Agro-ecological indicators of field-farming systems sustainability. I. Energy, landscape and soil management

Evaluation of the sustainability of farming systems management can be carried out with direct measurements, simulation models or indicators; the latter have the advantages of requiring a small amount of inputs, being fast to calculate and easy to interpret, allowing comparisons in space and time, and representing a synthesis of processes in complex systems. In this paper we propose a list of indicators which synthesise the state of the farming system or the management effects on the environment related to fossil energy use, landscape and soil management. We selected indicators from the literature which can be applied at the field and farm scale, based on data obtainable from the farmer and / or from existing agricultural databases; we excluded indicators based on direct measurements. In a second paper we will introduce indicators related to nutrients and pesticides use. The direct and indirect consumption of fossil energy can be calculated at different levels of detail and it is used to calculate the efficiencies of different systems (output/input ratios). Landscape indicators describe the presence and the density of various elements that compose the landscape (crops, linear elements, isolated shapes), allowing also, in one case, to compare landscape "demand" and "supply". The soil management indicators describe the relation between soil quality and crop management using: i) the crop sequence indicator that evaluates the goodness of each previous-successive crop combination in a rotation, assigning specific scores to the effects of one crop to another in terms of development of pathogens, pests and weeds, soil structure and nitrogen supply; ii) the organic matter indicator that evaluates if the management adopted by the farmer on a specific soil tends to accumulate or deplete soil organic matter; and iii) the soil cover index for evaluating soil protection by crops. Overall the indicators, based on a rather small data set, allow to conduct immediate syntheses of important agro-ecological aspects of farming systems.