ABSTRACT:

In natural drylands, the formation of pedogenic carbonate, or secondary calcite (CaCO3), is critical in shaping soil hydrologic and biogeochemical properties and modifying the global carbon cycle over geological time. When dryland ecosystems are converted to managed agricultural sites, irrigation water can supply HCO3- and Ca2+, accelerating rates of CaCO3 formation and releasing abiotic CO2. In this study, we used carbon isotopic composition of soil CO2 to assess its sources and used soil CO2 concentration gradients to estimate the diffusive CO2 effluxes from soil to atmosphere in an arid agricultural setting, a flood irrigated pecan orchard in western Texas, United States. Soil gases were collected from multiple soil depths at two sites within the pecan orchard, Pecan_Coarse and Pecan_Fine, which have contrasting soil textures and associated differences in soil salinity, pedogenic carbonate accumulation rates, and tree size.

A manuscript, titled "Flood Irrigation Drives the Temporal Variability of Soil Respiration, Pedogenic Carbonate Accumulation Rates, and soil CO2 production dynamics in arid agricultural soils" is under review by Applied Geochemistry. (Andrews et al.). Data contained in this resource include the measured concentrations and isotopic compositions of soil CO2, the chemistry of ground and surface water samples used for irrigation, and calculated CO2 efflux based on gas diffusion.

ABSTRACT:

This resource contains a Jupyter notebook with the workflow for modeling reactive transport in upscaled fractured media. The necessary files are included as code blocks in the Jupyter notebook. dfnWorks files are python files while PFLOTRAN input files are text files.

ABSTRACT:

This resource contains PFLOTRAN input decks for the simulations included in the manuscript titled Temporal and Spatial Heterogeneity of Mineral Dissolution Rates in Fractured Media. Supporting files including the databases are included and an excel file containing the domain averaged rates is included.