Subsurface leaching is a major pathway of phosphorus (P) loss from agricultural landscapes and soil P indices (SPIs) have been developed to assess P leaching risk. However, most SPIs are developed for well-drained agricultural soils, their ability to predict P leaching risk in hydromorphic soils remains underexplored. Using soil water P concentration data from a 3-year field monitoring (weekly or biweekly) and the SPIs from the same hydromorphic soils in an agricultural catchment in Western France, we tested the ability (Pearson r