Stream Corridor Soil Phosphorus Availability in a Forested-Agricultural Mixed Land Use Watershed.

Abstract

J. Environ. Qual. 48(1):185–192 This article was originally published with inconsistent calculations for the degree of phosphorus saturation (DPS) in Fig. 2c and 3a. The DPS data in these figures were calculated with the formula P/(Fe + Al) but our methods and other data presentation, including text in the caption for Fig. 3, used the formula P/0.5(Fe + Al). The DPS data in those figures should have been twice the values shown. While the use of the 0.5 multiplier may not have a firm basis in theory, we used it to be consistent with our past work in the same watershed. We provide the corrected figures here. Differences between (a) total P (TP) concentrations (mg P kg−1 soil), (b) modified Morgan's P (mg P kg−1 soil), and (c) degree of P saturation (DPS, %) concentrations among the different land uses studied and between their location in the sites (interior or streambank). The median is shown as a bold black line, the third and first quantiles as the upper and lower edges of the boxes (respectively), and the minimum and maximum values as their respective whiskers. Outliers are shown as black dots. The red line in Panel a marks a total P value of three SDs higher than the TP soil average for Vermont riparian soils. Statistically significant similarities among different land uses in each location are denoted by the use of the same letters (lowercase and uppercase for interior and streambank, respectively), whereas statistically significant differences between the interior and streambank of the same land use are denoted with an asterisk (p < 0.05). Soluble P vs. (a) degree of P saturation (DPS, %) and (b) modified Morgan's P (mg P kg−1 soil) concentrations among agricultural land uses (corn and hay) and their streambanks. The red line in Panel a marks the 20% “change point” between soluble P and DPS.