Carbon Soil Storage and Technologies to Increase Soil Carbon Stocks in the South American Savanna

The expansion of the agricultural frontiers that occurred in the last decades in the South American savanna (Cerrado), the second-largest biome in Brazil (covering an area of 204 million hectares), has accounted for a substantial portion of South America’s CO2 emissions. In this context, our research investigated the potential for soil carbon storage in the biome. The analysis of previous data (n = 197) shows a vertical distribution pattern of soil carbon stock: 26.17% for the upper 0–30 cm layer, 37.67% for the 30–100 cm layer, and 36.15% for the 100–200 cm layer. The total soil carbon storage for the biome is 13.5 ± 6.7 gigatons (n = 71) for the upper 0–30 cm layer, 30.5 ± 18.9 Gt (n = 64) for the 0–100 cm layer, and 47.8 ± 4.3 (n = 9) for the 0–200 cm layer. The results indicate that the soil carbon stock up to 1 m deep in the Cerrado ranges from 0.5% to 2.29% of the global soil organic carbon storage for this depth. Further research is necessary to investigate what happens at a depth of at least 2 m. The results also indicate that the soil under pasture lands constitutes the largest manageable pool for increasing soil carbon stocks via the restoration of degraded pastures.