The Fate of Applied Phosphorus in Four Ohio Soils1
- Veril V. Volk and
- E. O. McLean2
Four acid soils were selected on the basis of the level of available P and the magnitude of P fixing capacity (ability to retain soluble P against Bray P1 extracting solution). Water-soluble P labeled with P32 was applied at the rate of 3.4, 29.2, and 106 pp2m. parts of soil with and without additions of lime. The availability of the soil P to oats in the greenhouse was computed by the methods of Fried and Dean (also Larsen and Sokolov) and of Murdock and Engelbert. Fractionation of the phosphate compounds formed in the soil was also made by the method of Chang and Jackson.
Both the initial level of available P and the P fixing capacity were found to be important in determining the amount of plant response to applied P. A value indexes of available P generally increased with rate of application of P and lime. The application of soluble P to soils high in P fixing capacity decreased the availability (Bray P1 extractability) of the native P, while the added P tended to increase the availability of the native P in the low fixing soils. Almost all of the applied P was recovered in the Al and Fe phosphate components. There was a tendency for recovery of more than half of the applied P as FePO4 in the soils of high P fixing capacity and more than half as AlPO4 in those of low fixing capacity.Please view the pdf by using the Full Text (PDF) link under 'View' to the left.
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