A new study shows there could be more water pollution from nutrient runoff during winter as a result of warmer and wetter conditions.

In the past, winters mostly froze nitrogen and phosphorus on farmland, which kept it from polluting waters until the plants could absorb them in the spring.

Now these chemicals are thawing out and washing away, according to a new study from the Gund Institute for Environment.

That’s putting parts of the upper Midwest particularly at risk for water pollution, says Erin Seybold from the University of Kansas.

“It’s, on one hand, ‘How many nutrients are in the landscape?’ But then, on the other side, it’s also where you have the rain on snow risk, so it’s kind of the intersection of those two factors.”

These nutrients can cause algae blooms that make swimming dangerous and create dead zones that kill fish. Dennis, the Midwest Director of the USDA Climate Hub, says farmers can help prevent this by not applying nitrogen or manure to fields in the fall.

“If you’re losing the nitrogen to the water, that’s nitrogen that you don’t have available for your crop, so it’s a lose-lose in that situation.”

Reporting by Harvest Public Media’s Eva Tesfaye