Soils store about 2500 Pg carbon (C) in 2 m depth, and can act as a source or sink

of atmospheric carbon depending upon the historical and current land use. Globally about 1.1±0.5 Pg C yr-1 is emitted through land use and land use change. Conservation agriculture techniques have been promoted in tropical and subtropical ecosystems to increase crop yields and make croplands a net carbon sink. Based on our field results, we hypothesized that the global scale adoption of conservation agriculture practices can led to significant mitigation of greenhouse gases emissions. We used long term (30 years) field observations and a simulation model (Century) to simulate the soil carbon dynamics of a subtropical cropland. We coupled the Century model results with geospatial analysis to study the impact of global scale adoption of conservation management system. Our results indicated that simulated results underestimated the soil C change, and the inclusion of mineralogical controls can reduce this observed model bias. The scaling of results indicated that conservation agriculture has the potential to sequester 2.5±0.02 Pg C at 0-20 cm and 11.7±3 Pg C at 0-100 cm soil depth in 86 million ha area globally. This amount of sequestered C was equivalent to 11 years of current global land use and land use change emissions.

 

Daniel is a graduate student at the State University of Ponta Grossa, Brazil. He spent 6 months at EVS working on his dissertation research. In this presentation, he will summarize results of his two studies that combined long term field observation data with simulation and geospatial models to study the role of conservation agriculture to mitigate land use change emissions.