The interaction of the carbon cycle and other biogenic elements in the soil determines the overall biogeochemical stability and productivity of terrestrial ecosystems. Transformations among C and N, P, S, Ca, Mg, Fe, and Al are closely coupled through organic matter turnover, mineral weathering, sorption and desorption, complexation, precipitation and dissolution, and redox reactions; these processes regulate element availability, mobility, retention, and losses. This session brings together studies investigating the coupled biogeochemistry of carbon, nutrients, and major elements across soils and ecosystems. We welcome research addressing element interactions at molecular, mineral, microscale, and ecosystem levels, using spectroscopic, isotopic, molecular, and modeling approaches. We particularly encourage contributions linking elemental coupling with mineral–organic interactions, such as C-Fe, C-Ca, and C-Al; microbial processes governing C-N-P cycling in soil; nutrient availability for plants and interactions in the plant-soil-microorganism system; weathering; organic matter transformation under redox dynamics; and responses of C and nutrient cycling to environmental change and soil management.