This PossingerA_SoilChar_Inc_HBEF_Readme.txt file was generated on 20200220 by Angela R. Possinger ------------------- GENERAL INFORMATION ------------------- Title of Dataset: “Carbon and metal characterization and incubation studies conducted on soil samples collected in June 2016 from Hubbard Brook Experimental Forest” Author Information (Name, Institution, Address, Email) Principal Investigator: Angela R. Possinger* Cornell University 306 Tower Road Ithaca, NY 14853 USA arp264@cornell.edu Associate or Co-investigator: Scott W. Bailey US Forest Service 234 Mirror Lake Road North Woodstock, NH, 03262 USA scott.bailey@usda.gov Associate or Co-investigator: Thiago M. Inagaki Technical University Munich Chair of Soil Science 85354 Freising, Emil-Ramann-Str. 2 Germany thiago.inagaki@wzw.tum.de Associate or Co-investigator: Ingrid Kögel-Knabner Technical University Munich Chair of Soil Science 85354 Freising, Emil-Ramann-Str. 2 Germany koegel@wzw.tum.de Associate or Co-investigator: James J. Dynes Canadian Light Source 44 Innovation Boulevard Saskatoon, SK Canada S7N 2V3 james.dynes@lightsource.ca Associate or Co-investigator: Zachary A. Arthur Canadian Light Source 44 Innovation Boulevard Saskatoon, SK Canada S7N 2V3 zachary.arthur@lightsource.ca Associate or Co-investigator: Johannes Lehmann Cornell University 306 Tower Road Ithaca, NY 14853 USA cl274@cornell.edu *Present address: Virginia Tech Department of Forest Resources and Environmental Conservation 220 Ag-Quad Ln Blacksburg, VA 24061 Alternate Contact(s): Date of data collection (single date, range, approximate date): 20160601-20190501 Geographic location of data collection: Soil samples were collected from the Hubbard Brook Experimental Forest, Woodstock, NH, USA. Carbon K-edge X-ray absorption spectroscopy data was collected at the Canadian Light Source (Saskatoon, SK, Canada). Soil extraction and incubation data was collected in the Lehmann Laboratory at Cornell University, Ithaca, NY, USA. Iron K-edge X-ray absorption spectroscopy data was collected at the Cornell High Energy Synchrotron Source, Ithaca, NY, USA. Nuclear magnetic resonance data was collected at the Technical University of Munich, Freising, Germany. Information about funding sources or sponsorship that supported the collection of the data: Funding for this study was provided by the NSF IGERT in Cross-Scale Biogeochemistry and Climate at Cornell University (NSF Award #1069193) and the Institute for Advanced Study (IAS) from the Technical University of Munich (TUM) through the Hans-Fisher Senior Fellowship. Hubbard Brook Experimental Forest is operated and maintained by the US Forest Service, Northern Research Station, Newtown Square, PA. Additional research funds were provided by the Andrew W. Mellon Foundation and the Cornell College of Agriculture and Life Sciences Alumni Foundation. This work uses research conducted at the Cornell High Energy Synchrotron Source (CHESS) which is supported by the National Science Foundation under award DMR-1332208. Research was performed at the Canadian Light Source (CLS), which is supported by the Canada Foundation for Innovation, Natural Sciences and Engineering Research Council of Canada, the University of Saskatchewan, the Government of Saskatchewan, Western Economic Diversification Canada, the National Research Council Canada, and the Canadian Institutes of Health Research. -------------------------- SHARING/ACCESS INFORMATION -------------------------- Licenses/restrictions placed on the data, or limitations of reuse: These data are shared under a Creative Commons Attribution-NonCommercial 4.0 International (CC BY-NC 4.0)License (https://creativecommons.org/licenses/by-nc/4.0/). The data may be shared and re-used, but attribution to the original authors must be given and it may not be used for commercial purposes. The R script in this dataset are shared under a CC0 1.0 Universal (CC0 1.0) Public Domain Dedication (https://creativecommons.org/publicdomain/zero/1.0/). They may be shared and re-used. Proper attribution to the original author is expected. Recommended citation for the data: Possinger, A., Bailey, S., Inagaki, T., Koegel-Knabner, I., Dynes, J., Arthur, Z., and Lehmann, J. 2020. Carbon and metal characterization and incubation studies conducted on soil samples collected in June 2016 from Hubbard Brook Experimental Forest. [Dataset] Cornell University Library eCommons Repository. https://doi.org/10.7298/412j-t911 Citation for and links to publications that cite or use the data: Links to other publicly accessible locations of the data: Links/relationships to ancillary or related data sets: -------------------- DATA & FILE OVERVIEW -------------------- File list (filenames, directory structure (for zipped files) and brief description of all data files): 1. Filename: Fe-extractant.csv Short description: Concentration of iron (Al) in soils extractable by selective dissolution with acid ammonium oxalate, hydroxylamine-HCl, and citrate-dithionite (Figure 2 in Possinger et al., in revision for Geoderma) 2. Filename: Al-extractant.csv Short description: Concentration of aluminum (Al) in soils extractable by selective dissolution with acid ammonium oxalate, hydroxylamine-HCl, and citrate-dithionite (Figure 2 in Possinger et al., in revision for Geoderma) 3. Filename: Fe-total.csv Short description: Concentration of total iron (Fe) in soils by tera/meta-borate flux method (Figure 2 in Possinger et al., in revision for Geoderma) 4. Filename: Al-total.csv Short description: Concentration of total aluminum in soil samples by tetra/meta-borate flux method (Figure 2 in Possinger et al., in revision for Geoderma) 5. Filename: AlFe-Total-Ratio.csv Short description: Ratio of total aluminum and iron by tetra/meta-borate flux method (Figure 2 in Possinger et al., in revision for Geoderma) 6. Filename: WEOM_Oa_C_XANES.csv Short description: Carbon K-edge x-ray absorption fine structure (XANES) spectra for water-extractable organic matter from organic horizons of low and high saturation frequency locations (Supplementary Figure A2 in Possinger et al., in revision for Geoderma) 7. Filename: Mn-spodic.csv Short description: Concentrations of manganese (Mn) extractable by hydroxylamine and acid ammonium oxalate for spodic horizon bulk soils 8. Filename: MineralSoilCorrelation4419.csv Short description: Data table of bulk mineral soil characterization (e.g., pH, soil organic matter, total C, total N, selective extractions, water content) 9. Filename: test_11202.csv Short description: Iteration 1 test dataset for Random Forest model representing 25% of of rows at random from MineralSoilCorrelation4419.csv, entry 8 above. 10. Filename: test_11204.csv Short description: Iteration 2 test dataset for Random Forest model representing 25% of of rows at random from MineralSoilCorrelation4419.csv, entry 8 above. 11. Filename: test_11206.csv Short description: Iteration 3 test dataset for Random Forest model representing 25% of of rows at random from MineralSoilCorrelation4419.csv, entry 8 above. 12. Filename: test_11208.csv Short description: Iteration 4 test dataset for Random Forest model representing 25% of of rows at random from MineralSoilCorrelation4419.csv, entry 8 above. 13. Filenames: test_11210.csv Short description: Iteration 5 test dataset for Random Forest model representing 25% of of rows at random from MineralSoilCorrelation4419.csv, entry 8 above. 14. Filename: train_11202.csv Short description: Iteration 5 training dataset for Random Forest model representing 75% of of rows at random from MineralSoilCorrelation4419.csv, entry 8 above. 15. Filename: train_11204.csv Short description: Iteration 5 training dataset for Random Forest model representing 75% of of rows at random from MineralSoilCorrelation4419.csv, entry 8 above. 16. Filename: train_11206.csv Short description: Iteration 5 training dataset for Random Forest model representing 75% of of rows at random from MineralSoilCorrelation4419.csv, entry 8 above. 17. Filename: train_11208.csv Short description: Iteration 5 training dataset for Random Forest model representing 75% of of rows at random from MineralSoilCorrelation4419.csv, entry 8 above. 18. Filename: train_11210.csv Short description: Iteration 5 training dataset for Random Forest model representing 75% of of rows at random from MineralSoilCorrelation4419.csv, entry 8 above. 19. Filename: RF_pred_obs.csv Short description: Predicted and observed total carbon content derived from Random Forest model 20. Filename: Field_Sampling_Locations.csv Short description: Coordinates and site-level information for hydropedological unit sampling locations 21. Filename: Field_Profile_Descriptions.csv Short description: Transcription of field profile descriptions for soil samples collected at Hubbard Brook Watershed 3 22. Filename: Vegetation_Index.csv Short description: Table of tree species >0.1 m diameter nearby to soil profile sampling areas 23. Filename: Hydroxylamine-DOC.csv Short description: Values of dissolved organic carbon, soluble iron, and soluble aluminum in hydroxylamine-HCl extracts 24. Filename: Hydrox-DOC-ratios.csv Short description: Ratios of dissolved organic carbon, soluble iron, and soluble aluminum in hydroxylamine-HCl extracts 25. Filename: 12C14N_WH_2.txt Short description: NanoSIMS text image of 12C14N ion intensity for high saturation frequency soil, image replicate 1 26. Filename: 12C14N_WH_3.txt Short description: NanoSIMS text image of 12C14N ion intensity for high saturation frequency soil, image replicate 2 27. Filename: 12C14N_WH_4.txt Short description: NanoSIMS text image of 12C14N ion intensity for high saturation frequency soil, image replicate 3 28. Filename: 12C14N_WH_6.txt Short description: NanoSIMS text image of 12C14N ion intensity for high saturation frequency soil, image replicate 4 29. Filename: 12C14N_WH_9.txt Short description: NanoSIMS text image of 12C14N ion intensity for high saturation frequency soil, image replicate 5 30. Filename: 12C14N_WL_1.txt Short description: NanoSIMS text image of 12C14N ion intensity for low saturation frequency soil, image replicate 1 31. Filename: 12C14N_WL_2.txt Short description: NanoSIMS text image of 12C14N ion intensity for low saturation frequency soil, image replicate 2 32. Filenames: 12C14N_WL_4.txt Short description: NanoSIMS text image of 12C14N ion intensity for low saturation frequency soil, image replicate 3 33. Filenames: 12C14N_WL_5.txt Short description: NanoSIMS text image of 12C14N ion intensity for low saturation frequency soil, image replicate 4 34. Filename: 27Al16O_WH_2.txt Short description: NanoSIMS text image of 27Al16O ion intensity for high saturation frequency soil, image replicate 1 35. Filename: 27Al16O_WH_3.txt Short description: NanoSIMS text image of 27Al16O ion intensity for high saturation frequency soil, image replicate 2 36. Filename: 27Al16O_WH_4.txt Short description: NanoSIMS text image of 27Al16O ion intensity for high saturation frequency soil, image replicate 3 37. Filename: 27Al16O_WH_6.txt Short description: NanoSIMS text image of 27Al16O ion intensity for high saturation frequency soil, image replicate 4 38. Filename: 27Al16O_WH_9.txt Short description: NanoSIMS text image of 27Al16O ion intensity for high saturation frequency soil, image replicate 5 39. Filename: 27Al16O_WL_1.txt Short description: NanoSIMS text image of 27Al16O ion intensity for low saturation frequency soil, image replicate 1 40. Filename: 27Al16O_WL_2.txt Short description: NanoSIMS text image of 27Al16O ion intensity for low saturation frequency soil, image replicate 2 41. Filename: 27Al16O_WL_4.txt Short description: NanoSIMS text image of 27Al16O ion intensity for low saturation frequency soil, image replicate 3 42. Filename: 27Al16O_WL_5.txt Short description: NanoSIMS text image of 27Al16O ion intensity for low saturation frequency soil, image replicate 4 43. Filename: 56Fe16O_Ang_WH_2.txt Short description: NanoSIMS text image of 56Fe16O ion intensity for high saturation frequency soil, image replicate 1 44. Filename: 56Fe16O_WH_3.txt Short description: NanoSIMS text image of 56Fe16O ion intensity for high saturation frequency soil, image replicate 2 45. Filename: 56Fe16O_WH_4.txt Short description: NanoSIMS text image of 56Fe16O ion intensity for high saturation frequency soil, image replicate 3 46. Filename: 56Fe16O_WH_6.txt Short description: NanoSIMS text image of 56Fe16O ion intensity for high saturation frequency soil, image replicate 4 47. Filename: 56Fe16O_WH_9.txt Short description: NanoSIMS text image of 56Fe16O ion intensity for high saturation frequency soil, image replicate 5 48. Filename: 56Fe16O_WL_1.txt Short description: NanoSIMS text image of 56Fe16O ion intensity for low saturation frequency soil, image replicate 1 49. Filenames: 56Fe16O_WL_2.txt Short description: NanoSIMS text image of 56Fe16O ion intensity for low saturation frequency soil, image replicate 2 50. Filename: 56Fe16O_WL_4.txt Short description: NanoSIMS text image of 56Fe16O ion intensity for low saturation frequency soil, image replicate 3 51. Filename: 56Fe16O_WL_5.txt Short description: NanoSIMS text image of 56Fe16O ion intensity for low saturation frequency soil, image replicate 4 52. Filename: NanoSIMScorr.csv Short description: Table of Spearman Rank correlation coefficients for pixel intensity correlations between iron-carbon, iron-aluminum, and aluminum-carbon derived from NanoSIMS elemental map 53. Filename: Standards-7120.csv Short description: Iron K-edge X-ray absorption near edge structure standard compounds and soil samples with estimate of reduced Fe(II) by 7120 eV peak area 54. Filename: Fe-XANES-functions-HBEF.csv Short description: Iron (Fe) K-edge X-ray absorption spectroscopy first derivative spectra and fit of 7120 eV peak area for estimation of reduced Fe(II) 55. Filename: LCF_proportions.csv Short description: Proportion of crystalline, non-crystalline, and iron-organic complex components estimated by iron K-edge EXAFS linear combination fitting 56. Filename: XANES_LCF_proportions.csv Short description: Relative proportions of Fe(II) complex, Fe(III) complex, Fe(III) mineral, and Fe(II)/Fe(III) mineral components resulting from iron K-edge XANES linear combination fitting 57. Filename: XANES-LCF-residuals.csv Short description: Linear combination fitting results (output and error residuals) for iron K-edge X-ray absorption near edge structure (XANES) 58. Filename: EXAFS-LCF-residuals.csv Short description: Linear combination fitting results (output and error residuals) for iron K-edge extended X-ray absorption fine structure (EXAFS) 59. Filename: NEXAFS-Ratios.csv Short description: Ratios of carbon functional groups derived from peak height estimates in NEXAFS-functions-reduced.txt 60. Filename: NEXAFS-functions-reduced.csv Short description: Carbon K-edge X-ray absorption near edge structure spectra and peak height estimates for bulk soil samples, dissolved organic matter, soil with particulate organic matter removed, and damage tests 61. Filename: DamageTest_ratios.csv Short description: Carbon fine structure ratios from carbon K-edge X-ray absorption spectroscopy damage test 62. Filename: NMR_RawSpectra.csv Short description: Chemical shift and unprocessed nuclear magnetic resonance spectra for variable contact time experiment (not included in R script) 63. Filename: NMR-VCT-Slope-Updated-12-27-19.csv Short description: Change in 13C-nuclear magnetic resonance (NMR) signal intensity as a function of increasing contact time 64. Filename: NMR-VCT-Parameters-Updated-12-27-19.csv Short description: Calculated values of the magnitude of the variable contact time effect and the proton relaxation time for nuclear magnetic resonance variable contact time experiments across soil iron/carbon ratio levels 65. Filename: AnaerobicIncAll-updated-061919.csv Short description: Values for carbon mineralization, soluble metals, reduced Fe(II), and dissolved organic carbon from cyclic anaerobic-aerobic incubation experiment 66. Filename: Possinger_et_al_R_Code.R Short description: Detailed description of and code for figures, R-based computations, and statistical analyses for data included in this repository Relationship between files, if important for context: Use of data files for plotting, R-based computations, and statistical analyses is described in depth in Possinger_et_al_R_Code_Geoderma_Final.R. Additional related data collected that was not included in the current data package: If data was derived from another source, list source: If there are there multiple versions of the dataset, list the file updated, when and why update was made: -------------------------- METHODOLOGICAL INFORMATION -------------------------- Description of methods used for collection/generation of data: Data collection and generation methods are included in Chapter 2 of “Electrons, X-rays, and Soil Augers: Probing Soil Organo-Mineral Interactions with a Cross-Scale Analytical Toolbox”, a dissertation submitted to Cornell University by Angela R. Possinger. Additionally, data included in this repository in revision for Geoderma. In brief: Sample Collection: Soil samples were collected in June 2016 from the Hubbard Brook Experimental Forest Watershed 3. Three soil types defined with a hydropedological unit (HPU) framework developed by Bailey et al. (2014) were sampled: E, Bhs, and Typical podzols, corresponding to saturation frequency categories defined here as high, medium, and low saturation frequency, respectively. For each saturation frequency category, three profiles were sampled by horizon quantitatively. Soils were air-dried (40 degrees C) and sieved to 2 mm. Profiles and horizons were qualitatively described in the field for texture-by-feel, rock content, root content, color, and other descriptive factors required to confirm identity as E, Bhs, or Typical podzol HPUs. Bulk Soil Characterization: Soil pH, water content, and loss-on-ignition of organic matter were determined using standard protocols (Carter, 1993). Total C and N were determined by combustion (Carlo-Erba NC2500 elemental analyzer, CE Instruments Ltd, Wigan, UK). Selective extractions for soil metals (water, dithionite, acid ammonium oxalate, and hydroxylamine) and organic carbon (water and hydroxylamine) were conducted following Ross and Wang (1993) and extracts analyzed with inductively coupled plasma atomic emission spectrometry (ICP-AES) (Thermo iCAP 6500 series, ThermoFisher Scientific, Bellafonte, PA). Total elemental content was determined by the lithium tetra/meta borate flux method (Kurtz et al., 2000) and the extract analyzed in a 2% nitric acid matrix using a SpectroBlue inductively-coupled plasma optical emission spectrometry (ICP-OES) instrument (Ametek, Kleve, Germany). Nanoscale Secondary Ion Mass Spectrometry (NanoSIMS) imaging: Elemental maps (C, Fe, and Al) of soil particles from low and high saturation frequency soil particles were collected using nanoscale secondary ion mass spectrometry (NanoSIMS) (Cameca NanoSIMS 50L instrument, Gannevilliers, FR) using 1 ms/pixel dwell time. For each sample, 0.25 g of pre-incubated (14-d) air-dry soil (<2 mm) was briefly (~6-s) sonicated at low energy in 10 ml Nanopure® water. Suspension (100 microliter) was deposited on silicon wafers and air-dried. NanoSIMS imaging was conducted using prior optical microscope (Zeiss Axio Imager Z2, Oberkochen, DE) and scanning electron microscopy (JEOL JSM 5900LV, Tokyo, JP) measurements. Carbon X-ray Absorption Near Edge Structure (XANES): All C K-edge XANES measurements were conducted at the spherical grating monochromator (SGM) beamline of the Canadian Light Source (Saskatoon, SK). Partial fluorescence yield (PFY) spectra were collected using silicon drift detectors (SDD). The SGM sample chamber was operated under approximately 10E-06 Torr. Soil samples were air-dried, sieved to 2 mm, and ball-milled to a fine powder. Approximately 10 mg of soil was suspended in 500 microliters DI water and vortexed briefly (10 s). Water-extracted DOM was freeze-dried and finely pulverized. Carbon K-edge PFY spectra were collected for 40-60 point scans (probe size 50x50 µm) in slew mode (>100 µm spacing). Iron X-ray Absorption Spectroscopy (XAS): Fe XAS data were collected at the Cornell High Energy Synchrotron Source (CHESS) F3 hard X-ray beamline (Ithaca, NY). The F3 beamline is equipped with a hard-bend magnet source with a silicon (111) monochromator and silicon drift detector and is operated under room temperature and ambient pressure. Soil samples and standards were prepared as described in Inagaki et al. (2020). Total fluorescence yield scans (2-5) were normalized to incidence flux (I0) and calibrated to an in-line pure Fe foil for the pre-edge (-200 to -20 eV), near-edge (-20 to +12 eV), and post-edge (+12 to +425 eV) relative to the Fe K-edge (7112 eV). Step sizes were 5 and 1 eV and 0.05 wavenumber (1/Å) for the pre-, near- and post-edge, respectively, with 1, 2, and 5 s dwell time, respectively. Nuclear magnetic resonance variable contact time (NMR VCT): Solid-state cross polarized magic angle spinning (CPMAS)-13C NMR spectra were collected using a Biospin DSX 200 NMR spectrometer (Bruker, Rheinstetten, Germany). NMR spectra were collected using ball-milled soil samples and the following parameters: pulse delay of 0.4 sec, frequency of 6800 Hz, and accumulation of 100,000 scans. A line broadening (smoothing) value of 75 was used for all spectra. To determine the effect of contact time on signal intensity, 6 spectra were collected for each sample with contact times of 0.03, 0.25, 0.5, 1, 2, 3, and 4 ms. Incubation experiment: A spodic horizon soil from each saturation frequency (low, medium, and high) was incubated for a series of three periods with fluctuating aerobic-anaerobic conditions. Soils were pre-incubated (2-d at 50% field capacity and 30 degrees C) in 0.06-L glass vials within 0.4-L glass Mason jars (n=4 for each soil). Jars were modified with air-tight septa and moist conditions were maintained throughout the incubation with 2 mL Nanopure® water in the jar base. Jars were purged with CO2-free air for the first period (5 d, aerobic only), purged with either N2 or CO2-free air for the second period (7 d, anaerobic or aerobic control), and purged with CO2-free air for the final period (6 d, aerobic only). Cumulative carbon dioxide (CO2) was measured for each cycle using the potassium hydroxide (KOH) trap method (Whitman et al., 2014; Krounbi et al., 2018). After the anaerobic period, moist soils were sub-sampled in an anaerobic environment (<1 ppm O2 in N2 and H2 glove box). Water-extractable Fe2+, DOC, and total metals were determined on subsamples by extraction with N2-purged Nanopure water at a 1:8 soil:water ratio (2.5 hr shaking followed by 30 min centrifugation at 3000 rpm). After sub-sampling, jars were capped tightly and stored overnight at 7 degrees C before the final aerobic period. Water-extractable Fe2+, DOC, and total metals were quantified in the extracts after the anaerobic period using the ferrozine colorimetric method (Viollier et al., 2000; Huang and Hall, 2017), a Shimadzu TOC-VCPH/CPN analyzer (combustion method) (Shimadzu Corp, Kyoto, JP), and ICP-AES (Thermo iCAP 6500 series, ThermoFisher Scientific, Bellafonte, PA) respectively. References: Bailey, S.W., Brousseau, P.A., McGuire, K.J., Ross, D.S., 2014. Influence of landscape position and transient water table on soil development and carbon distribution in a steep, headwater catchment. Geoderma 226-227, 279-289. Carter, M.R., 1993 (Ed). Soil Sampling and Methods of Analysis. Canadian Society of Soil Science, Lewis Publishers, Boca Raton. Huang, W., Hall, S.J., 2017. Optimized high-throughput methods for quantifying iron biogeochemical dynamics in soil. Geoderma 306, 67-72. Inagaki, T.M, Possinger, A.R., Grant, K.E., Schweizer, S.A., Mueller, C.W., Derry, L.A., Lehmann, J., Kögel-Knabner, I., 2020. Subsoil organo-mineral associations under contrasting climate conditions. Geochim. Cosmochim. Acta 270, 244-263. Krounbi, L., van Es, H., Karanja, N., Lehmann, J., 2018. Nitrogen and phosphorus availability of biologically and thermochemically decomposed human wastes and urine in soils with different texture and pH. Soil Sci. 183(2), 51-65. Kurtz, A.C., Derry, L.A., Chadwick, O.A., Alfano, M.J., 2000. Refractory element mobility in volcanic soils. Geology 28(8), 683-686. Ross, G.J., Wang, C., 1993. Extractable Al, Fe, Mn, and Si, in: Carter, M.R (Ed.), Soil Sampling and Methods of Analysis. Canadian Society of Soil Science, Lewis Publishers, Boca Raton, pp. 239-246. Viollier, E., Inglett, P.W., Hunter, K., Roychoudhury, A.N., Van Cappellen, P., 2000. The ferrozine method revisited: Fe(II)/Fe(III) determination in natural waters. Appl. Geochem. 15, 785-790. Whitman, T., Zhu, Z., Lehmann, J., 2014. Carbon mineralizability determines interactive effects on mineralization of pyrogenic organic matter and soil organic carbon. Environ. Sci. Technol. 48 (23), 13727-13734. Methods for processing the data: Bulk Soil Characterization: Analytical replicates for basic soil characterization were averaged and background subtracted as appropriate. NanoSIMS: The OpenMIMS package (Gormanns et al., 2012) in ImageJ v 2.0.0 (Schneider et al., 2012) was used to align and sum NanoSIMS images. Images from multiple regions in each sample plate (n=5 for high and n=4 for low saturation frequency).) were analyzed for pixel intensity correlation between elements (C-Al, C-Fe, and Fe-Al) using Spearman Rank correlation in base R (R Core Team, 2017). Carbon K-edge XANES: Energy position was calibrated by alignment of the carboxylic acid peak of a citric acid standard (288.70 eV). The maximum scattering signal of a plasma-cleaned Au-coated silicon wafer was used as for incidence flux normalization. Note that this method adds spectral noise patterns from the gold wafer spectra (as observed in data file WEOM_Oa_C_XANES.csv). Damage tests were collected to assess development of spectral artifacts resulting from sample radiation damage. Spectra were normalized and flattened in Athena (Demeter 0.9.25) (Ravel and Newville, 2005) and relative peak heights determined in Fityk v. 1.3.1 for the ~285, ~286.5, and ~288.7 eV regions corresponding to aromatic, substituted aromatic, and carboxylic carbon, respectively (Solomon et al., 2011). Iron XAS: Spectral analysis and estimation of reduced iron(II) are described in detail in Inagaki et al., 2020. Briefly, a Gaussian function model was used to determine relative contribution of the 7120 eV region of the first derivative of normalized fluorescence. Additionally, further analysis of the Fe XANES dx/dμ(E) spectra was conducted with linear combination fitting (LCF) in Athena (Demeter 0.9.25) (Ravel and Newville, 2005; Lengke et al., 2006), and computation of extended X-ray absorption fine structure (EXAFS) forward Fourier transform (K-space) spectra for the 3-10 Å-1 wavenumber range in Athena (Demeter 0.9.25) (Ravel and Newville, 2005). Additionally, LCF was applied in Athena for the EXAFS K2-weighed spectra. NMR VCT: Spectra were integrated for the alkyl C (0 to 45 ppm), O/N alkyl C (45 to 110 ppm), aromatic C (110 to 160 ppm), and carboxylic C (160 to 220 ppm) regions (Knicker and Lüdemann, 1995). The log10-transformed signal intensity of each region was plotted as a function of contact time (Preston et al., 1984). The magnitude of the contact time effect was taken as the absolute value of the slope of a linear fit between 0.5-4 ms. The slope of the line from 0.5-4 ms was converted to T1ρH (proton spin-lattice relaxation time in the rotating frame) by the formula: Slope = -1/ T1ρH (Preston et al., 1984). Incubation Experiment: Soil dry weight of each water extract was determined by drying at 70°C and used to correct extract measurement values. References: Berry, A.J., O’Neill, H.St.C., Jayasuriya, K.D., Campbell, S.J., Foran, G.J., 2003. XANES calibrations for the oxidation state of iron in silicate glass. Am. Mineral. 88(7), 967-977. Chen, C., Dynes, J.J., Wang, J., Sparks, D.L., 2014. Properties of Fe-organic matter associations via coprecipitation versus adsorption. Environ. Sci. Technol. 48, 13751-13759. Gormanns, P., Reckow, S., Poczatek, C.J., Turck, C.W., Lechene, C., 2012. Segmentation of multi-isotope mass spectrometry data for semi-automatic detection of regions of interest. PLoS One 7(2), e30576. Inagaki, T.M, Possinger, A.R., Grant, K.E., Schweizer, S.A., Mueller, C.W., Derry, L.A., Lehmann, J., Kögel-Knabner, I., 2020. Subsoil organo-mineral associations under contrasting climate conditions. Geochim. Cosmochim. Acta 270, 244-263. Knicker, H., Lüdemann H.D., 1995. N-15 and C-13 CPMAS and solution NMR studies of N-15 enriched plant material during 600 days of microbial degradation. Org. Geochem. 23, 329-341. Lengke, M.F., Ravel, B., Fleet, M.E., Wanger, G., Gordon, R.A., Southam, G., 2006. Mechanisms of gold bioaccumulation by filamentous cyanobacteria from gold(III)-chloride complex. Environ. Sci. Technol. 40(20), 6304-6309. Ravel, B, Newville, M., 2005. Athena, Artemis, Hephaestus: data analysis for X-ray absorption spectroscopy using IFEFFIT. J. Synchrotron Rad. 12, 537-541. Preston, C.M., Dudley, R.L., Fyfe, C.A., Mathur, S.P., 1984. Effects of variations in contact times and copper contents in a 13C CPMAS NMR study of samples of four organic soils. Geoderma 33, 245-253. R Core Team, 2017. R: A language and environment for statistical computing. R Foundation for Statistical Computing, Vienna, Austria. URL https://www.R-project.org/. Schneider, C.A., Rasband, W.S. Eliceiri, K.W., 2012. NIH Image to ImageJ: 25 years of image analysis. Nature Methods 9(7), 671-675. Wojdyr, M., 2010. Fityk: a general-purpose peak fitting program. J. Appl. Cryst. 43(5-1), 1126-1128. Software- or Instrument-specific information needed to interpret the data, including software and hardware version numbers: Standards and calibration information, if appropriate: Environmental/experimental conditions: Describe any quality-assurance procedures performed on the data: People involved with sample collection, processing, analysis and/or submission: All authors, and in addition, Rong Huang of CHESS; Kelly Hanley, Michael P. Schmidt, Amrita Bhattacharyya, and Akio Enders of Cornell University; Dr. Carmen Höschen, Johann Lugmeier and Dr. Carsten Mueller, Technical University of Munich (NanoSIMS); Dr. Linda Pardo, Stephanie Duston, Brittany LeBeau, and Johali Sotelo (soil sample collection and field characterization). -------------------------- DATA-SPECIFIC INFORMATION -------------------------- 1. Filename: Fe-extractant.csv Short description: Concentration of iron (Al) in soils extractable by selective dissolution with acid ammonium oxalate, hydroxylamine-HCl, and citrate-dithionite Number of variables: 6 Number of cases/rows: 75 (not including header) Variable list, defining any abbreviations, units of measure, codes or symbols used: Column 1: SampleID. Description: Name of horizon sampled. Naming convention: Capital letter = watershed 3 transect (“U” for all samples). Number = sampling location (5, 6, or 7). Lowercase letter = replicate profile (a, b, or c). Upper/lowercase letters and numbers = Horizon ID (e.g., E, Bhs, Bh, Bs, etc.) Column 2: Horizon Description: Horizon type (factor), levels = transitional and spodic Column 3: SaturationFreq Description: Saturation frequency category (factor), levels = low, medium, high Column 4: Element Description: Element analyzed (iron, Fe for this file) Column 5: Value Description: Element concentration (mg element per kg dry soil) Column 6: Extractant Description: Extractant used (factor), levels = Dithionite, Hydroxylamine, Oxalate Missing data codes: Missing data cells marked “NA” Specialized formats or other abbreviations used: 2. Filename: Al-extractant.csv Short description: Concentration of aluminum (Al) in soils extractable by selective dissolution with acid ammonium oxalate, hydroxylamine-HCl, and citrate-dithionite Number of variables: 6 Number of cases/rows: 75 (not including header) Variable list, defining any abbreviations, units of measure, codes or symbols used: Column 1: SampleID. Description: Name of horizon sampled. Naming convention: Capital letter = watershed 3 transect (“U” for all samples). Number = sampling location (5, 6, or 7). Lowercase letter = replicate profile (a, b, or c). Upper/lowercase letters and numbers = Horizon ID (e.g., E, Bhs, Bh, Bs, etc.) Column 2: Horizon Description: Horizon type (factor), levels = transitional and spodic Column 3: SaturationFreq Description: Saturation frequency category (factor), levels = low, medium, high Column 4: Element Description: Element analyzed (aluminum, Al for this file) Column 5: Value Description: Element concentration (mg element per kg dry soil) Column 6: Extractant Description: Extractant used (factor), levels = Dithionite, Hydroxylamine, Oxalate Missing data codes: Missing data cells marked “NA” Specialized formats or other abbreviations used: 3. Filename: Fe-total.csv Short description: Concentration of total iron (Fe) in soils by tera/meta-borate flux method Number of variables: 6 Number of cases/rows: 25 (not including header) Variable list, defining any abbreviations, units of measure, codes or symbols used: Column 1: SampleID. Description: Name of horizon sampled. Naming convention: Capital letter = watershed 3 transect (“U” for all samples). Number = sampling location (5, 6, or 7). Lowercase letter = replicate profile (a, b, or c). Upper/lowercase letters and numbers = Horizon ID (e.g., E, Bhs, Bh, Bs, etc.) Column 2: Horizon Description: Horizon type (factor), levels = transitional and spodic Column 3: SaturationFreq Description: Saturation frequency category (factor), levels = low, medium, high Column 4: Element Description: Element analyzed (iron, Fe for this file) Column 5: Value Description: Element concentration (mg element per kg dry soil) Column 6: Extractant Description: Extractant used (factor), levels = Total Missing data codes: Missing data cells marked “NA” Specialized formats or other abbreviations used: 4. Filename: Al-total.csv Short description: Concentration of total aluminum in soil samples by tetra/meta-borate flux method Number of variables: 6 Number of cases/rows: 25 (not including header) Variable list, defining any abbreviations, units of measure, codes or symbols used: Column 1: SampleID. Description: Name of horizon sampled. Naming convention: Capital letter = watershed 3 transect (“U” for all samples). Number = sampling location (5, 6, or 7). Lowercase letter = replicate profile (a, b, or c). Upper/lowercase letters and numbers = Horizon ID (e.g., E, Bhs, Bh, Bs, etc.) Column 2: Horizon Description: Horizon type (factor), levels = transitional and spodic Column 3: SaturationFreq Description: Saturation frequency category (factor), levels = low, medium, high Column 4: Element Description: Element analyzed (aluminum, Al for this file) Column 5: Value Description: Element concentration (mg element per kg dry soil) Column 6: Extractant Description: Extractant used (factor), levels = Total Missing data codes: Missing data cells marked “NA” Specialized formats or other abbreviations used: 5. Filename: AlFe-Total-Ratio.csv Short description: Ratio of total aluminum and iron by tetra/meta-borate flux method Number of variables: 6 Number of cases/rows: 25 (not including header) Variable list, defining any abbreviations, units of measure, codes or symbols used: Column 1: SampleID. Description: Name of horizon sampled. Naming convention: Capital letter = watershed 3 transect (“U” for all samples). Number = sampling location (5, 6, or 7). Lowercase letter = replicate profile (a, b, or c). Upper/lowercase letters and numbers = Horizon ID (e.g., E, Bhs, Bh, Bs, etc.) Column 2: Horizon Description: Horizon type (factor), levels = transitional and spodic Column 3: SaturationFreq Description: Saturation frequency category (factor), levels = low, medium, high Column 4: Element Description: Element ratio analyzed (Al/Fe for this file) Column 5: Value Description: Element ratio (unitless) Column 6: Extractant Description: Extractant used (factor), levels = Total Missing data codes: Missing data cells marked “NA” Specialized formats or other abbreviations used: 6. Filename: WEOM_Oa_C_XANES.csv Short description: Carbon K-edge x-ray absorption fine structure (XANES) spectra for water-extractable organic matter from organic horizons of low and high saturation frequency locations (Supplementary Figure A2 in Possinger et al., in revision for Geoderma) Number of variables: 3 Number of cases/rows: 250 (not including header) Variable list, defining any abbreviations, units of measure, codes or symbols used: Column 1: Energy Description: X-ray absorption energy (eV) Column 2: High_sat_freq_norm Description: Normalized (edge step = 1) intensity of carbon K-edge XANES for high saturation frequency organic horizon water extract. Note: incidence flux normalization (by gold blank spectra) results in similar noise pattern, e.g. at ~295 eV. Column 3: Low_sat_freq_norm Description: Normalized (edge step = 1) intensity of carbon K-edge XANES for low saturation frequency organic horizon water extract. Note: incidence flux normalization (by gold blank spectra) results in similar noise pattern, e.g. at ~295 eV. Missing data codes: Missing data cells marked “NA” Specialized formats or other abbreviations used: 7. Filename: Mn-spodic.csv Short description: Concentrations of manganese (Mn) extractable by hydroxylamine and acid ammonium oxalate for spodic horizon bulk soils Number of variables: 5 Number of cases/rows: 16 (not including header) Variable list, defining any abbreviations, units of measure, codes or symbols used: Column 1: SampleID Description: Identity of soil sample used for iron K-edge EXAFS linear combination fitting following the convention: Capital letter = watershed 3 transect (“U” for all samples). Number = sampling location (5, 6, or 7). Lowercase letter = replicate profile (a, b, or c). Upper/lowercase letters and numbers = Horizon ID (e.g., E, Bhs, Bh, Bs, etc.) Column 2: SaturationFreq Description: Saturation frequency category (factor), levels = Low, Medium, High Column 3: TotalMn Description: Total manganese content by flux method (mg Mn per kg dry soil) Column 4: MnHydroxPercent Description: Hydroxylamine-extractable manganese as proportion of total Mn (%) Column 5: MnOxalatePercent Description: Oxalate-extractable manganese as proportion of total Mn (%) Missing data codes: Missing data cells marked “NA” Specialized formats or other abbreviations used: 8. Filename: MineralSoilCorrelation4419.csv Short description: Data table of bulk mineral soil characterization (e.g., pH, soil organic matter, total C, total N, selective extractions, water content) Number of variables: 38 Number of cases/rows: 36 (not including header) Variable list, defining any abbreviations, units of measure, codes or symbols used: Column 1: SampleID Description: Identity of soil sample used for iron K-edge EXAFS linear combination fitting following the convention: Capital letter = watershed 3 transect (“U” for all samples). Number = sampling location (5, 6, or 7). Lowercase letter = replicate profile (a, b, or c). Upper/lowercase letters and numbers = Horizon ID (e.g., E, Bhs, Bh, Bs, etc.) Column 2: Cmgkg Description: Soil carbon content, mg C per kg dry soil Column 3: Nmgkg Description: Soil nitrogen content, mg N per kg dry soil Column 4: CN Description: Carbon/nitrogen content ratio (unitless) Column 5: GravWater Description: Weight of water per weight dry soil (g water per g dry soil) (prior to air-drying for analysis) Column 6: ModelBD Description: Estimated bulk density based on soil organic matter content (g soil per cubic m soil) Column 7: VolWater Description: Weight of water per volume soil (cubic m water per cubic m soil) Column 8: pH Description: Soil pH Column 9: Depth Description: Horizon depth (distance from center of horizon to surface) (cm) Column 10: Horizon Description: Category of horizon (factor), levels = Eluvial, Spodic, Substratum, Transitional Column 11: NegDepth Description: Horizon depth (distance from center of horizon to surface) expressed as negative value (cm) Column 12: SaturationFreq Description: Saturation frequency category (factor), levels = Low, Medium, High Column 13: Site Description: Sampling location (factor), levels = 1, 2, 3 (corresponding to 5, 6, and 7 in sample ID) Column 14: Profile Description: Replicate profile (factor), levels = A, B, C (corresponding to a, b, and c in sample ID) Column 15: ODOE Description: Optical density of oxalate extract (absorbance, a.u.) Column 16: LOI Description: Loss-on-ignition of organic matter (by combustion) (%) Column 17: TotalAl Description: Total aluminum content by flux method (mg Al per kg dry soil) Column 18: TotalFe Description: Total iron content by flux method (mg Fe per kg dry soil) Column 19: TotalMn Description: Total manganese content by flux method (mg Mn per kg dry soil) Column 20: FeDithionite Description: Content of iron extractable by citrate-dithionite (mg Fe per kg dry soil) Column 21: AlDithionite Description: Content of alumninum extractable by citrate-dithionite (mg Al per kg dry soil) Column 22: FeHydrox Description: Content of iron extractable by hydroxylamine (mg Fe per kg dry soil) Column 23: AlHydrox Description: Content of aluminum extractable by hydroxylamine (mg Al per kg dry soil) Column 24: MnHydrox Description: Content of manganese extractable by hydroxylamine (mg Mn per kg dry soil) Column 25: MnOxalate Description: Content of manganese extractable by acid ammonium oxalate (mg Mn per kg dry soil) Column 26: FeOxalate Description: Content of iron extractable by acid ammonium oxalate (mg Fe per kg dry soil) Column 27: AlOxalate Description: Content of aluminum extractable by acid ammonium oxalate (mg Al per kg dry soil) Column 28: FeDithionitePercent Description: Dithionite-extractable iron as proportion of total Fe (%) Column 29: AlDithionitePercent Description: Dithionite-extractable aluminum as proportion of total Al (%) Column 30: FeHydroxPercent Description: Hydroxylamine-extractable iron as proportion of total Fe (%) Column 31: AlHydroxPercent Description: Hydroxylamine-extractable aluminum as proportion of total Al (%) Column 32: MnHydroxPercent Description: Hydroxylamine-extractable manganese as proportion of total Mn (%) Column 33: FeOxalatePercent Description: Oxalate-extractable iron as proportion of total Fe (%) Column 34: AlOxalatePercent Description: Oxalate-extractable aluminum as proportion of total Al (%) Column 35: MnOxalatePercent Description: Oxalate-extractable manganese as proportion of total Mn (%) Column 36: FeOxalateHydroxDifference Description: Difference between oxalate- and hydroxylamine-extractable iron (mg Fe per kg dry soil) Column 37: AlOxalateHydroxDifference Description: Difference between oxalate- and hydroxylamine-extractable aluminum (mg Al per kg dry soil) Column 38: MnOxalateHydroxDifference Description: Difference between oxalate- and hydroxylamine-extractable manganese (mg Mn per kg dry soil) Missing data codes: Missing data cells marked “NA” Specialized formats or other abbreviations used: 9-13: Filenames: test_11202.csv, test_11204.csv, test_11206.csv, test_11208.csv, test_11210.csv. Short description: Test datasets for Random Forest model representing 25% of of rows at random from MineralSoilCorrelation4419.csv, entry 8 above. Number of variables: 38 Number of cases/rows: 9 (not including header) Variable list, defining any abbreviations, units of measure, codes or symbols used: Column 1: SampleID Description: Identity of soil sample used for iron K-edge EXAFS linear combination fitting following the convention: Capital letter = watershed 3 transect (“U” for all samples). Number = sampling location (5, 6, or 7). Lowercase letter = replicate profile (a, b, or c). Upper/lowercase letters and numbers = Horizon ID (e.g., E, Bhs, Bh, Bs, etc.) Column 2: Cmgkg Description: Soil carbon content, mg C per kg dry soil Column 3: Nmgkg Description: Soil nitrogen content, mg N per kg dry soil Column 4: CN Description: Carbon/nitrogen content ratio (unitless) Column 5: GravWater Description: Weight of water per weight dry soil (g water per g dry soil) (prior to air-drying for analysis) Column 6: ModelBD Description: Estimated bulk density based on soil organic matter content (g soil per cubic m soil) Column 7: VolWater Description: Weight of water per volume soil (cubic m water per cubic m soil) Column 8: pH Description: Soil pH Column 9: Depth Description: Horizon depth (distance from center of horizon to surface) (cm) Column 10: Horizon Description: Category of horizon (factor), levels = Eluvial, Spodic, Substratum, Transitional Column 11: NegDepth Description: Horizon depth (distance from center of horizon to surface) expressed as negative value (cm) Column 12: SaturationFreq Description: Saturation frequency category (factor), levels = Low, Medium, High Column 13: Site Description: Sampling location (factor), levels = 1, 2, 3 (corresponding to 5, 6, and 7 in sample ID) Column 14: Profile Description: Replicate profile (factor), levels = A, B, C (corresponding to a, b, and c in sample ID) Column 15: ODOE Description: Optical density of oxalate extract (absorbance, a.u.) Column 16: LOI Description: Loss-on-ignition of organic matter (by combustion) (%) Column 17: TotalAl Description: Total aluminum content by flux method (mg Al per kg dry soil) Column 18: TotalFe Description: Total iron content by flux method (mg Fe per kg dry soil) Column 19: TotalMn Description: Total manganese content by flux method (mg Mn per kg dry soil) Column 20: FeDithionite Description: Content of iron extractable by citrate-dithionite (mg Fe per kg dry soil) Column 21: AlDithionite Description: Content of alumninum extractable by citrate-dithionite (mg Al per kg dry soil) Column 22: FeHydrox Description: Content of iron extractable by hydroxylamine (mg Fe per kg dry soil) Column 23: AlHydrox Description: Content of aluminum extractable by hydroxylamine (mg Al per kg dry soil) Column 24: MnHydrox Description: Content of manganese extractable by hydroxylamine (mg Mn per kg dry soil) Column 25: MnOxalate Description: Content of manganese extractable by acid ammonium oxalate (mg Mn per kg dry soil) Column 26: FeOxalate Description: Content of iron extractable by acid ammonium oxalate (mg Fe per kg dry soil) Column 27: AlOxalate Description: Content of aluminum extractable by acid ammonium oxalate (mg Al per kg dry soil) Column 28: FeDithionitePercent Description: Dithionite-extractable iron as proportion of total Fe (%) Column 29: AlDithionitePercent Description: Dithionite-extractable aluminum as proportion of total Al (%) Column 30: FeHydroxPercent Description: Hydroxylamine-extractable iron as proportion of total Fe (%) Column 31: AlHydroxPercent Description: Hydroxylamine-extractable aluminum as proportion of total Al (%) Column 32: MnHydroxPercent Description: Hydroxylamine-extractable manganese as proportion of total Mn (%) Column 33: FeOxalatePercent Description: Oxalate-extractable iron as proportion of total Fe (%) Column 34: AlOxalatePercent Description: Oxalate-extractable aluminum as proportion of total Al (%) Column 35: MnOxalatePercent Description: Oxalate-extractable manganese as proportion of total Mn (%) Column 36: FeOxalateHydroxDifference Description: Difference between oxalate- and hydroxylamine-extractable iron (mg Fe per kg dry soil) Column 37: AlOxalateHydroxDifference Description: Difference between oxalate- and hydroxylamine-extractable aluminum (mg Al per kg dry soil) Column 38: MnOxalateHydroxDifference Description: Difference between oxalate- and hydroxylamine-extractable manganese (mg Mn per kg dry soil) Missing data codes: Missing data cells marked “NA” Specialized formats or other abbreviations used: 14-18: Filenames: train_11202.csv, train_11204.csv, train_11206.csv, train_11208.csv, train_11210.csv Short description: Training datasets for Random Forest model representing 75% of of rows at random from MineralSoilCorrelation4419.csv, entry 8 above. Number of variables: 38 Number of cases/rows: 27 (not including header) Variable list, defining any abbreviations, units of measure, codes or symbols used: Column 1: SampleID Description: Identity of soil sample used for iron K-edge EXAFS linear combination fitting following the convention: Capital letter = watershed 3 transect (“U” for all samples). Number = sampling location (5, 6, or 7). Lowercase letter = replicate profile (a, b, or c). Upper/lowercase letters and numbers = Horizon ID (e.g., E, Bhs, Bh, Bs, etc.) Column 2: Cmgkg Description: Soil carbon content, mg C per kg dry soil Column 3: Nmgkg Description: Soil nitrogen content, mg N per kg dry soil Column 4: CN Description: Carbon/nitrogen content ratio (unitless) Column 5: GravWater Description: Weight of water per weight dry soil (g water per g dry soil) (prior to air-drying for analysis) Column 6: ModelBD Description: Estimated bulk density based on soil organic matter content (g soil per cubic m soil) Column 7: VolWater Description: Weight of water per volume soil (cubic m water per cubic m soil) Column 8: pH Description: Soil pH Column 9: Depth Description: Horizon depth (distance from center of horizon to surface) (cm) Column 10: Horizon Description: Category of horizon (factor), levels = Eluvial, Spodic, Substratum, Transitional Column 11: NegDepth Description: Horizon depth (distance from center of horizon to surface) expressed as negative value (cm) Column 12: SaturationFreq Description: Saturation frequency category (factor), levels = Low, Medium, High Column 13: Site Description: Sampling location (factor), levels = 1, 2, 3 (corresponding to 5, 6, and 7 in sample ID) Column 14: Profile Description: Replicate profile (factor), levels = A, B, C (corresponding to a, b, and c in sample ID) Column 15: ODOE Description: Optical density of oxalate extract (absorbance, a.u.) Column 16: LOI Description: Loss-on-ignition of organic matter (by combustion) (%) Column 17: TotalAl Description: Total aluminum content by flux method (mg Al per kg dry soil) Column 18: TotalFe Description: Total iron content by flux method (mg Fe per kg dry soil) Column 19: TotalMn Description: Total manganese content by flux method (mg Mn per kg dry soil) Column 20: FeDithionite Description: Content of iron extractable by citrate-dithionite (mg Fe per kg dry soil) Column 21: AlDithionite Description: Content of alumninum extractable by citrate-dithionite (mg Al per kg dry soil) Column 22: FeHydrox Description: Content of iron extractable by hydroxylamine (mg Fe per kg dry soil) Column 23: AlHydrox Description: Content of aluminum extractable by hydroxylamine (mg Al per kg dry soil) Column 24: MnHydrox Description: Content of manganese extractable by hydroxylamine (mg Mn per kg dry soil) Column 25: MnOxalate Description: Content of manganese extractable by acid ammonium oxalate (mg Mn per kg dry soil) Column 26: FeOxalate Description: Content of iron extractable by acid ammonium oxalate (mg Fe per kg dry soil) Column 27: AlOxalate Description: Content of aluminum extractable by acid ammonium oxalate (mg Al per kg dry soil) Column 28: FeDithionitePercent Description: Dithionite-extractable iron as proportion of total Fe (%) Column 29: AlDithionitePercent Description: Dithionite-extractable aluminum as proportion of total Al (%) Column 30: FeHydroxPercent Description: Hydroxylamine-extractable iron as proportion of total Fe (%) Column 31: AlHydroxPercent Description: Hydroxylamine-extractable aluminum as proportion of total Al (%) Column 32: MnHydroxPercent Description: Hydroxylamine-extractable manganese as proportion of total Mn (%) Column 33: FeOxalatePercent Description: Oxalate-extractable iron as proportion of total Fe (%) Column 34: AlOxalatePercent Description: Oxalate-extractable aluminum as proportion of total Al (%) Column 35: MnOxalatePercent Description: Oxalate-extractable manganese as proportion of total Mn (%) Column 36: FeOxalateHydroxDifference Description: Difference between oxalate- and hydroxylamine-extractable iron (mg Fe per kg dry soil) Column 37: AlOxalateHydroxDifference Description: Difference between oxalate- and hydroxylamine-extractable aluminum (mg Al per kg dry soil) Column 38: MnOxalateHydroxDifference Description: Difference between oxalate- and hydroxylamine-extractable manganese (mg Mn per kg dry soil) Missing data codes: Missing data cells marked “NA” Specialized formats or other abbreviations used: 19. Filename: RF_pred_obs.csv Short description: Predicted and observed total carbon content derived from Random Forest model Number of variables: 3 Number of cases/rows: 43 (not including header) Variable list, defining any abbreviations, units of measure, codes or symbols used: Column 1: Predicted Description: Predicted value of total soil carbon (mg kg dry soil) from Random Forest model (note: rows containing NA in dataset excluded) Column 2: Observed Description: Observed value of total soil carbon (mg kg dry soil) (note: rows containing NA in dataset excluded) Column 3: Iteration Description: Iteration of Random Forest model (factor, levels 1-5) Missing data codes: Specialized formats or other abbreviations used: 20. Filename: Field_Sampling_Locations.csv Short description: Coordinates and site-level information for hydropedological unit sampling locations Number of variables: 14 Number of cases/rows: 9 (not including header) Column 1: SaturationFreq Description: Saturation frequency category (factor), levels = high, medium, low Column 2: HPU Description: Hydropedological unit classification (factor), levels = typical, Bhs, E Column 3: Profile Description: Replicate profile ID (factor), levels = a, b, c Column 4: Latitude_N Description: Approximate latitude in decimal degrees N Column 5: Longitude_W Description: Approximate longitutde in decimal degrees W Column 6: Aspect (degrees magnetic north) Description: Asepct in degrees magnetic north Column 7: Slope (up) (%) Description: Slope upslope, % Column 8: Slope (down) (%) Description: Slope upslope, % Column 9: Physiography Description: Physiography classification (factor), levels = backslope, upper backslope, shoulder Column 10: Land shape Description: Land shape classification (factor), levels = nose, hollow foot, hollow Column 11: Depth to water table (cm) Description: Observed depth to water table in cm Column 12: Depth to redox (cm) Description: Observed depth to redoximorphic features in cm Column 13: Contour R Description: Contour angle to right (degrees) Column 14: Contour L Description: Contour angle to left (degrees) Missing data codes: “NA” is used for cells where observations are not applicable. “NR” is used where observations are missing/not recorded. Specialized formats or other abbreviations used: 21. Filename: Field_Profile_Descriptions.csv Short description: Transcription of field profile descriptions for soil samples collected at Hubbard Brook Watershed 3 Number of variables: 14 Number of cases/rows: 66 (not including header) Variable list, defining any abbreviations, units of measure, codes or symbols used: Column 1: SaturationFreq Description: Saturation frequency category (factor), levels = high, medium, low Column 2: HPU Description: Hydropedological unit classification (factor), levels = typical, Bhs, E Column 3: Profile Description: Replicate profile ID (factor), levels = a, b, c Column 4: Horizon Description: Pedogenic horizon classification (US system) Column 5: Top (cm) Description: Horizon top position (cm) Column 6: Bottom (cm) Description: Horizon bottom position (cm) Column 7: Matrix color Description: Major soil color by Munsell color system (Hue Value Chroma) Column 8: Minor colors Description: Minor soil colors (concentrations, depletions, patches) by Munsell color system (Hue Value Chroma) Column 9: Field texture Description: Texture-by-feel (factor), levels = SL (sandy loam), LS (loamy sand) Column 10: Structure Description: Structure classification where Number = grade (1 = weak, 2 = moderate), lowercase letter = size (f = fine, m = medium), uppercase letters = type (SBK = subangular blocky, GR = granular, M = massive) Column 11: Consistence Description: Consistence classification where fi = firm, vfi = very firm, fr = friable, vfr = very friable Column 12: Boundary Description: Horizon boundary, where first letter indicates distinctness (A = abrupt, C = clear) and second letter indicates topography (S = smooth, W = wavy) Column 13: Coarse fragments (%) Description: Visual Estimation of coarse fragments (>2mm) Column 14: Roots Description: Classification of root abundance, where F = few, C = common, M = many, NONE = none (below root penetration zone) Missing data codes: “NA” is used for cells where observations are not applicable. “NR” is used where observations are missing/not recorded. Specialized formats or other abbreviations used: 22. Filename: Vegetation_Index.csv Short description: Table of tree species >0.1 m diameter nearby to soil profile sampling areas Number of variables: 7 Number of cases/rows: 59 (not including header) Variable list, defining any abbreviations, units of measure, codes or symbols used: Column 1: Common name Description: Tree common name Column 2: Genus Description: Tree genus name Column 3: Species Description: Tree species name Column 4: DBH_cm Description: Tree diameter at breast height (cm) Column 5: Site Description: Location of sampling area, linked to initial locations for hydropedological units (factor), levels = E_podzol, Bhs_podzol, Typical_podzol Column 6: Approx_Lat_N Description: Approximate latitude of sampling location (decimal degrees N) Column 6: Approx_Long_W Description: Approximate longitude of sampling location (decimal degrees W) Missing data codes: Missing data cells marked “NA” Specialized formats or other abbreviations used: 23. Filename: Hydroxylamine-DOC.csv Short description: Values of dissolved organic carbon, soluble iron, and soluble aluminum in hydroxylamine-HCl extracts Number of variables: 5 Number of cases/rows: 24 (not including header) Variable list, defining any abbreviations, units of measure, codes or symbols used: Column 1: Horizon Description: Soil horizon ID, following the convention: Capital letter = watershed 3 transect (“U” for all samples). Number = sampling location (5, 6, or 7). Lowercase letter = replicate profile (a, b, or c). Upper/lowercase letters and numbers = Horizon ID (e.g., E, Bhs, Bh, Bs, etc.) Column 2: SaturationFreq Description: Saturation frequency category (factors), levels = low, medium, high Column 3: Soil Description: Category of soil used for hydroxylamine and water extractions (factors), levels = bulk, POMremoved (particulate organic matter removed) Column 4: Treatment Description: Cateogry of extractant (factor), levels = Water, Hydroxylamine Column 5: DOC Description: Dissolved organic carbon concentration in extract (mg DOC kg dry soil) Missing data codes: Missing data cells marked “NA” Specialized formats or other abbreviations used: 24. Filename: Hydrox-DOC-ratios.csv Short description: Ratios of dissolved organic carbon, soluble iron, and soluble aluminum in hydroxylamine-HCl extracts Number of variables: 4 Number of cases/rows: 27 (not including header) Variable list, defining any abbreviations, units of measure, codes or symbols used: Column 1: SaturationFreq Description: Saturation frequency category (factor), levels = low, medium, high Column 2: Ratio Description: Ratio of concentration of carbon (C), iron (Fe) and alumninum (Al) released in hydroxylamine extract to concenration in water extract (unitless) Column 3: Pair Description: Category for ratio of hydroxylamine extractable to water-extractable concentration (factor), levels = HydroxCWaterC, HydroxFeWaterFe, HydroxAlWaterAl Column 4: NormRatio Description: Ratio of hydroxylamine to water-extractable C, Fe, and Al normalized to maximum value (unitless) Missing data codes: Missing data cells marked “NA” Specialized formats or other abbreviations used: 25-51: Text images derived from nanoscale secondary ion mass spectrometry (NanoSIMS) for 12C14N, 27Al16O, and 56Fe16O Number of variables: 1 (pixel intensity) Number of cases/rows: 256x256 matrix Variable list, defining any abbreviations, units of measure, codes or symbols used: 256x256 matrix of pixel intensity (counts) without column or row names. Missing data codes: Specialized formats or other abbreviations used: 52. Filename: NanoSIMScorr.csv Short description: Table of Spearman Rank correlation coefficients for pixel intensity correlations between iron-carbon, iron-aluminum, and aluminum-carbon derived from NanoSIMS elemental maps Number of variables: 3 Number of cases/rows: 27 (not including header) Variable list, defining any abbreviations, units of measure, codes or symbols used: Column 1: SaturationFreq Description: Saturation frequency category (factor), levels = Low, Medium, High Column 2: Correlation Description: Spearman Rank correlation coefficient (Rs) (unitless) Column 3: Pair Description: Elemental pair used for correlation (factor), levels = FeC (iron-carbon), AlFe (aluminum-iron), AlC (aluminum-carbon) Missing data codes: Missing data cells marked “NA” Specialized formats or other abbreviations used: 53. Filename: Standards-7120.csv Short description: Iron K-edge X-ray absorption near edge structure standard compounds and soil samples with estimate of reduced Fe(II) by 7120 eV peak area Number of variables: 2 Number of cases/rows: 12 (not including header) Variable list, defining any abbreviations, units of measure, codes or symbols used: Column 1: Sample Description: Sample type (factor), levels = Low (low saturation frequency soil), Medium (medium saturation frequency soil), High (high saturation frequency soil), Ferrihydrite (Fe(III) standard), Nontronite (Fe(II)-substituted standard), Fayalite (Fe(II) standard) Column 2: ReducedFe Description: Estimate of reduced iron (FeII) by proportion of Gaussian peak area at 7120 in first derivation iron K-edge XANES spectrum (% of total area) Missing data codes: Missing data cells marked “NA” Specialized formats or other abbreviations used: 54. Filename: Fe-XANES-functions-HBEF.csv Short description: Iron (Fe) K-edge X-ray absorption spectroscopy first derivative spectra and fit of 7120 eV peak area for estimation of reduced Fe(II) Number of variables: 112 Number of cases/rows: 39 Variable list, defining any abbreviations, units of measure, codes or symbols used: Columns are labeled by material used in iron X-ray absorption spectroscopy measurement. For iron standards, materials are: Ferrihydrite, Fayalite, FeEDTA (iron-ethyldiamine tetraacetic acid), FeIICitrate (iron II citrate), FeIIICitrate (iron III citrate), and Nontronite. For soil samples, the name of the soil horizon uses the following convention: Capital letter = watershed 3 transect (“U” for all samples). Number = sampling location (5, 6, or 7). Lowercase letter = replicate profile (a, b, or c). Upper/lowercase letters and numbers = Horizon ID (e.g., E, Bhs, Bh, Bs, etc.) Columns 1, 8, 15, 22, 29, 36, 43, 50, 57, 64, 71, 78, 85, 92, 99, 106: “Energy” - X-ray absorption energy (electron volts, eV) for each material Columns 2, 9, 16, 23, 30, 37, 44, 51, 58, 65, 72, 79, 86, 93, 100, 107: “Data” - First derivative of X-ray fluorescence intensity (dx/dm(E)) (counts) Columns 3, 10, 17, 24, 31, 38, 45, 52, 59, 66, 73, 80, 87, 94, 101, 108: “G1” - Gaussian function under first derivative of X-ray fluorescence spectrum with center ~7112 eV (dx/dm(E)) (counts) Columns 4, 11, 18, 25, 32, 39, 46, 53, 60, 67, 74, 81, 88, 95, 102, 109: “G2” - Gaussian function under first derivative of X-ray fluorescence spectrum with center ~7114 eV (dx/dm(E)) (counts) Columns 5, 12, 19, 26, 33, 40, 47, 54, 61, 68, 75, 72, 90, 96, 103, 110: “G3” - Gaussian function under first derivative of X-ray fluorescence spectrum with center at 7120.0 eV (dx/dm(E)) (counts) Columns 6, 13, 20, 27, 34, 41, 48, 55, 62, 69, 76, 73, 91, 97, 104, 111: “G4” - Gaussian function under first derivative of X-ray fluorescence spectrum with center ~7124 eV (dx/dm(E))(counts) Columns 7, 14, 21, 28, 35, 42, 49, 56, 63, 70, 77, 74, 92, 98, 105, 112: “Model” - Model fit for first derivative of X-ray fluorescence curve (dx/dm(E))(counts) Column 1: EnergyFerrihydrite Column 2: DataFerrihydrite Column 3: G1Ferrihydrite Column 4: G2Ferrihydrite Column 5: G3Ferrihydrite Column 6: G4Ferrihydrite Column 7: ModelFerrihydrite Column 8: EnergyFayalite Column 9: DataFayalite Column 10: G1Fayalite Column 11: G2Fayalite Column 12: G3Fayalite Column 13: G4Fayalite Column 14: ModelFayalite Column 15: EnergyFeEDTA Column 16: DataFeEDTA Column 17: G1FeEDTA Column 18: G2FeEDTA Column 19: G3FeEDTA Column 20: G4FeEDTA Column 21: ModelFeEDTA Column 22: EnergyFeIICitrate Column 23: DataFeIICitrate Column 24: G1FeIICitrate Column 25: G2FeIICitrate Column 26: G3FeIICitrate Column 27: G4FeIICitrate Column 28: ModelFeIICitrate Column 29: EnergyFeIIICitrate Column 30: DataFeIIICitrate Column 31: G1FeIIICitrate Column 32: G2FeIIICitrate Column 33: G3FeIIICitrate Column 34: G4FeIIICitrate Column 35: ModelFeIIICitrate Column 36: EnergyGoethite Column 37: DataGoethite Column 38: G1Goethite Column 39: G2Goethite Column 40: G3Goethite Column 41: G4Goethite Column 42: ModelGoethite Column 43: EnergyNontronite Column 44: DataNontronite Column 45: G1Nontronite Column 46: G2Nontronite Column 47: G3Nontronite Column 48: G4Nontronite Column 49: ModelNontronite Column 50: EnergyU5aBhs Column 51: DataU5aBhs Column 52: G1U5aBhs Column 53: G2U5aBhs Column 54: G3U5aBhs Column 55: G4U5aBhs Column 56: ModelU5aBhs Column 57: EnergyU5bBhs Column 58: DataU5bBhs Column 59: G1U5bBhs Column 60: G2U5bBhs Column 61: G3U5bBhs Column 62: G4U5bBhs Column 63: ModelU5bBhs Column 64: EnergyU5bCB Column 65: DataU5bCB Column 66: G1U5bCB Column 67: G2U5bCB Column 68: G3U5bCB Column 69: G4U5bCB Column 70: ModelU5bCB Column 71: EnergyU5cBs Column 72: DataU5cBs Column 73: G1U5cBs Column 74: G2U5cBs Column 75: G3U5cBs Column 76: G4U5cBs Column 77: ModelU5cBs Column 78: EnergyU6bBhs1 Column 79: DataU6bBhs1 Column 80: G1U6bBhs1 Column 81: G2U6bBhs1 Column 82: G3U6bBhs1 Column 83: G4U6bBhs1 Column 84: ModelU6bBhs1 Column 85: EnergyU6cBhs1 Column 86: DataU6cBhs1 Column 87: G1U6cBhs1 Column 88: G2U6cBhs1 Column 89: G3U6cBhs1 Column 90: G4U6cBhs1 Column 91: ModelU6cBhs1 Column 92: EnergyU7aBhs1 Column 93: DataU7aBhs1 Column 94: G1U7aBhs1 Column 95: G2U7aBhs1 Column 96: G3U7aBhs1 Column 97: G4U7aBhs1 Column 98: ModelU7aBhs1 Column 99: EnergyU7bBhs1 Column 100: DataU7bBhs1 Column 101: G1U7bBhs1 Column 102: G2U7bBhs1 Column 103: G3U7bBhs1 Column 104: G4U7bBhs1 Column 105: ModelU7bBhs1 Column 106: EnergyU7cBhs Column 107: DataU7cBhs Column 108: G1U7cBhs Column 109: G2U7cBhs Column 110: G3U7cBhs Column 111: G4U7cBhs Column 112: ModelU7cBhs Missing data codes: Missing data cells marked “NA” Specialized formats or other abbreviations used: 55. Filename: LCF_proportions.csv Short description: Proportion of crystalline, non-crystalline, and iron-organic complex components estimated by iron K-edge EXAFS linear combination fitting Number of variables: 4 Number of cases/rows: 27 (not including header) Variable list, defining any abbreviations, units of measure, codes or symbols used: Column 1: SampleID Description: Identity of soil sample used for iron K-edge EXAFS linear combination fitting following the convention: Capital letter = watershed 3 transect (“U” for all samples). Number = sampling location (5, 6, or 7). Lowercase letter = replicate profile (a, b, or c). Upper/lowercase letters and numbers = Horizon ID (e.g., E, Bhs, Bh, Bs, etc.) Column 2: SaturationFreq Description: Saturation frequency category (factor), levels = High, Medium, Low Column 3: Proportion Description: Iron component proportion derived from iron K-edge EXAFS linear combination fit result (unitless) Description: Column 4: Component Description: Iron component categories (factor), levels = Crystalline, FeOrganic (iron-organic complex), NonCrystalline Missing data codes: Missing data cells marked “NA” Specialized formats or other abbreviations used: 56. Filename: XANES_LCF_proportions.csv Short description: Relative proportions of Fe(II) complex, Fe(III) complex, Fe(III) mineral, and Fe(II)/Fe(III) mineral components resulting from iron K-edge XANES linear combination fitting Number of variables: 3 Number of cases/rows: 36 (not including header) Variable list, defining any abbreviations, units of measure, codes or symbols used: Column 1: SaturationFreq Description: Saturation frequency category (factor), levels = Low, Medium, High Column 2: Proportion Description: Proportion of iron K-edge XANES component resulting from linear combination fit Column 3: Component Description: Category of iron component (factors), levels = FeIIComplex (Fe(II)-organic complex), FeIIFeIIIMineral (mixed Fe(II)/Fe(III) mineral), FeIIIComplex (Fe(III)-organic complex), FeIIIMineral (Fe(III) mineral) Missing data codes: Missing data cells marked “NA” Specialized formats or other abbreviations used: 57. Filename: XANES-LCF-residuals.csv Short description: Linear combination fitting results (output and error residuals) for iron K-edge X-ray absorption near edge structure (XANES) Number of variables: 34 Number of cases/rows: 83 (not including header) Variable list, defining any abbreviations, units of measure, codes or symbols used: For soil samples, the name of the soil horizon uses the following convention: Capital letter = watershed 3 transect (“U” for all samples). Number = sampling location (5, 6, or 7). Lowercase letter = replicate profile (a, b, or c). Upper/lowercase letters and numbers = Horizon ID (e.g., E, Bhs, Bh, Bs, etc.) Column 1: energy Description: X-ray absorption energy, electron volts (eV) Column 2: U7aBhs1 Description: First derivative of iron K-edge X-ray absorption fluorescence intensity (dx/dmuE) (arbitrary units) for sample U7aBhs1 Column 3: U7aBhs1fit Description: Linear combination fit result for sample U7aBhs1 (dx/dmuE) (arbitrary units) Column 4: U7aBhs1residual Description: Residual error of linear combination fit result for sample U7aBhs1 (dx/dmuE) (arbitrary units) Column 5: U7bBhs1 Description: First derivative of iron K-edge X-ray absorption fluorescence intensity (dx/dmuE) (arbitrary units) for sample U7bBhs1 Column 6: U7bBhs1fit Description: Linear combination fit result for sample U7bBhs1 (dx/dmuE) (arbitrary units) Column 7: U7bBhs1residual Description: Residual error of linear combination fit result for sample U7bBhs1 (dx/dmuE) (arbitrary units) Column 8: U7cBhs Description: First derivative of iron K-edge X-ray absorption fluorescence intensity (dx/dmuE) (arbitrary units) for sample U7cBhs Column 9: U7cBhsfit Description: Linear combination fit result for sample U7cBhs (dx/dmuE) (arbitrary units) Column 10: U7cBhsresidual Description: Residual error of linear combination fit result for sample U7cBhs (dx/dmuE) (arbitrary units) Column 11: U5aBhs Description: First derivative of iron K-edge X-ray absorption fluorescence intensity (dx/dmuE) (arbitrary units) for sample U5aBhs Column 12: U5aBhsfit Description: Linear combination fit result for sample U5aBhs (dx/dmuE) (arbitrary units) Column 13: U5aBhsresidual Description: Residual error of linear combination fit result for sample U5aBhs (dx/dmuE) (arbitrary units) Column 14: U6bBhs1 Description: First derivative of iron K-edge X-ray absorption fluorescence intensity (dx/dmuE) (arbitrary units) for sample U6bBhs1 Column 15: U6bBhs1fit Description: Linear combination fit result for sample U6bBhs1 (dx/dmuE) (arbitrary units) Column 16: U6bBhs1residual Description: Residual error of linear combination fit result for sample U6bBhs1 (dx/dmuE) (arbitrary units) Column 17: U6cBhs1 Description: First derivative of iron K-edge X-ray absorption fluorescence intensity (dx/dmuE) (arbitrary units) for sample U6cBhs1 Column 18: U6cBhs1fit Description: Linear combination fit result for sample U6cBhs1 (dx/dmuE) (arbitrary units) Column 19: U6cBhs1residual Description: Residual error of linear combination fit result for sample U6cBhs1 (dx/dmuE) (arbitrary units) Column 20: U5bBhs Description: First derivative of iron K-edge X-ray absorption fluorescence intensity (dx/dmuE) (arbitrary units) for sample U5bBhs Column 21: U5bBhsfit Description: Linear combination fit result for sample U5bBhs (dx/dmuE) (arbitrary units) Column 22: U5bBhsresidual Description: Residual error of linear combination fit result for sample U5bBhs (dx/dmuE) (arbitrary units) Column 23: U5bCB Description: First derivative of iron K-edge X-ray absorption fluorescence intensity (dx/dmuE) (arbitrary units) for sample U5bCB Column 24: U5bCBfit Description: Linear combination fit result for sample U5bCB (dx/dmuE) (arbitrary units) Column 25: U5bCBresidual Description: Residual error of linear combination fit result for sample U5bCB(dx/dmuE) (arbitrary units) Column 26: U5cBs Description: First derivative of iron K-edge X-ray absorption fluorescence intensity (dx/dmuE) (arbitrary units) for sample U5cBs Column 27: U5cBsfit Description: Linear combination fit result for sample U5cBs (dx/dmuE) (arbitrary units) Column 28: U5cBsresidual Description: Residual error of linear combination fit result for sample U5cBs (dx/dmuE) (arbitrary units) Column 29: AdsFh Description: First derivative of iron K-edge X-ray absorption fluorescence intensity (dx/dmuE) (arbitrary units) for ferrihydrite Column 30: AdsFhfit Description: Linear combination fit result for ferrihydrite (dx/dmuE) (arbitrary units) Column 31: AdsFhresidual Description: Residual error of linear combination fit result for ferrihydrite (dx/dmuE) (arbitrary units) Column 32: FeIIIEDTA Description: First derivative of iron K-edge X-ray absorption fluorescence intensity (dx/dmuE) (arbitrary units) for iron(III)-ethyldiamine tetraacetic acid Column 33: FeIIIEDTAfit Description: Linear combination fit result for sample iron(III)-ethyldiamine tetraacetic acid (dx/dmuE) (arbitrary units) Column 34: FeIIIEDTAresidual Description: Residual error of linear combination fit result for iron(III)-ethyldiamine tetraacetic acid (dx/dmuE) (arbitrary units) Missing data codes: Missing data cells marked “NA” Specialized formats or other abbreviations used: 58. Filename: EXAFS-LCF-residuals.csv Short description: Linear combination fitting results (output and error residuals) for iron K-edge extended X-ray absorption fine structure (EXAFS) Number of variables: 34 Number of cases/rows: 207 (not including header) Variable list, defining any abbreviations, units of measure, codes or symbols used: Column 1: k Description: Iron K-edge extended X-ray absorption fine structure (EXAFS) K-space wavenumber (X-axis) (1/Angstrom) Sample naming convention for columns 2-28 (soil horizon samples): Naming convention: Capital letter = watershed 3 transect (“U” for all samples). Number = sampling location (5, 6, or 7). Lowercase letter = replicate profile (a, b, or c). Upper/lowercase letters and numbers = Horizon ID (e.g., E, Bhs, Bh, Bs, etc.) Column 2: U7aBhs1 Description: Iron K-edge EXAFS K-space signal (forward Fourier transform) for sample U7aBhs1 (low saturation frequency) (k^2 chi(k) / A^2) Column 3: U7aBhs1fit Description: Iron K-edge EXAFS K-space linear combination fit result for sample U7aBhs1 (low saturation frequency) (k^2 chi(k) / A^2) Column 4: U7aBhs1residual Description: Iron K-edge EXAFS K-space linear combination fit residual error for sample U7aBhs1 (low saturation frequency) (k^2 chi(k) / A^2) Column 5: U7bBhs1 Description: Iron K-edge EXAFS K-space signal (forward Fourier transform) for sample U7bBhs1 (low saturation frequency) (k^2 chi(k) / A^2) Column 6: U7bBhs1fit Description: Iron K-edge EXAFS K-space linear combination fit result for sample U7bBhs1 (low saturation frequency) (k^2 chi(k) / A^2) Column 7: U7bBhs1residual Description: Iron K-edge EXAFS K-space linear combination fit residual error for sample U7bBhs1 (low saturation frequency) (k^2 chi(k) / A^2) Column 8: U7cBhs Description: Iron K-edge EXAFS K-space signal (forward Fourier transform) for sample U7cBhs (low saturation frequnecy) (k^2 chi(k) / A^2) Column 9: U7cBhsfit Description: Iron K-edge EXAFS K-space linear combination fit result for sample U7cBhs (low saturation frequency) (k^2 chi(k) / A^2) Column 10: U7cBhsresidual Description: Iron K-edge EXAFS K-space linear combination fit residual error for sample U7cBhs (low saturation frequency) (k^2 chi(k) / A^2) Column 11: U5aBhs Description: Iron K-edge EXAFS K-space signal (forward Fourier transform) for sample U5aBhs (medium saturation frequency) (k^2 chi(k) / A^2) Column 12: U5aBhsfit Description: Iron K-edge EXAFS K-space linear combination fit result for sample U5aBhs (medium saturation frequency) (k^2 chi(k) / A^2) Column 13: U5aBhsresidual Description: Iron K-edge EXAFS K-space linear combination fit residual error for sample U5aBhs (medium saturation frequency) (k^2 chi(k) / A^2) Column 14: U6bBhs1 Description: Iron K-edge EXAFS K-space signal (forward Fourier transform) for sample U6bBhs1 (medium saturation frequency) (k^2 chi(k) / A^2) Column 15: U6bBhs1fit Description: Iron K-edge EXAFS K-space linear combination fit result for sample U6bBhs1 (medium saturation frequency) (k^2 chi(k) / A^2) Column 16: U6bBhs1residual Description: Iron K-edge EXAFS K-space linear combination fit residual error for sample U6bBhs1 (medium saturation frequency) (k^2 chi(k) / A^2) Column 17: U6cBhs1 Description: Iron K-edge EXAFS K-space signal (forward Fourier transform) for sample U6cBhs1 (medium saturation frequency) (k^2 chi(k) / A^2) Column 18: U6cBhs1fit Description: Iron K-edge EXAFS K-space linear combination fit result for sample U6cBhs1 (medium saturation frequency) (k^2 chi(k) / A^2) Column 19: U6cBhs1residual Description: Iron K-edge EXAFS K-space linear combination fit residual error for sample U6bBhs1 (medium saturation frequency) (k^2 chi(k) / A^2) Column 20: U5bBhs Description: Iron K-edge EXAFS K-space signal (forward Fourier transform) for sample U5bBhs (high saturation frequency) (k^2 chi(k) / A^2) Column 21: U5bBhsfit Description: Iron K-edge EXAFS K-space linear combination fit result for sample U5bBhs (high saturation frequency) (k^2 chi(k) / A^2) Column 22: U5bBhsresidual Description: Iron K-edge EXAFS K-space linear combination fit residual error for sample U6bBhs1 (medium saturation frequency) (k^2 chi(k) / A^2) Column 23: U5bCB Description: Iron K-edge EXAFS K-space signal (forward Fourier transform) for sample U5bCB (high saturation frequency) (k^2 chi(k) / A^2) Column 24: U5bCBfit Description: Iron K-edge EXAFS K-space linear combination fit result for sample U5bCB (high saturation frequency) (k^2 chi(k) / A^2) Column 25: U5bCBresidual Description: Iron K-edge EXAFS K-space linear combination fit residual error for sample U6bBhs1 (medium saturation frequency) (k^2 chi(k) / A^2) Column 26: U5cBs Description: Iron K-edge EXAFS K-space signal (forward Fourier transform) for sample U5cBs (high saturation frequency) (k^2 chi(k) / A^2) Column 27: U5cBsfit Description: Iron K-edge EXAFS K-space linear combination fit result for sample U5cBs (high saturation frequency) (k^2 chi(k) / A^2) Column 28: U5cBsresidual Description: Iron K-edge EXAFS K-space linear combination fit residual error for sample U6bBhs1 (medium saturation frequency) (k^2 chi(k) / A^2) Column 29: AdsFh Description: Iron K-edge EXAFS K-space signal (forward Fourier transform) for ferrihydrite (Fe2O3*0.5H2O) (assessment of LCF model) (k^2 chi(k) / A^2) Column 30: AdsFhfit Description: Iron K-edge EXAFS K-space linear combination fit result for ferrihydrite (assessment of LCF model) (k^2 chi(k) / A^2) Column 31: AdsFhresidual Description: Iron K-edge EXAFS K-space linear combination fit residual error for ferrihydrite (assessment of LCF model) (k^2 chi(k) / A^2) Column 32: FeEDTA Description: Iron K-edge EXAFS K-space signal (forward Fourier transform) for iron-ethyldiamine tetraacetic acid (assessment of LCF model) (k^2 chi(k) / A^2) Column 33: FeEDTAfit Description: Iron K-edge EXAFS K-space linear combination fit result for iron-ethyldiamine tetraacetic acid (assessment of LCF model) (k^2 chi(k) / A^2) Column 34: FeEDTAresidual Description: Iron K-edge EXAFS K-space linear combination fit residual error for iron-ethdiamine tetraacetic acid (assessment of LCF model) (k^2 chi(k) / A^2) Missing data codes: Specialized formats or other abbreviations used: 59. Filename: NEXAFS-Ratios.csv Short description: Ratios of carbon functional groups derived from peak height estimates in NEXAFS-functions-reduced.txt Number of variables: 6 Number of cases/rows: 45 (not including header) Variable list, defining any abbreviations, units of measure, codes or symbols used: Column 1: Horizon Description: Identity of soil sample used for iron K-edge EXAFS linear combination fitting following the convention: Capital letter = watershed 3 transect (“U” for all samples). Number = sampling location (5, 6, or 7). Lowercase letter = replicate profile (a, b, or c). Upper/lowercase letters and numbers = Horizon ID (e.g., E, Bhs, Bh, Bs, etc.) Column 2: Ratio Description: Ratio of Gaussian peak height between carbon forms (unitless) Column 3: Pair Description: Forma of carbon derived from K-edge X-ray absorption spectrum used to generate ratios (factor), levels = Carboxylic-aromatic (carboxylic/aromatic C), Oaromatic-aromatic (substituted aromatic/aromatic C), Carboxylic-Oaromatic (carboxylic/substituted aromatic C) Column 4: Sample Description: Type of soil sample used for analysis (factor), levels = Bulk (bulk soil), DOM (dissolved organic matter), and POMremoved (particulate organic matter removed) Column 5: SaturationFreq Description: Saturation frequency category (factors), levels = Low, Medium, High Column 6: Norm.ratio Description: Ratio of Gaussian peak height between carbon types normalized to maximum ratio within each pair (unitless) Missing data codes: Missing data cells marked “NA” Specialized formats or other abbreviations used: 60. Filename: NEXAFS-functions-reduced.csv Short description: Carbon K-edge X-ray absorption near edge structure spectra and peak height estimates for bulk soil samples, dissolved organic matter, soil with particulate organic matter removed, and damage tests Number of variables: 130 Number of cases/rows: 250 (not including header) Variable list, defining any abbreviations, units of measure, codes or symbols used: Columns are labeled by soil sample type used in carbon X-ray absorption spectroscopy measurement. For soil samples, the name of the soil horizon uses the following convention: Capital letter = watershed 3 transect (“U” for all samples). Number = sampling location (5, 6, or 7). Lowercase letter = replicate profile (a, b, or c). Upper/lowercase letters and numbers = Horizon ID (e.g., E, Bhs, Bh, Bs, etc.) For certain samples (U5bBhs, U6bBhs1, and U7aBhs), text following an underscore (_) denotes the subset of sample (all other samples are bulk soils only). Following the underscore, Bulk = bulk soil, Hydrox = carbon in hydroxylamine extract, POMremoved = soil with particulate organic matter removed, and DOM = water-extractable dissolved organic matter. For samples U5bCB and U7aBhs1, additional samples are for damage tests (columns 91-130), denoted by DamageT1, DamageT2, DamageT3, and Damage T4, corresponding to 5, 10, 15, and 20 minutes of exposure time, respectively. Columns 1, 6, 11, 16, 21, 26, 31, 36, 41, 46, 51, 56, 61, 66, 71, 76, 81, 86, 91, 96, 101, 106, 111, 116, 121, 126: X-ray absorption energy (electron volts, eV) Columns 2, 7, 12, 17, 22, 27, 32, 37, 42, 47, 52, 57, 62, 67, 72, 77, 82, 87, 92, 97, 102, 107, 112, 117, 122, 127: X-ray absorption fluorescence intensity, normalized to carbon K-edge edge step (edge step = 1) (arbitrary units) Columns 3, 8, 13, 18, 23, 28, 33, 38, 43, 48, 53, 58, 63, 68, 73, 78, 83, 88, 93, 98, 103, 108, 113, 118, 123, 128: Gaussian function with peak center between 285-286.2 eV (aromatic C) (arbitrary units) Columns 4, 9, 14, 19, 24, 29, 34, 39, 44, 49, 54, 59, 64, 69, 74, 79, 84, 89, 94, 99, 104, 109, 114, 119, 124, 129: Gaussian function with peak center between 286-287.0 eV (substituted aromatic C) (arbitrary units) Columns 5, 10, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 85, 90, 95, 100, 105, 110, 115, 120, 125, 130: Gaussian function with peak center between 288.0-289.5 eV (carboxylic C) (arbitrary units) Column 1: EnergyU5aBhs Column 2: DataU5aBhs Column 3: G1U5aBhs Column 4: G2U5aBhs Column 5: G3U5aBhs Column 6: EnergyU5bBhs_Bulk Column 7: DataU5bBhs_Bulk Column 8: G1U5bBhs_Bulk Column 9: G2U5bBhs_Bulk Column 10: G3U5bBhs_Bulk Column 11: EnergyU5bBhs_Hydrox Column 12: DataU5bBhs_Hydrox Column 13: G1U5bBhs_Hydrox Column 14: G2U5bBhs_Hydrox Column 15: G3U5bBhs_Hydrox Column 16: EnergyU5bBhs_POMremoved Column 17: DataU5bBhs_POMremoved Column 18: G1U5bBhs_POMremoved Column 19: G2U5bBhs_POMremoved Column 20: G3U5bBhs_POMremoved Column 21: EnergyU5bBhs_DOM Column 22: DataU5bBhs_DOM Column 23: G1U5bBhs_DOM Column 24: G2U5bBhs_DOM Column 25: G3U5bBhs_DOM Column 26: EnergyU5bCB Column 27: DataU5bCB Column 28: G1U5bCB Column 29: G2U5bCB Column 30: G3U5bCB Column 31: EnergyU5cBs Column 32: DataU5cBs Column 33: G1U5cBs Column 34: G2U5cBs Column 35: G3U5cBs Column 36: EnergyU6bBhs1_Bulk Column 37: DataU6bBhs1_Bulk Column 38: G1U6bBhs1_Bulk Column 39: G2U6bBhs1_Bulk Column 40: G3U6bBhs1_Bulk Column 41: EnergyU6bBhs1_DOM Column 42: DataU6bBhs1_DOM Column 43: G1U6bBhs1_DOM Column 44: G2U6bBhs1_DOM Column 45: G3U6bBhs1_DOM Column 46: EnergyU6bBhs1_Hydrox Column 47: DataU6bBhs1_Hydrox Column 48: G1U6bBhs1_Hydrox Column 49: G2U6bBhs1_Hydrox Column 50: G3U6bBhs1_Hydrox Column 51: EnergyU6bBhs1_POMremoved Column 52: DataU6bBhs1_POMremoved Column 53: G1U6bBhs1_POMremoved Column 54: G2U6bBhs1_POMremoved Column 55: G3U6bBhs1_POMremoved Column 56: EnergyU6cBhs1 Column 57: DataU6cBhs1 Column 58: G1U6cBhs1 Column 59: G2U6cBhs1 Column 60: G3U6cBhs1 Column 61: EnergyU7aBhs1_Bulk Column 62: DataU7aBhs1_Bulk Column 63: G1U7aBhs1_Bulk Column 64: G2U7aBhs1_Bulk Column 65: G3U7aBhs1_Bulk Column 66: EnergyU7aBhs1_POMremoved Column 67: DataU7aBhs1_POMremoved Column 68: G1U7aBhs1_POMremoved Column 69: G2U7aBhs1_POMremoved Column 70: G3U7aBhs1_POMremoved Column 71: EnergyU7aBhs1_DOM_Hydrox Column 72: DataU7aBhs1_DOM_Hydrox Column 73: G1U7aBhs1_DOM_Hydrox Column 74: G2U7aBhs1_DOM_Hydrox Column 75: G3U7aBhs1_DOM_Hydrox Column 76: EnergyU7aBhs1_DOM Column 77: DataU7aBhs1_DOM Column 78: G1U7aBhs1_DOM Column 79: G2U7aBhs1_DOM Column 80: G3U7aBhs1_DOM Column 81: EnergyU7bBhs1 Column 82: DataU7bBhs1 Column 83: G1U7bBhs1 Column 84: G2U7bBhs1 Column 85: G3U7bBhs1 Column 86: EnergyU7cBhs Column 87: DataU7cBhs Column 88: G1U7cBhs Column 89: G2U7cBhs Column 90: G3U7cBh Column 91: EnergyU5bCBDamageT1 Column 92: DataU5bCBDamageT1 Column 93: G1U5bCBDamageT1 Column 94: G2U5bCBDamageT1 Column 95: G3U5bCBDamageT1 Column 96: EnergyU5bCBDamageT2 Column 97: DataU5bCBDamageT2 Column 98: G1U5bCBDamageT2 Column 99: G2U5bCBDamageT2 Column 100: G3U5bCBDamageT2 Column 101: EnergyU5bCBDamageT3 Column 102: DataU5bCBDamageT3 Column 103: G1U5bCBDamageT3 Column 104: G2U5bCBDamageT3 Column 105: G3U5bCBDamageT3 Column 106: EnergyU5bCBDamageT4 Column 107: DataU5bCBDamageT4 Column 108: G1U5bCBDamageT4 Column 109: G2U5bCBDamageT4 Column 110: G3U5bCBDamageT4 Column 111: EnergyU7aBhs1DamageT1 Column 112: DataU7aBhs1DamageT1 Column 113: G1U7aBhs1DamageT1 Column 114: G2U7aBhs1DamageT1 Column 115: G3U7aBhs1DamageT1 Column 116: EnergyU7aBhs1DamageT2 Column 117: DataU7aBhs1DamageT2 Column 118: G1U7aBhs1DamageT2 Column 119: G2U7aBhs1DamageT2 Column 120: G3U7aBhs1DamageT2 Column 121: EnergyU7aBhs1DamageT3 Column 122: DataU7aBhs1DamageT3 Column 123: G1U7aBhs1DamageT3 Column 124: G2U7aBhs1DamageT3 Column 125: G3U7aBhs1DamageT3 Column 126: EnergyU7aBhs1DamageT4 Column 127: DataU7aBhs1DamageT4 Column 128: G1U7aBhs1DamageT4 Column 129: G2U7aBhs1DamageT4 Column 130: G3U7aBhs1DamageT4 Missing data codes: Missing data cells marked “NA” Specialized formats or other abbreviations used: 61. Filename: DamageTest_ratios.csv Short description: Carbon fine structure ratios from carbon K-edge X-ray absorption spectroscopy damage test Number of variables: 5 Number of cases/rows: 24 (not including header) Variable list, defining any abbreviations, units of measure, codes or symbols used: Column 1: SaturationFreq Description: Saturation frequency category (factor), levels = high, low Column 2: Time Description: Time of beam exposure (minutes) Column 3: Ratio Description: Carbon fine structure signal intensity ratio value (unitless) Column 4: Pair Description: Components of carbon fine structure used for ratio (factor), levels = Carboxylic-aromatic, Oaromatic-aromatic, Carboxylic-Oaromatic Column 5: Norm.ratio Description: Carbon fine structure signal intenisty ratio value normalized to maximum value for each pair of components (unitless) Missing data codes: Specialized formats or other abbreviations used: 62. Filename: NMR_RawSpectra.csv Short description: Chemical shift and unprocessed nuclear magnetic resonance spectra for variable contact time experiment (not included in R script) Number of variables: 25 Number of cases/rows: 16384 (not including header) Variable list, defining any abbreviations, units of measure, codes or symbols used: For columns 2-25: Identity of soil sample used for NMR variable contact time experiements following the convention: Capital letter = watershed 3 transect (“U” for all samples). Number = sampling location (5, 6, or 7). Lowercase letter = replicate profile (a, b, or c). Upper/lowercase letters and numbers = Horizon ID (e.g., E, Bhs, Bh, Bs, etc.) Corresponding iron/carbon ratio for samples: U5bBhs, C/Fe = 0.098; U6bBhs1, C/Fe = 0.18; U5aBhs, C/Fe = 0.16; U7cBh, C/Fe = 0.31; U7aBhs1, C/Fe = 0.21; U7bBhs1, C/Fe = 0.31 Column 1: ChemicalShiftPPM Description: Values of chemical shift (in parts per million) for nulear magnetic resonance (NMR) spectra Column 2: U7bBhs1_0.5ms Description: Nuclear magetic resonance signal raw intensity (counts) for sample U7bBhs1 at 0.5 ms contact time Column 3: U7bBhs1_1ms Description: Nuclear magetic resonance signal raw intensity (counts) for sample U7bBhs1 at 1 ms contact time Column 4: U7bBhs1_3ms Description: Nuclear magetic resonance signal raw intensity (counts) for sample U7bBhs1 at 3 ms contact time Column 5: U7bBhs1_4ms Description: Nuclear magetic resonance signal raw intensity (counts) for sample U7bBhs1 at 4 ms contact time Column 6: U6bBhs1_0.5ms Description: Nuclear magetic resonance signal raw intensity (counts) for sample U6bBhs1 at 0.5 ms contact time Column 7: U6bBhs1_1ms Description: Nuclear magetic resonance signal raw intensity (counts) for sample U6bBhs1 at 1 ms contact time Column 8: U6bBhs1_3ms Description: Nuclear magetic resonance signal raw intensity (counts) for sample U6bBhs1 at 3 ms contact time Column 9: U6bBhs1_4ms Description: Nuclear magetic resonance signal raw intensity (counts) for sample U6bBhs1 at 4 ms contact time Column 10: U5bBhs_0.5ms Description: Nuclear magetic resonance signal raw intensity (counts) for sample U5bBhs at 0.5 ms contact time Column 11: U5bBhs_1ms Description: Nuclear magetic resonance signal raw intensity (counts) for sample U5bBhs at 1 ms contact time Column 12: U5bBhs_3ms Description: Nuclear magetic resonance signal raw intensity (counts) for sample U5bBhs at 3 ms contact time Column 13: U5bBhs_4ms Description: Nuclear magetic resonance signal raw intensity (counts) for sample U5bBhs at 4 ms contact time Column 14: U7aBhs1_0.5 Description: Nuclear magetic resonance signal raw intensity (counts) for sample U7aBhs1 at 0.5 ms contact time Column 15: U7aBhs1_1ms Description: Nuclear magetic resonance signal raw intensity (counts) for sample U7aBhs1 at 1 ms contact time Column 16: U7aBhs1_3ms Description: Nuclear magetic resonance signal raw intensity (counts) for sample U7aBhs1 at 3 ms contact time Column 17: U7aBhs1_4ms Description: Nuclear magetic resonance signal raw intensity (counts) for sample U7aBhs1 at 4 ms contact time Column 18: U5aBhs_0.5ms Description: Nuclear magetic resonance signal raw intensity (counts) for sample U5aBhs at 0.5 ms contact time Column 19: U5aBhs_1ms Description: Nuclear magetic resonance signal raw intensity (counts) for sample U5aBhs at 1 ms contact time Column 20: U5aBhs_3ms Description: Nuclear magetic resonance signal raw intensity (counts) for sample U5aBhs at 3 ms contact time Column 21: U5aBhs_4ms Description: Nuclear magetic resonance signal raw intensity (counts) for sample U5aBhs at 4 ms contact time Column 22: U7cBh_0.5ms Description: Nuclear magetic resonance signal raw intensity (counts) for sample U7cBh at 0.5 ms contact time Column 23: U7cBh_1ms Description: Nuclear magetic resonance signal raw intensity (counts) for sample U7cBh at 1 ms contact time Column 24: U7cBh_3ms Description: Nuclear magetic resonance signal raw intensity (counts) for sample U7cBh at 3 ms contact time Column 25: U7cBh_4ms Description: Nuclear magetic resonance signal raw intensity (counts) for sample U7cBh at 4 ms contact time Missing data codes: Missing data cells marked “NA” Specialized formats or other abbreviations used: 63. Filename: NMR-VCT-Slope-Updated-12-27-19.csv Short description: Change in 13C-nuclear magnetic resonance (NMR) signal intensity as a function of increasing contact time Number of variables: 8 Number of cases/rows: 96 Variable list, defining any abbreviations, units of measure, codes or symbols used: Column 1: SampleID Description: Identity of soil sample used for NMR analysis following the convention: Capital letter = watershed 3 transect (“U” for all samples). Number = sampling location (5, 6, or 7). Lowercase letter = replicate profile (a, b, or c). Upper/lowercase letters and numbers = Horizon ID (e.g., E, Bhs, Bh, Bs, etc.) Column 2: ContactTime Description: Length of contact time setting for cross-polarization magic angle spinning (CPMAS) NMR (ms) Column 3: SaturationFreq Description: Saturation frequency category (factor), levels = low, medium, and high Column 4: LogIntensity Description: Log10 of signal intensity for each carbon type (integrated area of NMR spectral regions) (arbitrary units) Column 5: Group Description: Carbon form (factor), levels = Alkyl, Aromatic, Carboxylic, ONalkyl Column 6: Cmgkg Description: Total carbon content (mg C per kg dry soil) Column 7: Fe_tot_mgkg Description: Total iron content (mg Fe per kg dry soil) Column 8: CFe_ratio Description: Ratio of total carbon to total iron in soil sample (unitless) Missing data codes: Missing data cells marked “NA” Specialized formats or other abbreviations used: 64. Filename: NMR-VCT-Parameters-Updated-12-27-19.csv Short description: Calculated values of the magnitude of the variable contact time effect and the proton relaxation time for nuclear magnetic resonance variable contact time experiments across soil iron/carbon ratio levels Number of variables: 10 Number of cases/rows = 24 (not including header) Variable list, defining any abbreviations, units of measure, codes or symbols used: Column 1: Sample Description: Identity of soil sample used for NMR analysis following the convention: Capital letter = watershed 3 transect (“U” for all samples). Number = sampling location (5, 6, or 7). Lowercase letter = replicate profile (a, b, or c). Upper/lowercase letters and numbers = Horizon ID (e.g., E, Bhs, Bh, Bs, etc.) Column 2: SaturationFreq Description: Soil saturation frequency category (factor), levels = low, medium, and high Column 3: Cmgkg Description: Total carbon content, mg carbon per kg dry soil Column 4: Fe_tot_mgkg Description: Total iron content, mg iron per kg dry soil Column 5: FeC Description: Total iron to total carbon ratio in soil samples (unitless) Column 6: CFe Description: Ratio of total carbon to total iron in soil sample (unitless) Column 7: Group Description: Carbon form (factor), levels = Alkyl, Aromatic, Carboxylic, ONalkyl Column 8: Slope Description: Change in signal intensity (arbitrary units) with increasing contact time (ms) (slope of simple linear model) Column 9: T1rhoH Description: Proton relaxation time (milliseconds) Column 10: Magnitude Description: Magnitude of variable contact time effect (absolute value of slope) Missing data codes: Missing data cells marked “NA” Specialized formats or other abbreviations used: 65. Filename: AnaerobicIncAll-updated-061919.csv Short description: Values for carbon mineralization, soluble metals, reduced Fe(II), and dissolved organic carbon from cyclic anaerobic-aerobic incubation experiment Number of variables: 14 Number of cases/rows: 24 (not including header) Variable list, defining any abbreviations, units of measure, codes or symbols used: Column 1: SaturationFreq Description: Saturation frequency category (factor), levels = low, medium, high Column 2: Treatment Description: Incubation conditions (factor), levels = Anaerobic, Control Column 3: DOCTotalC Description: Dissolved organic carbon (DOC) mobilized normalized to total soil carbon content (g DOC per kg soil C) Column 4: InitialRate Description: Soil carbon mineralization rate after initial 5-day aerobic incubation (mg CO2 per kg soil C per day) Column 5: Cmgkg Description: Soil carbon content (mg C per kg dry soil) Column 6: AnaerobicRateChange Description: Change in carbon mineralization rate from initial after anaerobic incubation (%) Column 7: ReducedTotalFe Description: Reduced iron (Fe2+) as proportiona of total soluble Fe (%) Column 8: CO2DOC Description: Carbon dioxide mineralized after final aerobic incubation normalized to dissolved organic carbon produced after anaerobic incubation (mg CO2 per mg DOC) Column 9: SolubleAl Description: Water-soluble aluminium concentration after anaerobic incubation (mg Al per kg dry soil) Column 10: TotalAl Description: Total soil aluminum content by flux method (mg Al per kg dry soil) Column 11: SolubleAlTotalAl Description: Water-soluble aluminum as a proportion of total aluminum (%) Column 12: SolubleFe Description: Water-soluble iron concentration after anaerobic incubation (mg Fe per kg dry soil) Column 13: TotalFe Description: Total soil iron content by flux method (mg Fe per kg dry soil) Column 14: SolubleFeTotalFe Description: Water-soluble iron as a proportion of total iron (%) Missing data codes: Missing data cells marked “NA” Specialized formats or other abbreviations used: 66. Filename: Possinger_et_al_R_Code_Geoderma_Final.R Short description: Detailed description of and code for figures, R-based computations, and statistical analyses for data included in this repository Number of variables: NA Number of cases/rows: NA Variable list, defining any abbreviations, units of measure, codes or symbols used: NA This file is an R script, with sections separated by display item in Possinger (2019) dissertation Chapter 2 and manuscript in revision to Geoderma. Missing data codes: Specialized formats or other abbreviations used: