1. Workshop on Climatic Analysis and Mapping for Agriculture
Leibniz-Centre for Agricultural Landscape Research (ZALF) e. V.
Model based evaluation of agro-environmental measures in the federal state of Brandenburg/Germany concerning nitrogen pollution of ground and surface water
K. Christian Kersebaum
Bettina Matzdorf
Joachim Kiesel
Annette Piorr
Jörg Steidl
Workshop on Climatic Analysis
and Mapping for Agriculture
Bologna 14. – 17. June 2005
WMO / COST / FAO

2. Outline Introduction Meteorological characterisation of the study area
Agro-environmental measures in the Federal state of Brandenburg
Modelling diffuse nitrogen leaching from the root zone for different agricultural management options
Identification of vulnerability zones for water resources
Evaluation of actual agro-environmental measures
Conclusions

3. Development and realization of measure programs and management plans
Introduction: Requirements of the Water Framework Directive of the EU
Collecting data about the present status of ground water and surface water
Description of the STATUS QUO (water quality) and evaluation
Definition of a target status
Development and realization of measure programs and management plans

4. Development of measure programs
Goal: Most efficient allocation of measures for the reduction of nutrient pollution of water resources
Status quo analysis on land use related emissions
Identification of land use induced problematic areas
Estimation of activity requirements
Development and evaluation of mitigation options
Catalogue of potential measures
Side specific evaluation regarding the targets and the consequences for productivity (-> socio-economic effects)
Allocation of measures to enhance their effectiveness
Weighting the emissions from agricultural land on the basis of the retention potential of soils and aquifers
Allocation within the region according to a priority ranking

5. Climatic zoning regarding average air temperature (1961-1990)

6. Climatic zoning regarding average precipitation (1961-1990)

7. Climatic zoning regarding average potential evapotranspiration
( )

8. Spatial distribution of agro-environmental measures
in Brandenburg Germany (status 2000/2001)
on arable land on grassland
B1 controlled integrated horticulture
B5 conversion arable land to pasture
B3-G organic legume production
B3-D organic farming permanent crops
B3-A organic arable farming
B4 soil conservation measures
B3-G organic grassland
A5 special nature conservation
A7 extensive fruit areas
A3 restricted grassland
A2 extensive grassland riversides
A1 extensive grassland

9. Methods: Scheme of the nitrogen model HERMES

10. Scenarios for the evaluation of agro-environmental measures
Agriculture:
conventional arable management (= reference for no agro-environmental measures)
Organic farming (with actual live stock density)
pasture intensive
grassland extensive
set aside
Grounwater level (water management)
6 constant gw distances: 30, 60, 100, 150, 200, 500 cm below ground
all variants were simulated for
8 soil types
5 climatic zones with representative stations and years
Smallest common geometry after intersection of
soil map, gr.water map, CORINE land cover, field block map - > ca polygons
Simulation of cases:
8 soils x 6 gw-levels x 8 livestock density classes x 5 land use systems x 5 climates
= 9600 cases

11. Simulated N-leaching for conventional and extensive management systems
(100% Scenarios)
Fundamentals
Medium range soil map
Groundwater distances: HYM 50/DEM 25
weather: DWD representative stations
Land use: Corine / biotope types
fertilization: Brandenburg Agro Report
Live stock density: Agricultural statistics
pasture intensive
pasture extensive
N leaching from root zone
[kg N ha-1]
no agriculture/no data
Berlin
arable land conventional
organic farming

12. Simulated nitrate leaching from the root zone of agricultural used land
in Brandenburg considering the actual percentage of agro-environmental measures
Nitrate leaching [kg N ha-1]
no leaching
Fundamentals
Medium range soil map
Groundwater distances: HYM 50/DEM 25
weather: DWD representative stations
Land use: Corine / biotope types
fertilization: Brandenburg Agro Report
Live stock density: Agricultural statistics
Agro-enironmv. measures: InVeKos data
non agricultural land

13. Model based estimation of the site specific nitrate leaching risk
(according to Federal State Soil Research, Lower Saxony Hannover)
Main land use type and soil texture field capacity of eff.root zone (FCrt)
Weather data, soil, land use simulation groundwater recharge (GWR)
GWR [mm year-1]
Soil solution exchange frequency [% year-1] = x (ExF)
FCrt [mm year-1]
Assessment of the downward displacement respectively nitrate leaching risk:
ExF [% year-1] < < < < > 250
Risk very low low medium high very high

14. Estimation of areas with high impact risk for groundwater
N leaching risk
very low
very high
non agricultural land
vulnerability
high
medium
low
Assessment of potential risk for groundwater pollution

15. Potential risk for groundwater pollution with nitrogen in Brandenburg
Risk classes
0 (very low risk)
1 (low risk)
2 (medium risk)
3 (high risk)
4 very high risk)

16. groundwater affected sites
Assessment of surface water pollution risk based on travel times
recharge areas
wet
drained
sites
ditches
groundwater affected sites
river
Acc. to Steidl, 2001
transit time
years
pollution
risk small
very high
high
very high
weighting
factor:
( x leaching root zone)

17. Classification of Brandenburg
regarding the potential impact on surface water for nitrogen pollution
fundamentals:
Travel time analysis
(Kunkel & Wendland, 1999)
N-decay in aquifer
(Wendland & Kunkel, 1999)
classes of potential impact
High relevance
relevant
small relevance
small relevance,if GW-distance controlled
not relevant
Non agricultural land
Not evaluated

18. Effects of the present agro-environmental measures
in Brandenburg regarding the reduction of nitrogen leaching
Reduction of N leaching [kg N ha-1]
no effect
non agricultural land
rivers
lakes

19. Distribution of agro-environmental measures (AEM) between areas
vulnerable or non-vulnerable for nutrient pollution of water resources
non vulnerable areas
AEM in non vulnerable areas
not estimated
vulnerable areas
AEM in vulnerable areas

20. Summary
simulations based on spatial agro-meteorological information can be used for the site specific assessment of agricultural management effects regarding water pollution.
evaluation of agro-environmental measures considering the targets of the EU Water Framework Directive requires a characteristic of sites regarding their potential impact on ground and surface water.
evaluation of agro-environmental measures in Brandenburg showed that the measures are effective in most of the cases to reduce nitrogen leaching from the root zone. Nevertheless, 75% of the measures were placed in areas with low impact on the water resources.
the effect of the present agro-environmental measures regarding the aims of the Water Framework Directive are therefore not at an optimum.
the method gives a good indication for a targeted allocation of measures and can be used as a basis for the development of measure plans to enhance the effectiveness for the improvement of water quality.

21. Thank you for your attention