PHOSPHORUS IN FLORIDA WATERSHEDS: SCIENCE AND APPLICATIONS
Module 4: Recent Developments in Techniques for Evaluating Phosphorus Release from Soils
Module 4: Recent Developments in Techniques for Evaluating Phosphorus Release from Soils
Lecture 1: Degree of P saturation & the P saturation ratio: Theory and calculations
Describes why the degree of P saturation ratio (DPS) is used and how to calculate it, including the extractants that can be used for DPS calculations. Explains the P saturation ratio (PSR), the preferred extractants, and molar calculations. Describes the change point concept and the difference between soil test phosphorus (STP) and PSR.
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References
- Beck et al., 2004. Soil Sci. Soc. Am. J. 68:1762−1771.
- Breeusma, A and S. Silva. 1992. Phosphorus fertilization and environmental effects in The Netherlands and the Po region (Italy). Rep. 57. Winard Staring Center, Wageningen, The Netherlands.
- Freese, D., R. Lookman, R. Merckx, and W.H. van Riemsdijk. 1995. New method for assessment of long-term phosphate desorption from soils. Soil Sci. Soc. Am. J. 59:1295–1300.
- Khiari, L., L.E. Parent, A. Pellerin, A.R.A. Alimi, C. Tremblay, R.R. Simard, and J. Fortin. 2000. An agri-environmental phosphorus saturation index for acid coarse-textured soils. J. Environ. Qual. excessive losses of P from agricultural land continue to 29:1561–1567
- Maguire, R.O., and J.T. Sims. 2002. Soil testing to predict phosphorus leaching. J. Environ. Qual. 31:1601−1609.
- Nair, V.D., and D.A. Graetz. 2002. Phosphorus saturation in Spodosols impacted by manure. J. Environ. Qual. 31:1279-1285.
- Nair, V.D., K.M. Portier, D.A. Graetz, and M.L. Walker. 2004. An environmental threshold for degree of phosphorus saturation in sandy soils. J. Environ. Qual. 33:107–113.
- Paulter, M.C., and J.T. Sims. 2000. Relationships between soil test phosphorus, soluble phosphorus, and phosphorus saturation in Delaware soils. Soil Sci. Soc. Am. J. 64:765-733.
- Sims, J.T., R.O. Maguire, A.B. Leytem, K.L. Gartley, and M.C. Pautler. 2002. Evaluation of Mehlich 3 as an agri-environmental soil phosphorus test for the mid-Atlantic United States of America. Soil Sci. Soc. Am. J. 66:2016−2032.