After reading this article you will learn about the cation and anion exchange in soils. Cation Exchange in Soils: Cations surrounding the soil colloidal complex i.e. clay and humic micelle are called exchangeable cations because they can be reversibly replaced equivalently by other cations. For example when ammonium chloride is applied to the soil, then ammonium ions gradually and reversibly [...]
After reading this article you will learn about phosphate retention and fixation in soil. Kaolinite has a strong affinity for phosphate anions. Phosphate anions can be attracted to soil constituent with the force strong enough to make them insoluble and difficulty available to plant roots. Tisdale and Nelson (1975) have differentiated phosphate retention from phosphate fixation by the fact in [...]
After reading this article you will learn about the pH of soil and factors affecting it. pH of Soil: When soils contain more hydrogen ions than hydroxyl ions, they are acidic in reaction. If they contain more hydroxyl ions than hydrogen ions, they are alkaline in reaction. If they contain equal number of hydrogen and hydroxyl ions, they are neutral [...]