New study outlines options to incentivize farmers to use less nitrogen

Eleven states have committed to reduce nutrient loads used in agriculture that are affecting the Mississippi River.

Updated: June 27, 2022 - 12:48am

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Excess nitrogen runoff from as far away as Illinois corn farms is killing fish in the Gulf of Mexico. Scientists have been monitoring the effect of nitrogen on the Mississippi River and in the Gulf of Mexico since the 1990s. Algae blooms from nitrogen have created a dead zone the size of Rhode Island that is so oxygen-deprived that fish and aquatic life cannot survive.

Researchers say that 67% of corn growers use more nitrogen than they need on their crops.

Doctoral graduate German Mandrini, who studied remedies for nitrogen runoff from Illinois farms when he was at the University of Illinois, told The Center Square that Illinois is particularly important because “agriculture is one of the main sectors that provides nitrogen to the Mississippi.”

“When you put too much, more than what the crops use, then the nitrogen stays in the soil,” Mandrini said. “It eventually starts to move from agricultural soil, to ground water to fresh water and it slowly goes to the Mississippi River and down to the Gulf of Mexico.”

Eleven states, including Illinois, have committed to reduce nutrient loads used in agriculture that are affecting the Mississippi River.

One promising path is the more accurate application of nitrogen so that less of the fertilizer leaches into the soil after the crop is harvested. When corn is harvested, much of the nitrogen used to fertilize the crop is removed with the crop. If farmers do not apply so much excess nitrogen, less of the fertilizer will remain behind when the crop is harvested.

By incentivizing farmers to use cover crops and other strategies, Illinois had hoped to reduce excess nitrogen runoff by 15% by the end of this year. But the fertilizer impact has only worsened.

Scientists at the University of Illinois have just published a new study that outlines four different policy options that could incentivize farmers to use less nitrogen and contain more excess runoff on their farms, instead of allowing it to leach into groundwater and make its way to the Mississippi.

Nicolas Martin, assistant professor in the Department of Crop Sciences at the University of Illinois, is co-author of the study. He said the goal was to start a discussion by providing policy options – not to come up with definitive solutions.

The proposed policies range from imposing a tax on nitrogen, charging farmers a fee for excess nitrogen usage, nitrogen removal at harvest from nitrogen applied as fertilizer and charging a fee for it and, finally, a voluntary nitrogen reduction program.

Mandrini said reducing the leaching of excess nitrogen while making sure that farmers can maximize their profits was the aim of the study.

“It is a complex problem,” Mandrini said. “Farmers want to do the right thing as long as they can protect their profits.”

Conserving more nitrogen on farms can be costly. The researchers are interested in designing incentives that will compensate farmers for their efforts.