Daisy by UUzgpZav

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									            Daisy
  Basic modelling concepts

                  Søren Hansen
The Royal Veterinary and Agricultural University
      Department of Agricultural Sciences
Laboratory for Agrohydrology and Bioclimatology
               Højbakkegård Allé 9
                Dk-2630 Taastrup
                    Denmark
            Braunschweig workshop
           Validation of agro-ecosystem models
  A comparison of results of different models applied to the
                       same datasets
 The simulation results obtained from 19 participants of the
workshop “Validation of Agro-ecosystem Models” were
compared and discussed. Although all models were applied to
the same data set, the results differ significantly. From the
results it can be concluded that the experience of a scientist
applying a model is as important as the difference between
various model approaches. Only one model simulated all main
processes like water dynamics, plant growth and nitrogen
dynamics with the same quality, the others are able to
reproduce the measured dynamic only in part.
Diekkrüger et al., Ecological Modelling 1995.
Weather Data      Bioclimate                                                                                                             Vegetation
                       SVAT                                                                                                                 Growth
Management       Light distribution                                                                                                      Photosynthesis
    Data           Interception                                                                                                           Respiration
                Snow accumulation                                                                                                           Uptake



               Soil




                                                                                                                                                  Soil matrix

                                                                                                                                                                Macropores
                                                                                                                                                 Macropores
                                                                                                                            Macropores
 Soil Data     Uptake




                                                                                                        Macropores
                                                                          Macropores
 Vegetation




                                                  Macropores
               Turnover
   Data        Sorption
               Transport
               Phase
               change




                                                                                       Organic Matter
 DAISY                                                         Ammonium




                                                                                                                                         Water
                                                                                                                     Heat
                            Pesticide

                                        Nitrate




 Simulation
                                                                                                                                                          Numeric layer
 Model
   Weather Data – Daily Values
• Minimum Dataset         • Full Dataset (FAO-
  (Makkink equation)        Penman-Montheith)
   – Global radiation       –   Global radiation
   – Air temperature        –   Air temperature
   – Precipitation          –   Humidity
                            –   Wind speed
• Additional data           –   Precipitation
   – Reference
     Evapotranspiration
       Weather Data – Hourly Values
• Full Dataset (Sparse Canopy – Shuttleworth &
  Wallace)
   –   Global radiation
   –   Air temperature
   –   Humidity
   –   Wind speed
   –   Precipitation

• Additional data
   – Ref. Evap.
                    Precipitation & Irrigation
                                                                  Evaporation
         Evaporation
                                                                                    Transpiration
                            Snow fall                         Rain fall
                                               EI  Min WI / t; E p,C 
                Snowpack                                     Intercepted water
       P                       Ta  T1                              Pr  P  Ps        dr
                                                                               Et   S r dz
        T2  Ta
       Percolation                   Evaporation Throughfall
  Ps                          T1  Ta  T2
                                                                                        0
                 P
        T2  T1
                                                                           Soil Evaporation
       0
                               T2  Ta
                                 Ponded water
                J w , S  J w , d  J w ,C

              w, d 
                        
                     W )tk;LE p,S
        Esp JMin( P sI /Infiltration
                         o e
                                        I ai     
            C L  W                                 
J w,C  Max  I ai   I  ( P  I 0 )  J w,d Soil ; 0 
             t      t                                
                                                EI  water max
                                          Es  Min qs ; E p ,S           Esp 

                   Capillary rise                         Percolation
        Potential Evapotranspiration
                             E p  kc Er
• crop factor and reference evapotranspiration
• crop factor as function of time (Feddes, 1987)
• crop factor as function of development state (Allen et al.,1998)


  Daisy
             
       E p  kc ,soil e   0.4 Lai
                                              
                                      kc ,crop 1  e   0.4 Lai
                                                                    E
                                                                      r
         Crop factor, kc (Feddes, 1987)
Month       May              June           July    August
Decade     1 2 3           1 2 3          1 2 3    1 2 3
Grass†     1.0   1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0
Cereal     1.0   1.0 1.0 1.2 1.2 1.2 1.0 0.9 0.8 0.6
Maize      0.5   0.7 0.8 0.9 1.0 1.2 1.3 1.3 1.2 1.2 1.2 1.2
Potato           0.7 0.9 1.0 1.2 1.2 1.1 1.1 1.1 1.1 1.1 1.1
Beet       0.5   0.5 0.5 0.8 1.0 1.0 1.2 1.1 1.1 1.1 1.2 1.2



† Short grass 5-15 cm (Grass 15-25 cm, kc=1.1)
                      Precipitation

              Snow fall               Rain fall
Sublimation                                       Evaporation


                          Snowpack



        Solid water       Melting       Liquid water
             in                              in
         snowpack                        snowpack
                          Freezing


                                Percolation
      Soil Water Processes
         Flow, q
                                     h 
                            q-K        +1 
  Soil Water: θ, h, K                z 
                        Uptake Kh
                             K            S
         Flow, r M  h  - M hr 
            q        t     z  z  z
S r  4 L
             s - ln  rr2 L 
 Soil Water: θ, h, Kp
      M  hp    Kdh
                   h
                                  Uptake
                   
         Flow, q



 Soil Water: θ, h, K
                                  Uptake

         Flow, q
                       L

                                  Unsaturated Soil

                Percolation   q
          GWT
Ks        h
                                                x
                 Drain flow
Kb                                         d
      Saturated Soil

                Deep percolation         Aquitard
Ka
                              2
                    Kb d 
Aquifer         h        
                              q
                                 Lx  x 2   b
                                              Kd
                    Ks  Ks                   Ks
                 Daisy Carbon Flow Model


     Plant         Photosynthesis                      Organic
                                              Yield
   Respiration                                        Fertilizer
                                                       Carbon
                                    Harvest
                    Crop Carbon

Soil Microbial             Residue Incorporation
 Respiration                 Rhizodeposition


                             Soil Carbon
                        Structural                   Metabolic    Recalcitrant


                                               AOM
                                           AOM
                    N                                N
                         C
                          C-AOM1                         C-AOM2



 ESOM 2 f SOM 2 SMB1 SOM 2             NH4, NO3


                    N
                                             
                                     rmCSMB1SMB growth respiration
                                                   N
                         C
                          C-SMB1                         C-SMB2



                                         CO2

     f SOM 2 SMB1 SOM 2
                    N                                N
                         CC-SOM1                         C
                                                         C-SOM2
                                           SOM

SOM 2  KSOM 2 fSOM 2 T  fSOM 2  h CSOM 2
                  temp        water
       Fertilization
      + Atm. Depo.
                                          Nitrogen Processes
                        Fertilization                                                       Fertilization
                                                  Harvest
                       (Org. Matter)                                                        + Atm. Depo


                                  Residuals +
                                Rhizodeposition        Plant-N
                                                                                   Uptake
                 Org-N

                                              Uptake
                           Net-
                       Mineralization
                                                                  Immobilization




                 NH4+                                                                 NO3-
                                                  Nitrification

Volatilization                    Leaching                         Denitrification                  Leaching
         Nitrogen Processes
                                                                                       Denitrification
            in a soil layer
NH4+ Transport                                                                NO3- Transport



    Rhizodeposition
                              
            d = Min F d ( )  ; K d N ni
                                              *
                                             Uptake
                                               d                           Root-N

          Org-N             = *C CO
                            *
                  J           d  qC
                        D d , q
                                           NO3
                                                  2                          Uptake
                                             z
                                                       NO3
      
                                                               V T,h  N am
                                         Immobil.
                         
       L 4CD  CNet-    ln   1 C
                             2       2
        NO3  Cr  2
                                                           
                  
                    D
       tMineralization      , q 
                                   1
                                              NO3
                                                            =  0
                                                                 
                                                       qCNO3  n  NO3
                                                                        n
                     z                      z                 K n + N am
      
            2  1 C   2 Cr
                      ln                                   
 u   Lqr                                                 2
              
                  1  ln 
                  2              2

           NH4+ 1   / 2 C   2  1 C                                   NO3-
           
             2 1                               r
                                               Nitrification
       Lqr                                                else
      
              2
                                            
                     1 1   / 2    2   1
                     NH4+ Transport                                                   NO3- Transport
                       q
               = r ;              = (rr2 L) -1/ 2
                     2 D
 Daisy Crop Model
                                      CO2          Light    Temperature


                                                                           Canopy
                                                 Photosynthesis
                                                                           Structure

                                    Assimilate                             Stress
CO2                                                                        Factors
                                      Pool
           Maintenance
           Respiration
                                     Release
                           Many parametres are a                          Senescence



                   CO2
                                   Partitioning
                                  function (DS)the
                                                of                  CO2
                                             CO2
      Conversion          development stage (DS)                                 Conversion
                                Conversion                  Conversion


Storage
                         Leaf                        Root                 Stem
 Organ

                                Leaf Death                  Root Death

                       Leaf                         Root
                     Residues                      Residues
      Development stage (DS)
• DS phases
  – Emergence phase (sowing/planting to emergence)
     • DS in the interval –1 to 0
  – Vegetative phase
     • DS in the interval 0 to 1
  – Reproductive phase
     • DS in the interval 1 to 2
     Development stage (DS)
        Emergence phase
• Temperature sum model
• Parameters
  – Soil temperature threshold
  – Soil temperature sum at emergence


     DS  1 
                Max T    soilT  threshold   ;0
                           Sum
                         Temergence
        Development stage (DS)
           Vegetative phase                                     1.4




                                  Temperature Effect
                                                                1.2
• Temperature sum model                                         1.0
                                                                0.8

• Default model                                                 0.6
                                                                0.4
                                                                0.2
  – Parameters                                                  0.0
                                                                      0       10         20          30         40
     • Development rate [day-1]                                                    Temperature
                                                                1.1
     • Temperature effect

                                           Photoperiod Effect
                                                                1.0
     • Photoperiod effect
                                                                0.9


                                                                0.8
                                                                      0   3    6   9      12    15    18   21    24
                                                                                       Day length


DS   veg fveg temperature fveg  daylength  t
              temp               phot
     Development stage (DS)
       Reproductive phase
• Temperature sum model
• Default model
  – Parameters
    • Development rate [day-1]
    • Temperature effect


    DS  1    f       temp
                    rep rep     temperature t
              Crop Photosynthesis
• Light Distribution
   – Leaf area distribution of                       Composite Canopy
     individual crops                       Crop 2

   – Composite canopy              Crop 1

   – Distribution of absorbed               LAD
     PAR
      • Beers’ law
   – Partitioning of distributed
     absorbed PAR among
     crops
                      Crop Photosynthesis
                                                                                                6
 • Light response curve




                                                                  Photosynthesis [g CO2/m2/h]
                                                                                                5

     – Intensity of absorbed                                                                    4

       PAR, Sa                                                                                  3


     – Temperature effect
                                                                                                2

                                                                                                1
     – Senescence                                                                               0

     – Water and Nitrogen Stress                                                                    0      200      400       600
                                                                                                        Absorbed PAR [W/m2]


                                                                                                                
FLeaf  f    Phot
            Temp    (T ) f    Phot
                             DS      ( D) fPhot
                                          W  Stress   f    Phot
                                                           N  Stress                           Fm 1  exp   Sa 
                                                                                                            Fm  
         Crop Photosynthesis
• Canopy photosynthesis
  – Integration over the canopy
                          Lai
            FCanopy           FLeaf ( S a ( L))dL
                      0

  – Where L is the LAI accumulated from the top
    of the canopy
        Maintenance Respiration
• Maintenance Respiration
  –   Root
  –   Leaf
  –   Stem
                              i
                                  Rm  rm (T ) W
                                       i             i
  –   Storage organ (grain)

                                           All
• Total maintenance                Rm   Rm     i
  Respiration
                                            i
               Partitioning
                                      1.0
• Allocation of                       0.8




                       Partitioning
                                      0.6                                        Shoot
  assimilates to:                     0.4
                                                 Root
   • Root
                                      0.2
                                      0.0

   • Leaf
                                            0          0.5           1           1.5     2
                                                             Development Stage

   • Stem
   • Storage Organs                   1.0
                                      0.8
                      Partitioning



     (Grain)                          0.6                    Stem
                                      0.4                                        Grain
                                      0.2       Leaf
                                      0.0
                                            0          0.5           1           1.5     2
                                                             Development Stage
                                          Growth Respiration
• Conversion Efficiency
• Growth respiration (CO2-evolution)
• Simple biochemical analysis (Vertregt & Penning de Vries, 1987)
                                   0.50
                                                                       y = -0.7813x + 0.8321
         CO2 evolution [g/g Ass]




                                   0.45
                                                                            R2 = 0.9811
                                   0.40

                                   0.35

                                   0.30
                                                                       Stem
                                   0.25
                                                                               Leaf
                                   0.20
                                       0.50   0.55        0.60        0.65        0.70         0.75
                                                 Conversion Efficiency [g DM/g Ass]
        LAI development
• Leaf weight
• Specific leaf area
• LAI-modifier (function of development stage)

      Lai  leaf fleaf  DS Wleaf
                       1.1
                       1.0
        LAI-modifier




                       0.9
                       0.8
                       0.7
                       0.6
                       0.5
                             0.0   0.5          1.0          1.5   2.0
                                         Development stage
        Crop Nitrogen Relations
• Maximum N content (uptake)
• Critical N content (production)
• Minimum N content, Non functional
  limit (production)
                                              7
                                                                                        Leaf
                       N concentration [% ]   6
                                                                                        Stem
                                              5
                                                                                        Grain
                                              4
                                                                                        Root
                                              3
                                              2
                                              1
                                              0
                                                  0.0   0.5          1.0          1.5           2.0
                                                              Development Stage

								
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