Diapositive 1

1
Soil NO inventory from large scale farming in
France impact on atmospheric NO2 and O3
concentrations Achieved during 2 national French
projects GICC et PNCA In Collaboration with
INRA (Grignon) P. Laville, B. Gabrielle, A. L.
Palluis LA (Toulouse) D. Serça, J.
Cortinovis SA (Paris) M. Beekmann, F. Ravetta
INRA (Dijon) C. Hénault
2

• 1/ Field NO flux measurements (Auradé (32) and
  Grignon (78))
• On Wheat, Maïs, Sunflower
• 2/Laboratory Measurements soil incubations
• -gt NO production according to the
  nitrification rate
• 3/ Development and validation of NO emission
  Model
• 4/ Achievement of NO soil inventory impact on
  atmospheric pollution (Chimère)

3
Examples of In Situ Measurements Auradé (Midi
Pyrenees), Grignon (Ile de France)
Grignon

• Annual Variations of NO flux
• - Outside nitrogen input periods A background
  level 1 à 3 gN-NO/ha/d
• After nitrogen inputs largest NO emissions
  during 3 to 4 weeks
• Largely dependent on
• temperature- humidity ammonia concentration of
  the soils

4
Biological processes involved on N2O et NO
productions
Dénitrification (anaerobie)
Nitrification (aerobie)
K3(t)
N2
N2O,NO
K1(t)
K2(t)
NO2-
NH4
NO3-
K2(t)
NO
N2O(t) K1(t) K2(t) - K3(t)
NO(t) K2(t)
5
NO emission model by nitrification process
2
NO 2 VN VN FN x FW x FT
Km 50
Simplified equation NO0.0901.AF.(0.8166 Wp
-6.6868). exp (Ln(2.1).T/10)
6
Examples of modeled NO fluxes using
environmental soil inputs (Temperature,
humidity, NH4)
7
Spatial and temporal Extrapolation of NO
agricultural soil fluxes

• - Simplified version on NO emission algorithm
  (NH4, Wp et T sol)
• NO0.0901.AF.(0.8166 Wp -6.6868). exp
  (Ln(2.1).T/10)
• Nitrification rate 10 NH4/jour (T 10C,
  Wp20)
• - Statistical survey on agricultural practices at
  regional scale
• -gt Distribution of arable land areas by crop
  types
• -gt Dates et nitrogen quantity inputs for each
  type of crops
• gt to set up a chronological function of
  nitrogen inputs according to the land use and to
  the agricultural practices

8
Survey on nitrogen use by crop and by region
57 SAU
TAS
TAS
9
Comparison between TAS et SAU for each regions
SAU totale 277 725 km² TAS 160 171 km²
(57 de la SAU)
10
Comparison between synthesis nitrogen deliveries
(UNIFA) And the amounts estimated according to
our survey qté TAS
DN 0.147 millions tonnes (7)
TAS 57 de la SAU
-2.4 millions tonnes of synthesis nitrogen
fertilizers/year (65 in ammonia form) -1.4
millions tonnes of nitrogen manure /year
11
Steps to interpolate temporally the exogenous
soil NH4 content

• Equiprobability of Inputs N1 (35 kg) et N2 (65
  kg) during 21 days
• - during 21jours addition N1/21 et N2/21
• Nitrification of 10/day
• Area under function N1N2

4
65 kg
Oats in Ile de France.
2
1start 1st input. 3start 2d input. 2end 1st
input. 4end 2d input.
N-NH4 kg/ha.
35 kgN
3
1
DOY
12
Chronology nitrogen inputs gt time series of NH4
content in region
exogenous
endogenous
A background level of 0.9 kg N-NH4/ha
115 kg/ha
59 kg/ha
13
Example of NO simulated fluxes obtained from the
MM5 model outputs (T et Wp), and the temporal NH4
content time series
Flux Grignon 2003
14
Yearly Balance of NO soil emissions in France
15
Annually soil NO emissions
14.5 ktN-NO/year 47.7 ktNO2/year on 57SAU In
rough approximation soil NO flux
84ktNO2/year 11 /transport and 5 / all
sources (CITEPA) Methodology EMEP/CORINAIRgt EF
0.7 (2.4MtN/an) 55.2ktNO2/an (Bouwman, 2002)
16
Impact on atmospheric chemistry (modeling with
CHIMERE).
Additional O3 concentration linked to arable soil
NO sources mean estimates for June 2003 (max 3
ppb)
Mean arable land NO emissions (June 2003) (Max 8
g N/ha/d)
17
Conclusions

• Positive item
• Improvement in seasonal variation on NO Fluxes gt
  seasonal nitrogen inputs
• taken into account.
• - Parameterizations on NO flux versus soil
  humidity

18
Conclusions

• insufficient Item
• No variability of emissions depending on soil
  type
• Only NO from nitrification is considered and
  the denitrification ?
• Emissions from animal manure were not study
• Variation of background NH4 not take account
  (annually balance 0.5 ppm gt80 of fluxes)
  gtSimulate net mineralization
• And the other ecosystems or arable lands?