Soil filtering capacity towards groundwater protection from pesticide and nitrates

This work presents two new web-based, freely-available dynamical tools, named the pesticide fate tool and nitrate fate tool to assess the groundwater vulnerability to both pesticides and nitrate within the geospatial Decision Support system (s-DSS) of LandSupport. The pesticide fate tool is based on the extended transfer function model (TFM-ext), specifically expanded to simulate the transport of reactive solutes, i.e., pesticides, from the surface, through the unsaturated zone, till the groundwater table depth. The nitrate fate tool is based on the coupling of the crop-growth ARMOSA model, used to simulate the nitrate leaching within the most biological active zone (i.e., the rooting depth of the soil) and the TFM-ext model, used to assess the transport of nitrate till the groundwater table depth. The tools leveraged the COMPSs programming framework, which allows to parallelize the execution of multiple model runs. Principal inputs of the tools are: soil physical and hydrological properties, climate, groundwater table depth, type of crops and managements (seeding, harvesting, tillage, irrigation, fertilization, pesticides and residual management). Results are shown through the LandSupport GUI both as coloured maps and cumulative charts, representing the relative concentration of solute arrivals at the water table. The work presents the tool implementations for different case studies across three European regions (AU, HU, IT), with different spatial scales (from local to regional scales) and pedo-climatic conditions, as examples of application of the LandSupport s-DSS in supporting the Water, Pesticides and Nitrate directives, demonstrating that they represent valuable instruments for public authorities, environmental planners, as well as agricultural extension services