Farming Carbon: Harnessing Roots, Microbes, and Soil Minerals for Soil-Based Carbon Drawdown

Jennifer Pett-Ridge, Lawrence Livermore National Lab

Abstract:
Since the dawn of agriculture, cultivated soils have lost a vast amount of carbon to the atmosphere. To repay this debt, and help limit global warming impacts, we must quickly scale processes of at­mospheric CO2 removal (CDR). Soils store 3000 Gt of carbon in organic matter and inorganic carbonate minerals—more carbon than the atmosphere and terrestrial biosphere combined. Despite the loss of nearly 500 Gt CO2 equivalents (CO2e) due to soil cultivation in the past century, there is clear potential for soil-based CDR. Recent estimates suggest global croplands could sequester 1–5 Gt CO2e per year. But there is significant debate regarding the best approach for soil CDR, and the mechanisms that lead to persistent soil carbon. Most of the organic matter in soil is microbial necromass, shaped by the traits of diverse organisms. To understand how soil microorganisms lead to stable soil carbon, it is critical to understand how microbial ecophysiological traits are linked to soil organic matter formation, and how complex cross-kingdom interactions—involving diverse bacteria, fungi, archaea, protists, microfauna and viruses—shape soil carbon availability and loss. Geographic patterns of biophysical constraints and mineral capacity also constrain the potential for promoting stabilized soil carbon. I will present results from studies where we have used quantitative stable isotope probing (SIP), metagenomics/transcriptomics, and biogeochemical modeling to understand soil carbon persistence and will share new ideas for soil-based opportunities for climate mitigation.

Bio:
Jennifer Pett-Ridge is a LLNL Distinguished Member of Technical Staff adjunct professor at UC Merced and investigator at UC Berkeley’s Innovative Genomics Institute. She studies microbiome interactions in soil ecosystems, using quantitative systems biology tools such as stable isotope probing, NanoSIMS imaging, and computational modeling. She leads several DOE team projects, focused on the mechanisms that lead to soil carbon persistence (the Microbes Persist Soil Microbiome Scientific Focus Area), the capacity and costs of carbon dioxide removal in the USA (Roads to Removal) and novel bio- and geoengineering approaches for soil-based carbon drawdown (Terraforming Soil Energy Earthshot Research Center). Pett-Ridge is a fellow of the Ecological Society of America and recipient of a DOE Early Career award, Geochemical Society Endowed Biogeochemistry Medal, and the DOE Office of Science Ernest Orlando Lawrence Award.

#modeling #simulation #agronomy #climatechange #decarbonization #farming #agriculture #carbonmitigation #carbonremoval #decarbonization #soil #soilmechanics #soilscience