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Member Research & Reports

Member Research & Reports

Iowa Researchers Recommend Changes to State’s Water Protection Policies

According to newly published research, Iowa comes up short in limiting manure runoff when soil conditions are unfavorable and could look to another Midwestern state for examples on how to better protect water flowing into the Mississippi River.

[Photo: Mr. David Osterberg]

An Iowa Policy Project (IPP) report, co-authored by University of Iowa professor of occupational and environmental health Mr. David Osterberg and UI graduate students Mr. Nick Fetty and Mr. Nathan Wong, examines Iowa policies in relation to research about the consequences of ag-based pollution in Iowa waters and in the dead zone where the Mississippi River empties into the Gulf of Mexico.

“Iowa does not place strong limits on manure application on frozen, snow-covered or saturated ground. The state has too few inspectors, and the rules can be confusing to farmers who are expected to follow them,” said Mr. Osterberg.

The report also examines action taken by the state of Ohio in response to serious issues with runoff there. The report recommends for Iowa:

While much of the attention to water pollution in Iowa has focused on the negative impact on cities and waterways in the state, a broader concern is for the impact on the Mississippi River and states downstream.

Nutrient runoff is part of the cause of the hypoxic region, or “dead zone,” in the northern Gulf of Mexico. Hypoxia in the Gulf is caused by excess nitrogen and phosphorous from Mississippi River tributaries. Some of those nutrients come from manure.

“By reducing runoff caused by inappropriate manure application, the nutrient load to the hypoxic zone could be significantly reduced,” the report stated.

The full report is available at