Fuente: Wipo "precision farming" A method of selecting a treatment recommendation for nitrogen loss in a field includes measuring a first characteristic of a soil sample that is related to biologic nitrogen loss to produce a measured value. A second characteristic of the soil sample is measured and is used to select a sample group for the soil sample. The measured value is scaled based on the soil sample group the soil sample is placed into to form a scaled measure and the scaled measure is used to select a treatment recommendation.