Carbon Fluxes From Different Pools in a Mined Area Under Reclamation in Minas Gerais State, Brazil

Despite the benefits of grass cultivation and organic fertilization in mining areas undergoing reclamation, these practices may be associated to CO2 emissions and soil organic matter (SOM) losses by priming effect. In the present study, we evaluated the changes on SOM pools and C–CO2 emissions in a bauxite-mined area under reclamation fertilized with poultry litter (PL) (0, 10, 20, and 40 Mg ha−1) and cultivated with Brachiaria brizantha. Increases of about 3·5 times in the soil labile C were observed 1 year after experiment establishment. High C–CO2 fluxes and a significant positive priming effect were observed in the presence of B. brizantha, increasing native C mineralization by nearly 4·9 times. Nevertheless, no net soil C loss was detected, probably because of the C inputs derived from B. brizantha, which offset these losses. In fact, the grass increased total organic C by 45% when fertilized with 40 Mg PL ha−1. The data obtained suggest that the cultivation of B. brizantha fertilized with PL can be a promising option for rapid recovery in SOM in areas under reclamation. Copyright © 2016 John Wiley & Sons, Ltd.