E. Priesack and S. Gayler

Workshop Halle 18.-20.Sept. 2005

Modelling Soil-Plant-Atmosphere Interactions of the long-term experiment

Bad Lauchstädt

Originally Expert-N is an agro-ecosystem model which can be applied to consult farmers to

• optimize (N-) fertilization

• predict crop growth

• understand dynamics of agro-ecosystems

• avoid groundwater pollution by nitrate

• reduce nitrous oxide emissions

Rooted Zone

Groundwater

Unsaturated Zoneleaching

Lateral Flow

Lateral Flow

Water BalancePrecipitation

Infiltration

Evaporation

Interception Run off

Transpiration

Root WaterUptake

capillary rise

root zone

groundwater

unsaturated zone

N-fixation

organic fertiliser

mineral fertiliser

nitrification

NH4+ NO2

- NO3-

organic N

mineralisation

immobilisation

N removed by harvesting

NH3 N2 N2ONOx

volatilisation denitrification

NO3- - leaching

lateral transport

lateral transport

Nitrogen Balance

N-deposition

Model application needs input data about

• basic soil parameters

• climatic and weather conditions

• land use management

Expert-N Datamanagement

ASCII

interface

Expert-N Simulatorsystem control process calculation

graphical

output

ASCII

output

ASCII

interface

SQL interface

ASCII

interface

External geographic data

GIS ArcView

SQL interface

Manual data input

Expert-N DatabaseSimulation-Objects / MSWD-Library

ASCII

interface

External data storage

Litter

Manure Humus

ManureSurfmanure

roots

LitterSurfresidues mineralisation

added organic matter

Soil Organic Matter Pools Mineralisation Module

according to the model SOILN (Johnsson et al. 1987)

Wetter Bad Lauchstaedt (1902 – Wetter Bad Lauchstaedt (1902 – 2002)2002)

Bodenhorizonte Profil 1Bodenhorizonte Profil 1

PflanzendatenPflanzendaten

MineraldüngungMineraldüngung

Organische DüngungOrganische Düngung

BodenbearbeitungBodenbearbeitung

SimulationsobjekteSimulationsobjekte

Expert-N Model ConfigurationExpert-N Model Configuration

daily CO2 emission

0

5

10

15

20

25

30

35

40

27.08

.200

3

16.10

.200

3

05.12

.200

3

24.01

.200

4

14.03

.200

4

03.05

.200

4

22.06

.200

4

11.08

.200

4

30.09

.200

4

19.11

.200

4

08.01

.200

5

kg(C

O2-

C)/

(ha*

d)

d_CO2_Em

Reihe2

Mineralisation Model Mineralisation Model CalibrationCalibration

DC

0102030405060708090

100

08.08.1997 21.12.1998 04.05.2000 16.09.2001 29.01.2003 12.06.2004

( -

)

Yield

0

5000

10000

15000

20000

25000

08.08.1997 21.12.1998 04.05.2000 16.09.2001 29.01.2003 12.06.2004

kg/h

a

vegetative biomass above ground

storage organs

Expert-N Plant SimulationExpert-N Plant Simulation

N-Uptake

0

50

100

150

200

250

300

350

08.08.1997 21.12.1998 04.05.2000 16.09.2001 29.01.2003 12.06.2004

kg

(N)/

ha

80

85

90

95

100

105

110

1999 2000 2001 2002 2003 2004

rTOC (0-200cm) (sim.) rTOC (0-20cm) (meas.)

Observed and simulated rTOC

values as function of time

Mineralisation Model Mineralisation Model ParametrisationParametrisation

Long-term Simulation Long-term Simulation (1906-2002):(1906-2002):

YieldYieldstorage organs (kg/ha)

0

2000

4000

6000

8000

10000

12000

14000

16000

18000

20000

0 2000 4000 6000 8000 10000 12000 14000 16000 18000 20000

measured

sim

ula

ted

relative TOC (1903-2002)

0

20

40

60

80

100

120

00/01/1900 08/09/1913 18/05/1927 24/01/1941 03/10/1954 11/06/1968 18/02/1982 28/10/1995 06/07/2009

kg/h

a

rTOC(0-200cm) sim. rTOC(0-20cm) meas.

Long-term Simulation Long-term Simulation (1906-2002):(1906-2002):relative TOCrelative TOC

Results are only very preliminary:

Plant growth (potato!) and

C- and N cycling needs further calibration

Steps IIb and IIc were not considered

ConclusionsConclusions