Autoria: ANDRADE, C. A. de; TRETTEL, M.; GERDES, L; BARBOSA, C. M. P; RODRIGUES, P. H. M.; LIGO, M. A. V.; NOGUEIRA, S. F.; LIMA, M. A. de; CARVALHO, T. A.; BETTANIN, V. C.; SANTOS, J. de O.; VASO, L. M.

Resumo: In Brazil, agriculture contributes to the emission of greenhouse gases, but has great power to sequester carbon (C) in the soil. The objective of this research was to quantify the C stock in the soil due to land use change (LUC) from forest (Atlantic Forest biome) to Urochloa brizantha pasture, obtaining LUC factors; as well as determining C sequestration rates resultant of the adoption of better pasture management practices. The soil C stocks with the change of land use from forest to pasture was investigated in two locations, one with Dystrophic Red Oxisol and Dystrophic Red Argisol, and the other with Dark Red Oxisol, in the cities of Nova Odessa and Pirassununga, both in the State of São Paulo. Soil C stocks were obtained from soil sampling in pits with an auger, in different layers, down to 100 cm deep. The LUC factor was calculated from the ratio between the C stock in the forest soil and the C stock in the soil under pasture, for each location and soil type. The intensification of pasture management was studied in Pirassununga, resultant ofnitrogen fertilization and deferred or rotated grazing, while in Nova Odessa nitrogen fertilization and intercropping between U. brizantha and Macrotyloma axillare were tested. Soil sampling to obtain initial C stocks and after two years of implementing the new management was carried out in a similar way to that mentioned for LUC, but only considering the soil downto 30 cm deep. The factors for LUC varied between 0.76 and 0.98, demonstrating that inadequate management can affect the C stock in the soil in relation to the forest (standard IPCC value of 1), but that these factors increased when an appropriate management was applied, varying between 1.04 and 1.18, when compared to the IPCC factor standard value of 1.17. Furthermore, management practices resulted in C sequestration rates ranging between 1.2 and 4.4 t C ha-1 year-1, relatively high values that demonstrate the high potential of soils under pasture for C sequestration.

Ano de publicação: 2023

Tipo de publicação: Artigo em anais e proceedings

Unidade: Embrapa Meio Ambiente

Palavras-chave: Emissions factor, Gases de efeito estufa, Greenhouse gas emissions, Macrotyloma axillare, Nitrous oxide, Urochloa brizantha, Óxido nitriso