Data

Understanding the microbial determinants of soil carbon persistence is critical for climate-smart agriculture; however, the life-history strategies and taxa governing soil organic carbon (SOC) accrual in agroecosystems remain unresolved. Using soils from a 33-year fertilization experiment, our initial microcosm studies revealed key microbial taxa and their contrasting metabolic strategies driving SOC mineralization versus accumulation. Y-strategists, characterized by rapid growth and enriched genes for central metabolism and amino acid biosynthesis, drive SOC accumulation through the efficient incorporation of substrates into biomass. Conversely, A-strategists promote SOC mineralization via decomposition of complex polymers like lignin. We further validated these findings using 222 metagenome-assembled genomes (MAGs) of core A/Y strategists derived from 634 soil metagenomes spanning global agroecosystems, confirming the broad relevance of these metabolic strategies. This two-step approach, integrating mechanistic experimentation with global validation, establishes a framework linking microbial taxonomy and functional traits to SOC turnover, offering new avenues for managing carbon accrual in agricultural soils.