Submitted to: Communications in Soil Science and Plant Analysis
Publication Type: Review Article
Publication Acceptance Date: 2/20/2001
Publication Date: 4/30/2001
Citation: Sharpley, A.N., Kleinman, P.J., Mcdowell, R. 2001. Innovative management of agricultural phosphorus to protect soil and water resources. Communication In Soil Science Plant Analysis. 32(7&8):1071-1100. Interpretive Summary: Phosphorus (P) is an essential element for plant growth and its input has long been recognized as necessary to maintain profitable crop production. Phosphorus inputs can also increase the biological productivity of surface waters. Thus, reducing P loss in runoff is of prime importance in minimizing accelerated eutrophication of fresh waters. More intensive crop pand livestock production in many parts of the world has generally increase the potential for P export from watersheds. Thus, a greater understanding of where P is coming from, how much P in soil and water is too much, and how and where can we reduce these losses and inputs, is needed to develop economically and environmentally sound P management systems. This paper examines factors affecting the potential for agricultural P loss and outlines management options that can be directed at controlling nonpoint sources of agricultural P. Best management practices that address the two factors affecting the potential for agricultural P loss, source factors an transport factors, are presented.
Technical Abstract: Agriculture, particularly livestock agriculture, is receiving increasing public scrutiny due to non-point source phosphorus (P) pollution and eutrophication. Much of today's situation may be attributed to system level trends in specialization and intensification that result in excess P entering livestock farms. Balancing P at the farm gate represents a necessary step for long-term soil and water quality protection. Remedial management combines source and transport control that confront critical areas of P export in surface and subsurface runoff from agricultural landscapes. Source management seeks to immobilize P in the environment through such strategies as reducing soluble P in manure, targeting P application to soils with high retention capacities, and managing soil P. Transport controls employ an understanding of loss or transfer mechanisms to avoid P application on areas with a high transport potential. Also, the epotential for P transport can be reduced by implementation of conservation practices such as reduced tillage, terracing, and stream buffers. However, implementation of agricultural management strategies that minimize P export must consider the cost-effectiveness of alternative measures, as low practice adoption may limit or impede water quality benefits.