Two methods for energy analysis and environmental accounting (Gross Energy
Requirement and Emergy Synthesis) are critically discussed in order to explore their
ability to provide a comprehensive evaluation of the performance and environmental
sustainability of human-dominated production processes. In order to allow a
quantitative comparison, two cropping systems, namely 1 ha of corn production in Italy,
and 1 ha of willow production in Sweden, are investigated by means of the parallel
application of both methods. Results provided by the two methods and their respective
theoretical features are compared and discussed in order to point out limits and
potentialities of both approaches. The study shows that the two methods account for
different - although complementary - categories of input flows, use different conversion
factors, and answer to different questions and concerns