Arable systems have to not only provide food for the masses, but they now have to be multi-functional. Thus they need to be managed to preserve the environment, satisfy social preference and provide a living for farmers, which may be conflicting objectives. Because it has the benefit of a common currency, emergy accounting has, therefore been used to assess the economic and environmental ‘health’ of the system. Currently, the emergy evaluation focuses on the impact of farm management practices on crop production at the field level and includes data on climatic inputs, such as sunlight and rainfall, and purchased inputs, such as fertilizers, labour and machinery. There is a need to understand how crop management practices may be developed and used to optimise the management of these components, particularly those reducing or reversing adverse environmental impacts whilst maintaining economic sustainability. Early results have shown that for Scottish agriculture spring barley and spring oats demonstrate the highest sustainability value. Therefore, these crops can be seen as utilizing renewable resources to their best effect and not exerting pressure on the agricultural environment. This result is very much influenced by the level of additional purchased inputs to the system (fertilisers and machinery). The addition of factors such as labour, soil type, and socio-economic factors related to the costs (£) of inputs will help to build a more robust picture of agriculture in Scotland.

• http://www.cep.ees.ufl.edu/emergy/index....