Theme 24: Deforestation

Description

The objective of this study was to investigate the change in carbon stocks in soil following deforestation of the Atlantic forest in the South of Bahia State (Brazil) and replacement with productive pastures of Brachiaria humidicola either in monoculture or with the introduction of the forage legume Desmodium ovalifolium. Carbon stocks in the 0-30 cm layer were 44.5 Mg ha-1 under the original forest and found to be approximately 42 Mg ha-1 C 10 years later. At this time pastures of B. humidicola with or without the presence of D. ovalifolium were formed and grazed continuously for a further nine years until 1997. To 30 cm depth, C stocks increased during this time to 49.3 Mg ha-1 in the grass-only pasture and 52.4 Mg ha-1 in the mixed pasture which suggests that the presence of the legume enhanced C accumulation under the Brachiaria pastures. Analysis of the 13C abundance of samples taken to 100 cm depth in 1997 revealed that there was significant accumulation of organic matter derived from the Brachiaria to a depth of 50 cm in the soil and this material was of high C:N ratio (22-27).

Share

COinS
 

Carbon Accumulation in Soils under Brachiaria Pastures in the Atlantic Forest Region of the South of Bahia, Brazil

The objective of this study was to investigate the change in carbon stocks in soil following deforestation of the Atlantic forest in the South of Bahia State (Brazil) and replacement with productive pastures of Brachiaria humidicola either in monoculture or with the introduction of the forage legume Desmodium ovalifolium. Carbon stocks in the 0-30 cm layer were 44.5 Mg ha-1 under the original forest and found to be approximately 42 Mg ha-1 C 10 years later. At this time pastures of B. humidicola with or without the presence of D. ovalifolium were formed and grazed continuously for a further nine years until 1997. To 30 cm depth, C stocks increased during this time to 49.3 Mg ha-1 in the grass-only pasture and 52.4 Mg ha-1 in the mixed pasture which suggests that the presence of the legume enhanced C accumulation under the Brachiaria pastures. Analysis of the 13C abundance of samples taken to 100 cm depth in 1997 revealed that there was significant accumulation of organic matter derived from the Brachiaria to a depth of 50 cm in the soil and this material was of high C:N ratio (22-27).