Fertilization and pH effects on processes and mechanisms controlling dissolved inorganic phosphorus in soils

摘要: Abstract We used of a set mechanistic adsorption models (1-pK TPM, ion exchange and Nica-Donnan) within the framework component additive (CA) approach in an attempt to determine effect repeated massive application inorganic P fertilizer on processes mechanisms controlling concentration dissolved phosphorus (DIP) soils. studied surface layer Luvisol with markedly different total concentrations as result history (i.e. or no for 40 years). Soil pH was made vary from acid alkaline. solutions were extracted water CaCl 2 (0.01 M). The occurrence montmorillonite led us binding properties Ca ions this clay mineral. Satisfactory results obtained using generic values model parameters soil-specific ones, which either determined directly by measurements estimated literature. showed that largely controlled variations DIP that, because kinetic constrains, only little Ca-phosphates may be precipitated under alkaline conditions, particularly fertilized treatment. mineral-P pool initially present both treatments did not dissolve significantly during course experiments. onto soil minerals also promoted through electrostatic interactions. intensity mechanism high neutral conditions. Changes function these environmental variables can related changes contribution various adsorption. extra adsorbed treatment compared control mainly illite. This mineral major P-fixing constituent repulsion interactions between deprotonated hydroxyl sites sufficiently counterbalanced ions. drastic increase observed at due lower Fe oxides kaolinite. In addition confirming validity our soils, investigation predominant geochemical process even soil, have important promoting However influence dissolution field conditions remained questionable.