Presentation in Lednice 1st July 2004 - CORE

D A R C O F

Presentation in Presentation in LedniceLednice 11stst July 2004July 2004

Impact of Organic farming on aquatic environment Impact of Organic farming on aquatic environment

ByBy

Erik Steen Erik Steen KristensenKristensen and Marie and Marie TrydemanTrydeman KnudsenKnudsenDanish Research Centre for Organic Farming Danish Research Centre for Organic Farming

((www.DARCOF.dkwww.DARCOF.dk))

DARCOF (Danish Research Centre for Organic

Farming)

D A R C O F

Presentation of DARCOF

• Established in 1996 by the government

• Initiate and coordinate R & D in organic agriculture

• Communicate the results and contribute to further education

• “Centre without walls”: 20 Institutes, 140 Scientists

• 30-50 research projects, 40-60 mill Dkr (5-8 mill €) per year

D A R C O F

Outline

1. Problems in European aquatic environment

2. Development in organic farming

3. Effect of conversion to organic mixed/dairy farming

4. Effect of conversion to organic arable farming

5. Conclusion

Nitrate concentration in European rivers

Source: European Environment Agency (http://dataservice.eea.eu.int/atlas/viewdata/viewpub.asp?id=546)

Development since 1955Extension 1994-96

Nitrate in groundwater


European Environment Agency, 2003

Nitrate Vulnerable Zones


Phosphorus concentration in European rivers og lakes

Source: European Environment Agency (http://dataservice.eea.eu.int/atlas/viewdata/viewpub.asp?id=546 )

Rivers (1994-96) Lakes and reservoirs

European Environment Agency, 2003

Indicators Assessments

Nitrate in groundwater

No decrease (or increase) in levels of nitrate in Europe’s groundwater.

Nitrate drinking water limit values exceeded in one third of the groundwater bodies.

Nitrate in drinking water a common problem across Europe.

Nutrients in rivers

Concentrations of phosphate have decreased in the rivers of the EU and accession countries during the 1990s.Nitrate concentrations in rivers stable throughout the 1990s - highest in western Europe where agriculture is most intensive.

Phosphorus in lakes

Eutrophication of European lakes is decreasing.

Still many lakes and reservoirs with high concentrations of phosphorus - highest in accession countries.

Nutrients in marine waters

Nutrient concentrations in Europe’s seas have generally remained stable over recent years.

Status of European waters

D A R C O F

Outline





5. Conclusion

D A R C O F

Development of organic farming in EU-15 countries

http://www.organic.aber.ac.uk/stats.shtml

0

20000

40000

60000

80000

100000

120000

140000

160000

180000

1988

1990

1992

1994

1995

1996

1997

1998

1999

2000

2001

2002

Tota

l hec

tare

s

0

1000

2000

3000

4000

5000

6000

7000

8000

Num

ber

of fa

rms

Hectares Farms

Development of organic farming in Denmark

Organic farms in Denmark 2003

11

0

Others

15

42

Clover/ grass

0,6525192400Others (incl. pigs/poultry)

51059

0,072583530Arable farms

1328151,2850115770Mixed/dairy farms

6,4178.000483700Organic, total

Perma-nentgrass

Silage(maize +

pea/barley)

Cereals,maturity

Live-stockunits/

ha

%TotalPer

farm

Land useArea, ha

NumberFarm types

(Plantedirektoratet 2003)

D A R C O F

Outline





5. Conclusion

Characteristics of Danish dairy farms

44594764Animal feed consumption, FU/DE

44005700Average yield, FE/ha

68557373Milk production per cow, Kg milk/cow

4151Cereal yield, hkg/ha,

1,281,46Stocking rate, DE/ha

10068Agricultural area, ha

12899Livestock units (DE)

81,961,3Number of cows per farm

OrganicConventional

Average

FØI-statistik, 1999Kristensen et al., 2003

N surplus on dairy farms (kg N ha-1 year-1)


-100

-50

0

50

100

150

200

250

Farm type

kg N

per

ha

Rainfall

Imported fodder

Mineral fertilizer

Organic fertilizer

N2 fixation

Exported crops

Milk

Meat

Organic

Conventional

Input: 238

Output: - 39 Output: - 57

N surplus: 105

Input: 144

N surplus: 181

INPUT

OUTPUT

N surplus and N loss on dairy farms (kg N ha-1 year-1)

181

105

-119

-54

-36-26

-25-26

-119

-54

-26

-26

-36

-25

105

181

-200

-150

-100

-50

0

50

100

150

200

Farm type

kg N

per

ha

N surplus

Ammoniavolatilation

Denitrification

N leaching

Organic

Conventional


N surplus on dairy farms(Kg N ha-1 year-1)


Note: The numbers below the symbols shows the stocking rate (animal units per ha) of the study.

0

50

100

150

200

250

1988 1993 1998 2003

Years

N s

urpl

us (k

g N

per

ha)

OrganicConventional1.76

1.7 1.46

1.24 1.24

1.30

1.46

1.30

Nitrate leaching from grassland (Foulum) ofdifferent age, composition and management

Grass-clover Ryegrass

kg N

O3-

N h

a-1 y

r-1

0

25

50

75

100

125

kg N

O3-

N h

a-1 y

r-1

0

25

50

75

100

125

0 1 7 7 0 1 7 7

1 2 8 8 1 2 8 8

Production year

Production year

2000-20012001-2002

GrazedCut

P surplus of dairy farms(Kg P ha-1 year-1)

Studielandbrugene, 1997-2001Halberg et al., 2003

http://www.vmp3.dk/Files/Filer/Rap_fra_t_grupper/VMP_III_Final_med_bilag.pdf

-20

0

20

40

60

80

100

0 1 2 3 4 5 6

Dyretæthed, DE/ha

P-ov

ersk

ud b

edri

ft, k

g P/

ha

Konv. planteavl u. dyrKonv. planteavl m. sl.svinKonv. svin indeKonv. svin frilandKonv. kvægØko. kvægØko. svin friland

P surplus on dairy farms(Kg P ha-1 year-1)

Studielandbrugene, 1997-2001Halberg et al., 2003

http://www.vmp3.dk/Files/Filer/Rap_fra_t_grupper/VMP_III_Final_med_bilag.pdf

-15

-10

-5

0

5

10

15

20

25

30

Farm type

kg P

per

ha

Imported fodder

Mineral fertilizer

Organic fertilizer

Exported crops

Milk

Meat

Organic

ConventionalInput: 34

Output: 8

Output: - 17

P surplus: 8

Input: 16

P surplus: 17

OUTPUT

INPUT

D A R C O F

Outline





5. Conclusion

Nutrient dynamics

Crop rotation experimentRotation 1 Rotation 2 Sædskifte 4

S. barley:ley Grass-clover S. wheat* Lupin*

S. barley:ley Grass-clover W. wheat* Peas/barley*

S. oats* W. wheat* W. cereals* Peas/barley*

*: Cover crops are used

Experimental treatments:• Crop rotation (proportion of cereals)• +/- cover crop• +/- animal manure (40% af norm)

1997 1998 1999 2000 2001

kg/h

a (8

5% D

M)

0

2000

4000

6000

8000

JyndevadFoulumFlakkebjerg

Winter wheat ÷ manure

Grain yield in rotation 2

Foulum

0

5

10

15

20

25

30

35

FlakkebjergJyndevad

ppm

10

20

30

NO3-NK

97 98 99 00 97 98 99 00 97 98 99 00

Concentrations of nitrate-N and K in soil water

Jyndevad Foulum Flakkebjerg Holeby

Nitr

ate-

N (k

g N

/ha)

0

20

40

60

80

100Without cover cropWith cover crop

ba

a

a

b

a

N leaching in rotation 2

Model simulation of N balance on Danish arable farms

• Organic scenarios:• Basic: Crop rotation dominated by spring cereals with catch crops in

40% of crops and 20% clover/grass.

• + catch crops: Catch crops (white clover/rye grass) in 70% of the crops.

• 0 fertilisation: No manure is used.

• Conventional scenarios:

• Basic: Crop rotation dominated by winter cereals and catch crops in 6% of the crops.

• + catch crops: Catch crops (ryegrass) in 36% of the crops.

Note: Scenarios are representative for Danish agriculture.

Model simulation of N balance on Danish arable farms

• N balance at field level (incl. N leaching and changes in soil Norganic matter) - calculated for scenarios using the FASSET model at:

• Three soil types (Sandy soil, loamy sand and sandy loam)

• Two levels of soil organic matter (high and low).

N surplus on arable farms (kg N ha-1 year-1)

Berntsen et al., 2004

-150

-100

-50

0

50

100

150

200

Farm type

kg N

per

ha

Mineral fertilizer

Organic fertilizer

N2 fixation

Other inputs

Grain yield

Straw and coarsefodder

ConventionalOrganic

Basic+ catch crops Basic

no fertili-sation

+ catch crops

N surplus: 61 N surplus: 38 N surplus: 40 N surplus: 31 N surplus: 60

Input: 103

Input: 151 Input: 147 Input: 150 Input: 150

Output: - 110

Output: - 72 Output: - 86 Output: - 91

Output: - 112

INPUT

OUTPUT

N surplus and N loss on arable farms (kg N ha-1 year-1)


11 19

-9 -8 -4

-36 -27-32 -36

-29

-11-11

-8 -10-10

31 40 38

-3-3

-2-2

6160

-80

-60

-40

-20

0

20

40

60

80

100

Farm type

kg N

per

ha

N surplus

Ammonia volatilation

Denitrification

N leaching

Soil N pool

ConventionalOrganic

Basic+ catch crops Basic

no fertili-sation

+ catch crops

N leaching on arable farms (kg N ha-1 year-1)

Org

anic

Basi

s

+ ca

tch

crop

0 fe

rtilis

atio

n

Con

vent

iona

l

Basi

s

+ ca

tch

crop

Sandy loam (low )

Loamy sand (low )

Sand (low ) 0

10

20

30

40

50

60

N le

achi

ng (k

g N

ha-

1 ye

ar-1

)

Cropping systems

Soil type and level of

organic matter

Sandy loam (low)Sandy loam (high)Loamy sand (low)Loamy sand (high)Sand (low)Sand (high)


Change in soil N pool on arable farms (kg N ha-1 year-1)

Org

anic

Bas

is

+ ca

tch

crop

0 fe

rtilis

atio

n

Con

vent

iona

l

Bas

is

+ ca

tch

crop

Sandy loam (low )

Loamy sand (low )Sand (low )

-30

-20

-10

0

10

20

30

40

Soil

N p

ool (

kg N

ha-

1 ye

ar-1

)

Cropping system

Soil type and level of organic matter

Sandy loam (low )

Sandy loam (high)

Loamy sand (low )

Loamy sand (high)

Sand (low )

Sand (high)


D A R C O F

Conclusion

• Nitrate leaching from agriculture is a common problem for European aquatic environment

• Conversion to organic mixed/dairy farming decrease leaching of N because of decreased stocking rate and level of N-fertilizer

• Conversion to organic arable farming increase soil fertility, but has little effect on leaching of Nitrate at least at farm level and on a short term

• Organic farming has positive environmental benefits on the soil and the ecosystem

Assessment of environmental impact of organic farming

Source: Hansen et al. (2001)

Presentation in Lednice 1st July 2004 - CORE

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