Life Cycle Inventory of 23 Dairy Farms in South-Western Sweden

In this study, data on resource use and emissions for dairy farms in southwestern Sweden were collected and analysed with Life Cycle Assessment (LCA) methodology. The purpose of the study was to gain increased knowledge of the environmental impact of today´s milk production and of the variations between farms regarding resource use and emissions. Data were collected from 23 dairy farms in the Halland and Västra Götlands regions. The farms were divided into three groups: 1) Conventional high (Conv High); producing >7 500 kg ECM/ha (nine farms) 2) Conventional medium (Conv Med); producing < 7 500 kg ECM/ha (eight farms) 3) Organic (six farms) Data on concentrate feed production were upgraded from earlier work by collating statistics and information from different feed and food industries. All the studied farms participated in the advisory programme " Greppa Näringen " and had detailed information on feed and fertiliser consumption. In addition to this, data on use of diesel, electricity, pesticides and plastic were collected at the farms. For ammonia, nitrate, nitrous oxide and methane, different emission models were used in order to infer the losses. The functional unit (reference unit) in the study was " one kg of energy corrected milk " at the farmgate. Emissions of ammonia and nitrate, as well as pesticide use, were also evaluated per hectare of arable land at the farms. The systems analysed included all phases in the life cycle of fertilisers, feed products, diesel, pesticides and plastics. Transport steps were also taken into account. Buildings, machinery and medicines were not included. Allocation between milk and meat was done on an economic basis, distributing 90 % of the impact to milk and 10 % to the meat. Economic allocation was also used in the Life Cycle Inventory (LCI) of concentrate feed. In the LCIs of the 23 dairy farms, the results were presented as use of resources (energy, nutrients and land), use of pesticides, emissions of greenhouse gases, emissions of nutrifying and acidifying substances. The LCI results were statistically analysed in oneway ANOVA to establish the results that showed the least significant difference between the three farm groups. There was no significant difference in the use of energy resources between the two conventional groups. The overall energy use was significantly lower for the organic farm group in comparison with the conventional groups, and it was the total lower use of fossil fuels that explained this difference …