An analysis of agricultural sustainability of cropping systems in arable and dairy farms in an intensively cultivated plain

In Lombardy region (northern Italy) agricultural systems are mostly based on cereals and forage crops, and are normally intensively cultivated. To monitor and analyse the most important agri-environmental issue of this area (water pollution by nitrates and plant protection products, non-renewable fossil energy exploitation, weed dynamics), we conducted an integrated agronomic, environmental and economic assessment of arable and dairy farming using indicators. The structural and management data about farming and cropping systems were collected by periodic interviews over a 3-year period in seven (three arable and four dairy) representative farms. The nitrogen surplus calculated at field scale ranged from low (27 kg N ha(-1)) to high (339 kg N ha(-1)) values, depending by the amount of chemical and organic fertilisers applied. Fossil inputs ranged from 11.2 to 46.0 GJ ha(-1); the highest values were due to the high use of machinery and chemical inputs. The efficiency factor in energy transformation (an indicator of the dependence of food and feed production on non-renewable energy) ranged from 5.0 to 12.2. Large variability was also observed for economic performance (gross margin; from -364 to 1078 (sic) ha(-1)). The lowest values were observed where the total costs of production (fixed and variable) were elevated. The simplification of cropping systems was responsible for a high probability of weed populations development. The values of Load Index, an indicator describing the potential toxicity of plant protection products on non-target organisms, showed an elevated use of active substances due to the dominance of maize. The indicator-based assessment, founded on a relatively simple data collection procedure, described crop management by combining different aspects into few quantities and highlighted its critical environmental issues. The work represents a starting point for improving cropping system management in the study area; the same procedure could be re-applied if data about improved management scenarios were available. (C) 2010 Elsevier B.V. All rights reserved.