SOIL 414: Soil Chemistry and Fertility

Solid phase: Origin and distribution of charge on soil colloid surface, point of zero charge, electrical characteristics of soil/water interface, double layer theory; mechanism of cation and anion fixation in soils.  Sulphur, aluminium, pyrite in the formation of soil acidity.  Liquid phase: composition, concentration, activities and activity coefficients, Debye-Huckle theory; Chemical factors affecting plant growth: growth expressions, Mitscherlich’s law of diminishing returns, Liebig’s law of the minimum.  Methods of evaluating soil fertility; principles of soil fertility management – fertilizer application, liming, lime requirement of soils, reactions of lime in soils.  Management of acidic, saline and sodic soils.  Soil and plant factors affecting N availability to plants, behavior of P fertilizers and their availability in soils.