The Quantitative Estimate of Bioavailable Inorganic Phosphorus Content in Forest Soils by the Modification of the Anion-Exchange Resin Method

Abstract

The anion-exchange resin (AER) method for the estimation of bioavailable phosphorus was slightly optimised for soils with high contents of readily soluble organic compounds as well as for those having very dif- ferent clay and sand contents. The method based on a strong base anion exchanger, the active group of trimethyl benzyl ammonium, the field moist soil, and the enclosure of resin beds in a bag was very different soils under relatively uniform outer conditions where the determination of the absorbance of (blue) phosphate-molybdate complex at 870 nm is used. The motivation of the proposed method comes from distinctive features of forest soils where marked differences are commonly encountered between clay/silt/sand contents, pH-values, and the contents of organic substances. A modestly new methodology was applied for the evaluation of seasonal phosphorus dynamics in a forest environment. The recommended rapid assay for available phosphorus was statistically compared with other procedures. Considerable seasonal effects on the bioavailable P contents were demonstrated.