Influence of Organic Matter and Lime on the Transformation of Applied Phosphate in Acidic Lowland Rice Soils

The transformation of added water soluble phosphate in acidic low land rice soils and the influence of application of organic matter and lime on such transformation was studied.

The amount of added phosphate remaining in the soluble form declined very sharply in all the three soils Organic matter treatment maintained higher amount of phosphorus in the soluble form than that in the control. Effect of lime in this respect was not so pronounced.

Application of both organic matter and lime lowered significantly the fixation as aluminium phosphate. Application of organic matter greatly reduced the fixation as iron phosphate in all the soils but this effect was most pronounced in the case of laterite soil of Midnapore. Application of lime also significantly lowered the fixation as iron phosphate; this effect was most prominent in the case of Kalimpong soil. Fixation as calcium phosphate was comparatively low in all the three soils. Application of organic matter did not bring about any important change in fixation as calcium phosphate. Lime, however, caused increased fixation in this form.