神奈川県における水田土壌の主成分分析による土地分級
1979 年 23 巻 2 号 p. 118-133
詳細
1979 年 23 巻 2 号 p. 118-133
Application of the system for soil classification for soil productivity in paddy soil is generally useful. But, in case of study of correlation between soil and crop yield, it is necessary to subdivide soil series further to soil unit based on land classification. The author tried to use the data of potential soil productivity, which was obtained based on the cultivation experiment of 49 locations in Kanagawa prefecture. However, there were no direct correlation between soil characteristics and soil productivity. To approach this problem, the author has developed a scoring method which is based on the data obtained from principal component analysis for land classfication. The first principal component of soil profile is the factor concerning "land moisture" and 35% of 10 characteristics can be explained by the present method. The second principal component is the factor concerning "texture of top soil" and 56% of 10 characteristics can be explained by the first and the second principal components. The third principal component is the factor conserning "oxidation-reducation potential" and 73% of 10 characteristics can be explained by these three components. The first principal component of chemical property characteristics of top soil is the factor concerning "fertility" and 49% of 9 characteristics used can be explained by this component. The second principal component is the factor concerning "content of soil potash" and 70% of 9 characteristics can be explained by these two components. The third principal component is the factor concerning "content of fertilizered potash" and 84% of 9 characteristics can be explained by these three components. The second principal component of "texture of top soil" showed a high relationship (r : -0.533) with hulled rice yield. In other words, when the top soil has a fine texture, yield of rice is high and vice verse. High clay content soil possesses a high nutrient absorption ability in term of both quantity and quality, and high rate of uptake of nutrient by rice plant can be expected.
