PEARL model for pesticide behaviour and emissions in soil-plant systems

In the EU the risk of leaching of plant protection products is assessed according to the new regulation 1107/2009. For the assessment of this risk the FOCUS Groundwater scenarios have been developed. The PEARL model is one of the models that can be used to calculate the leaching concentration in groundwaterfor these scenarios. At the national level, the GeoPEARL model is used to assess the 90th percentile in space of the plant protection product in its area of use. In this report a description is given of all processes considered to describe the fate of the plant protection product in the plant-soil system, such as transport inthe soil matrix and in the macropore domain of the soil, transformation, volatilisation and sorption in soil, and processes at the plant canopy (volatilisation, penetration into the plant tissue and phototransformationon the plant surface). The PEARL model is integrated with the hydrological model SWAP. This report describes the most important processes to describe the hydrology of the soil system. Furthermore, the recent additions of the PEARL model for paddy rice systems, as well as those to simulate the fate ingreenhouse systems are also presented.