DOI: 10.5061/dryad.63xsj3v9w
title: Data from: Effect of soil pH and minerology on the sorption and desorption of phosphite and phosphate in Ultisols of the Southeastern Coastal Plain

description: The development of transgenic crop varieties capable of utilizing
 phosphite (Phi) as a phosphorus (P) source is a promising strategy to
 increase P use efficiency while decreasing reliance on phosphate
 (Pi)-based fertilizers. However, little information is available on Phi
 sorption and desorption in soils. We conducted batch experiments to
 investigate the sorption of Phi and Pi by three Ultisols from the Coastal
 Plain of the southeastern United States. At the soils' acidic field
 pH (pH 4.7–6.2), Pi had a higher affinity than Phi for soil solids, where
 maximum sorbed concentrations of Pi were an average of 44% greater than
 those of Phi. The sorption of both P species decreased when experiments
 were repeated adjusting soil pH to 6.5. More Phi than Pi was recovered
 during desorption experiments, indicating that Phi was more reversibly
 sorbed and, therefore, may be more plant-available than Pi. Multiple
 linear regression between calculated linear distribution coefficients (KD;
 10 mg P L−1 input solutions) and soil properties suggested that
 amorphous Al- and Fe-oxides controlled Pi sorption. Alternatively,
 amorphous Al-oxides and gibbsite controlled Phi sorption. Our results show
 that a lower affinity of Phi than Pi in Ultisols could improve P
 availability for plant uptake of Phi-based fertilizers but may increase
 the risk of soil P buildup over time.
description: # Data from: Effect of soil pH and minerology on the sorption and
 desorption of phosphite and phosphate in Ultisols of the Southeastern
 Coastal Plain
 [https://doi.org/10.5061/dryad.63xsj3v9w](https://doi.org/10.5061/dryad.63xsj3v9w) The dataset includes phosphate and phosphite isotherms, maximum sorbed concentrations of phosphate and phosphite, calculated linear distribution coefficients, percent of phosphate and phosphite recovered during desorption experiments, and raw X-ray diffraction data.  ## Description of the data and file structure All data are provided in a Microsoft Excel sheet. Separate tabs correspond to individual figures or tables and a labeled in the Excel sheet. All units are provided along with a brief description of the experimental methodology. Detailed methodology is provided in the manuscript. The provided data will allow the user to recreate all figures and calculated values presented in the manuscript.  The tab labeled "Figure 1" provides measured solution concentrations (mg/L) and calculated sorbed concentrations (mg/kg) of phosphate and phosphite by five soils. Full soil names (under the "Soil" column) along with their manuscript abbreviations (under the "Abbreviation in Manuscript" column) are provided. Experiments conducted at field pH or at pH 6.5 are indicated under the "pH Treatment" column.  The tab labeled "Figure 2" provides calculated maximum sorbed concentrations (mg/kg) of phosphate and phosphite by five soils. Full soil names (under the "Soil" column) along with their manuscript abbreviations (under the "Abbreviation in Manuscript" column) are provided. Experiments conducted at field pH or at pH 6.5 are indicated under the "pH Treatment" column.  The tab labeled "Table 2" provides calculated linear distribution coefficients (KD, L/kg) for phosphate and phosphite sorption by five soils. Calculated percentages of phosphate and phosphite recovered from each soil during desorption experiments are also given. Full soil names (under the "Soil" column) along with their manuscript abbreviations (under the "Abbreviation in Manuscript" column) are provided. Experiments conducted at field pH or at pH 6.5 are indicated under the "pH Treatment" column.  The tab labeled "Supplemental Figure S1" provides raw X-ray diffraction data for the bulk soils used in the study. The data are given as X-ray intensity (counts/second) vs. angle (2-theta).  ## Code/software All data are provided in a Microsoft Excel sheet.