dusik u tlu

Zed Rengel

Univ Western AustraliaPerth

Ukupna kolicina nitrata u tlu- u 1.5-m profilu tla -

Ukupna kolicina nitrata u tlu- u 1.5-m profilu tla -

Kolicina nitrata21 srpnja 74 46 3527 rujna 33 13 429 studenog 44 24 17

Dolling et al. 1995

Lupina psenica pasnjak

21 lipnja – 26 rujna 24 20 3

Ukupna kolicina ispranog nitrata, kg/ha

- dolje do 1 m u profilu tla -

Ukupna kolicina ispranog nitrata, kg/ha

- dolje do 1 m u profilu tla -

------------------------------ kg/ha -----------------------------

Heterogenost concentracije nitrata u tlu- blok 5 m × 5 m × 5 m, mali blok od 25 cm x 25 cm x 25 cm -

mg/kg

mg/kg

Nakon 41 dana rasta

Lupinus pilosus Lupinus angustifolius

L. angustifolius

0.0

0.1

0.2

0.3

*

L. pilosus Uniformno visoka opskrba nitratima(1500 / 1500 µM)

Razlicita opskrba nitratima(1500 / 250 µM)

Rat

a pr

iman

jani

trat

a(µ

mol

m-2

s-1 )

Plitki korijeni

Kompenzacija u primanju nitrata, L. angustifolius- rata primanja plitkim korijenima opskrbljenih visokom koncentracijom nitrata -

Dunbabin, Rengel & Diggle 2001 Aust J Agric Res 52, 505-512.

L. angustifolius

0.0

0.1

0.2

0.3

**

L. pilosus

Rat

a pr

iman

jani

trat

a(µ

mol

m-2

s-1 )

Duboki korijeni


Uniformno visoka opskrba nitratima(1500 / 1500 µM)


Kompenzacija u primanju nitrata, L. angustifolius- rata primanja dubokim korijenima opskrbljenih visokom koncentracijom nitrata -

L. angustifolius

0.00

0.02

0.04

0.06

*

L. pilosus

0.01

0.03

0.05


Kompenzacija u primanju nitrata, L. angustifolius- rata primanja plitkim korijenima opskrbljenih niskom koncentracijom nitrata -

Uniformno niska opskrba nitratima(250 / 250 µM)


Rat

a pr

iman

jani

trat

a(µ

mol

m-2

s-1 )

Plitki korijeni

1

1.2

1.4

1.6

1.8

2

2.2

L. angustifolius

Duboki korijeni Plitki korijeniU

odn

osu

nabi

ljeop

skrb

ljene

unifo

rmni

nni

trat

ima

Kompenzacija rasta korijena, L. pilosus

Rata rasta Broj novihlaterala

L. pilosus

Rata rasta Broj novihlaterala

0.8

Pov

ecan

jeS

man

jenj

e

Visoka opskrbljenost plitkih korijena nitratima,niska opskrbljenost dubokih korijena nitratima


Biljke su bile stare 21 dan na pocetku tretmana,Rast nakon 9 dana

Kratak opis modela

Koristenje modela za istrazivanje rastakorijena i primanja nitrata

u heterogenom tlu

Komponenta modela za reakciju korijena

Koristenje modela u simulaciji poljskihpokusa

ROOTMAP3-D model arhitekture

korijena

Modul za voduDrenaza, redistribucija, evaporacija, primanje

Modul za hranivaIspiranje, masovni tok,

difuzija, primanje

Modul za distribucijuresursa

Kontrolira rast korijena i primanja hraniva na bazi

isplativosti ulaganja

Model koji simulira reakciju pojedinacnih korijena, kaoi cijelog korijenovog sistema, u odnosu na opskrbu

asimilatima koja varira u prostoru i vremenu

Dunbabin, Diggle, Rengel & Van Hughten 2002. Plant Soil 239, 19-38.

Vanjska opskrbaresursima

(npr. nitrati, voda)

Potraznja na nivou cijele biljke

(bazirana na resursima koji su naraspolaganju za koristenje u biljci)

Lokalni signalikoji pokazujupotencijalnu

opskrburesursima

Lokalni interni zahtjevi zaresursima

Opskrba asimilatima za rast i odrzavanje, ovisno o lokalnojakviziciji resursa i prioritetima

Stvarna reakcija kroz primanjehraniva ili rast biljke (ovisno o

resursima) bazirana na opskrbii potrebama

Lokalni opskrbni sistem

(korijeni, korijenove kvrzice, stabljika)

Osnovnametodologija modela

Dunbabin, Diggle, Rengel & Van Hughten 2002. Plant Soil 239, 19-38.

Kratak opis modela


u heterogenom tlu



lokalni volumens visokimnitratima

nitrat = ljubicasta voda = svjetlo plava nitrati + voda

Lokalnivolumensuhog tla

Lokalni volumens visokimnitratima


Pocetni profil tla


Lokalni volumens visokimnitratima

Ne-reagirajucikorijenov sistem kojiraste na osnovu pre-

definiranih pravila

Ispiranje nitrata u profilu tla nakonuzastopnih kisa

Korijenovi sistemkoji reagira nalokalni okolis

Kratak opis modela


u heterogenom tlu



y = 0.97x

r2 = 0.90

0

0.5

1

1.5

2

2.5

3

3.5

0.0 0.5 1.0 1.5 2.0 2.5 3.0 3.5

Gustoca korijena

Poljski pokusi (cm/cm3)

Mod

elira

nipo

daci

(cm

/cm

3 )

y = 0.96x

r2 = 0.86

0

2

4

6

8

10

12

14

0 2 4 6 8 10 12 14

Sadrzaj nitrata u tlu

Poljski pokusi (kg nitrate/ha)

Mod

elira

nipo

daci

(kg

nitr

ate/

ha)

Korelacija izmedju

modeliranih i poljskih

podataka

L. angustifolius je rasla na polju

1995 i 1996

Dunbabin, Diggle & Rengel 2002. Plant Soil 239, 39-54.

Gustoca korijena (cm/cm3)

0

20

40

60

80

100

120

140

0 2 4

146 DAS

0 2 40

20

40

60

80

100

120

140108 DAS

0

20

40

60

80

100

120

140

0 1 2

Field Data

Modelled data

79 DAS

Dub

ina

(cm

)

DAS=dana nakon sijanja

Rast korijena simuliran modelom- L. angustifolius (rasla na polju 1996) -


0

20

40

60

80

100

120

140

0 5 10 15

Poljski podaci

Modelirani podaci

86 DAS

0

20

40

60

80

100

120

140

0 5 10 15

106 DAS

0

20

40

60

80

100

120

140

0 5 10 15

217 DAS

Sadrzaj nitrata (kg NO3--N/ha)

Dub

ina

(cm

)

DAS=dani nakon sijanja

Nitratni profili simulirani modelom- L. angustifolius (rasla na polju) -


0.04

0.08

0.12

0.16

25 75 125 175 225

0 - 10 cm dubina

0.04

0.08

0.12

0.16

25 75 125 175 225

120 - 150 cm dubina

Dani nakon sijanja

Kol

icin

avo

deu

tlu(v

/v)

Poljski podaci

Modelirani podaci

Profil vode tla simularog modelom- L. angustifolius (rasla na polju 1996) -


0.04

0.08

0.12

0.16

25 75 125 175 225

30 - 50 cm dubina

Izvor/sink za nitrate

1995

32

Lupina: primanje -21

Capeweed: primanje -0

mineralizirano 60

ispiranje -32 (-35)

zavrsno 39

1996

57

-26

-28

69

-26 (-23)

46

pocetni

Nitratni budget simuliran modelom- u 1.5 m simuliranog profila -

Dunbabin, Diggle & Rengel 2002. Plant Soil 239, 39-54.Izmjereno i objavljeno: Anderson et al. 1988

------ kg nitrata / ha ------

Kratak opis modela


u heterogenom tlu



Riblja kost razgranati

Plasticnost rasta korijena

Relativna efikasnost primanja nitrata

Staticnaopskrbanitratima

Dinamicnaopskrbanitratima

1 1.1 1.2 1.3 1.4 1.5 1.6 1.7

Plasticnost rasta korijena

Plasticnost primanjanitrata

Plasticnost primanjanitrata

1 1.1 1.2 1.3 1.4 1.5 1.6 1.7

Riblja kost razgranat

Simulirana efikasnost primanja nitrata za razne arhitekture korijena- plasticitet primanje nitrata ili plasticitet rasta korijena je bio onemogucen -

Dunbabin, Rengel & Diggle (2004). Func. Ecol. 18, 204-211

0

0.2

0.4

0.6

0.8

1.0

1.2

1.4

Riblja kost (fina)L. angustifoliusriblja kost (fina)

L. pilosus(duboka)

L. pilosus(plitka) highly branched

Dub

ina

(m)

Modelirane arhitekture korijena

Razne arhitekture su identicne po ‘troskovima’ (tj. ista kolicina asimilata je koristena)

(s istim volumenom korijena)

Dunbabin, Diggle & Rengel (2003). Plant Cell Environ. 26, 835-844

Dani nakon sijanja

0

10

20

30

40

0 7 14 21 28 35 42 49 56 63 70 77 84 91 98 105

Izmjerene padaline u Moora 1995 (Anderson et al., 1998)

0

10

20

30

40

0 7 14 21 28 35 42 49 56 63 70 77 84 91 98 105

Ista ukupna kolicina kao i u primjeru abore, ali pljuskovi su odgodjeni za kasnije u sezoni

-1

Primanje nitrata raznim arhitekturama korijena

Riblja kostdebela

Riblja kostfina

L. angustifoliusdebela

L. angustifoliusfina

L. pilosusduboka

L. pilosusplitka

Highly branched

Smanjenje dubine zakorijenjivanja, povecanje gustoce korijena

11

14

17

20

23

26

29

Primanje nitrata (L)

E=rani pljuskovi u sezoniL=pljuskovi kasnije u sezoni

108 dana nakon sijanja Dunbabin, Diggle & Rengel (2003). Plant Cell Environ. 26, 835-844

Primanje nitrata (E)

Totalna primljena kolicina

-1

11

14

17

20

23

26

29

Isprani nitrati (E)


Isprani nitrati (L)

E=rani pljuskovi u sezoniL=pljuskovi kasnije u sezoni

Ispiranje nitrata - razne arhitekture korijena -Totalna isprana kolicina

Riblja kostdebela

Riblja kostfina

L. angustifoliusdebela

L. angustifoliusfina

L. pilosusduboka

L. pilosusplitka

Highly branched

Smanjenje dubine zakorijenjivanja, povecanje gustoce korijena

108 dana nakon sijanja

-2-1


Rata primanja po povrsini korijena

0

2

4

6

0 20 40 60 80 100

L. pilosus (plitak)

L. pilosus (dubok)

E=rani pljuskovi u sezoni(izmjereno u Anderson et al 1988)

Dani nakon sijanja



0

2

4

6

0 20 40 60 80 100

Riblja kost (fina)

Highly branched

-2-1

Rata primanja po povrsini korijena

Dani nakon sijanja


E=rani pljuskovi u sezoni(izmjereno u Anderson et al 1988)

Zakljucci

Sistemi opskrbe/potreba (supply/demand) se mogu koristiti zasimuliranje reakcija korijena na okolis

Kapacitet simuliranja reagirajuceg korijenovog sistemaomogucava studiranje interakcija izmedju korijena i heterogenog okolisa

Rast korijena, primanje nitrata i sadrzaj vode su uspjesnomodelirani u sistemu lupina-tlo

Uspjeh u primanju nitrata je balans izmedju brzine akvizicije i velicine ukupnog volumena eksploatiranog tla s jedne strane I brzine ispiranja nitrata s druge

Dr Vanessa Dunbabin (UWA, now Univ Tasmania)Dr Art Diggle (State Dept of Agric)

Acknowledgements

2-2.5

1.5-2

1-1.5

0.5-1

0-0.5

42 days after sowing

Root length density

(cm/cm3)

*

*

*

*12-15

9-12

6-9

3-6

0-3

92 days after sowing

*

*

*

*

50-60

40-50

30-40

20-30

10-20

0-10*

*

*

*

Nitrate leached (kgNO3

--N/ha)

50-60

40-50

30-40

20-30

10-20

0-10

*

*

*

*

Root length density and cumulative nitrate leached after the main rainfall event- four L. angustifolius plants grown in the field in 1996 -

750/750 250/250

Nitrate concentration in upper/lower compartment, µM

250/750 750/250

L. angustifolius

0

5

10

15

20

25

30

35 shallow roots

deep roots

Root growth as influenced by the nitrate supply- first order laterals -

250/750

L. pilosus

0

5

10

15

20

25

30

35

750/750 250/250 750/250

Roo

t gro

wth

(cm

day

-1)

Dunbabin et al. 2001. Aust J Agric Res 52, 495.

21-d-old plants at t=0,growth after 9 days.

750/750 250/750 250/250 750/250

Nitrate concentration in upper/lower compartment, µM

L. angustifolius

0

2

4

6

8

10

12

14 shallow roots

deep roots

Root growth as influenced by the nitrate supply- second order laterals -

250/750 750/250

Roo

t gro

wth

(cm

day

-1)

Dunbabin et al. 2001. Aust J Agric Res 52, 495.

16L. pilosus

750/750 250/2500

2

4

6

8

10

12

14

16

21-d-old plants at t=0,growth after 9 days.

0

5

10

15

20

25

30

35

40

250/750 250/250 750/250 750/750 750/750 250/750 250/250 750/250

Experimental data

Modelled data

upper root system

lower root system

Nitrate supply in upper/lower compartment (µM)

Roo

t gro

wth

(cm

day

-1)

Modelling root growth of L. pilosus- first order laterals -

Dunbabin et al. 2002. Plant Soil 239, 19.

0

0.05

0.1

0.15

0.2

0.25

0.3

750/750 750/250 1500/1500 1500/250 750/750 250/750 1500/1500 250/1500

upper root system lower root system

Experimental data Modelled data

Modelling nitrate uptake by L. angustifolius- in the high nitrate patch when split-nitrate supply -

Nitrate supply in upper/lower compartment (µM)

Nitr

ate

upta

ke r

ate

(µm

ol m

-2s-

1 )

Dunbabin et al. 2002. Plant Soil 239, 39.

.

Parameter description Symbol L. angustifolius L. pilosus Units

root radius 0 a0 1.0 0.8 mm



unit N growth rate 0* µgN0 0.08 0.08 µm mol-1 s-1



unit nN growth rate 0* µgnN0 3.5 4.2 µm mol-1 s-1



unit N branch density 1* µbN1 5.9 3.5 branches m -1 mol-1

unit N branch density 2* µbN2 2.1 3.5 branches m -1 mol-1

unit nN branch density 1* µbnN1 0.42 1.2 branches m -1 mol-1

unit nN branch density 2* µbnN2 0.42 0.42 branches m -1 mol-1

branch lag time 0 Tbl0 192 216 h

branch lag time 1 Tbl1 528 291 h

initial branch angle θ 90 90 deg

deflection index D 0.25 0.25 unitless

unit N fix* µfix 0.05 0.05 mol nodule-1 s-1

unit nodule cost* µnodm 0.075 0.075 mol nodule-1

unit nodule growth rate* µnodg 9 9 nodule mol-1

total seed reserve (N+nN)see

d

56 265 mol

N down regulation factor ω 1.6 1.1 unitless

max. N net influx rate Fmax 5.3 2.6 nmol m-2 s-1

kinetic constant Km 0.119 0.115 mol m-3

poten. transpiration rate Tmax 2.55*10-8 1.89*10-8 m3 m-2 s-1

Parameters used in the model for simulation of lupin root growth and nutrient uptake in nutrient solution (determined by parameter fitting and from experimental data) for three orders of branching: tap root (0), primary laterals (1), secondary laterals (2). The branch lag time = the time lag before a branch will grow (eg. a primary lateral) from a node on the previous branching order (eg. the tap root).

Parameter description Symbol L. angustifolius Units

root radius 0 a0 1.0 mmroot radius 1 a1 0.5 mmroot radius 2 a2 0.3 mmroot radius 3 a3 0.2 mmunit N growth rate 0* µgN0 0.08 µm mol-1 s-1

unit N growth rate 1* µgN1 0.12 µm mol-1 s-1



unit nN growth rate 0* µgnN0 3.5 µm mol-1 s-1




branch spacing 0 µbN0 8 mmbranch spacing 1 µbN1 8 mmbranch spacing 2 µbnN0 5 mmbranch spacing 3 µbnN1 5 mmbranch lag time 0 Tbl0 192 hbranch lag time 1 Tbl1 528 hbranch lag time 2 Tbl1 528 hinitial branch angle θ 90 degdeflection index D 0.25 unitlessunit N fix* µfix 0.05 mol nodule-1 s-1

unit nodule cost* µnodm 0.075 mol nodule-1

unit nodule growth rate* µnodg 9 nodule mol-1

total seed reserve (N+nN)se

ed

56 mol

maximum N net influx rate Fmax 5.3 nmol m-2 s-1

kinetic constant Km 0.119 mol m-3

potential transpiration rate Tmax 2.55*10-8 m3 m-2 s-1

displacement dependentdispersivity

ε 30 mm

nitrate diffusion coefficient D 1.9*10-9 m2 s-1

Parameters used in the model for simulation of lupin root growth and nutrient uptake in soil [4 orders of branching: tap root (0), primary laterals (1), secondary laterals (2) and tertiary laterals (3)]. The branch lag time represents the time lag before a branch will grow (eg. a primary lateral) from a node on the previous branching order (eg. the tap root).

* represents those parameters previously calibrated in the model through simulating nutrient solution experiments.

Field data were used only to initialise the environmental variables required by the model, eg. soil bulk density, initial soil water contents, drained upper limit and wilting point parameters and rainfall

Model Output

The intensity of the bluebackground shows the water content and the black dotsblack dotsrepresent the nitrate content in soil

Model OutputL. angustifolius

plants growing in sandy soil

The intensity of the blue backgroundshows the water content and the black dotsblack dotsrepresent the nitrate content in soil

Model OutputL. angustifoliusplants growing in sandy soil

The intensity of the bluebackgroundshows the water content and the intensity of pinkcolour (also black dotsblack dots) represent the nitrate content in soil

initial soil profile

local high nitrate patch

root systems responding to their local environment

nitrate leaching through soil profile after successive rain events

local dry patch

- root elongation rate

- branching density

- duration of apical non-branching

- soil resistance

- time of appearance of each branching order

- axis initiation parameters

- direction of branching

φ

γφ = angle of deflection

γ = orientation of deflection

old direction

new direction

Root branching

1

65

3

4

2

7

node

pointers

nullΩ

Ω

ΩΩΩΩ

ΩΩ

Ω

Ω Ω

Ω

Extensible tree: data structure to store information on root architecture

∆π π π

C C CI

4 D f1

1

1 r RL

1

r RLL L L0

n

L 02

v 02

v

= − = − −−

Θ

If the influx, In, is known, the driving force for the diffusive flux can be calculated

CL = average soil solution concentration of the bulk soil

CL0 = solution concentration at the root surface

RLv = root length density

θ = volumetric soil water content

DL = diffusion coefficient in water

f = tortuosity factor

r0 = root radius

b∂ CL∂ t = 1r

∂∂ r rDeb∂ CL∂ r + v

0r0C

L

CL = soil solution concentration in the bulk soil v0 = water flux across the soil-root interface

De = effective diffusion coefficient in soilb = buffer power

r = radial distance from the root axis r0 = root radius

Transport equation

incorporating diffusion and mass flow

-

-1

Uptake of nitrate by various root architectures

herringbonecoarse

herringbonefine

L. angustifoliuscoarse

L. angustifoliusfine

L. pilosusdeep

L. pilosusshallow

dichotomous

decreasing rooting depth, increasing rooting density

11

14

17

20

23

26

29

nitrate uptake (L)

nitrate leached (E)

E=high leaching events early in the seasonL=high leaching events late in the season

at 108 days after sowing Dunbabin, Diggle & Rengel (2003). Plant Cell Environ. 26, 835-844

nitrate leached (L)

nitrate uptake (E)

ENGINE

StaticEnvironment

Processes

Scoreboard

Clock

A B C DE F1234567

Scoreboard Display Module

(Spreadsheet-like)

Manager Module

Bulk Density Module

Wilting Point

Graphics Display Module

NitrateModule

WeatherModule

DynamicProcesses

ExternalControlModule

PlantModule

Plant2

Plant1

Plant3

Model structure

Engine interacts with modules, with modelling activities synchronised by the clock.

The scoreboard represents the simulation volume, containing all 3-D parameter values.

-2-1

Uptake of nitrate by various root architectures


Uptake rate per surface area

0

2

4

6

0 20 40 60 80 100

L. pilosus (shallow)

L. pilosus (deep)

Herringbone (fine)

dichotomousx

….

E=high leaching events early in the season (as measured by Anderson et al 1988)

Nitrate leaching from topsoilcauses topsoil acidification

Change in soil pH

Lupinus angustifolius

0.20.0-0.2-0.4-0.6

Trifolium subterraneum

0.20.0-0.2-0.4-0.6

80

60

40

20

0

Dep

th (

cm)

Tang, Raphael, Rengel & Bowden 2001 Aust J Soil Res 38, 837-849.

Simulating nitrate uptake efficiency of root architectures

1.8(±0.11)

herringbone

0.78(±0.21)

highly branched

Relative nitrate uptake efficiency

Averaged over 30 simulations and 5 replicates

(dynamic/static nitrate supply)

Dunbabin, Rengel & Diggle (2003). In: Innovative Soil-Plant Systems for Sustainable Agricultural Practices, pp.2-16.

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