Inleiding na “AquaCrop”

1.Inleiding na “AquaCrop”

Training modules

Food and Agriculture OrganizationLand and Water Division

February 2010 prepared by Dirk Raes

Simulasie is deur ‘n wiskunde model gedoen

Simulasie as “tool” om riglynne te maak

Eenvoudige voorstel van ‘n presies sistem

Deel van die realitiet dat die ingenieur will hê

Sistem: grond-plant-atmofeer kontinuum (SPAC)

atmosfeer

plant

grond

irrigationrainfall

capillaryrise

deeppercolation

evapo-transpiration

runoff

kan vinnig bestuur van lande beplan toets goeie strategie in ander plekke / gewasse formuleer gids

Verduideliking van model (SPAC)

Kalibrasie/Validasie

Veldproewe

Kalibrasie/Validasie van model

Om opbrengs teen water te evalueer

irrigation (I)rainfall (P)

capillaryrise deep

percolation

sto

r ed

so

il w

at e

r (m

m)

field capacity

threshold

wilting point

evapo-transpiration

(ET)

(CR)

(DP)0.0

Om opbrengs teen oor water te meetVoor goeie voorstelle kan gemaak word, proewe moet oor aantal jare (met verskillende klimaat); ‘n reeks plant datuums; verkillende omgewingtoestande ens gedoen word.

Soek ‘n model wat kan: is gebaseer op akuraat plantphisiologiese & grondwater balans & prosese

AquaCrop maak gebruik van ‘n relatiewe klien hoeveelheid parameters (explicit and mostly intuitive) en probeer om balans tussen eenvoudigheid, akuraatheid en ‘robustness’ te vind.

model om gewas opbrengs reaksie met water te skat

benoodig net beskikbare insette (klimaat, grond, gewas & velddata)

is maklik om te gebruik

kan maklike geverifikeer word (eenvoudig veld meetings simulasie resultate)

is toepaslike oor bree veld met aanvaarbaar akuratheid

tyd

1. Gewas Ontwikkeling

Blaardak groei

maksimum blaardak bedekking blaardak

verouderingbogrond

ondergrondopervlakte

Wortelzoon toeneem

maksimum “effektiewe” worteldiepte is bereik

In plaas van BlaarAreaIndeks (Leaf Area Index) (LAI)

AquaCrop gebruik groenblaardakbedekking (green canopy cover) (CC)

CC = Grond oppervlakte bedek deur groenblaardak

eenheid grond oppervlakte area

Reeks van 0 (skoon grond opervlakte) na 1 (volle blaardakbedekking)

0 % 100 %

eenheid grond oppervlakte area

Grond oppervlakte bedek deur

groenblaardak

Canopy Cover / Blaardak meeting ?

Neem oorhoofse

foto

Meet CC van af foto (sagtewaarde)

groenblaardakbedekking(CC)

3 %19 %

75 %

90 %

Winterkoring (Walshoutem, Belgium)

20 Oktober 2008

16 Maart 2009

14 April 2009

12 Mei 2009

Blaardak ontwikkeling (geen stremming nie)

Gewas karakteries (insette)

maksimum blaardak

veroudering

logisties vergelyking

Groei siklus (dae) plant Volwasse gewas


capillaryrise deep

percolation

sto

red

so

il w

at e

r (m

m)

field capacity

threshold

wilting point

evapo-transpiration

(ET)

(CR)

(DP)0.0

Water stremming(bo) drumpel

1

3

Blaar groei

Blaardak veroudering

FC

PWP


capillaryrise deep

percolation

sto

red

so

il w

at e

r (m

m)

field capacity

threshold

wilting point

evapo-transpiration

(ET)

(CR)

(DP)0.0

Blaar groei


CCBlaardak ontwikkeling

Wortel ontwikkeling

Zr

tyd

tyd

Grond water balans

Blaardak ontwikkeling(geen waterstreming)

Blaardak ontwikkeling(werklike grondwater toestande)

Groen Blaardak Bedekking

time

1

24

5

simulationGrondwater balans

reggestel blaardak bedekking vir waterstreming

3CC

Tyd


capillaryrise deep

percolation

sto

red

so

il w

at e

r (m

m)

field capacity

threshold

wilting point

evapo-transpiration

(ET)

(CR)

(DP)0.0

Blaar groei



Wortel ontwikkeling

Zr

tyd

tyd

Grond water balans

2. Gewas Transpirasietranspirasie


Transpirasie = Kcb x ETo

geen waterstremming nie

Verwysings-evapotranspirasie

gewaskoeficient

weer toestande

Karakter van transpiring gewas

Verdampings krag van atmosfeer

gewas karakteries (integrasie van efekte van karakter waar gewas verskil van verwysingsgras)

groenblaardakbedekking = CC


capillaryrise deep

percolation

sto

red

so

il w

at e

r (m

m)

field capacity

threshold

wilting point

evapo-transpiration

(ET)

(CR)

(DP)0.0

Blaar groei



Wortel ontwikkeling

Zr

tyd

tyd

Grond water balans

Tr = Kcb ETo

CC


capillaryrise deep

percolation

sto

red

so

il w

at e

r (m

m)

field capacity

threshold

wilting point

evapo-transpiration

(ET)

(CR)

(DP)0.0

Water stremming(bo) drumpelpunt

1

3

Blaar groei


FC

PWP

stomata sluiting2


capillaryrise deep

percolation

sto

red

so

il w

at e

r (m

m)

field capacity

threshold

wilting point

evapo-transpiration

(ET)

(CR)

(DP)0.0

Blaar groei



Wortel ontwikkeling

Zr

tyd

tyd

Grond water balans

CC

stomata sluiting

Tr = Ks Kcb ETo

H O2

CO2

2. Gewas Transpirasie3. Biomassa produksie

Plantblare absorbeer CO2 van uit atmosfeer deur gaatjies genoem stomata / huidmondtjies en, selfde tyd, water verdamp van blare in proses genoem transpirasie. Fotosintesis verander die geabsorbeerde CO2 na koelhidrate wat bousteen van die plant biomassa is.


Daar is ‘n stabel & konserwetiewe verhouding tussen

B:

bo

gro

nd

bio

mas

sa (

kg/m

2)

Σ(Tr) : kumulatiewe gewas transpirasie (mm water)

WP

Biomassa (B) & kumulatiewe transpirasie ( Σ(Tr) )

biomassa waterproduktiewiteit

kg(biomass) / m2.mm(water)

ETc (mm x 1000)0.0 0.3 0.6 0.9

Bio

ma

ss

(kg

m-2

)

0

1

2

3

SorghumSunflowerChickpeaWheat

Σ(Tr) mm x 1000

Verdeel Tr deur EToWP is genormaliseer vir klimaat

WP WP*

(T/ETo)

0 40 80 120 160

Ab

ove

-gro

un

d b

iom

ass (

g m

-2)

0

1000

2000

3000

Sunflower N0

WheatChickpea

Sunflower N1

Sorghum N0

Sorghum N1

Data from Steduto & Albrizio, 2005, Agric. & For. Meteor. Σ(Tr/ETo)

WP

WP*

WP*

Gewasgroepe met dieselfde WP*

C3: WP* = 15 - 2

0 g/m2

C4: W

P* = 3

0 - 3

5 g/

m2

For spesiefiek klimaat toestande

WP* vir mielies

Data from ICASA, IAEA & UniMelb

0

5000

10000

15000

20000

25000

30000

35000

0 20 40 60 80 100 120

Bio

mas

sa (k

g/h

a)

(ETa/ETo)

China99Ghana01Hawaii83Hungary 0NHungary 175 kgN/haGainesville irrigated 400NSpain96Full irrigationSpain96 50%irriC4 29kg/ha.mm line

Mielies

Σ(Tr/ETo)


capillaryrise deep

percolation

sto

red

so

il w

at e

r (m

m)

field capacity

threshold

wilting point

evapo-transpiration

(ET)

(CR)

(DP)0.0

Blaar groei



Wortel ontwikkeling

Zr

tyd

tyd

Grond water balans

CC

stomata sluiting

Water Produktiewetiet

B = WP* x Σ ( )

WP*

TrETo

Tr = Ks Kcb ETo

Biomassa

1. Gewas ontwikkeling

2. Gewas Transpirasie3. Biomassa produsie

4. Opbrengs formulasie


capillaryrise deep

percolation

sto

red

so

il w

at e

r (m

m)

field capacity

threshold

wilting point

evapo-transpiration

(ET)

(CR)

(DP)0.0

Blaar groei



Wortel ontwikkeling

Zr

tyd

tyd

Grond water balans

CC

stomata sluiting

Water Productivity

B = WP* x Σ ( )

WP*

TrETo

Tr = Ks Kcb ETo

Biomassa

Biomassa

B = totaal bogrond biomassa stam, blare, blomme, graan, …

Harvest Index (HI) = (oesindeks)fraksie van B wat die oesbare produk is

Opbrengs

Y


capillaryrise deep

percolation

sto

red

so

il w

at e

r (m

m)

field capacity

threshold

wilting point

evapo-transpiration

(ET)

(CR)

(DP)0.0

B = WP* x Σ ( )

Canopy development

Root development

BiomassaZr

time

soil water balanceWP* Water

Productivity

leaf expansion

canopy senescence

root zone exapansion

Y

Harvest Index

Opbrengs

Tr = Ks Kcb ETo

TrETo

time

CC

CC

HI

stomatal closure


2. Gewas transpirasie3. Biomassa produksie

4. Opbrengs formalasie

5. Insetdata

ETo (reference evapotranspiration)

grass reference surface(well watered, optimal growing)

ETo calculatorETo computed from meteorological datawith the FAO Penman Monteith equation


Rainfall

Air temperature (Tmin and Tmax)


Rainfall

Air temperature (Tmin and Tmax)

[CO2] (for future climates)

1990 2000 2010 2020 2030 2040 2050 20600

100

200

300

400

500

600

year

CO2 concentration (ppm)

Affects:- Crop development- Crop transpiration- Biomass production- Harvest Index

Crop characteristicsCanopy development (non-limiting conditions)

WP*

Crop characteristics

Cotton, Maize, Paddy Rice, Potato, Quinoa, Soybean, Tomato, Sunflower, Sugarbeet, Wheat

Calibrated crops

Canopy development (non-limiting conditions)

local callibration (variety, sowing density)

adjust

Soil characteristicsirrigation (I)

rainfall (P)

capillaryrise deep

percolation

sto

red

so

il w

at e

r (m

m)

field capacity

threshold

wilting point

evapo-transpiration

(ET)

(CR)

(DP)0.0

saturationfield capacity

wilting point

saturated hydraulic conductivity

Indicative valueshttp://hydrolab.arsusda.gov/soilwater/Index.htm

Irrigation schedule• when• how much

Irrigation management

Irrigation method

Generate irrigation schedule• when = time criterion• how much = depth criterion

Field management

Field surface practices

Field management

Field surface practices Mulches

Field management

Field surface practices

Level of soil fertility

Mulches

– non limiting– near optimal– moderate– poor

Automatic adjustment of crop development

The model is useful to develop irrigation strategies under water deficit conditions to study the effect of location, soil type, sowing date, … to study the effect of various land management techniques, to predict climate change impacts on crop production, etc.

rainfed irrigation

conditions


2. Gewas transpirasie3. Biomassa produksie

4. Opbrengs formalasie

5. Insetdata

6. Beperkende faktore

6. Beperkende faktoreirrigation (I)

rainfall (P)

capillaryrise deep

percolation

sto

red

so

il w

at e

r (m

m)

field capacity

threshold

wilting point

evapo-transpiration

(ET)

(CR)

(DP)0.0

waterkwaliteit

uniformheid van landerye jaarlikse gewasse

Inleiding na “AquaCrop”

Documents

Transcript of Inleiding na “AquaCrop”