Analyses of mineral element balances between 1997 and 1999 from dairy farms in the south of Sweden

Mineral balances, especially nitrogen balances, are analysed for 138 dairy farms over 3 consecutive years, 1997, 1998 and 1999, together with analyses of annual changes in strategy concerning the use of mineral fertiliser at the farm scale. Information was obtained from mineral balance sheets of dairy farmers who shipped milk to the dairy plant Dairy Skane. The mineral balance sheets for N, P and K were constructed using the farm gate model and a balance was calculated for the whole farm. Arable land was approximately 65 hectares and the annual milk delivery per hectare was around 6800 kg. Nitrogen surplus per hectare among dairy farms in the south of Sweden is lower than that found in the intensive milk production regions in Western Europe. Dairy farms that had an output of both crop and animal products had a lower N surplus and a higher N efficiency. The N surplus among the investigated dairy farms decreased between 1997 and 1999. Input of N from purchased mineral fertiliser decreased significantly from the first year.