This data release comprises four datasets that represent Phosphorus concentration in the A and C horizon of soils within the conterminous United States. The source dataset is a slight modification of the data published in the report "Geochemical and mineralogical data for soils of the conterminous United States", http://pubs.usgs.gov/ds/801/. Data were interpolated for use in models associated with the National Water Quality Assessment program of the USGS. Two datasets are of Phosphorus in soil A horizon and C horizon, interpolated using Inverse Distance Weight (IDW) algorithm. Two datasets are of Phosphorus in soil A horizon and C horizon, interpolated using IDW, and then aggregated to Geologic Mapping Units (GMUs).

This spatial data layer is a cell-based Raster model characterizing the contribution of phosphorus (P) to streams from weathering and erosion of surficial geologic materials for the conterminous United States, and has been created as part of the SPARROW (Spatially Referenced Regressions on Watershed Attributes) water-quality model implementation. SPARROW provides estimates of total nitrogen and phosphorus load in surface waters from point and non-point sources. This data set represents only potential for P contributions, and does not include N. The characterization of contribution of P from geologic materials will help separate the effects of natural or background sources from anthropogenic sources of P, such as from municipal wastewater or agricultural practices. The potential of a watershed to contribute P from naturally occurring geologic materials in the watershed to the adjacent receiving stream is characterized using geochemical data from bed-sediment samples (USGS National Geochemical Survey, National Uranium Resource Evaluation (NURE), Smith 1979) collected from first-order streams in relatively undisturbed watersheds. Bed sediment samples were collected from 1975 through 1980. The bed-sediment phosphorus concentrations (BSPconc) in this data set represent BSPconc in the absence of anthropogenic sources and therefore spatial variation in BSPconc can be used to indicate spatial variation in the potential to contribute naturally occurring P from the geologic materials in the watershed to the stream. A continuous mapped distribution of BSPconc in headwater streams for the conterminous U.S. was prepared by summarizing BSPconc from 50,740 bed-sediment samples by geologic unit using regional-scale geologic map units (GMU's). The GMU's delineate areas with similar lithochemistry based on geologic age as well as ecoregion units. GMU’s were created by combining surficial geology (Hunt, Charles D., 1979) with Level IV Ecoregion units (U.S. Environmental Protection Agency 2011). This data set represents the mean BSPconc value for each GMU. The spatial pattern of BSPconc in headwater streams is offered as a data layer, representing best available information at the regional scale, with the caveat that its performance as a surrogate for contribution of P from watershed geologic materials to in-stream levels of P is weakened by not accounting for variability across headwater streams in the rates of net deposition and processing of P in the streambed.

This spatial data layer is a cell-based Raster model characterizing the contribution of phosphorus (P) to streams from weathering and erosion of surficial geologic materials for the conterminous United States, and has been created as part of the SPARROW (Spatially Referenced Regressions on Watershed Attributes) water-quality model implementation. SPARROW provides estimates of total nitrogen and phosphorus load in surface waters from point and non-point sources. This data set represents only potential for P contributions, and does not include N. The characterization of contribution of P from geologic materials will help separate the effects of natural or background sources from anthropogenic sources of P, such as from municipal wastewater or agricultural practices. The potential of a watershed to contribute P from naturally occurring geologic materials in the watershed to the adjacent receiving stream is characterized using geochemical data from bed-sediment samples (USGS National Geochemical Survey, National Uranium Resource Evaluation (NURE), Smith 1979) collected from first-order streams in relatively undisturbed watersheds. Bed sediment samples were collected from 1975 through 1980. The bed-sediment phosphorus concentrations (BSPconc) in this data set represent BSPconc in the absence of anthropogenic sources and therefore spatial variation in BSPconc can be used to indicate spatial variation in the potential to contribute naturally occurring P from the geologic materials in the watershed to the stream. A continuous mapped distribution of BSPconc in headwater streams for the conterminous U.S. was prepared by summarizing BSPconc from 50,740 bed-sediment samples by geologic unit using regional-scale geologic map units (GMU's). The GMU's delineate areas with similar lithochemistry based on geologic age as well as ecoregion units. GMU’s were created by combining surficial geology (Hunt, Charles D., 1979) with Level IV Ecoregion units (U.S. Environmental Protection Agency 2011). This data set represents the mean BSPconc value for each GMU. The spatial pattern of BSPconc in headwater streams is offered as a data layer, representing best available information at the regional scale, with the caveat that its performance as a surrogate for contribution of P from watershed geologic materials to in-stream levels of P is weakened by not accounting for variability across headwater streams in the rates of net deposition and processing of P in the streambed.

This dataset contains estimates of phosphorus inputs and outputs for all HUC-8 subbasins across the contiguous United States for the years 2002, 2007, and 2012 as well as estimates of legacy P surplus.

This spatial data set was created by the U.S. Geological Survey (USGS) to represent the extent of soils with very high levels of phosphorus retention potential in the Pacific Northwest region of the United States (Hydro Region 17; Major River Basin 7 (MRB7)).

This data set provides estimates of different forms of naturally occurring soil phosphorus (P) including labile inorganic P, organic P, occluded P, secondary mineral P, apatite P, and total P on a global scale at 0.5-degree resolution. The data were assembled from chronosequence information and global spatial databases to develop a map of total soil P and the distribution among mineral bound, labile, organic, occluded, and secondary P forms in soils. Uncertainty was calculated for the different forms. The data set has no explicit temporal component -- data were nominally for the pre-industrial period ca. 1850.The estimated global spatial variation and distribution of different soil P forms presented in this study will be useful for global biogeochemistry models that include P as a limiting element in biological production by providing initial estimates of the available soil P for plant uptake and microbial utilization (Yang et al., 2013).There is one netCDF data file (.nc) with this data set.

This data set provides concentrations of soil phosphorus (P) compiled from the peer-reviewed literature that cited the Hedley fractionation method (Hedley and Stewart, 1982). This database contains estimates of different forms of naturally occurring soil phosphorus, including labile inorganic P, organic P, occluded P, secondary mineral P, apatite P, and total P, based on the analyses of the various Hedley soil fractions.The recent literature survey (Yang and Post, 2011) was restricted to studies of natural, unfertilized, and uncultivated soils since 1995. Ninety measurements of soil P fractions were identified. These were added to the 88 values from soils in natural ecosystems that Cross and Schlesinger (1995) had compiled. Cross and Schlesinger provided a comprehensive survey on Hedley P data prior to 1995. Measurement data are provided for studies published from 1985 through 2010. In addition to the Hedley P fraction measurement data Yang and Post (2011) also compiled information on soil order, soil pH, organic carbon and nitrogen content, as well as the geographic location (longitude and latitude) of the measurement sites.

This spatial data set was created by the U.S. Geological Survey (USGS) to represent the amount of fertilizer phosphorus that was applied to farm land in the Pacific Northwest region of the United States (Hydro Region 17; Major River Basin 7 (MRB7)) during 2002.

This spatial data set was created by the U.S. Geological Survey (USGS) to represent the amount of fertilizer phosphorus that was applied to farm land in the Pacific Northwest region of the United States (Hydro Region 17; Major River Basin 7 (MRB7)) during 2002.

This spatial data set was created by the U.S. Geological Survey (USGS) to represent the extent of soils with moderate phosphorus retention potential in the Pacific Northwest region of the United States (Hydro Region 17; Major River Basin 7 (MRB7))