EXTRACTION OF ORGANIC PHOSPHORUS FROM SOILS WITH SODIUM BICARBONATE

Abstract

Sodium bicarbonate extractable organic phosphorus increased with increasing pH of extractant, temperature, time of extraction, and soil/solution ratio. The inclusion of an acid pretreatment resulted in higher organic phosphorus levels than bicarbonate extraction only.The proposed method involves extraction with 0.5 M sodium bicarbonate at pH 10.0 for 16 hours at 90 °C following acid pretreatment with 0.5 N hydrochloric acid for 1 hour. Under these conditions 98.8% of the total organic phosphorus, as estimated by the method of Mehta et al., was extracted.