Nutrient balances are used to clarify the efficiency of the use of nutrients and the amount of unused nutrients in agriculture. Monitoring of nutrient balances in field cultivation is important for the condition of the field and also for controlling of water protection. Optimizing the use of nutrients is important in potato farming because it has an influence to the amount and quality of crop and on the other hand it has an impact on finance by the use of inputs. The aim of this thesis work was to use nutrient balance calculation to find out the amount of nutrients remaining on the ground and to estimate the risk of nutrients leakage on a farm specialized in food potato cultivation. A target was also to clarify how crop rotation can be improved in order to achieve a better use of nutrients. Nutrient balance calculations are made for the fields used for potato farming. Information on normal farming activities, such as fertilization and harvesting has been recorded accurately on the farm. The material used for calculations was fertilization and harvesting data over the period 2010 – 2012, as well as fertility information. In all fields used for potato cultivation, nitrogen balance was on average deficient, phosphorus balance was surplus and potassium balance close to equilibrium. Variation was great between the different sectors and between years. To maintain and improve the good growth potential of land under cultivation, the farm should pay attention especially to the crop rotation.