PROBLEM TO BE SOLVED: To enable a soil diagnostic result of an area not good in nutrient condition and physical condition of the soil to be obtained even if too many soil sampling points are set so as to be utilized for the subsequent soil making and basal fertilizer.SOLUTION: This soil diagnostic method includes: a growth distribution detection process； a soil sampling point determination process； and a soil diagnostic process. The growth distribution detection process detects a distribution of the growth condition of crops in a farm field. The sampling point determination process determines one or a plurality of soil sampling points P1 to P5 including the soil sampling points P1 to P4 included in the area which is relatively not good in the growth condition. The soil diagnostic process diagnoses at least either of the soil nutrition condition or the soil physical property in each of the soil sampling points P1 to p5 based on the soil samples taken at the soil sampling points P1 to P5.SELECTED DRAWING: Figure 3【課題】採土地点を過剰に多く設定しなくても、土壌の養分状況や物理状況が良好でない領域の土壌診断結果を得られるようにし、その後の土づくりや基肥等に活かせるようにする。【解決手段】この土壌診断方法は、生育分布検出工程と、採土地点決定工程と、土壌診断工程と、を含む。前記生育分布検出工程では、圃場内での作物の生育状態の分布を検出する。前記採土地点決定工程では、前記生育分布検出工程で得られた検出結果に基づいて、生育状態が相対的に良好でない領域内に含まれる採土地点Ｐ１～Ｐ４を含む、１つ又は複数の採土地点Ｐ１～Ｐ５を決める。前記土壌診断工程では、前記採土地点Ｐ１～Ｐ５で採取された土壌サンプルに基づいて、前記採土地点Ｐ１～Ｐ５のそれぞれでの土壌養分状況又は土壌物理性状況の少なくとも何れかを診断する。【選択図】図３
