A global dataset and map of soil phosphorus retention / sorption for assessing phosphorus use efficiency and loss to water

Soil phosphorus (P) retention can inform both P use efficiency and the potential for dissolved P loss from soil to water. We compiled and harmonised global measurements of topsoil (0–20 cm) P retention to produce a consistent database and predictive global map. Data from international soil surveys, national repositories, and published studies were screened for coordinate accuracy, methodological consistency, sampling depth, and duplication. After filtering, 6,478 observations from 68 countries were paired with climatic, land-use, soil, and ecological variables at 10-km 2 resolution. Several modelling approaches were assessed, with quantile random forests selected to predict the median, 20 th , and 80 th percentiles of global P retention. Predictions were generated on a 10-km 2 grid consistent and resampled to finer resolution for visualisation purposes without increasing the effective spatial detail. The resulting maps show broad spatial patterns and associated uncertainties that reflect major controls such as soil weathering intensity and hydrology, as well as soil physical properties indirectly related to texture. The dataset provides observation-based, quantitative estimates of topsoil P retention that improve upon earlier qualitative global assessments derived from soil classification. These data are intended for application at catchment to regional scales to support assessments of P use efficiency and dissolved P loss risk, rather than fine-scale management decisions.