This dataset of deep soil oxygen and carbon dioxide concentrations spans two years of observations from observational research in: hardwood forests, pine forests, and agricultural fields. An accompanying dataset includes the locations of buried PVC chambers used to sample and analyze soil air. The specific names of research plots in the soil gas concentration dataset have been removed as they are not pertinent for the current manuscript under revision which is entirely focused on the methodological development of the apparatus designed and used over the course of this research. Because there is a plot of one treatment's (hardwood forest) average O2 and CO2 the treatment "H" for hardwood forests was preserved. All other data points had simply been used in validation analyses comparing gas-chromatography CO2 measurements to field measurements and, as such, their treatments have no bearing in the methods paper to be published in PLoS. All statistical analyses were conducted on field and laboratory measurements obtained via the "FPGA" contained in this soil gas measurement dataset. The gap-filled column in this soil gas dataset was solely used for visualization when plotting heatmaps.