Outline of the presentation

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1 Session Author: Life cycle assessment of organic milk production in Denmark Lisbeth Mogensen, Marie T. Knudsen, John E. Hermansen, Troels Kristensen, Thu Lan T. Nguyen U N I V E R S I T Y O F A A R H U S Faculty of Agricultural Sciences

2 Outline of the presentation Introduction Aim of the study Materials An organic dairy farm in Denmark Methods Life cycle assessment (LCA) Results Improvement options Conclusion

3 Aim of this study Estimate the GreenHouse Gas (GHG) emission of Danish organic milk through Life-Cycle Assessment (LCA) based on data that typically are available at the farm Suggest possibilities for reduction of the GHG emission on farm gate

4 Materials Typical annual data from an organic dairy farm: Economic turnover Manure account Production performance

5 The herd Cows Heifers Bull calves No ) 142 1) Milk yield, kg 9000 Housing Cubicles Deep litter Deep litter Summergrazing 8 h per day 24 hours 2) 0 1) Sold at 60 kg 2) For heifers > 6 months 3) High number due to extended the herd size

6 The fields 320 ha in rotation on sandy soil 21 ha permanent pasture Ha % Grass clover Cereals for whole crop Cereals for maturity Carrots 10 3

7 Methods Life cycle assessment (LCA) N 2 O N2 O CO 2 Soy bean from Argentina N 2 O Fertilizer production CO 2 CO 2 CO 2 CH 4 Milk

8 The system boundaries: INPUT Materials Manure Feed Seed Energy Diesel Electricity Chemicals Other Emissions to the air (CO 2, N 2 O, CH 4, NH 3 ) The farm Emissions to soil and water (NO 3-, PO 4 3- ) OUTPUT Crops Milk and meat Byproducts transport transport transport transport Fertilizer and feed production Farm Processing Supermarket Consumer

9 Functional unit (FU) 1) GHG emission of the whole farm (kg CO 2 -eq/farm/year) 2) After biological allocation: GHG per 1 kg milk ex farm (kg CO 2 -eq/kg milk)

10 Inventory: Input and output Emissions to air (CO 2, N 2 O, CH 4, NH 3 ) INPUT Materials 3000 t slurry 302 t barley 80 t soy meal 137 t straw N 2 fixation Seed Energy 29,954 l diesel 6237 l diesel (contractor) 280,023 kwh el Chemicals Other Stable Cattle manure The farm Fields 128 ha grassclover 77 ha whole crop 104 ha cereals 10 ha carrots Emissions to soil and water (NO 3-, PO 4- ) OUTPUT Milk 1,726,751 kg (sold) Meat 69,751kg live weight (sold) Crops 700 t carrots (sold) 233 t DM silage (store) Manure 692 t cattle slurry (sold) 359 t cattle slurry (store)

11 CO 2 emission from external input Input of CO 2 -eq emission, kg 1 kg barley kg soy bean meal kg N plant from manure litre diesel kwh electricity 0.655

12 CH 4 emission estimation CH 4, kg Area Amount Emission Factor Enteric fermentation Kg DMI x MJ/kg DM / (55.65 MJ/kg CH 4 ) 0.06 Manure - slurry - deep litter - pasture Non-digestible organic DMI + organic matter used as bedding CH 4 formation capacity=0.22 (IPCC, 2006)

13 N 2 O emission estimation N 2 O, kg direct Indirect N 2 O Area Amount Emission Factor Stable & storage N manure ex animal - slurry deep litter 0.01 Application N manure ex storage - manure pasture 0.02 Crop residues Sum ha * kg N per ha per year 0.01 Grassland 50 N Other arable crop 30 N From NH 3 NH 3 -N 0.01 From leacing N0 3 -N=0.33*(N manure ex storage+n import fertilizer) (IPCC, 2006)

14 Total farm GHG emission Kg CO 2 -eq. Total farm GHG 2,347,600 Per ha 6,880 Per kg milk before allocation 1.36 Per kg milk allocated 1.02 Per kg meat allocated 16.1

15 GWP hotspots INPUT ENERGY ON FARM EMISSIONS 16% 12% 72% 36% Seed Feed Production of fertilizer Diesel El Transport of fertilizer N 2 O from fields CH 4 from animals Kg CO 2 -eq Klimabelastning (tons CO 2 ækv./bedrift per year)

16 Contribution per GHG 17% 50% 33% CO2 N2O CH4

17 Improvement options Increased N efficiency Reduced N application: 140 to 115 kg N/ha Import of N reduced by 8,000 kg Crop yield at same level

18 Total farm GHG reduced by 5% IMPORT 14% ENERGY EMISSIONs 13% 73% Basic Seed Feed Diesel El N 2 O at fields CH 4 from herd Klimabelastning (tons CO 2 ækv./bedrift per year)

19 Conclusion Farm GHG can be calculated based on typical farm data Improvement in farm GHG in the present case: 5% of total Farm GWP only one of several impact categories in a LCA (acidification, nutrient enrichment, land use etc.)