Site-specific management of grassland offers numerous advantages, such as increasing yields and forage quality, protecting natural resources and promoting biodiversity. Application maps based on yield data are required for practical implementation. These can be obtained using sensors on the forage harvester or by satellite in conjunction with growth models. Both methods were tested under practical conditions in the DigiMilch experimental field. The sensor-based method proved to be very accurate and practical. Although the satellite-based method still offers potential for improvement, it nevertheless represents a practical and future-orientated solution. We investigated the question of what quality and quantity of yield data is necessary to map the yield potential of each individual area as realistically as possible.