Monday, November 13, 2006
117-7
Implications of Phosphorus Leaching in Soils Included in the Soil Characterization Database.
Major Mays, USDA/Natural Resources Conservation, 2711 S. 74th St., 2711 S. 74th St., Lincoln, NE 68506, United States of America, Moustafa Elrashidi, USDA-NRCS,NSSC Federal Bldg, Rm 152, 100 Centennial Mall N, Lincoln, NE 68508-3866, and David Hammer, USDA/Natural Resources Conservation Service, 100 Centennial Mall N, Federal Building, Room 152, Lincoln, NE 68508-3866.
The objectives of this project are to: 1) determine soil properties that leaching of phosphorus (P) in soil profiles, 2) determine soil properties and sampling depths supported by research that may be useful for setting criteria for interpretations for P leaching potential, and 3) find definitive (supporting) examples that may be used to support objective 1. Phosphorus leaching has long been recognized in some soils with detectable amounts in ground water. However, in other soils, researchers reported banded P movement of up to three centimeters from the point of injection. While research may appear to provide conflicting results, there are soil properties and site conditions that control P leaching in soils. These controlling factors include soil texture, application rate, preferential flow, rainfall/irrigation rate, pH, and depth to water table. In order to predict phosphorus movement, it is important to not only understand the runoff P, but also the potential for internal loss of P when conditions are favorable. Data from the Soil Characterization Database are used to identify/verify examples of controlling factors mentioned above.