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

PARALLEL SESSION 1A: WATER FOOTPRINT 8 th Int. Conference on LCA in the
Parallel session 1a: Water Footprint
Agri-Food Sector, 1-4 Oct 2012
Water footprint of pastoral farming systems in New Zealand
Marlies A. Zonderland-Thomassen 1* , Stewart F. Ledgard 1 , Mark Lieffering 2
1 AgResearch Ltd, Private Bag 3123, Hamilton 3240, New Zealand
2 AgResearch Ltd, Palmerston North, New Zealand
Corresponding author. E-mail: marlies.zonderland-thomassen@agresearch.co.nz
ABSTRACT
Global livestock production has a major challenge ahead in meeting increased food requirements without increasing the environmental
burden. A need exists to assess the impacts of water consumption associated with New Zealand (NZ) livestock products. A
water footprint (WF) approach compliant with Life Cycle Assessment (LCA) principles was used to assess the stress-weighted WF
using a water stress index. The stress-weighted WF was 0.01 and 7.1 L H2O-eq/kg fat-and-protein-corrected milk (FPCM) for dairy
farming in the Waikato and Canterbury regions respectively. The stress-weighted WF of NZ beef was 0.2 L H2O-eq/kg live weight
(LW), whereas for sheep meat it was 0.1 L H2O-eq/kg LW. Water consumption associated with irrigation dominated the WF of dairy
farming in the Canterbury region, as well as the WF of beef and sheep meat, which highlights the importance of targeting water use
efficient practices in irrigated regions.
Keywords: water footprint, water stress index, eutrophication potential, pastoral farming
1. Introduction
Global livestock production has a major challenge ahead in securing food production without increasing
the environmental burden. Water consumption and pollution are associated with a range of activities, and at a
global scale, most of the water use occurs in agricultural production (Mekonnen and Hoekstra, 2012). Agriculture
is a water-intensive human activity and water availability can be limited in certain areas and seasons.
Globally, a key agricultural system is dairying and New Zealand (NZ) is the world’s largest dairy exporting
country trading at least 95% of the 16,500 million litres of milk that was processed in NZ in 2010, equal to
26% of NZ’s total export revenue. Milk production is inevitably linked with water consumption for animal
feed production (Neal et al., 2011) and can be a significant contributor to water pollution (Monaghan et al.,
2007; Ledgard et al., 2009). Sheep and beef farming is also dominant in NZ agriculture. Red meat and related
products contributed NZ$6.5 billion or 15% of NZ’s total export revenues in 2009. It is important that
NZ milk and red meat suppliers are prepared with information on the water footprint (WF) of their products.
This will enable them to understand the potential for reducing their WF and achieving a comparative advantage
relative to products from other countries.
2. Methods
A literature review showed various WF approaches exist or are under development (e.g., Bayart et al.,
2010; Berger and Finkbeiner, 2010). For the red meat and dairy supply chains, both water quality and water
quantity are relevant. A WF approach compliant with Life Cycle Assessment (LCA) principles was used to
assess the stress-weighted WF following Ridoutt et al., (2010). The eutrophication potential (EP) of NZ
dairy, beef and sheep farming systems (Guinée et al., 2002) was also assessed.
New Zealand red meat is derived from sheep and cattle that are raised under a variety of mixed production
systems across a range of climatic conditions. To deal with variation in production systems, survey data
from seven representative sheep and beef farm systems from throughout NZ were used ( B+L NZ statistics
2009/2010). These data were used to calculate a weighted average sheep and beef farm representative of beef
and sheep meat production for NZ. Across the seven farm classes, the average total effective land area
ranged from 245 to 8,872 ha for class 7 (South Island intensive finishing) to class 1 (South Island high country),
respectively (Table 1). The average rate in stock units for beef cattle and sheep per effective hectare
ranged from 1.1 (class 1) to 10.6 (class 7). The predominant source of feed for sheep and beef animals was
grazed pasture. Low levels of feed supplements made on-farm (ranging between 0.4 kg DM/ha in farm
class 1 and 292 kg DM/ha in farm class 7) were fed to the animals to overcome pasture shortages in summer
or winter and to optimise production.
For dairy farm systems, data from the two contrasting regions of Waikato (North Island, non-irrigated,
moderate rainfall) and Canterbury (South Island, irrigated, lower rainfall) were used (Zonderland-Thomassen
and Ledgard, 2012). The annual rainfall was 677 mm in Canterbury compared to 1264 mm in the Waikato
region (Table 1). Most Canterbury farms, therefore, apply irrigation between spring and autumn (on average
565 mm/ha/year).
Table 1. Farm characteristics of the dairy farm, and beef and sheep systems
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