Organic matter Carbon 1 Carbon sequestration 1 Chemical composition 1 Cycling 1 Fertilizers and other Amendments 1 Humus 1 Litter (plant) 1 Manures 1 Nitrogen 1 Nutrient availability 1 Plant residues 1 Rhizosphere 1 Soil Biology 1 Soil Chemistry and Mineralogy 1 Soil Fertility 1 Soil amendments 1 Soil biology 1 Soil chemistry 1 Soil clays 1 Soil colour 1 Soil fauna 1 Soil fertility 1 Soil flora 1 Soil management 1 Soil organic matter 1 Soil structure 1 Soil water 1 Sustainability 1 Sustainable agriculture 1