FORMS OF PHOSPHORUS IN A SEQUENCE OF SOILS DEVELOPED ON FRASER RIVER ALLUVIUM

Abstract

The distribution of different forms of phosphorus was determined for soil samples and particle size fractions from a sequence of soils developed on Fraser River alluvium. The values for inorganic P when apportioned as aluminum-P, iron-P, reductant-P and calcium-P were found to be dependent on soil-forming processes. Calcium-P levels decreased and iron-P and organic-P levels increased with increasing distance from the river, and with more pronounced profile development. Changes in the relative amounts of these various forms of soil P occurred over relatively short distances and affected the amounts of P extracted in standard soil testing methods. P levels depended very little on soil texture for the majority of the soils, although there was some evidence in favor of fine particle sizes over the sand fractions as a source of P in one of the profiles.