Some observations on the mechanism of phosphorus fixation in some soils of British Guiana

Abstract

A study has been made of the distribution of the various fractions of phosphorus in the Blairmont clay soils. Nearly three-fifths of the total phosphorus is present in the organic and inorganic alkali-soluble forms.The organic alkali-soluble phosphorus and the exchangeable phosphorus vary in direct relation to cane production and to phosphorus content of the juice. The Truog phosphorus values are nil for all three soils and do not give a satisfactory indication of the phosphorus-supplying ability of the soils.The soils have a high anion exchange capacity (23· mmol. of phosphorus per 100 g. of soil). It is indicated that the high fixing power of these soils for phosphorus is largely a mechanism of anion exchange reactions.