Chapter 3
2012-3-21 Assessment of Climate/Change Impacts 1 of 46
3.4 Crop growth and its modeling
3.4.1 Components of plant growth
3.4.2 Empirical models
3.4.3 Process-based models
3.4.4 Case studies
Chapter 3
2012-3-21 Assessment of Climate/Change Impacts 2 of 46
3.4.1 Components of plant growth
(1) Development
(2) Dry matter accumulation
photosynthesis
respiration
water use
(3) Environmental constrains(stresses)
Chapter 3
2012-3-21 Assessment of Climate/Change Impacts 3 of 46
Crop Growth Models
? Classification
Empirical models
Process-based models
? Purpose
Simulation of crop growth
Crop growth management and risk
assessment
Component of land surface process modeling
Chapter 3
2012-3-21 Assessment of Climate/Change Impacts 4 of 46
3.4.2 Empirical Crop Models
? Larger time steps
? Statistical relationships
? Potential productivities
Chapter 3
2012-3-21 Assessment of Climate/Change Impacts 5 of 46
3.4.2 Empirical Crop Models
? Multiply method
? AEZ method(Agro-Ecological Zone,
FAO)
? Miami model-- NPP
Chap,3
Chapter 3
2012-3-21 Assessment of Climate/Change Impacts 6 of 46
Multiply method
Yp=E?(?Q)?f(t)?f(w)?HI
===========
E,radiation use efficiency
?Q,sum of radiation within growing season
f(t),modifying function of temperature
f(w),modifying function of water balance
HI,harvest index(ratio of economic yield to
biomass,0.35～ 0.45 for wheat,0.3～ 0.4 for
soybean
Chapter 3
2012-3-21 Assessment of Climate/Change Impacts 7 of 46
Multiply method
黄秉维,Yp ＝ 0.93× Q
Yp,photosynthetically potential productivity (kg/ha)
Q,solar radiation（ cal/cm2）
coefficient,0.93=α(1－ β)(1－ γ)(1-a)× b(1－ c)(1－ d)
× e/(1-δ)/(1-f)
α,percent of PAR,47％
β,transmission of solar radiation,5％
γ,percent of solar radiation absorbed by non-
photosynthecally organs,10％
Chapter 3
2012-3-21 Assessment of Climate/Change Impacts 8 of 46
Multiply method
a,reflectivity,6.5％
b,energy need for per unit carbohydrates
formed,10 Enstain/?g
c,8.6Enstain/cal
e,mass of per unit carbohydrates,3× 10－ 5g/?g
d,percent of dry matter for respiration,25％
f,percent of dry matter for non-organic,8％
δ:percent of plant moisture,15％
Chapter 3
2012-3-21 Assessment of Climate/Change Impacts 9 of 46
Multiply method—f(t)
Modified functions for temperature,
于沪宁 -赵丰收,
Ft＝ 4.301× 10-2?t-5.771× 10-4?t2
Chapter 3
2012-3-21 Assessment of Climate/Change Impacts 10 of 46
Multiply method—f(t)
李世奎,
0.027× t － 0.162 [6℃, 21℃)
0.086× t － 1.41 [21℃, 28℃ ）
Ft 温 ＝ 1 [28℃, 32℃ ）
-0.083× t+3.67 [32℃, 44℃ ）
0 （ t<6℃ ）（ 44℃ <t）
Exp.{-2[(t-t0)/10]2} (t<t0)
Ft 凉 ＝
Exp.{- [(t-t0)/10]2} (t>t0)
t,measured temperature
t0,optimal temperature
Chapter 3
2012-3-21 Assessment of Climate/Change Impacts 11 of 46
Multiply method—f(w)
孙慧南,
R/E0 R< E0
F(w) ＝ 1 R -E0 ≤runoff
< 1 R -E0 >runoff
R,rainfall
E0,evaporation from water
Chapter 3
2012-3-21 Assessment of Climate/Change Impacts 12 of 46
Multiply method—f(w)
李世奎,
(1-C)R/ETm (1-C)R < ETm
f(w)＝ 1 (1-C)R > ETm
C,runoff coefficient,0.2
R,rainfall
ETm,crop water requirement
Chapter 3
2012-3-21 Assessment of Climate/Change Impacts 13 of 46
Multiply method—f(w)
FAO,
F(w) ＝ Ky.（ 1-ETa/ ETm）
Ky,crop yield coefficient responding to
water supply
ETa,actual evaportranspiration
ETm,crop water requirements
Chapter 3
2012-3-21 Assessment of Climate/Change Impacts 14 of 46
AEZ method
Yp=[F?f(Y0)?Y0+(1-F)?f(Yc)?Yc]}
?CL?CN?HI?f(w)
===========
Y0, potential net dry matter in clear sky
Yc,potential net dry matter in overcast
F,modifying function for radiation
f(Y0),f(Yc),modifying function of temperature
Chapter 3
2012-3-21 Assessment of Climate/Change Impacts 15 of 46
AEZ method
CL,modifying coefficient for leaf area
index(LAI)
CN,modifying coefficient for respiration
HI,harvest index(ratio of economic yield
to biomass
f(w),modifying function of water balance
Chapter 3
2012-3-21 Assessment of Climate/Change Impacts 16 of 46
Reference crop evapotranspiration (ETo)
the evapotranspiration rate from a
reference surface,not short of water
The reference surface is a hypothetical
grass reference crop with specific
characteristics,
AEZ method
–crop water requirement
Chapter 3
2012-3-21 Assessment of Climate/Change Impacts 17 of 46
Crop evapotranspiration under standard
conditions (ETc)
the evapotranspiration from disease-free,
well-fertilized crops,grown in large fields,
under optimum soil water conditions,and
achieving full production under the given
climatic conditions
AEZ method
–crop water requirement
Chapter 3
2012-3-21 Assessment of Climate/Change Impacts 18 of 46
Crop evapotranspiration under non-
standard conditions (ETc adj)
the evapotranspiration from crops grown
under management and environmental
conditions that differ from the standard
conditions
AEZ method
–crop water requirement
Chapter 3
2012-3-21 Assessment of Climate/Change Impacts 19 of 46
3.1.3 Water Use
Chapter 3
2012-3-21 Assessment of Climate/Change Impacts 20 of 46
Miami model
NPP = min [f(t),f(P)]
f(t) = 3000/(1+exp(1.315-0.119t) g/m2 yr
f(p) = 3000(1-exp(-0.000664p)) g/m2 yr
NPP = 3000(1-exp(-0.0009695(ET-20)) g/m2 yr
===========
NPP,Net primary production
t,annual average temperature
p,annual rainfall
ET,annual evaportranspiration
Chapter 3
2012-3-21 Assessment of Climate/Change Impacts 21 of 46
3.4.3 Process-based Crop Models
? Smaller time steps,daily
? Processes of crop growth
? Statistical relationships for some
parameters and processes based on
experiments
Chapter 3
2012-3-21 Assessment of Climate/Change Impacts 22 of 46
(1) Phasic development simulation
(2) Physiological processes
(3) Relationships with environmental
factors
(4) Examples,CERES,ALMANAC
Components of the Process-based
Crop Models
Chapter 3
2012-3-21 Assessment of Climate/Change Impacts 23 of 46
Thermal time
HUI= GDD/PHU
Ecological form
leaves/day = f(t)
(1) Phasic development simulation
Chapter 3
2012-3-21 Assessment of Climate/Change Impacts 24 of 46
? Photoperiod,
leaf numbers
thermal time to tasseling
? Vernalization (0-8oC),
leaf numbers
? Maturity type
(1) Phasic development simulation
Chapter 3
2012-3-21 Assessment of Climate/Change Impacts 25 of 46
? Biomass accumulation by photosythesis
Leaf growth,function of biomass
accumulation
? Consumption of dry matter by
respiration
? Distribution of dry matter:root,leaf,
stem,etc,
(2) Physiological processes
Chapter 3
2012-3-21 Assessment of Climate/Change Impacts 26 of 46
? The ability of plants to harness energy
from the sun to fix atmospheric CO2 into
a range of more complex organic
molecules,
CO2+H2O— light→ CH2O+O2
Photosynthesis
Chapter 3
2012-3-21 Assessment of Climate/Change Impacts 27 of 46
Three separate components
? Light reactions
To generate light energy compounds ATP and NADPH
? Dark reactions
To form sugars through biochemical reduction of CO2
? Supply of CO2
to the site of reduction in the chloroplast
Photosynthesis
Chapter 3
2012-3-21 Assessment of Climate/Change Impacts 28 of 46
Light Use Efficiency
? Carbon formation by energy during a
time interval
Photosynthesis
Chapter 3
2012-3-21 Assessment of Climate/Change Impacts 29 of 46
? time interval
hourly,daily,weekly,monthly,seasonal
? carbon form
dry matter above ground,total plant
? radiation
intercepted/absorbed solar radiation
(SR) or PAR
Light Use Efficiency
Chapter 3
2012-3-21 Assessment of Climate/Change Impacts 30 of 46
? Monteith (1977),1.4gDM/(MJ ISR) for
seasonal canopy
? Gallagher and Biscoe (1978),3.0gDM/(MJ
APAR) for seasonal wheat and barley
? Unsworth et al,(1984),1.4gDM/(MJ ISR)
for measuring soybean
? Muchow and Coates (1987),2.1-
2.4gDM/(MJ IPAR) for seasonal sorghum
Light Use Efficiency
Chapter 3
2012-3-21 Assessment of Climate/Change Impacts 31 of 46
? Light distribution in canopy-- Beer’s law
I = Io exp(-k LAI)
LAI (Leaf Area Index),leaf models
LAI = sum of leaf area/surface area
k,extinction coefficient
? Depends on the canopy structure
Light Use in canopy
Chapter 3
2012-3-21 Assessment of Climate/Change Impacts 32 of 46
? Water use efficiency (water balance)
? Nutrient absorption
? Stress of environmental factors
(3) Relationships with environmental factors
Chapter 3
2012-3-21 Assessment of Climate/Change Impacts 33 of 46
? Process-based model
? Sensitivity analysis
? Calibration
? Validation
Examples,CERES,ALMANAC
Chapter 3
2012-3-21 Assessment of Climate/Change Impacts 34 of 46
CERES-crop family DSSAT
Crop-Environment Resource Synthesis
? Cereals,wheat,maize,rice,sorghum,etc,
? Grain legumes,soybean,alfafa,etc,
? Roots and tubers,cotton,potato,etc,
CERES
Chapter 3
2012-3-21 Assessment of Climate/Change Impacts 35 of 46
DSSAT
Decision Support System for Agrotechnology
Transfer
Developed by INSNAT (International
Benchmark Sites Network for
Agrotechnology Transfer)
19 conditions for crops,grass,shrubs and
trees
CERES
Chapter 3
2012-3-21 Assessment of Climate/Change Impacts 36 of 46
Inputs,
? Weather
? Soil
? Crop management
? Simulation control
CERES
Chapter 3
2012-3-21 Assessment of Climate/Change Impacts 37 of 46
Outputs,
? Yield
? Growth process
? Water use
? Nitrogen/carbon
? Pest
CERES
Chapter 3
2012-3-21 Assessment of Climate/Change Impacts 38 of 46
Simulation processes,
? Phenological development
? Extension growth of leaves,stems,and roots
? Biomass accumulation and partitioning
? Soil water balance and water use by crops
? Soil nitrogen transformations,uptake by
crops,and partitioning among plant parts
CERES
Chapter 3
2012-3-21 Assessment of Climate/Change Impacts 39 of 46
Agricultural Land Management
Alternatives with Numerical Assessment
Criteria
? Crops,grasses,shrubs,and trees
? Developed from EPIC (Erosion
Productivity Impact Calculator,
Environmental Policy Integrated Climate)
ALMANAC
Chapter 3
2012-3-21 Assessment of Climate/Change Impacts 40 of 46
Inputs,
? Weather,***.wth
? Soil
? Crop Parameters
? Tillage Management
? Simulation control,***.dat
ALMANAC
Chapter 3
2012-3-21 Assessment of Climate/Change Impacts 41 of 46
Outputs,
All output variables with different steps
****.out,
ALMANAC
Chapter 3
2012-3-21 Assessment of Climate/Change Impacts 42 of 46
Simulation processes,
? Phenological development
? Potential growth
? Water use
? Nutrient uptake,nitrogen,phosphorus
ALMANAC
Chapter 3
2012-3-21 Assessment of Climate/Change Impacts 43 of 46
? Growth constraints,5 stress factors
Water use- root growth stress
Crop yield- HI
Winter dormancy
Day length reduction
Frost damage
ALMANAC
Chapter 3
2012-3-21 Assessment of Climate/Change Impacts 44 of 46
? Tillage,
affecting bulk density
? Agriculture management
irrigation
fertilizer
lime
pesticide
ALMANAC
Chapter 3
2012-3-21 Assessment of Climate/Change Impacts 45 of 46
? Tillage,
affecting bulk density
? Agriculture management
irrigation
fertilizer
lime
pesticide
ALMANAC
Chapter 3
2012-3-21 Assessment of Climate/Change Impacts 46 of 46
Thanks
2012-3-21 Assessment of Climate/Change Impacts 1 of 46
3.4 Crop growth and its modeling
3.4.1 Components of plant growth
3.4.2 Empirical models
3.4.3 Process-based models
3.4.4 Case studies
Chapter 3
2012-3-21 Assessment of Climate/Change Impacts 2 of 46
3.4.1 Components of plant growth
(1) Development
(2) Dry matter accumulation
photosynthesis
respiration
water use
(3) Environmental constrains(stresses)
Chapter 3
2012-3-21 Assessment of Climate/Change Impacts 3 of 46
Crop Growth Models
? Classification
Empirical models
Process-based models
? Purpose
Simulation of crop growth
Crop growth management and risk
assessment
Component of land surface process modeling
Chapter 3
2012-3-21 Assessment of Climate/Change Impacts 4 of 46
3.4.2 Empirical Crop Models
? Larger time steps
? Statistical relationships
? Potential productivities
Chapter 3
2012-3-21 Assessment of Climate/Change Impacts 5 of 46
3.4.2 Empirical Crop Models
? Multiply method
? AEZ method(Agro-Ecological Zone,
FAO)
? Miami model-- NPP
Chap,3
Chapter 3
2012-3-21 Assessment of Climate/Change Impacts 6 of 46
Multiply method
Yp=E?(?Q)?f(t)?f(w)?HI
===========
E,radiation use efficiency
?Q,sum of radiation within growing season
f(t),modifying function of temperature
f(w),modifying function of water balance
HI,harvest index(ratio of economic yield to
biomass,0.35～ 0.45 for wheat,0.3～ 0.4 for
soybean
Chapter 3
2012-3-21 Assessment of Climate/Change Impacts 7 of 46
Multiply method
黄秉维,Yp ＝ 0.93× Q
Yp,photosynthetically potential productivity (kg/ha)
Q,solar radiation（ cal/cm2）
coefficient,0.93=α(1－ β)(1－ γ)(1-a)× b(1－ c)(1－ d)
× e/(1-δ)/(1-f)
α,percent of PAR,47％
β,transmission of solar radiation,5％
γ,percent of solar radiation absorbed by non-
photosynthecally organs,10％
Chapter 3
2012-3-21 Assessment of Climate/Change Impacts 8 of 46
Multiply method
a,reflectivity,6.5％
b,energy need for per unit carbohydrates
formed,10 Enstain/?g
c,8.6Enstain/cal
e,mass of per unit carbohydrates,3× 10－ 5g/?g
d,percent of dry matter for respiration,25％
f,percent of dry matter for non-organic,8％
δ:percent of plant moisture,15％
Chapter 3
2012-3-21 Assessment of Climate/Change Impacts 9 of 46
Multiply method—f(t)
Modified functions for temperature,
于沪宁 -赵丰收,
Ft＝ 4.301× 10-2?t-5.771× 10-4?t2
Chapter 3
2012-3-21 Assessment of Climate/Change Impacts 10 of 46
Multiply method—f(t)
李世奎,
0.027× t － 0.162 [6℃, 21℃)
0.086× t － 1.41 [21℃, 28℃ ）
Ft 温 ＝ 1 [28℃, 32℃ ）
-0.083× t+3.67 [32℃, 44℃ ）
0 （ t<6℃ ）（ 44℃ <t）
Exp.{-2[(t-t0)/10]2} (t<t0)
Ft 凉 ＝
Exp.{- [(t-t0)/10]2} (t>t0)
t,measured temperature
t0,optimal temperature
Chapter 3
2012-3-21 Assessment of Climate/Change Impacts 11 of 46
Multiply method—f(w)
孙慧南,
R/E0 R< E0
F(w) ＝ 1 R -E0 ≤runoff
< 1 R -E0 >runoff
R,rainfall
E0,evaporation from water
Chapter 3
2012-3-21 Assessment of Climate/Change Impacts 12 of 46
Multiply method—f(w)
李世奎,
(1-C)R/ETm (1-C)R < ETm
f(w)＝ 1 (1-C)R > ETm
C,runoff coefficient,0.2
R,rainfall
ETm,crop water requirement
Chapter 3
2012-3-21 Assessment of Climate/Change Impacts 13 of 46
Multiply method—f(w)
FAO,
F(w) ＝ Ky.（ 1-ETa/ ETm）
Ky,crop yield coefficient responding to
water supply
ETa,actual evaportranspiration
ETm,crop water requirements
Chapter 3
2012-3-21 Assessment of Climate/Change Impacts 14 of 46
AEZ method
Yp=[F?f(Y0)?Y0+(1-F)?f(Yc)?Yc]}
?CL?CN?HI?f(w)
===========
Y0, potential net dry matter in clear sky
Yc,potential net dry matter in overcast
F,modifying function for radiation
f(Y0),f(Yc),modifying function of temperature
Chapter 3
2012-3-21 Assessment of Climate/Change Impacts 15 of 46
AEZ method
CL,modifying coefficient for leaf area
index(LAI)
CN,modifying coefficient for respiration
HI,harvest index(ratio of economic yield
to biomass
f(w),modifying function of water balance
Chapter 3
2012-3-21 Assessment of Climate/Change Impacts 16 of 46
Reference crop evapotranspiration (ETo)
the evapotranspiration rate from a
reference surface,not short of water
The reference surface is a hypothetical
grass reference crop with specific
characteristics,
AEZ method
–crop water requirement
Chapter 3
2012-3-21 Assessment of Climate/Change Impacts 17 of 46
Crop evapotranspiration under standard
conditions (ETc)
the evapotranspiration from disease-free,
well-fertilized crops,grown in large fields,
under optimum soil water conditions,and
achieving full production under the given
climatic conditions
AEZ method
–crop water requirement
Chapter 3
2012-3-21 Assessment of Climate/Change Impacts 18 of 46
Crop evapotranspiration under non-
standard conditions (ETc adj)
the evapotranspiration from crops grown
under management and environmental
conditions that differ from the standard
conditions
AEZ method
–crop water requirement
Chapter 3
2012-3-21 Assessment of Climate/Change Impacts 19 of 46
3.1.3 Water Use
Chapter 3
2012-3-21 Assessment of Climate/Change Impacts 20 of 46
Miami model
NPP = min [f(t),f(P)]
f(t) = 3000/(1+exp(1.315-0.119t) g/m2 yr
f(p) = 3000(1-exp(-0.000664p)) g/m2 yr
NPP = 3000(1-exp(-0.0009695(ET-20)) g/m2 yr
===========
NPP,Net primary production
t,annual average temperature
p,annual rainfall
ET,annual evaportranspiration
Chapter 3
2012-3-21 Assessment of Climate/Change Impacts 21 of 46
3.4.3 Process-based Crop Models
? Smaller time steps,daily
? Processes of crop growth
? Statistical relationships for some
parameters and processes based on
experiments
Chapter 3
2012-3-21 Assessment of Climate/Change Impacts 22 of 46
(1) Phasic development simulation
(2) Physiological processes
(3) Relationships with environmental
factors
(4) Examples,CERES,ALMANAC
Components of the Process-based
Crop Models
Chapter 3
2012-3-21 Assessment of Climate/Change Impacts 23 of 46
Thermal time
HUI= GDD/PHU
Ecological form
leaves/day = f(t)
(1) Phasic development simulation
Chapter 3
2012-3-21 Assessment of Climate/Change Impacts 24 of 46
? Photoperiod,
leaf numbers
thermal time to tasseling
? Vernalization (0-8oC),
leaf numbers
? Maturity type
(1) Phasic development simulation
Chapter 3
2012-3-21 Assessment of Climate/Change Impacts 25 of 46
? Biomass accumulation by photosythesis
Leaf growth,function of biomass
accumulation
? Consumption of dry matter by
respiration
? Distribution of dry matter:root,leaf,
stem,etc,
(2) Physiological processes
Chapter 3
2012-3-21 Assessment of Climate/Change Impacts 26 of 46
? The ability of plants to harness energy
from the sun to fix atmospheric CO2 into
a range of more complex organic
molecules,
CO2+H2O— light→ CH2O+O2
Photosynthesis
Chapter 3
2012-3-21 Assessment of Climate/Change Impacts 27 of 46
Three separate components
? Light reactions
To generate light energy compounds ATP and NADPH
? Dark reactions
To form sugars through biochemical reduction of CO2
? Supply of CO2
to the site of reduction in the chloroplast
Photosynthesis
Chapter 3
2012-3-21 Assessment of Climate/Change Impacts 28 of 46
Light Use Efficiency
? Carbon formation by energy during a
time interval
Photosynthesis
Chapter 3
2012-3-21 Assessment of Climate/Change Impacts 29 of 46
? time interval
hourly,daily,weekly,monthly,seasonal
? carbon form
dry matter above ground,total plant
? radiation
intercepted/absorbed solar radiation
(SR) or PAR
Light Use Efficiency
Chapter 3
2012-3-21 Assessment of Climate/Change Impacts 30 of 46
? Monteith (1977),1.4gDM/(MJ ISR) for
seasonal canopy
? Gallagher and Biscoe (1978),3.0gDM/(MJ
APAR) for seasonal wheat and barley
? Unsworth et al,(1984),1.4gDM/(MJ ISR)
for measuring soybean
? Muchow and Coates (1987),2.1-
2.4gDM/(MJ IPAR) for seasonal sorghum
Light Use Efficiency
Chapter 3
2012-3-21 Assessment of Climate/Change Impacts 31 of 46
? Light distribution in canopy-- Beer’s law
I = Io exp(-k LAI)
LAI (Leaf Area Index),leaf models
LAI = sum of leaf area/surface area
k,extinction coefficient
? Depends on the canopy structure
Light Use in canopy
Chapter 3
2012-3-21 Assessment of Climate/Change Impacts 32 of 46
? Water use efficiency (water balance)
? Nutrient absorption
? Stress of environmental factors
(3) Relationships with environmental factors
Chapter 3
2012-3-21 Assessment of Climate/Change Impacts 33 of 46
? Process-based model
? Sensitivity analysis
? Calibration
? Validation
Examples,CERES,ALMANAC
Chapter 3
2012-3-21 Assessment of Climate/Change Impacts 34 of 46
CERES-crop family DSSAT
Crop-Environment Resource Synthesis
? Cereals,wheat,maize,rice,sorghum,etc,
? Grain legumes,soybean,alfafa,etc,
? Roots and tubers,cotton,potato,etc,
CERES
Chapter 3
2012-3-21 Assessment of Climate/Change Impacts 35 of 46
DSSAT
Decision Support System for Agrotechnology
Transfer
Developed by INSNAT (International
Benchmark Sites Network for
Agrotechnology Transfer)
19 conditions for crops,grass,shrubs and
trees
CERES
Chapter 3
2012-3-21 Assessment of Climate/Change Impacts 36 of 46
Inputs,
? Weather
? Soil
? Crop management
? Simulation control
CERES
Chapter 3
2012-3-21 Assessment of Climate/Change Impacts 37 of 46
Outputs,
? Yield
? Growth process
? Water use
? Nitrogen/carbon
? Pest
CERES
Chapter 3
2012-3-21 Assessment of Climate/Change Impacts 38 of 46
Simulation processes,
? Phenological development
? Extension growth of leaves,stems,and roots
? Biomass accumulation and partitioning
? Soil water balance and water use by crops
? Soil nitrogen transformations,uptake by
crops,and partitioning among plant parts
CERES
Chapter 3
2012-3-21 Assessment of Climate/Change Impacts 39 of 46
Agricultural Land Management
Alternatives with Numerical Assessment
Criteria
? Crops,grasses,shrubs,and trees
? Developed from EPIC (Erosion
Productivity Impact Calculator,
Environmental Policy Integrated Climate)
ALMANAC
Chapter 3
2012-3-21 Assessment of Climate/Change Impacts 40 of 46
Inputs,
? Weather,***.wth
? Soil
? Crop Parameters
? Tillage Management
? Simulation control,***.dat
ALMANAC
Chapter 3
2012-3-21 Assessment of Climate/Change Impacts 41 of 46
Outputs,
All output variables with different steps
****.out,
ALMANAC
Chapter 3
2012-3-21 Assessment of Climate/Change Impacts 42 of 46
Simulation processes,
? Phenological development
? Potential growth
? Water use
? Nutrient uptake,nitrogen,phosphorus
ALMANAC
Chapter 3
2012-3-21 Assessment of Climate/Change Impacts 43 of 46
? Growth constraints,5 stress factors
Water use- root growth stress
Crop yield- HI
Winter dormancy
Day length reduction
Frost damage
ALMANAC
Chapter 3
2012-3-21 Assessment of Climate/Change Impacts 44 of 46
? Tillage,
affecting bulk density
? Agriculture management
irrigation
fertilizer
lime
pesticide
ALMANAC
Chapter 3
2012-3-21 Assessment of Climate/Change Impacts 45 of 46
? Tillage,
affecting bulk density
? Agriculture management
irrigation
fertilizer
lime
pesticide
ALMANAC
Chapter 3
2012-3-21 Assessment of Climate/Change Impacts 46 of 46
Thanks
