ALTERRA

Organic matter / nitrogen

simulations with SWAP/ANIMOJoop Kroes & Piet Groenendijk

ALTERRA

Purpose of modelling efforts

Prediction of environmental impacts of: Fertilization legislation Water management Land use Special combating measuresWith respect to: Nitrate concentrations in groundwater N & P transport to surface waters Soil P saturation degree Trace gas emissions (just started)

ALTERRA

Key EC Directives Key EC Directives Nitrates 91/676 Nitrates 91/676 Water Framework Water Framework

2000/60/EC2000/60/EC

Marine Conventions Marine Conventions (e.g. (e.g. OSPAR, HELCOMOSPAR, HELCOM, ,

Barcelona);Barcelona);

Introduction

ALTERRA

Time scales considered

Water Framework Directive / Nitrate Directive related

Duration: 10 – 50 year Frequency: annual estimates

Generates input to surface quality models: Duration: 1 – 10 years Frequency: daily or weekly

ALTERRA

Dutch assessment approach for N/P leaching

to gw/sw Characterized by shallow groundwater tables

(deltas; wetlands)

Intensive land use (agriculture, urbanisation)

Process oriented modelling approach

National and regional assessments with the same approach

Consensus between research organisations

ALTERRA National assessmentNational assessmentSTONE model chainSTONE model chain

ALTERRA

Plots: calculation units

soil

hydrology

crops

historical P-accumulation

management

fertilization

relation with deep groundwater

Regional appraoch

ALTERRA

transpiration

Saturatedzone

Plant

precipitation

soil-evaporation

Surface waters

Deep Groundwater

surface runoff

- Transport of soilwater- Macro pores

interception

Atmosphere

drainage/subsurfaceinfiltration

drainage/subsurfaceinfiltration

deep percolation/seepage

Unsaturatedzone

snow melt

Hydrological pathways

ALTERRA

PLANT

Gross Rainfall/Irrigation

Interception

SNOW

POND

SOIL

surfacewater

Snowfall

Nett Rainfall/Irrigation

Runon

Runoff

Soil Evaporation

Plant Evaporation

Infiltration/Exfiltration

Drainage/Infiltration

Up/downward seepage

Melt

Precipitation

Inundation

Sublimation

Flow between sub systems

ALTERRASolution soil water flow equation

• Field conditions require numerical solution• Numerical solution needs:

– water retention function (h)– hydraulic conductivity function K()

– root water extraction function S(h)– initial conditions– top and bottom boundary conditions

hSz

z

hhK

t

hhC

1

ALTERRAModelling of crop growth : Wofost sub model

Ta/Tp

LAI

ALTERRA

Animo model

ALTERRA

Transport en transformation processes as influenced byaeration, temperature, drought-stress and pH

Fertilizer Manure Cropresidues

Deposition Biol.N-fixation

Yield LeachingVolatilization Denitrification

ALTERRA

Fresh Org.MatterExudates

NO3

CO2

NH4

PO4

sorption

NH3

CO2

diff-precip

Diss. Org.Matter

CO2

CO2

sorption

Humus / biomass

Groundwater

Tile drains

Surface runoff

Streams and canals

Field ditches

Atmosphere

Manure and fertilizers

Crops

N2

Crop uptake

ALTERRA

Parameterizarion of organic matter pool

}7.4)(7.4exp{ 6.06.0

0

tY

Yt

tttt eaFRaFReaFReaFRY

Y 02.02.02

0)

18.0

2.0)1(

98.1

2()

18.0

2.01()1()

98.1

21( 1 ANIMO:

Empirical relation:

0705.01096.00673.00066.0

4767.16904.01394.00105.023

23

a

FRAnimo parameters related to empirical relation:

ALTERRA

cattle slurry

empirical rel.

* * * * * * * * * * * * ANIMO