PELMO

About PELMO

General Information

PELMO is a one dimensional simulation model simulating the vertical movement of pesticides in soil by chromatographic leaching. The first version of PELMO was released in 1991 (Klein, 1991). PELMO is based on the US-EPA’s PRZM 1 model ( Carsel et al, 1984), but was improved with regard to the requirements of the German authorities responsible for the registration of pesticides. The actual version used for the FOCUS simulations is PELMO 3.2.

PELMO developer: Michael Klein (klein@ime.fraunhofer.de)
Affiliation: Fraunhofer Institute for Molecular Biology and Applied Ecology
PELMO web site: https://www.ime.fraunhofer.de/en/Research_Divisions/Division_AE/Software_E/focus-pelmo.html

Short Model Description

After the release of the first version of PELMO in 1991 the runoff routines were upgraded and routines for estimating the volatilsation of pesticides were added in 1995. (version 2.01) PELMO 2.01 was validated within a joined project of the Industrieverband Agrar (IVA), the German Environmental Protection Agency and the Fraunhofer-Institut für Umweltchemie und Ökotoxikologie in Schmallenberg shared by the KfA Jülich and the SLFA Neustadt (Klein et al, 1997). In 1998 a complementary tool was added to PELMO 2.01 in order to enable the transformation of the applied a.i. to possible metabolites and to allow for further metabolism including the formation of CO2 (PELMO 3.0; Jene, 1998). Recently, additional validation tests in lysimeters and field plots have been performed (Fent et al, 1998). The PELMO version that is used for the implementation of the FOCUS-scenarios was developed in 1999 (PELMO 3.2). It was necessary to slightly change the format of the scenario data files and the handling of leap years because of the needs of the FOCUS-scenarios. A number of changes were also made in the output routines to make sure that the present version of FOCUSPELMO is echoed in the output according the decisions of the Focus version control group. Minor changes were also made in the routine that is estimating soil temperatures based on air temperatures to make sure that the results are correct also for soil depths below 1.0 m. Finally, the runoff routine in PELMO was c alibrated based on field experiments by introducing a new parameter in the model (“fraction of soil water available for runoff”).

Table 1 Summary of the processes in PELMO. [* = turned off for the FOCUS scenarios]

 


Process Approach
water movement capacity-based water flow (tipping bucket approach) using a daily time step for all hydrological processes, preferential flow and capillary rise are not considered
pesticide movement convection dispersion equation based on a daily time step
crop simulation changing root zone during growing season, changing foliage (areal extent) during growing season, crop interception of water*, crop interception of pesticides*, foliar washoff*, foliar degradation*
degradation in soil first order degradation rate, correction of rate constant with depth, soil moisture and soil temperatures
pesticide sorption to soil Kd, Koc, Freundlich equation for sorption option for increase of sorption with time option for automated pH-dependence*
pesticide volatilization (from soil) simple model using Fick’s and Henry’s law
runoff Soil Conservation Service curve number technique
soil erosion* Modified Universal Soil Loss Equation
soil temperature an empirical model that uses air temperatures
plant uptake simple model based on soil concentrations
pesticide applications applications may be foliar sprays, applied to the soil surface, or incorporated into the soil; for soil incorporated applications a variety of soil distributions can be specified
metabolism a sophisticated scheme with up to 8 metabolites (A -> B as well as A -> B <> C) may be simulated simultaneously with the parent


Role and Place in FOCUS scenarios calculation

The major objective of FOCUS is to implement a harmonised approach for European Tier 1 risk assessments according to Council Directive 91/414/EEC. The process implementation of each model was adjusted and harmonised scenario definitions were implemented in windows shells around the individual simulation models. Similar to PRZM PELMO has advantages in a computer environment with limited hardware recourses. On standard PCs (e.g. Pentium III, 400 MHz, 64 MB) the typical computing time for a standard Tier 1 run with 9 scenarios is about 5 to 10 minutes. FOCUSPELMO allows efficient and user friendly calculations for compounds up to eight metabolites.

Current use outside FOCUS

PELMO is offically used by the Umweltbundesamt (UBA, the German Environmental Protection Agency, and the Biologische Bundesanstalt (BBA, Federal Biological Research Centre, www.jki.bund.de) to assess the leaching potential of pesticides within the registration process in Germany for about ten years. Special scenarios describing the German climate and soil conditions are used for this purpose. It is possible to do PELMO simulations according to the German procedure using FOCUSPELMO as all necessary input files are provided within the FOCUSPELMO package.

Excerpt of existing model documentation

Model documentation

  • Anderson, E.A. (1978): Initial Parameter Values for the Snow Accumulation and Ablation Model. Part IV.2.2.1, National Weather Service River Forecast System - User's Manual, NWS/NOAA, U.S. Dept. of Commerce, Silver Springs, MD., March 31, 1978.
  • Carsel, R.F., C.N. Smith, L.A. Mulkey, J.D. Dean, and P. Jowise (1984).  User's manual for the pesticide root zone model (PRZM): Release 1.  EPA-600/3-84-109.  U.S. EPA, Athens, GA.
  • Haith, D.A., and R.C. Loehr (Eds.) (1979):  Effectiveness of Soil and Water Conservation Practices for Pollution Control.  U.S. Environmental Protection Agency, Athens, GA.  EPA-600/3-79-106.
  • Jene, B. (1998): PELMO 3.00 Manual extension, Staatliche Lehr- und Forschungsanstalt für Landwirtschaft, Weinbau und Gartenbau, D-67435 Neustadt/Wstr.
  • Klein, M.: PELMO(1995): Pesticide Leaching Model, User manual version 2.01. Fraunhofer-Institut für Umweltchemie und
  •  
  • Ökotoxikogie, D57392 
  • OECD (1997):  Approved draft proposal for an updated OECD guideance document No. 106: Adsorption/Desorption. OECD Guidlines for Testing of Chemicals, 1-44.
  • PRZM 2.0 and 3.12 manuals.

References for PELMO applications

  • Fent, G., B. Jene and R. Kubiak (1998). Performance of the Pesticide Leaching Model PELMO 2.01 to predict the leaching of bromide and 14C-Benazolin in a sandy soil in comparison to results of a lysimeter- and field study. Staatliche Lehr- und Forschungsanstalt für Landwirtschaft, Weinbau und Gartenbau (SLFA) Neustadt. Poster Abstract 6B-030, IUPAC Congress Book of Abstracts, London 1998
  • Hassink, J., Klein, M., Klein A. and W. Kördel (1993): Fate of Herbicides in Soils under Different Types of Land use. BCPC 827-834
  • Klein M. (1994), Evaluation and Comparison of Pesticide Leaching models for Registration Purposes, Results of Simulations performed with the Pesticide Leaching Model, Journal of Environmental Science  & Health, A29(6),1197-1209 (1994)
  • Klein M. (1997), Statistical distribution of pesticide concentrations in leachate - results of a Monte-Carlo analysis performed with PELMO, Chemosphere, 35, 379-389
  • Klein M. (1998): Comprehensive tracer studies on the environmental behaviour of pesticides: the lysimeter consept in F. Führ, R.J. Hance, J.R. Plimmer, J.O. Nelson (eds.), ACS Symposium series 699, 246-258, Washington.
  • Klein M. (1999):Monte-Carlo Analysis Using Pesticide Fate Models, J. Pesticide Sci. 24, 55-59.
  • Klein, M. and H. Klöppel (1993), Usefulness of models for the prediction of run-off events - comparison with experimental data, The science of the Total Environment, Supplement.
  • Klein, M., Hosang, J., Schäfer, H., Erzgräber, B., Resseler, H. (2000): Comparing and evaluating pesticide leaching models. Results of simulations with PELMO, Agricultural Water Management 44 (1-3) (2000) pp. 263-281
  • Klein, M., Müller, M., Dust, M., Görlitz, G., Gottesbüren, B., Hassink, J., Kloskowski, R., Kubiak, R., Resseler, H., Schäfer, H., Stein B. and H. Vereecken (1997), Validation of the pesticide leaching model PELMO using lysimeter studies performed for registration, Chemosphere 35 No 11, 2563-2587.
 

Download PELMO

Download PELMO

Warning (valid for all FOCUS_PELMO versions) : The user has to take care that application rates are always defined in chronological order. FOCUS PELMO does not check the dates or warn the user about unreasonable application patterns.

Latest Version : FOCUS_PELMO_6.6.4gw_6.6.1soil

Package FOCUS_PELMO_6.6.4_September2021.zip (21/September/2021, 8 MB) replacing the 09/June/2021 version (see Advice below)
Test Results These can be found in the package zip file

Getting started:

The scenarios defined in this download package and shell generate tier 1 groundwater outputs that are in accordance with European Commission, 2014. Sanco/13144/2010 version 3, 613pp and Generic Guidance for Tier 1 FOCUS Ground Water Assessments (version 2.3)

The package also delivers Tier-3A PEC soil as defined in EFSA, 2017. EFSA guidance document  for predicting environmental concentrations of active substances of plant protection products and transformation products of these active substances in soil. EFSA Journal 2017;15(10):4982, doi: 10.2903/j.efsa.2017.4982, 115 pp. (https://www.efsa.europa.eu/en/efsajournal/pub/4982)

 

Comments

Advice for users associated with PEC soil assessments

When using PELMO to calculate Tier-3A PEC soil, users need to take note of what is outlined in the release notes and follow the instructions that have been included there. This will ensure correct model simulations for delivering the PECsoil described in the EFSA, 2017 guidance. It is planned that future releases of PELMO will include resolutions for each point highlighted in the release notes for which a work around instruction has been given.

 

Information (16/January/2024)
FOCUS-PELMO 6.6.4 was tested by the FOCUS Version Control Group prior to release considering the groundwater and soil modelling guidance in force in June 2021.  Although this (and previous) versions of FOCUS-PELMO contained routines to consider transformation resulting from photodegradation, these were not subject to FOCUS Version Control Group evaluation as this mechanism was not derived from the formal guidance in force at the time of release.  Therefore, when using these modelling routines it is necessary to bear in mind that what uncertainty there is regarding the performance of these functions against the recently released guidance related to photo metabolites has not been assessed by FOCUS version control.  This is not related to any lack of process in the development and testing of FOCUS-PELMO, it is simply an artefact of the procedures that require testing against guidance at the time of release and there are aspects of the other FOCUS models that are in a similar position, although they are not yet subject to guidance changes.  Testing of the photodegradation routines in FOCUS-PELMO against the new guidance is being planned as well as the implementation of the guidance in other FOCUS models, so further testing needs for potentially new versions of the models are being considered.
 

Advice (21/September/2021):

If you already installed the earlier PELMO download package that was dated 09/June/2021 then it’s possible and appropriate to continue to use that installation. You should however not make use of the shell wpelmo.exe functionality ‘AppDate recommendations for the selected crop’. If you are a user that wishes to use this functionality of the shell, please use the installation package now available, dated September 2021. This package contains a corrected ‘Crop_interception.tab’ file, that means appropriate AppDate recommendations are now made, which was not always the case with the June installation package.

 

Advice (25/August 2021):

When existing PSM-files are loaded into the shell DegT50-values of metabolites in the first row (e.g. A1) are shown also for respective metabolites in the second row (i.e. A2). This only occurs when using the new “formation fraction view” of the shell. It’s a pure display problem, information in all input and output files are nevertheless stored and processed correctly. The user can easily check this by switching to the traditional “formation rate view” where this display issue does not occur. This will be fixed within the next release of the software. For the time being it is recommended to use the traditional “formation rate view” when existing PSM-files are modified where metabolites need to be defined in the bottom row (i.e., A2,B2,C2,D2).

Version : FOCUS_PELMO_5.5.3

Package FOCUS_PELMO_5.5.3.zip (27/May/2013, 7 MB)
Test Results Word
Getting Started
Comments The scenarios defined in this download package and shell generate tier 1 outputs that are in accordance with Sanco/13144/2010 version 1, 604pp and Generic Guidance for Tier 1 FOCUS Ground Water Assessments (version 2.0)

FOCUS_PELMO_4.4.3

Package FOCUS_PELMO_4.4.3.zip (11/Apr/2011, 7 MB)
Test Results Word
Getting Started
Comments The scenarios defined in this download package and shell generate tier 1 outputs that are in accordance with Sanco/13144/2010 version 1, 604pp and Generic Guidance for Tier 1 FOCUS Ground Water Assessments (version 2.0)

FOCUS_PELMO_3.3.2

Package FOCUS_PELMO_3.3.2.exe.zip (25/Jul/2002, self extracting file into 15 files, 15.3 MB)
Test Results HTML, Word
Getting Started
Comments Warning (25/August/2005): Option "Relative application dates" may lead to unwanted changes of the application dates in the input file.

When reloading pesticide input files into the shell, that use the option "relative application dates", the listbox indicating "before/after" the respective crop status is not always updated (left blank). If the file is saved again the application dates in the input file are changed compared to the initial version of the input file.

Workaround:
If the user notices that problem he should reset manually the correct value for the option "before/after" before saving the file.


Warning (23/June/2004) : The maturation and harvest dates in Sevilla are swapped. The user should not consider relative application dates for the following location/growth stage combination:
  • Sevilla
  • application related to harvest or maturation date
    Instead either absolute application dates should be entered or the application dates should be related to the emergence date.

    (more about this version ...)

FOCUS_PELMO_2.2.2

Package FOCUS_PELMO_2.2.2.exe.zip (1/Oct/2001, self extracting file into 19 files, 17.5 MB)
Test Results HTML, Word
Getting Started
Comments Warning (23/June/2004) : The maturation and harvest dates in Sevilla are swapped. The user should not consider relative application dates for the following location/growth stage combination:
  • Sevilla
  • application related to harvest or maturation date
    Instead either absolute application dates should be entered or the application dates should be related to the emergence date.

    (more about this version ...)

 

FOCUS_PELMO_1.1.1

Package FOCUS_PELMO_1.1.1.zip (5/Dec/2000, 6 files, 41 MB)
Test Results HTML, Word
 
Getting Started
Comments Important Note (19/Dec/2000) : The license agreement which is included in the FOCUS PELMO 1.1.1 package (file PELMO License Agreement) does not apply until further notice.

Warning (22/Jan/2001) : There is an error in the format of one of the FOCUS PELMO 1.1.1 scenario data files. Simulations using the combination strawberry and Sevilla are currently not running. Instead PELMO writes a short error message into the file ECHO.PLM. This problem has no influence on any other combination of crops and locations. The bug will be fixed soon.

Warning (06/Mar/2001) : A small bug has been discovered in FOCUS_PELMO_1.1.1 that may lead to some confusion if simulations are performed using the combination "Thiva/apples/recommended irrigation". Because of wrong headers in a number of meteorological data files "irrigation for grass (+alfafa)" is written into the PELMO echo file instead of "irrigation for apples". However, that does not influence any simulation result, FOCUSPELMO is always using the correct irrigation pattern (apples).

NOTE : the installation procedure for this version of FOCUS_PELMO is slightly different from the latest version !

 

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