1. General Model Information

Name: Nitrate Leaching and Economic Analysis

Acronym: NLEAP

Main medium: terrestrial
Main subject: hydrology, agriculture
Organization level: Landscape, Ecosystem
Type of model: ordinary differential equations, not specified
Main application: decision support/expert system, research
Keywords: nitrate, leaching, soils, management, solute transport, regional scale, GIS interface, economic analysis


Marvin J. Shaffer
Great Plains Systems Research Unit
P.O. Box E, 301 S. Howes
Fort Collins, Colorado 80522

Phone: 970 490-8337
Fax: 970 490-8333
email: shaffer@gpsr.colostate.edu
Homepage: http://www.gpsr.colostate.edu/GPSR/employees/marv.htm


USDA-ARS Fort Collins in cooperation with USDA-ARS Akron, Co and Michigan State University.
Shaffer, M.J., A.D. Halverson and F.J. Pierce.


Nitrate Leaching and Economic Analysis Package (NLEAP) is a field-scale computer model developed to provide a rapid and efficient method of determining potential nitrate leaching associated with agricultural practices.
It uses basic information concerning on-farm management practices, soils, and climate to project N budgets and nitrate leaching indices.
NLEAP calculates potential nitrate leaching below the root zone and to ground water supplies. NLEAP has three levels of analysis to determine leaching potential: an annual screening, a monthly screening, and an event-by-event analysis.

The NLEAP (Nitrate Leaching and Economic Analysis) package is a process oriented predictive simulation model (Shaffer et al., 1991). The model contains a user-oriented front end for assessment and planning purposes. The model calculates NO3-N leaching indices for agricultural areas as a function of soils, management and climate.

The model requires soils, daily weather and management data for input. The model can be executed over a range of time scales, from a single event to annual. The spatial scale of the model is field to regional scales. The model has been calibrated / validated against lysimeter , field plot, and farm field data from eight states.

Sources of the abstract:
Detailed GPSR Product Description

II. Technical Information

II.1 Executables:

Operating System(s): DOS

II.2 Source-code:

Programming Language(s): FORTRAN and C

II.3 Manuals:

II.4 Data:

III. Mathematical Information

III.1 Mathematics

III.2 Quantities

Model needs soils, climate, and management data as inputs.

III.2.1 Input

Model needs soils, climate, and management data as inputs.
Model Input Data Source: Soils and climate data are available on
  • National Eutrophication Study Database database (4 regionswithin U.S.) Management data must be supplied by users. Tables, graphs, and written text output. Monthly and annual

    III.2.2 Output

    Tables, graphs, and written text output. Monthly and annualoutput-drainage volume, NO3, residual N.
    Temporal Scale: Event based to monthly to annual.
    Spatial Scale: Field scale to regional (with GIS).

    IV. References

    Shaffer, M.J., A.D. Halverson and F.J. Pierce. 1991.Nitrate leaching and economic analysis package (NLEAP):model description and application. In Managing Nitrogen for GroundwaterQuality and Farm Profitability. Eds. Follett et al., pp 285-322. SoilScience Society of America, Madison, Wisconsin.

    V. Further information in the World-Wide-Web

    VI. Additional remarks

    Global change implications:This model can be used forglobal change research by examining the relationship between soil types and nitrogen leaching.

    Last review of this document by: T. Gabele: 17 - Sep - 1997 -
    Status of the document:
    last modified by Tobias Gabele Wed Aug 21 21:44:46 CEST 2002

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