department of agroecology danish institute of agricultural sciences dynamic nh 3 model emep...
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Department of AgroecologyDanish Institute of Agricultural Sciences
Dynamic NH3 model
•EMEP atmospheric dispersion model.•Deposition estimates used in policymaking•Needs emission estimates
–Europe-wide (50 x 50 km grid).–High temporal resolution (3 hours).
•Work in progress.
Department of AgroecologyDanish Institute of Agricultural Sciences
• Sources:– Housing.
– Storage.
– Field.
The model
Storage
Field
Animalhousing
Animal
• Mass flow model:– Ammoniacal N.– Organic N.– Dry matter.– Water.
• Hourly timestep
Department of AgroecologyDanish Institute of Agricultural Sciences
NH4+ Organic-N H2O
NH3 H2O
Manure
Animal housingManure storage
Department of AgroecologyDanish Institute of Agricultural Sciences
NH4+ Organic-N H2O
NH3
NH4+
H2O
H2O
Manure
Soil
Field application
Department of AgroecologyDanish Institute of Agricultural Sciences
NH3 emission
Area of manure * Amount of NH4+ * Henry-factor
Amount of water * Transport resistance
Department of AgroecologyDanish Institute of Agricultural Sciences
Animal house emission
Area of manure * Amount of NH4+ * Henry-factor.
Amount of water * Transport resistance
Number of animalsFloor area per animal
Number of animalsUrea-N per animal
TemperatureManure pH
Number of animalsVolume per animal
Ventilation rateHousing factor
Department of AgroecologyDanish Institute of Agricultural Sciences
Animal house emission
Area of manure * Amount of NH4+ * Henry-factor.
Amount of water * Transport resistance
Number of animalsFloor area per animal
Number of animalsUrea-N per animal
TemperatureManure pH
Number of animalsVolume per animal
Ventilation rateHousing factor
= parameter
Department of AgroecologyDanish Institute of Agricultural Sciences
• Lots of data.
Parameterisation & testing
• Lots of time.
• (see presentation on later today).
• Temporary parameterisation using Dk emissions.
• Synthetic weather data.
Department of AgroecologyDanish Institute of Agricultural Sciences
Ammonia emission
0
50
100
150
200
250
300
350
400
450
500
0 50 100 150 200 250 300 350 400
Day number
Emis
sion
(kg/
day)
Housing
Storage
field application
Total
Grazing
10 000 finishing pigs per 50 x 50km
Ammonia emission (kg/day)
Department of AgroecologyDanish Institute of Agricultural Sciences
• Meteorological e.g.– Daily temperature, rainfall, wind speed etc.
• Structural (vary with location) e.g.– Number of animals.– Type of animal housing.
• Operational (vary with time & location) e.g.– Housing dates and ventilation rates.– Manure application dates.
Inputs
Department of AgroecologyDanish Institute of Agricultural Sciences
Structural input examples
• For each animal type:– Animal numbers.– Ammoniacal-N and organic N excreted per
animal.– Housing/storage type.
• Dairy cattle.
Department of AgroecologyDanish Institute of Agricultural Sciences
Animal numbers
• EUROSTAT Farm Structural Survey:– Animal numbers by type.– Regularly updated.
• Some data missing.
• NitroEurope project
Department of AgroecologyDanish Institute of Agricultural Sciences
Dairy cattle
Department of AgroecologyDanish Institute of Agricultural Sciences
Nitrogen excretion
• Use IPCC methodology:• Feed intake, faecal dry matter production.
• Data:• Milk production per cow (FSS).
• Assumptions:• Diet quality, growth, weight.
Department of AgroecologyDanish Institute of Agricultural Sciences
Annual N excretion for dairy cattle
0
20
40
60
80
100
120
140
160
kg
N p
er
ye
ar
Department of AgroecologyDanish Institute of Agricultural Sciences
0
20
40
60
80
100
120
140
160
4000 5000 6000 7000 8000 9000
milk production (litres/a)
N e
xcre
ted
(kg
/a)
Total N excreted
TAN (IPCC)
TAN (DK)
Department of AgroecologyDanish Institute of Agricultural Sciences
Manure type
• Housing type depends on farm size?• Small volumes – solid manure cheapest.• Large volumes – slurry cheapest.• Relate probability of slurry to farm size.• Use farm size (FSS) to estimate slurry/solid.
• Example from Denmark
Department of AgroecologyDanish Institute of Agricultural Sciences
-0.2
0
0.2
0.4
0.6
0.8
1
1.2
0 100 200 300 400 500 600 700
Livestock units
Pro
po
rtio
n s
lurr
y
Department of AgroecologyDanish Institute of Agricultural Sciences
• Simple dynamic model.• Estimate livestock heat production.
– CIGAR (2002)
• Calculate ventilation necessary to maintain:– A target inside temperature (forced ventilation).
• Maximum and minimum ventilation rates.• Heating.
– Inside temperature 4C above ambient (free).
Operational example - ventilation
Department of AgroecologyDanish Institute of Agricultural Sciences
-10
-5
0
5
10
15
20
25
0 50 100 150 200 250 300 350 400
Day number
Te
mp
era
ture
(C
els
ius
)
Housing
Ambient
Forced ventilation
Department of AgroecologyDanish Institute of Agricultural Sciences
• Lack harmonised data at European scale.– But may be available at country scale.
• Operational management affected by legislation.
• Modelling– How accurate?– Useful for scenarios.
Conclusions (1)
Department of AgroecologyDanish Institute of Agricultural Sciences
• Data required for many purposes.– Ammonia, Greenhouse gasses, Nitrate leaching,
Erosion.– Secondary PM formation.
• EU project.– Data collection.– Modelling.
Conclusions (2)
Department of AgroecologyDanish Institute of Agricultural Sciences
Department of AgroecologyDanish Institute of Agricultural Sciences
• Depth of storage.
Parameters - storage
• Manure pH and temperature.
• Organic N degradation coefficient.
• Transport resistance.
Department of AgroecologyDanish Institute of Agricultural Sciences
• Start/stop date for applications
Parameters - field
• Maximum application capacity.
• Application rate.
• Transport resistance constant.
• Infiltration rate.
• Duration of emission.
Department of AgroecologyDanish Institute of Agricultural Sciences
Department of AgroecologyDanish Institute of Agricultural Sciences
• Dirty floor area per animal.
Animal housing
• Manure pH and temperature.
• Transport resistance.