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An investigation was undertaken to identify the extractability of P through different extractants and to determine the critical limits of P for wheat. The study was made with five extractants in sixteen selected soils of Bangladesh. The amount of extractable P varied markedly depending on the soils and extractants used. Although the ability of P extraction was different for different extractants, their trends of P displacement from soil into solution were mostly similar. All the extractants used in this study correlated well with each other. The application of P encouraged plant growth with the effect of P being large with P fertilization up to 100 mg kg-1. A critical limit of extractable P for wheat was determined by two approaches: graphical and statistical for indicating that below this level of soil P an economic crop response is expected.