ARS | Publication request: Phosphorus concentration and loading reductions followin changes in fertilizer application and formulation on managed turf

Submitted to: Journal of Environmental Monitoring
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: September 14, 2012
Publication Date: November 12, 2012
Repository URL: http://handle.nal.usda.gov/10113/56388
Citation: King, K.W., Balogh, J., Agrawal, S.G., Tritabaugh, C., Ryan, J. 2012. Phosphorus concentration and loading reductions followin changes in fertilizer application and formulation on managed turf. Journal of Environmental Monitoring. 14(11):2929-2938.

Interpretive Summary: Phosphorus is a leading cause of eutorophication in streams and freshwater lakes worldwide. Phosphorus loads from managed turf systems have been shown to exceed recommended levels to protect against eutrophication prompting the turf industry to explore alternative management practices to reduce phosphorus losses. We measured water quality at a golf course in Duluth, MN following two different management approaches, a traditional approach and an approach that used reduced rates and organic formulations. Phosphorus loss following reduction in application rates and use of organic formulations were significantly less than losses using the traditional approach. These findings highlight the need for the turf industry and in particular turf managers to investigate the feasibility of changing their fertility management related to phosphorus.

Technical Abstract: All current and future efforts to address water quality impairment must focus on phosphorus. Phosphorus is a natural element in the environment and is an essential element of all life. However, excess phosphorus, particularly in surface waters can lead to severe eutrophication. Identifying source areas, quantifying contributions, and evaluating management practices are required to address current and future eutrophication concerns. A before-after study was conducted from 2003-2010 on a sub-area of Northland Country Club Golf Course in Duluth, MN to assess the impacts of two different phosphorus management approaches (Period 1: traditional application and timing using commercially available synthetic blends; Period 2: reduced rate, low dose applications, and organic formulations). Outflow median dissolved reactive phosphorus (DRP) and total phosphorus (TP) concentrations were significantly less in Period 2 compared to Period 1. There was no statistical difference in the TP loading in Period 1 (0.25 kg ha-1 yra-1) compared to Period 2 (0.25 kg ha-1 yr-1) or between the DRP loading in Period 1 (0.15 kg ha-1 yr-1) compared to Period 2 (0.09 kg ha-1 yr-1). However, the reductions in load were equivalent to 20% for TP and 40% for DRP. By switching to organic phosphorus formulations and reducing application rates by greater than 50%, a significant reduction in DRP and TP was achieved. Based on these findings it is recommended that turf managers explore the feasibility of altering their fertility management related to phosphorus. Specifically, the recommendations are to investigate the use of organic formulations, low dose applications, and overall rate reductions.