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United States Department of Agriculture

Agricultural Research Service

Research Project: ENHANCED MODELS AND CONSERVATION PRACTICES FOR WATERSHED RESOURCE MANAGEMENT AND ASSESSMENT

Location: Grassland, Soil and Water Research Laboratory

Title: A possible trade-off between clean air and clean water

Author
item Smith, Douglas
item Stephensen, M
item King, Kevin
item Jarvie, H
item Haney, Richard
item Williams, Mark

Submitted to: Journal of Soil and Water Conservation
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 5/23/2017
Publication Date: 7/1/2017
Citation: Smith, D.R., Stephensen, M., King, K.W., Jarvie, H.P., Haney, R.L., Williams, M.R. 2017. A possible trade-off between clean air and clean water. Journal of Soil and Water Conservation. 72(4):75A-79A. doi:10.2489/jswc.72.4.75A.

Interpretive Summary: Since 2002 algal blooms in Lake Erie have become more intense and damaging to the lake's ecosystem. These blooms have been linked to increased soluble phosphorus from rivers that flow into the lake, as this form of phosphorus is the most readily available for algae. Also during this time, reductions in atmospheric sulfur emissions have resulted in marked increases in rainfall chemistry. This pilot study explores whether relationships exist between changes in precipitation chemistry and increased soluble phosphorus loss from soils and fertilizers. Six soils and six fertilizers were extracted with water mimicking precipitation in 1990 (more acidic) and 2011 (less acidic). Soluble phosphorus increased in four of the six soils, by as much as 1.1 mg/kg when extracted with 2011 precipitation compared to that of 1990. Likewise, there was an increase in soluble phosphorus extracted from four of six fertilizers. This preliminary study is not definitive proof that changes in precipitation chemistry are responsible for the increased soluble phosphorus loading to Lake Erie; however, these results suggest that we cannot dismiss this mechanism as a contributing factor. The implications of this work are that it proposes one mechanism that may contribute to increasingly severe algal blooms that are occurring in vital water bodies, and further study is warranted to evaluate this mechanism further.

Technical Abstract: Harmful algal blooms in Lake Erie have increased since 2002, coincidentally during this same period soluble reactive phosphorus loads have increased from rivers that flow into the lake. Also during this time, reductions in atmospheric sulfur emissions have resulted in marked increases in rainfall pH. This pilot study explores whether relationships exist between changes in precipitation chemistry and increased soluble reactive phosphorus loss from soils and fertilizers. Six soils and six fertilizers were extracted with water mimicking precipitation in 1990 (pH 4.4) and 2011 (pH 5.1). Soluble reactive phosphorus increased in four of the six soils, by as much as 1.1 mg/kg when extracted with 2011 precipitation compared to that of 1990. Likewise, there was an increase in soluble reactive phosphorus extracted from four of six fertilizers. This preliminary study is not definitive proof that changes in precipitation chemistry are responsible for the increased soluble reactive phosphorus loading to Lake Erie; however, these results suggest that we cannot dismiss this mechanism as a contributing factor. The implications of this work are that it proposes one mechanism that may contribute to increasingly severe algal blooms that are occurring in vital water bodies, and further study is warranted to evaluate this mechanism further.

Last Modified: 08/19/2017
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