Gross methane production and consumption estimated for intact soil cores from agricultural plots including environmental covariates and example raw isotope pool dilution data

This study was performed to determine how different soil moistures, soil sources, and
agricultural practices affected the gross CH4 fluxes (i.e., rates of methanogenesis) of
soils. We extracted intact soil cores from two agricultural sites in the USA in row crop
plots under conventional, no-till, and organic management. We then took them to the lab,
manipulated their moisture levels, incubated them at room temperature for 22 weeks, and
measured gas fluxes at weeks 6 and 21. We developed and utilized a new form of CH4 isotope
pool dilution (IPD) to estimate gross CH4 production and consumption fluxes. This new method
can measure IPD in a bag headspace that loses volume over time due to sampling. We fit the
IPD model to the data and extracted gross CH4 production (P) and consumption (K) constants.
These along with calculated fluxes and covariates measured (e.g., moisture, inorganic N) are
reported in the main data table.