ARS | Publication request: Downstream approaches to phosphorus management in agricultural landscapes: Regional applicability and use

Submitted to: Science of the Total Environment
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: October 8, 2012
Publication Date: January 7, 2013
Citation: Kroger, R., Dunne, E.J., Novak, J., King, K.W., Mclellan, E., Smith, D.R., Strock, J., Boomer, K., Tomer, M., Noe, G.B. 2013. Downstream approaches to phosphorus management in agricultural landscapes: Regional applicability and use. Science of the Total Environment. 442:263-274.

Interpretive Summary: Phosphorus (P) is a critical plant nutrient for high crop yields, however, its loss from soil to downstream aquatic systems can result in water quality problems. Poor water quality from excess P concentration in freshwater systems is caused by eutrophication, which creates algal blooms and results in oxygen depletion. Recent examples of P-impacted water bodies include the Great Lakes, Florida Everglades, Chesapeake Bay, Florida Keys, and the Gulf of Mexico. A key response to improve water quality is how to effectively reduce off-site P movement using natural landscape features and understand practices that can sequester P. We have identified both in-stream features and landscape level practices to reduce P delivery from landscapes to downstream aquatic systems. For example, downstream approaches involving stream-side riparian buffers, wetlands, controlled drainage, and in-stream techniques (impoundment ponds) can effectively be used to reduce P loss. Phosphorus can be sequestered using in-stream wetlands that reduce both soluble and sediment P movement. Effective P mitigation strategies are available; however, choice and placement of the in-stream and landscape features to reduce P movement and/or sequester P will determine the success of water quality improvement. Conservationists and water resource managers may find this review of interest for an improved understanding of alternate strategies for mitigating P water quality problems.

Technical Abstract: This review provides a synthesis of conservation practices that are aimed at improving water quality by retaining phosphorus (P) downstream of runoff genesis. The review is structured around specific downstream practices that are prevalent in various parts of the United States, but also focuses on the specific hydrological and biogeochemical processes of P associated with each of those practices that make them efficient for P retention. The practices are structured linearly as you move through the landscape, from the edge-of-field, to adjacent aquatic systems conducive to management strategies, and ultimately to downstream P retention.