Natural and anthropic energy flows in agricultural biomass production - Study
Agricultural production (cultivated terrestrial plants grown for nutritional, material and energy provision) is recognised as being a main provisioning ecosystem service. Nevertheless biomass obtained through agricultural activities is not a mere product of natural ecosystems, but requires substantial human input to be obtained. This report presents a further development in disentangling the nature and anthropic contributions to agricultural biomass production by means of energy flows. We identify and quantify the respective natural and human energy inputs into main cropping systems in Europe.... The energy quantification is based on the emergy concept, which is the energy needed, directly and indirectly, to make a product. Natural components include sun radiation energy, wind, rainfall, flowing water and groundwater, and topsoil. Human components consist of purchased inputs (e.g. fertilizers, machinery) and human labour. Overall, the emergy results show that the energy used to produce biomass in cropping systems mainly originates from human inputs, particularly from the use of artificial fertilisers and ploughing and tilling, and overall is higher in cropland than in grasslands. By applying the emergy concept we are able to assess the intensity of farming management practices. Emergy helps, therefore, to analyse the provisioning ecosystem services derived from agriculture considering the intensity of their production system. At the same time, it offers a new approach to identify ways to achieve a maximum crop yield considering the balance between natural and human resources, and therefore support resource efficiency in agricultural production. The outcomes of this study should be considered as a first methodological approximation based on the available data and models.