LCA Food 2012 in Saint Malo, France! - Manifestations et colloques ...

PARALLEL SESSION 3C: SHEEP AND DAIRY PRODUCTION SYSTEMS 8 th Int. Conference on LCA in the
Agri-Food Sector, 1-4 Oct 2012
Table 1. Resource use, energy use and output per ha of crops (farm gate)
Feed Grass silage Maize silage Barley Rape seed Soybean
Place of production Denmark Denmark Denmark Denmark Brazil
Input
Dairy farm Dairy farrn Crop farm Crop farm
Mineral fertiliser 1) , kg N/ha 118 39 119 178 0,3
Mineral fertiliser, kg P/ha 32 45 23 30 13
Mineral fertiliser, kg K/ha 192 139 49 82 25
Manure, kg total N 170 170 0 0 0
Diesel, /ha 102 207 118 118 26
Seed, kg 13 5 150 106
Electricity, kWh/ha 2) Output
378 34 17 23 0
Crop yield, kg DM/ha 8269
11325 4121 3321 2300
(kg/ha)
1) Calcium ammonium nitrate
(-)
(-) (4848) (3590) (2544)
2) Electricity used for watering was assumed to be based on natural gas
Estimation of emissions
Factors used for estimating emissions are shown in Table 2. For the Danish grown crops, factors for estimating
nitrous oxide emissions were from IPCC (2006) whereas those for ammonia emission were national
emission factors. For soybean, data from Ecoinvent (2010) was updated using IPCC guidelines (IPCC,
2006).
Table 2. Factors for estimation of emissions from crop production and inventory of GHG emissions embod-
ied in different inputs
Emission source Amount Emission
322
Factor (EF)
N2O direct, kg Spreading of
- slurry kg N in manure ab storage 0.01 1)
Source -
EF
- fertiliser N in fertiliser 0.01
Crop residues,
Crop: kg N/ha/year 0.01 1) + 2)
kg N pr ha per year Grass 60
Maize, whole crop 25
Other arable crops 28
NH3-N, kg Spreading of 2)
- slurry kg N in manure ab storage 0.12
- fertiliser N in fertiliser 0.022 2)
Crop residues Grass
0.5 kg / ha 3)
Other arable crops
2.0 kg / ha
N2O, kg
indirect
From NH3 NH3-N 0.01 1)
From leaching NO3-N=0.33*( manure-N + fertiliser-N) 0.0075 4) + 1)
Input Fertiliser-N
Fertiliser-P
Fertiliser-K
Seed
Diesel
Electricity (natural gas
based)
4.4 kg CO2/kg N
2.7 kg CO2/kg P
0.8 kg CO2/kg K
0.4 kg CO2/kg
3.3 kg CO2/L
0.66 kg CO2/kWh
1) IPCC (2006)
2) Mikkelsen et al., (2006)
3) Gyldenkærne and Albrektsen (2008)
4) Nielsen et al., (2009)
5) Elsgaard (2010). GHG emissions from average N-fertiliser (Calcium ammonium nitrate) used in Denmark:
60% of this N-fertiliser is imported from Yara, where it is produced in accordance with Best Available Techniques
for N2O emission reduction , and 40% of the N-fertiliser is imported from Baltic
6) Nielsen et al., (2003)
7) GHG emissions rate from growing 1 kg barley was used for approximation of GHG emissions per kg seed
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