Soil Classification Based on their Chemical Composition Using Principal Component Analysis

Principal component analysis (PCA), was used to group of 54 soil samples collected from different agricultural locations in the western part of Thailand. Soil chemical compositions were measured by Scanning Electron Microscope (SEM) and Energy Dispersive X-ray Microanalysis (EDX). The basic result indicated decreased amount of O, Si, Al, Fe, C, K, Mg, Ca, Ti and Na. The first three principal components were used and accounted for 44.0%, 19.5 % and 15.0 % of total variation of the data, respectively. Score plots of first three principal components were used to map with soil textures classified as clay, clay loam and medium loam. The results showed some relationships between chemical contents and soil textures. PCA was shown to be a useful tool for soil texture classification based on their chemical compositions