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

PARALLEL SESSION 2A: LAND USE 8 th Int. Conference on LCA in the
Agri-Food Sector, 1-4 Oct 2012
mated using the Australian indicator set. The indicators of interest include GWP, eutrophication, land use,
water use and energy demand. However, only a subset will be presented within this paper, that being GWP.
2.3 Horticultural systems
Within the framework of this project, modelling at farm level was required in order to minimise use of
average data to represent farms of differing sizes and in different regions. This is consistent with the purpose
to compare and contrast impacts from farms in different geographical locations, with differing levels of inputs
and outputs. A case study approach was taken, with lettuce supplied to the Sydney market selected as
the commodity of choice. Lettuce was selected for the following reasons: it is a perishable crop and is ideally
situated close to market; its relative economic importance within Sydney’s horticultural production; a reasonable
field planting area is occupied by lettuce in Sydney; and lettuce is a dietary staple in the Australian
diet, unlikely to be displaced from the supply chain. The lettuce market, being highly competitive, price
driven and with an absence of market policies, is likely to expand using growers that can increase their production
with the least expense. Regional geographical locations identified based on ability to expand at
minimal cost, recent production growth and seasonality considerations included specific regions in the states
of Victoria and Queensland. Growing areas for lettuce in Victoria and Queensland are approximately 900km
from the Sydney market by road.
Data was collected from two field farms in Sydney (LF1 and LF2), a hydroponic farm in Sydney (LF3)
and a larger field farm in Victoria (LF4). Hydroponic growing (LF3) represented a low technology growing
system, with no climate control and simple plastic shadecloth structures. Additional data will be collected
from Queensland in the near future. Data was collected for iceberg, cos and/or baby cos lettuce. Process inputs
captured within the system boundary for each farm, and calculated emissions to the compartments of
air, soil and water included those identified in Figure 2.
INPUTS:
Seeds/transplants
Fertilisers
Composts
Manures
Pesticides
Herbicides
Fungicides
Wetting agents
Irrigation water
Fuel
Electricity
Capital equipment
Lettuce at farm
INPUTS:
Packaging
Washing
Capital equipment
Electricity
Transport
Lettuce at Sydney
market
EMISSIONS to AIR:
N2O
CO2
VOC
EMISSIONS TO
SOIL/WATER:
Nitrate
Phosphate
Sulfate
Pesticide
Figure 2. Process inputs captured within the system boundary for farms.
2.4 Urban systems
IMPACTS:
Global Warming
Eutrophication
Land use
Water use
Cumulative energy
demand
According to Sydney’s Metropolitan Plan (NSW Department of Planning 2010) there are two dominant
forms of urban housing: greenfield and infill. Greenfield requires large tracts of peri-urban land to be converted
en masse into detached low density housing. Infill development requires the purchase and demolition
of existing, dated, structures, and the construction of new, mid to high-rise apartment complexes in inner
suburban areas. From scenario 1 the model requires the impacts from 1 ha of greenfield development to be
estimated, while scenario 2 requires impacts from 1 ha (equivalent) of infill development (equivalency based
on housing a certain population). An initial challenge was how to model infill development given that infill
does not directly replace peri-urban horticultural land as greenfield housing systems do, on a per hectare
basis. By calculating the number of houses per hectare in a greenfield development, and the associated persons
per hectare based on population statistics, the corresponding number of infill style apartments to house
the same population could be determined. For the purposes of this study, the typical greenfield house is a
250m 2 detached single level brick veneer house, with concrete slab and tiled roof on a 550m 2 block of land.
An average of 2.5 persons lives in a typical greenfield house in Australia (ABS in Crawford and Fuller
2011). Using this information, and determining the number of houses (18.18 houses per ha) and population
per hectare (45.45 persons per ha) for a typical greenfield development, the equivalent number of infill
apartments was ascertained. The average population of a mid-rise apartment in inner suburban Australia is
estimated at 1.6 per apartment (Crawford, 2011). Therefore 28.4 apartments would be needed to house the
same population as 1 ha of greenfield housing, for those scenarios requiring infill development. It was assumed
that these apartments were housed in one mid-rise (four or five storeys) high-density apartment block.
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