Mineralogy 47 Soil Chemistry and Mineralogy 17 Petrology 13 Crystallography 12 Minerals 11 Geology 10 SCIENCE / Earth Sciences / Mineralogy 9 Soil Fertility 9 Soil fertility 9 Soil organic matter 8 Soil Biology 7 Soil chemistry 7 Agricultural chemistry 6 Earth science 6 Pollution and Degradation 6 Water Resources 6 Chemical composition 5 Cycling 5 Geochemistry 5 Grasslands 5 Grasslands and Rangelands 5 Nitrogen 5 Phosphorus 5 Plant nutrition 5 Soil biology 5 Soil mineralogy 5 Soil science 5 Soils 5 Erosion 4 Erosion: Soil and Water Conservation 4