Ingen lysbildetittel

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Johannes Deelstra Agricultural University,
Wageningen, The Netherlands Jordforsk
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Modelling in monitored catchments
Experiences from case studies in Norway
SOIL/SOILN_NO in the Skuterud catchment SOILNDB
in the Mørdre catchment
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Location of catchments in the JOVÅ-programme
North pole
president Bush
Volvo
EU, y/n
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The Skuterud catchment
In operation since 1993
Land use Area ( ha) Agricultural area
272 forest area 129 Bogs 10 roads,
farms 13 Housing area 25 Total
area 449
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The Mørdre catchment
In operation since 1991
Land use Area (ha) Agricultural area
444 Forest 192 Bogs
27 Housing area, roads, etc 18 Sum
681
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Measurement programme in JOVÅ-catchments
Discharge measurement Water sampling and
analysis(TDS, Ntot, Ptot)
runoff(mm) N,P,SS loss (ha-1)
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Measurement programme in JOVÅ-catchments (contd)

• Collection of information on farming practices
• type of crop
• fertiliser application
• yield
• sowing/harvesting dates
• type/date of soil tillage

In addition soil mapping, profile
descriptions additional determinations of soil
physical parameters
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Simulation Skuterud
The Soil model

• water and heat transport in the vertical profile
  
• daily meteorological data and soil physical
  parameters, initial values
• numerous switches to set

SOILN_NO, Norwegian version of the Swedish SOILN
model
- includes major nitrogen and carbon processes -
many inputs from SOIL - nitrogen application
including the dates of application, type of
crops, sowing and harvesting dates, crop yield
ploughing dates - MATLAB
NITROGEN LEACHING FROM THE ROOT-ZONE TO TILE
DRAINAGE/GROUNDWATER.
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Skuterud
Simulation for each farmer field
Simulations No measures With measures Optimal
fertiliser application Catch crops Irrigation
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Nitrogen runoffno measures
Skuterud
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Optimal fertiliser application
Skuterud
Nitrogen loss with optimal fertiliser application
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Catchcrops
Skuterud
Nitrogen loss when catchcrops
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Irrigation
Skuterud
Nitrogen loss when irrigation
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Comparison of measures
Skuterud
Effects() Opt. fert. appl. 4.7 , Catchcrops
20, Irrigation 12
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Nitrogen leaching maps
Skuterud
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Mørdre - SOILNDBLarsson et al. (2001), SLU

• A shell in Visual Basic, coupling SOIL og
  SOILN(SLU)
• To quantify N-loss from agricultural areas

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Input og parameterisering

• Input preperation through Excel into
  SOILNDB-database
• climatological data
• soilsdata
• farming practices (fert., soil prep., etc)
• Parameter setting
• through SOILNDB-database (possibility to change)
• through changing program-code

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Soils

• soil physical parameters (pF, ksat, texture, org.
  matter)
• two alternative sources
• from soil database in SOILNDB (10 USDA jordarter
  og 7 Nordic soil types.
• own data

Farming practices
crop type, fertiliser, type and quantity soil
tillage, type, date
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Simulation procedure Mørdre
Simulation for individual farmer fields (input
farmer information) for 2 ha units(input SSB)
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Results runoff(mm)
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Results nitrogen losses
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Summary

• both models user friendly
• SOIL/SOILN_NO/SOILNDB, one dimensional -
  catchment?
• one dimensional model
• size of catchment(limits?)
• surface runoff?
• validation of modelling results
• against total catchment runoff justified?
• what about flow processes?
• how to deal with variability in catchments
• soil physical parameters,
• sowing/harvesting, fertiliser application