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

The pesticide model is used in combination with the hydrological model SWAP. Various agricultural situations and ways of applying pesticides can be simulated. The model accounts for different sorption mechanisms, in equilibrium and non-equilibrium domains of the soil. Pesticide transport in the liquid and gas phases is described by a convection dispersion type equation, which is supplemented with sink terms. Comprehensive reaction schemes are processed in matrix form. The rate in first-order transformation kinetics is dependent on temperature, soil moisture content and depth in soil. Besides computing persistence and distribution of the pesticide compounds in soil, the model computes volatilisation into the air, lateral drainage to water courses and leaching to the groundwater.