Persistent soil carbon enhanced in Mollisols by well-managed grasslands but not annual grain or dairy forage cropping systems

• DOI: 10.1073/pnas.2118931119
• Publication Date: 2022-02-10T21:31:06Z
• Authors: Yichao Rui; Randall D. Jackson; M. Francesca Cotrufo; Gregg R. Sanford; Brian J. Spiesman; Leonardo Deiss; Steven W. Culman; Chao Liang; Matthew D. Ruark
• Keywords: Mollisol; Soil carbon; Monocropping; Cropping system; Crop Rotation

Intensive crop production on grassland-derived Mollisols has liberated massive amounts of carbon (C) to the atmosphere. Whether minimizing soil disturbance, diversifying rotations, or re-establishing perennial grasslands and integrating livestock can slow reverse this trend remains highly uncertain. We investigated how these management practices affected organic (SOC) accrual distribution between particulate (POM) mineral-associated (MAOM) matter in a 29-y-old field experiment North Central United States assessed microbial traits were related changes. Compared conventional continuous maize monocropping with annual tillage, systems reduced diversified rotations cover crops legumes, manure addition did not increase total SOC storage MAOM-C, whereas pastures managed rotational grazing accumulated more MAOM-C (18 29% higher) than all cropping after 29 y management. These results align meta-analysis data from published studies comparing efficacy health worldwide. Incorporating legumes into enhanced POM-C, biomass, C-use efficiency but significantly necromass accumulation, storage. Diverse, rotationally grazed pasture potential persistent C Mollisols, highlighting key role well-managed climate-smart agriculture.