In this study, nutrient balances at farm-gate are calculated for nitrogen, phosphorus and potassium for ten organic, grassland-based dairy farms in Austria. Based on the results for the nutrient balance at farm-gate, three models were set up with varying reductions of concentrate feed. Nutrient balance Nitrogen balance at the farm-gate showed a surplus of between +25 and +69 kg/ha/year. The median value for the nutrient balance of the examined farms has been determined as +42 kg/ha/year and shows a small surplus in comparison to other published research results. The results for the phosphorus balance range from -1 to +8 kg/ha/year. Except for farm No. 10 the mean value of all farm-gate balances of +2 kg/ha/year can be classified as even. The results for potassium balance are between -1 and +36 kg/ha and year. The calculated mean value of 12 kg/ha for all investigated dairy farms is in agreement with estimates found in literature and can be interpreted as even. Models Within Model I the applied concentrate feed per cow and year was reduced by 25 %. The same is the case for Model II, but a reduction of milk production due to the decrease of concentrate and an increase of forage is assumed. In Model II the reduction of milk production per cow is compensated for by an increase in the number of dairy cows in order to keep the quantity of produced milk constant. Model III is based on a reduction of the applied concentrate feed by 50 % per cow and year. The assumptions and proceedings are identical to those for Model II. In Model I and II the nitrogen balance is reduced by an average 4 kg/ha and year. The phosphorus balance is reduced by about1 kg/ha and year. The mean value for the potassium balance is reduced by 1 kg/ha and year. Results from Model III show a median change of 7 kg/ha/year for nitrogen, 1 kg/ha/year for phosphorus and 3 kg/ha/year for potassium.