AbstractBecause of water resources eutrophication and the need for water protection strategies, the estimation of diffuse phosphorus (P) leaching losses from agricultural soils has become an important issue. The objective of this study was to numerically depict P leaching and transformation processes to clarify the dominant factors controlling the P dynamics in soils and to investigate interactions between P and carbon (C) and nitrogen (N) cycles. We expanded the existing WASMOD modeling package with a P subroutine and tested model performance on an experimental data set from a 12 y lysimeter study.