Land use change effect on organic matter dynamics and soil carbon sequestration in the Brazilian Cerrado: a study case in Mato Grosso do Sul state (Midwest-Brazil).

LEITE, D. D. F. S.; FONTANA, A.; NOBREGA, G. N.; SANTOS, F. M.; ALVES, B. J. R.; DA SILVEIRA, J. G. da; CORDEIRO, R. C.; CERRI, C. E. P.; SANTOS, R. A. F. dos; RODRIGUES, R. de A. R.

Land use change effect on organic matter dynamics and soil carbon sequestration in the Brazilian Cerrado: a study case in Mato Grosso do Sul state (Midwest-Brazil).

Autores

DA SILVEIRA, J. G. da

CORDEIRO, R. C.

CERRI, C. E. P.

SANTOS, R. A. F. dos

RODRIGUES, R. de A. R.

Descripción

ABSTRACT - Pasture restoration and conservative agricultural practices, such as those used in Integrated Crop-Livestock- Forestry Systems (ICLF), can enhance soil protection and SOC stocks. This study, conducted in the Mato Grosso do Sul state, aimed to analyze the effect of land use conversion on C and N stocks and Soil Organic Matter (SOM) fractions to comprehend the C and N dynamic in 1-meter depth. Soil samples were collected in five different land uses in adjacent areas on the same farm: (1) Native Vegetation (NV); (2) Extensive Pasture (EP); (3) Managed Pasture (MP); (4) Integrated Crop-Livestock (ICL); and (5) Integrated Livestock-Forestry (ILF). Disturbed soil samples were collected using a soil auger at seven soil depths for elemental and isotopic analysis for soil C and N. Undisturbed samples were collected to assess the soil bulk density. The soil physical fractionation obtained the Particular Organic Matter (POM) and Mineral Associated Organic Matter (MAOM). The C and N stock varied from 86.02 in MP and 67.37 Mg ha- 1 in ICL and was statistically similar for all studied land uses. The delta 13C signature varied between land uses and through the soil profile, with more negative values for NV and ILF (-27.83 and-21.73 parts per thousand, respectively) in the topsoil. The POM fraction indicated changes in land use, and the POM in ICL shows the potential to restore soil C and health since it is just in the second year of intervention. The managed pastures with grass species Brachiaria promoted better soil C and N content and stocks. This study pointed out other alternatives to land use, such as integrated systems (ICL and ILF), which should be the target for the Brazilian policies to mitigate greenhouse gas emissions and enhance the diversification and resilience of the agroecosystem.
Available online 17 December 2024.