Abstract

                                The P fixation capacity of the four major soil groups of Tamil Nadu was estima- tod. The P fixation capacity of the soils ranged from 20 to 183 mg P/100 g of soil with a mean value of 85 mg P/100 g of soil. The soils studied were found to differ widely in their P fixation capacity, the highest value of P fixation capacity was recorded in the high level latorita soils of Ootacamund and the lowest in the alluvial soil of Melalathur. The P fixation capacity was found to be positively correlated with clay (r=0.632), total R30, (r=0.483). Also, (r=0.533). The relationships of P fixa- tion capacity with clay, total R₂Os. Fejos, free Fes0, and organic carbon were more close in acid soils than neutral and alkaline soils. In alkaline soils, the influence of free CaCO was more, whereas in the neutral soils. Fo,O,. CEC and exchangeable Ca influenced the P fixation capacity of soils.

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