Land use change often has impacts on soil characteristics leading to a change in ecosystem carbon (C) cycling, especially on soil C storage. In Brazil, the substitution of the native Cerrado (Brazilian savanna) vegetation by agricultural activities can be impacted soil carbon stocks. Most of these agricultural areas are grasslands, of which are in some stage of degradation. The objective of this research was to investigate the long-term effects of land use change in native Cerrado (Brazilian Savanna) on soil C storage. Experimental sites consisted of degraded and improved palisadegrass pastures (Brachiaria decumbens), no-tillage systems, riparian vegetation and native forest. The management systems were established at least sixteen years. The results showed that the riparian vegetation and well-managed pasture were important sinks for atmospheric C, with greater stocks of soil C to 100 cm depth. Large losses of soil carbon occurred in degraded pasture, especially in the 0-20 cm depth, where the carbon stocks of the soil were 42, 41, 34 and 12% lower than systems of riparian vegetation, well-managed pasture, native forest and no-tillage, respectively. The results suggest that systems of land use can accumulate or lose C stored in the soil due to management. In addition, well-managed pastures may promote soil C accumulation in subtropical ecosystems.

Sponsored by Fapemig, CNPq/INCTca and Capes, Brazil.