover crop species (C) | ** | ||||
| Cu X C | ** | ||||
| CVCu (%) | 28.82 | ||||
| CVC (%) | 27.01 | ||||