Agrosilvopastoral Systems and Well-Managed Pastures Increase Soil Carbon Stocks in the Brazilian Cerrado

• Published in: Rangeland ecology & management Vol. 73; no. 6; pp. 776 - 785
• Main Authors: de Freitas, Igor Costa, Ribeiro, Juliana Martins, Araújo, Nayara Christina Almeida, Santos, Marcia Vitória, Sampaio, Regynaldo Arruda, Fernandes, Luiz Arnaldo, Azevedo, Alcinei Mistico, Feigl, Brigitte Josefine, Cerri, Carlos Eduardo Pellegrino, Frazão, Leidivan Almeida
• Format: Journal Article
• Language: English
• Published: Lawrence the Society for Range Management 01.11.2020; Elsevier Inc; Elsevier Limited
• Subjects: 13C abundance; Agricultural production; Conversion; Corn; Ecosystems; Forestry; Grasses; integrated production system; Land use; Livestock; Livestock grazing; Monoculture; N stocks; Organic matter; Organic soils; OTHER PAPERS; Pasture; Pasture management; Productivity; Soil chemistry; Soil improvement; Soil management; Soil organic matter; Soil properties; Soil quality; Soils; Vegetation; Brazil; integrated production system; N stocks; soil organic matter; 13C abundance; soil quality
• ISSN: 1550-7424; 1551-5028
• DOI: 10.1016/j.rama.2020.08.001

Agrosilvopastoral systems have been promoted as sustainable models that combine crops, livestock grazing, and forestry in the same area. We hypothesize that agrosilvopastoral systems can improve soil C and N stocks over time. Therefore, in this study, we aimed to evaluate the changes in soil C and N stocks after conversion of low-productivity pasture into well-managed pasture and agrosilvopastoral land in the Brazilian Cerrado. Soil samples were collected in 2016 and 2018 at 0–5, 5–10, 10–20, and 20–30 cm depths from the following areas: integrated crop-livestock-forest (ICLF), marandu grass (Brachiaria brizantha) monoculture (MAR), low productivity pasture of signal grass (Brachiaria decumbens) monoculture (PAST), and native vegetation (NV; “Cerrado”). The C and N content and stocks, 13C natural abundance, and C contents in the physical and chemical fractions of soil organic matter (SOM) were measured. The ICLF and MAR systems promoted faster recovery of soil C and N stocks at all soil depths compared with PAST. The C content of the free light fraction of SOM under the ICLF and MAR systems increased, reaching values similar to NV up to 20 cm. The C content was higher in the humin fraction at all depths in all areas, and for this measurement, the ICLF system performed remarkably compared with PAST at a depth of 5–10 cm. Our findings support the hypothesis that conversion of low-productivity pasture into agrosilvopastoral and actively managed pasture systems leads to improvements in soil quality and C and N stocks in the Brazilian Cerrado.