Abstract

                                A detailed knowledge of the pattern of fixation existing over a period of time will enable one to decide upon the type of phosphate fertilizer to be applied to bring about the minimum waste of fertilizer through fixation. Soils are known to differ considerably with reference to their capacity to fix applied soluble phosphates. Variation in soil reaction, clay minerals, lime and free sesquioxides have been demonstrated to bring about appreciable differences in the capacity of soils in the matter of fixation or availabilisation of phosphates. In Madras State a number of dissimilar groups of soils occur and detailed information regarding phosphate availability changes with time in these soils is not available. The present work was taken up to obtain such detailed information.

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