Modelling the phosphorus cycle in European agricultural soils under current and different management scenarios

Phosphorous (P) is an essential nutrient for all crops, yet excess P leads to the pollution of the environment. Additionally, the mineral P fertilizer production uses rock P, a non-renewable resource that is on the critical raw materials list of the European Commission. This context calls for action to find ways to increase P use efficiency and reduce the loss of P to the environment. To come up with effective solutions, process-based models, such as DayCent, can help depict and investigate the effects of scenarios on the P cycle. On top of the calibrated Nitrogen and Carbon submodels, the P submodel of the biogeochemical model DayCent has recently been calibrated and tested using European long-term experiments. DayCent has a detailed representation of soil biogeochemistry and can reproduce the major effects of climate and agricultural management on crop production. We exemplify the possibility of the model to represent the current European agricultural soil P budget, including changes in the P pools in space and time. For this task, the model is run with data-derived soil characteristics and complemented with state-of-the-art input data sets. Additionally, the model is used to project the influence of various agricultural management scenarios from 2019 until 2030 and 2050 compared with a baseline of current agricultural practices targeted at different European biogeochemical hotspot areas. Finally, the detailed model and scenario results showcase a promising tool for assessing biogeochemical cycles in agricultural soils, including their interconnections.