Soil quality. Determination of soil microbial diversity. Method by phospholipid fatty acid analysis (PLFA) & phospholipid ether lipids (PLEL) analysis Soils, Quality, Soil testing, Microbiological analysis, Microorganisms, Microbiology, Biological analysis & testing, Chemical analysis & testing, Determination of content, Lipids, Fatty acids, Phosphorus organic compounds, Fat extraction methods, Chromatography