Determining the environmental burdens and resource use in the production of agricultural and horticultural commodities

Natural Resource Management Institute,
Cranfield University
Silsoe Research Institute, U.K.

Executive Summary

The research addresses key questions underpinning the development of sustainable production and consumption systems that are based on domestically produced agricultural and horticultural commodities. It quantifies the resource use and environmental burdens arising from the production of ten key commodities and delivers accessible models that enable resource use and emissions arising from various production options in England and Wales to be examined in detail. The commodities examined are: bread wheat, potatoes, oilseed rape, tomatoes, beef, pig meat, sheep meat, poultry meat, milk and eggs.

The overall research aim agreed with Defra was to model the environmental burdens and resource use involved in producing ten agricultural and horticultural commodities using the principles of Life Cycle Assessment (LCA), and to deliver these models in a user-accessible form such as Microsoft Excel. The specific project objectives were to identify and define the major productions systems in England and Wales and the related process flow charts, to establish the relevant mass and energy flows and other necessary data and their uncertainties, to code the LCA models in a package, such as Microsoft Excel, with all the main data readily accessible and published, to use the LCA model to analyse these production systems and demonstrate that the model can compare production systems and can identify high risk parts the systems, and to publish and publicise the research outputs.

All inputs into on-farm production for each commodity were traced back to primary resources such as coal, crude oil and mined ore. All activities supporting farm production, such as feed production and processing, machinery and fertiliser manufacture, fertility building and cover crops, were included. The system included soil to a nominal depth of 0.3 m. Where appropriate (tomatoes, potatoes), commodities were defined as national baskets of products, for example tomato types such as loose and on-the-vine tomatoes, each included as their proportion of national production. Abiotic resources used (ARU) were consolidated onto one scale based on relative scarcity. Individual emissions, such as carbon dioxide (CO2) and nitrous oxide (N2O), were quantified and aggregated into impacts for global warming (GWP), eutrophication (EP) and acidification (AP). Organic production systems were analysed for each commodity, as well as variations on non-organic (or contemporary conventional) production.

Interactions between inputs, outputs and emissions were represented by functional relationships derived from process models wherever possible, so that as systems are modified they respond holistically to specific changes. For example, crop yields and nitrogen supply, dairy cow diet formulation and milk yield, and grass productivity, emissions, animal grazing and fertiliser applications are functionally related. Process simulation models were also used to derive the long term outcomes of nitrate leaching, soil, crop type and nitrogen supply.

Source
Defra project report IS0205
Natural Resource Management Institute,
Cranfield University
Silsoe Research Institute, U.K.
August 2006

Full Report (1.6 MB)

 

Posted February 2008