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. Overview of selected farms.
Characteristics Specialised dairy farm Mixed farm
Region Mountain region Lowlands
Elevation above sea level (m) 800 500
Summer feeding period (days) 200 215
Winter feeding period (days) 165 150
Farm size (ha) 25.1 51
Share permanent grassland 100% 52%
Share arable crops 0% 48%
Crops Permanent meadows and pastures Permanent meadows and pastures, ley, silage
maize, triticale, peas, potatoes, winter wheat
Livestock (LU a ) 24.77 52.16
Stocking density (LU a /ha) 0.98 0.99
Number of dairy cows 20 40
Milk production b per cow 5300 kg 6425 kg
Cattle housing system Loose housing system Loose housing system
a Swiss livestock units
b fat and protein corrected milk (FPCM)
Table 2. Farm-specific characterisations of selected GHG mitigation measures.
Measure Specification of measure
Composting livestock
manure
Due to better aeration of manure, CH4 and N2O emissions can be reduced. However, additional use of
machinery and fleece is necessary for compost preparation.
Increased number of An increased number of lactations (up to 3.6) decreases the share of cattle in an unproductive stage and
lactations
cows
of dairy thus total methane emissions
Use of dual-purpose Cattle race ‘Original Braunvieh” is used instead of ‘Swiss Braunvieh”. Changes in milk yield were esti-
cattle breeds
mated according to Mahrer (2011)
Use of photovoltaics Photovoltaics are used on the total roof area (Dairy farm: 500 m 2 , mixed farm: 900 m 2 ) of the farms under
consideration of local solar radiation levels.
Conversion to full- Enhance the share of pastures for allowing the cattle herd to graze outside during the summer feeding
grazing system period. This leads to a reduction of manure management emissions and energy use due to grassland management
Machine use during Machines and tractors were assumed to be used beyond the amortisation period up to their technical life
technical life time time.
Shade trees on pastures Planting of walnut trees (Juglans regia) on pastures (5 on dairy farm; 20 on mixed farm)
Energy-efficient
cooling devices
milk Installation of waste heat recovery devices from milk cooling for warm water heating
Concentrate-free feeding
rations
Concentrate use in feeding rations of dairy cows and offspring is substituted by grass-based fodder
Application of Eco Studies show that an application of ‘eco-efficient driving” can save 10-20% fuel compared to standard
drive mode
driving practice
Optimisation of machines
and tractors
We assumed that farmers purchase and use the more energy efficient tractor (instead of an average tractor)
Use of solar heat Solar heat is used for heating process water
Reduced tillage Ploughing is replaced by cultivator, except after ley (measure only on the mixed farm). Fuel can be saved
and soil carbon stocks is likely to be increased but was assumed to remain constant as reliable figures were
unavailable for a situation where ploughing is reduced instead of completely stopped.
2.3. Farm model
We built a single-farm model based on a LCA approach which enabled us to calculate the GHG emissions
and energy use of a farm in different conditions, using ecoinvent and other data sources as well as data from
own assessments (Schader et al., 2012a).
Main components of the model are the plant and the livestock production module which take into account
all processes and inputs relevant for defining the production inventories (Fig. 1). Inventories are based on
ecoinvent (Nemecek und Kägi, 2007) and own inventories of organic production processes. The model is
able to reflect interactions between plant and livestock production including emissions of purchased inputs,
in line with life cycle assessment methodology as defined in ISO14040 and 14044.
GHG emissions were calculated based on the production inventories according to the IPCC guideline
(2006) and PAS2050. For calculating on-farm N2O emissions a model was employed, which specifically
takes into account the mode of action of organic fertilisers when applied to the soil (Meier et al., 2012). En-
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