Solubility of Phosphorus in Some Genetically Related Loess-Derived Soils1
- Curtis L. Godfrey and
- F. F. Riecken2
Phosphorus solubility studies were made on five loessderived soils showing increased profile development in relation to their location along a traverse from southwestern. Iowa to northern Missouri. The pH of the extractant varied from about 2.0 to 11.0. This technique was used to determine the general chemical nature of the inorganic phosphorus compounds in each profile.
The results showed the acid, near neutral, and alkaline soluble phosphorus to be a function of the position of the sample in the profile and to be further related to the degree of profile development—the A, B, and C horizons showing definite solubility patterns. The A horizons yielded about equal yet small amounts of phosphorus both in the acid and alkaline media. In the B horizons the alkaline extractions removed much more phosphorus, while in the C horizons the acid media not only solubilized more phosphorus but very much more than at any other position in the profiles. All horizons of all profiles showed low soluble phosphorus in the neutral media. The more strongly developed profiles tended to be lowest in soluble phosphorus showing the tendency of the soil development processes to fix the phosphorus compounds into less soluble forms. The study indicates that soil weathering tends to change the inorganic phosphorus from calcium forms to iron, aluminum, and adsorbed forms, but that organic matter retards this action and forms other complexes both alkaline and acid soluble.Please view the pdf by using the Full Text (PDF) link under 'View' to the left.
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