Posts

An agricultural tile empties water into an Iowa Stream
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Surprising Phosphorus Trends

We now know that total phosphorus concentrations have significantly decreased at a dozen sites on Iowa’s rivers. Phosphorus, along with nitrate, is commonly used as fertilizer; both contribute to nutrients in Iowa’s rivers and streams and ultimately all the way downstream to the Gulf of Mexico.
Corn plants stretching as far as you can see on the left, and soybeans going just as far on the right
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Understanding Changes in Raccoon River Nitrate

As Iowa farmers have planted more acres of corn to meet the demand driven by the corn-based ethanol industry, many models predicted that nitrate concentrations in Iowa streams would increase accordingly. However, recent IIHR research based on water monitoring and published in the Journal of Soil and Water Conservation casts doubt on these predictions.