NLES-CAT

Acronym:

NLES-CAT

Liaise ownership:

yes

Description:

N-LES is an empirical model for calculation of annual values of root zone nitrogen leaching. The model comprises a combination of additive and multiplicative effects. N-LES was developed on 600 observations of annual leaching of nitrogen from the root zone from both experimental fields and fields in normal agricultural production in Denmark. The model explained 68% of the observed variation. The systematic effects included in the model are: level of total-nitrogen added in the crop rotation; fertilization in spring; autumn fertilization; nitrogen left by grazing animals; effect of ploughing-in of grass; soil type (clay- and humus-content); water percolation through the root zone, and crop type. In Denmark, percolation has been calculated by EVACROP, which comprises rather simple conceptual models for describing vegetation and for calculating the water balance.
N-LES has since 1992 been used in Denmark as a tool for evaluating the effect of policy measures for combating diffuse nitrogen pollution from the agricultural production under Nitrate Direvtive, WFD and Danish Action Plans.

Input variables:

EVACROP describes development of LAI and roots, and calculates evaporation from soil and transpiration from plants, and water percolating through the root zone. N-LES being a statistical model implements as such no processes
Main input data:
level of total-nitrogen added in the crop rotation; fertilization in spring;
autumn fertilization;
nitrogen left by grazing animals;
nitrogen fixation by leguminous plants;
timing of ploughing-in of grass;
soil type;
water percolation through the root zone;
crop type (main crop and winter or catch crop)
Field root zone nitrogen leaching data or measured nitrogen concentration just below the root zone of individual fields. Alternatively flow and nitrogen concentration data from tile drained subcatchments. For catchments with zero subsurface nitrogen retention/removal the model can be validated on river data (flow, nitrogen concentration, nitrogen load). NERI is working on an add-on module for estimating subsurface retention/removal. Combined with this module N-LES could be validated on river data for all catchments.
 

Output variables:

Annual estimates of nitrogen leaching and water leackage from the root zone on agricultural fields.

Time Horizon:

Countries:

Documentation for the end user:

N-LES is a one-dimensional model, which calculates nitrogen leaching out of the root zone on an annual basis operating on the field as the smallest unit.
Field root zone nitrogen leaching data or measured nitrogen concentration just below the root zone of individual fields. Alternatively flow and nitrogen concentration data from tile drained subcatchments. For catchments with zero subsurface nitrogen retention/removal the model can be validated on river data (flow, nitrogen concentration, nitrogen load). NERI is working on an add-on module for estimating subsurface retention/removal. Combined with this module N-LES could be validated on river data for all catchments
 

Scientific documentation:

NLES has been documented in a 5th Framework Programme ' EUROHARP' in 2009.
 
Kronvang, B., Behrendt, H., Andersen, H.E., Arheimer, B., Barr, A., Borgvang, S.A., Bouraoui, F., Granlund, K., Grizzetti, B., Groenendijk, P., Schwaiger, E., Hejzlar, J., Hoffmann, L., Johnsson, H., Panagopoulos, Y., Porto, A. Lo., Reisser, H., Schoumans, O., Anthony, S., Silgran, M., Venohr, M., Larsen, S.E.. (2009) Ensemble modelling of nutrient loads and nutrient load partitioning in 17 European catchments. Journal of Environmental Monitoring, 11: 572-583.
Schoumans, O.F., Silgram, M. ,Groenendijk, P., Bouraoui, F., Andersen, H. E., Kronvang, B., Behrendt, H., Arheimer, B., Johnsson, H., Panagopoulos, Y., Mimikou, M., Porto, A. Lo., Reisser, H., Le Gall, G., Barr, A., Anthony, S.G. (2009) Description of nine nutrient loss models: capabilities and suitability based on their characteristics. Journal of Environmental Monitoring, 11: 506-514.
Schoumans et al., 2009: Evaluation of the difference of eight model application to assess diffuse annual nutrient losses from agriculture. Journal of Environmental Monitoring, 11: 540-553.
 
 

Contact:

Department of Bioscience, Aarhus University

Environmental impacts:

E Mail:

HEA@DMU.DK