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

PARALLEL SESSION 7C: FOOD CHAIN AND FOOD WASTE 8 th Int. Conference on LCA in the
Agri-Food Sector, 1-4 Oct 2012
For B and C production was in the east of England, on canes grown for seven years in fields covered with
polytunnels during fruiting. In this case in the first year the ground is prepared, beds formed and soil sterilised
(e.g. with chloropicrin). The canes are produced on a separate farm, cold stored prior to planting, then
planted directly through plastic into the pre-prepared beds. On an annual basis (for seven crops) fertilisers
are applied through drip irrigation including nitrogen fertiliser as ammonium nitrate or potassium nitrate.
Irrigation uses water from an aquifer. Fruit is hand-harvested then transported directly to the packhouse.
Yield averages 12t/ha per year for the seven cropping years. In the packhouse the fruit is graded and cleaned,
before being placed into punnets with a plastic film lid. Punnets are cooled in a cold store prior to distribution
in refrigerated trucks. At the end of the season the soil between the beds is pulverised to reduce compaction.
At the end of the seven years the crop is grubbed out, the ground sub-soiled and the plastic rolled up
and recycled. For C, the product system included frozen storage from the assumed time of harvest (July)
until the time of delivery to the retail distribution centre (RDC). These production techniques are commonlyencountered
ones producing for the UK supply pattern, although they are not the only ones.
2.2. Boundaries
The product systems incorporated production of fertilisers, canes, packaging, fuels and all other inputs. Production
of material for polytunnels was included, but other capital equipment was excluded so that the calculations
of global warming potential were compliant with PAS 2050 (2008). For the production system in
B&C, an additional year of operation without any crop production was included as an allowance for cane
production, for which direct data were unavailable.
2.3. Data
Primary data from individual operating locations were used to characterise agricultural operations, with expert
consultation used to fill data gaps. Background data for inputs such as fertilisers, fuel and polyethylene
film were taken from the ecoinvent database v2. Data characterising outdoor production of raspberry canes
in the UK were based on the data provided for raspberry fruit production outdoors in the UK and advice from
a horticultural expert on likely per ha yields. Methane and nitrous oxide emissions were calculated using the
method set out in the IPPC’s (2006) Guidelines for National Greenhouse Gas Inventories. This aligned the
method with PAS 2050:2008. A single set of data, from one of the operating locations, was used to characterise
all packhouse operations and packaging.
A dataset for chilling and short-term cold storage of soft fruit was developed to characterise packhouse operations
and storage prior to transhipment either to the RDC or to a long-term cold-storage location. This
embodied data provided by one business participating in the study. To create an appropriate dataset for an
equivalent operation in Spain, the source of electricity used was changed from the UK grid to the Spanish
one; energy consumption was assumed to be the same in both locations – i.e. any additional cooling energy
required in the warmer climate of Spain was ignored. A dataset characterising frozen storage was also developed,
encompassing energy use and refrigerant loss and account for the burdens of providing a unit volume
of cold storage capacity for a unit time; energy use in cold stores was taken from a review of UK facilities
(Evans n.d); a mixture of gases was used to represent emissions to air to reflect the range of gases used
(R404A and NH3). It is worth noting that the range of specific energy use (energy use per volume) in cold
stores found by Evans is very wide for each temperature regime studied (a factor of 8 between most and least
efficient) and this performance variation dwarfs any differences between the energy requirements associated
with the different temperature regimes (i.e. “frozen” and “chilled”). Because most LCA results for food
products relate to a unit mass of product, figures for mass of product per unit of storage volume were taken
from Brunel University (2009) to calculate the cold storage volume needed for 1kg raspberries. Finally, a
dataset for the unit operation of road transport in refrigerated trucks was developed using values for fuel
consumption, vehicle utilisation and refrigerant loss given by Brunel University (2009); emissions per unit of
fuel used were taken from ecoinvent v2.1
2.4. Impact Assessment
Impact assessment was conducted for environmental categories deemed relevant to the project. Category and
impact assessment method selection also reflected Defra’s desire for the study’s results to be as compatible
as possible with results from previous LCAs of UK agricultural commodities, particularly those produced by
Williams et al., (2009). Therefore, CML midpoint methods were used for the categories global warming,
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