Soil formation process

+ VNU SPEA NGUYEN XUAN HAI 2012 ! + Why soil – and soil science – matters ? “Why we know more about distant celestial objects than we about the ground beneath our feet?” Root of life: the soil forms the central link between the climate and biogeochemical systems Soil Formation process What’s soil? Atmosphere Biosphere Soil Lithosphere Hydrosphere Soil functions Environment for plant growth Habitat of the organisms Agricultural plants SOIL Air exchange Save geological events, climatic, biological and human history Waste decomposition Water purification and waste Resource materials, medicine and the arts Definition Parent material Relief (Topography) Organism Soil Time (Dokučaev, 1883) Climate Soil = f (clropth) Soil layers (horizon) The process of soil formation affects the profile with different horizons Horizon in soil profile be distinguished by physical and chemical characteristics O: Humus A: Surface horizon B: Subsurface horizon C: Weathered parent material gradational contact R: Fresh parent material (Bedrock – đá gốc) Soil colors [...]... Soil resources The process of soil formation Transformation: Weathering of rock and other materials Sandstone in Australia The process of soil formation Transformation: Weathering of rock and other materials Formation of secondary minerals (eg, formation of clay minerals from the mica) Mica cristalls (Muscovite from Brasil) Illite (clay mineral) Formation of secondary minerals The process of soil formation. .. resistance varies among minerals Figure from: Brady c and Weil R The nature and properties of soils 13th ed Prentice Hall, NJ, 1996 transformation A+B→C translocation Paul & Clark, 1996 The interaction of environmental factors in the development of biological soil Soil has the following characteristics: •  Soil horizons or layers be distinguished from the original material formed as a result of the... (eg, formation of clay minerals from the mica) Mica cristalls (Muscovite from Brasil) Illite (clay mineral) Formation of secondary minerals The process of soil formation Transformation: Weathering of rock and other materials Formation of secondary minerals (eg secondary minerals of iron and aluminum) Goethite: α-FeOOH Hematite: Fe2O3 red sand dunes (Australia) Gibbsite: Al(OH3) Ferrihydrite: Fe2O3*nH2O... + Weathering: Combination of destruction and synthesis resulting from physical and chemical processes Physical weathering: breakdown of rock and mineral particles by physical forces such as erosion or frost action Chemical weathering: breakdown due to chemical activity such as dissolution, hydrolysis,