PROBLEM TO BE SOLVED: To provide fertilization design method that can determine the nitrogen application amount in a field more readily than before.SOLUTION: The present invention has: a step S31 of measuring the color of a leaf and the number of stems of a crop in growth of this period a step S32 of calculating the absorbed nitrogen amount of the crop from the measured leaf color and the number of stems a step S34 of calculating the present soil nitrogen amount by subtracting a nitrogen application amount S33 which has been thrown in this period, from the absorbed nitrogen amount and a step S35 of calculating a next nitrogen application amount necessary for growing a crop in the next period from the soil nitrogen amount and the proper nitrogen amount for growing a crop.SELECTED DRAWING: Figure 3COPYRIGHT: (C)2018,JPO&INPIT【課題】従来よりも容易に圃場内の窒素施用量を決定することができる施肥設計方法を提供する。【解決手段】今期生育中の作物の葉色および茎数を測定しS31、測定した葉色および茎数から作物の吸収窒素量を求める段階S32と、吸収窒素量から今期投入済み窒素施用量S33を減算することで、現在の地力窒素量を求める段階S34と、地力窒素量と作物を生育させるための適正窒素量から次期の作物を生育させるために必要な次期生育用窒素施用量を求める段階S35と、を有する。【選択図】図3
