The Nature of Phosphorus in Soils

The Nature of Phosphorus in Soils
Lowell Busman, John Lamb, Gyles Randall, George Rehm, and Michael Schmitt, University of Minnesota extension, FO-06795-GO, 1998

Phosphorus (P) is an essential element classified as a macronutrient because of the relatively large amounts of P required by plants. Phosphorus is one of the three nutrients generally added to soils in fertilizers. One of the main roles of P in living organisms is in the transfer of energy. Organic compounds that contain P are used to transfer energy from one reaction to drive another reaction within cells. Adequate P availability for plants stimulates early plant growth and hastens maturity. Although P is essential for plant growth, mismanagement of soil P can pose a threat to water quality. The concentration of P is usually sufficiently low in fresh water so that algae growth is limited. When lakes and rivers are polluted with P, excessive growth of algae often results. High levels of algae reduce water clarity and can lead to decreases in available dissolved oxygen as the algae decays, conditions that can be very detrimental to game fish populations.

The Phosphorus Cycle
Forms of Phosphorus in Soils
Fate of Phosphorus Added to Soils
Predicting the Availability of Phosphorus in Soils
Soil Phosphorus and Water Quality