Submitted to: Soil Science Society of America Journal
Publication Type: Review Article
Publication Acceptance Date: January 29, 2008
Publication Date: February 28, 2008
Citation: Dao, T.H. 2008. Review of Modeling Phosphorus in the Environment. Soil Science Society of America Journal. 72(2):278.
Phosphorus (P) is a key component of fertilizer inputs in plant agriculture and a critical ingredient of diets in animal nutrition. Elevated levels of environmental P and nitrogen have often resulted in algal blooms and accelerated eutrophication of lakes and streams, and degrade fragile ecosystems of estuaries and coastal waters. Mathematical models are increasingly used in the evaluation and development of mitigation strategies and management practices to attenuate impacts of agriculture on the environment. "Modeling Phosphorus in the Environment” is a timely review of basic processes that affect the movement of P in the environment. The book is a compendium of contemporary research and management models with a module to simulate P transport, including models with the well-recognized acronyms of SWAT, HSPF, AnnAGNPS, ANSWERS-2000, WEND-P, and GWLF. While transport mechanisms of dissolved and particulate P are thoroughly examined, the book does not extensively address the speciation of phosphorus forms that exist in soil and water systems, and at the soil-water-air interface. Phosphorus is used as a generic term in the title of the book as well as in the models, regardless of the P species’ chemical formula or chemical classes. Many of the soil P algorithms and geochemical modules in the models were based on concepts developed in 1980’s, embodied in the Groundwater Loading Effects of Agricultural Management Systems (GLEAMS). Although many advances have been made in the understanding of the biogeochemistry of inorganic and organic forms, factors influencing P speciation and release mechanisms over the last two decades, current P models have yet to substantially link these processes with surface transport and movement in the vadose zone. Translating the knowledge of inorganic and organic release mechanisms into consistent algorithms that link them to transport processes remains a challenging task that will be a necessary development in future P models.