Project number: 74310
Lead contractors: Cranfield University
Start & end date: Mar 2010 – June 2010
Actual end date: September 2010
The environmental consequences of livestock production systems are becoming ever more important. Following on the from the life cycle analysis work EBLEX commissioned to calculate the carbon footprint of different beef and lamb systems, this work will model the water footprint of the same systems.
- To model water use during beef and lamb production systems common in England, according to the Water Footprinting Network’s protocol
- To record the characteristics of a water footprint and clarify how the results should be interpreted
- To report the results of this work in the Beef and Lamb Environmental Roadmap Part 2.
The water-footprint is composed of three parts:
1. Green – evapo-transpiration of rain water
2. Blue – drinking, cleaning, processing water
3. Grey – polluted water that needs to be diluted to meet water quality standards
The water footprint data will be synthesised so that the baseline footprint of each production systems of interest can be identified as well as making the best estimate of the national totals for lamb and beef. Commentary will be made on the relative significance of the blue, green and grey water-footprints as well as what opportunities there may be for improvement for farmers. This includes the opportunity costs of water use (and the surpluses that can be expected in many areas where precipitation exceeds evapo-transpiration).
This report attempts to quantify the water footprint of English beef and lamb production, to calculate the water required to produce a tonne of beef and lamb meat. All water required by grass and crops in addition to drinking water and other requirements are included. Water use is considered in three categories; green, blue and grey water. Results show that beef has a water footprint of 17,700 m3/t carcase weight and lamb 57,800 m3/t. Of these, 84% and 97% respectively is green water use, i.e. evapotranspiration of rainfall on crop and grassland. Without this breakdown there is no distinction between rainfall and irrigation supply (blue water), which means that UK beef production may appear similar in impact to countries where irrigation of feed crops is dominant. This report highlights the importance of considering water use in context; in this case, for a temperate, wet climate such as England where crop and grassland water requirements are adequately met by green water from rainfall. Upland and hill production systems have higher water footprints, mostly because grass yield is lower. However, it is shown that rainfall surplus per tonne grass production is still highest in these regions, so that export of water for other human purposes is possible from these regions.
A press release was distributed in October 2010 and the report will be used extensively by the press office when dealing with the issue of environmental impact of beef and lamb systems.
The results have also been included in the Beef and Lamb Environmental Roadmap Part 2.