1. General Model Information

Name: PESTicide Leaching and Accumulation

Acronym: PESTLA

Main medium: terrestrial
Main subject: biogeochemistry, hydrology
Organization level: ecosystem
Type of model: partial differential equations (finite differences,1D)
Main application:
Keywords: non-point source, pesticide, soil, liquid volume fraction, soil temperature, pesticide concentration, richards equation, convection-dispersion equation, nonlinear adsorption isotherms, sink terms, first order kinetics, finite difference numerics


Dr.ir. J.J.T.I. Boesten
DLO Winand Staring Centre (SC-DLO)
P.O.Box 125
6700 AC Wageningen



The PESTLA model consists of submodels for water and heat flow and for pesticide behaviour. The submodels for water and heat flow are based on Darcy's law and Fourier's law. The submodel for water flow is SWACROP which implies that a range of upper and lower boundary conditions can be specified. The submodel for heat flow assumes that the surface temperature of the soil is equal to the air temperature. The relationship between heat conductivity and moisture content is fixed. The submodel for pesticide behaviour is based on the convection/dispersion equation for transport in the liquid phase. Transport in the gas phase is ignored. Sorption is described via a Freundlich isotherm and is proportional to organic matter. Transformation proceeds with first-order kinetics and depends on temperature, moisture content and soil depth. Plant uptake of pesticide is passive. Pesticide an be applied to the soil surface or incorporated to a specified depth. The model is used in the Dutch pesticide registration procedure as a first screening tool.

SC-DLO DLO Winand Staring Centre, Wageningen UR

II. Technical Information

II.1 Executables:

Operating System(s): Operation system(s): Windows?
Availability and support of PESTLA model (commercial)

II.2 Source-code:

Programming Language(s): FORTRAN ?

II.3 Manuals:

see II.1

II.4 Data:

see II.1

III. Mathematical Information

III.1 Mathematics

III.2 Quantities

III.2.1 Input

III.2.2 Output

IV. References

Boesten, J.J.T.I., L.J.T. van der Pas & J.H. Smelt, 1993.
Field test of the PESTLA model for ethoprophoson a sandy soil. In: H.J.P. Eijsackers & T. Hamers (eds.), Integrated soil and sediment research: A basisfor proper protection, 241-245. 1993
Kluwer Academic Publishers, Dordrecht. 763 pp.

Boesten, J.J.T.I., 1994.
Simulation of bentazon leaching in sandy loam soil form Mellby (Sweden) with thePESTLA model.
Journal of Environmental Science and Health A29: 1231-1253

Bosch, H. van den & J.J.T.I. Boesten, 1994.
Validation of the PESTLA model: field test for leaching oftwo pesticides in a humic sandy soil in Vredepeel (the Netherlands).
Report 82, DLO-Winand Staring Centre, Wageningen, Netherlands, 59 pp

Boesten, J.J.T.I., 1993.
User's manual for version 2.3 of PESTLA.
Internal Communication 275, SC-DLO.

V. Further information in the World-Wide-Web

VI. Additional remarks

Last review of this document by: J. Bierwirth: 08/2000
Status of the document:
last modified by Tobias Gabele Wed Aug 21 21:44:47 CEST 2002

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