A fertilization design device calculates a fertilization amount of a field to be fertilized and includes the following units. A database reception unit receives one or both of growth data indicating growth potential of the field and soil data indicating plant growth potential of soil in the field and receives position data as position coordinate information for the field. A designated position reception and retrieval unit receives a freely selected position designated by a user and retrieves information of the freely selected position from the position data. A user input fertilization amount value reception unit receives a fertilization amount value freely set by the user for the freely selected position or for a range including the freely selected position. A calibration curve generation unit generates a calibration curve, based on one or both of the growth data and the soil data, the position data, and the fertilization amount value.
