DURAND — While farmers have to contend with rain events that can put nitrogen out of reach of their plants’ roots, communities are dealing with waterways polluted by leaching nitrogen.
These are among the side effects that come with growing corn and its high demand for artificial fertilizers, which are energy intensive, expensive and polluting.
Walter Goldstein of the Mandaamin Institute in Elkhorn has been breeding corn for nitrogen efficiency and nitrogen-fixing capability, in an effort to potentially cut down on the need for as heavy fertilizer application as is common on many farms, he said.
“We’re trying to get away from using nitrogen fertilizer, we’re trying to use the natural symbionts and cooperators and find plants that will have these partnerships so that we can make a more efficient and less polluting system,” Goldstein said Oct. 3 at a nitrogen-efficient corn field day at Weiss Family Farms near Durand.
Goldstein’s work with the Mandaamin Institute since 2011 has been focused on breeding a variety of nitrogen-fixing corn that would not only work in Wisconsin but would continue to produce high yields and not lose nutritional value, he said.
“We bred intensively to try to get this quality and this nitrogen efficiency and the yield together,” Goldstein said. “That’s been a lot of our effort.”
Goldstein founded the non-profit Mandaamin Institute after working 25 years as research director at Michael Fields Agricultural Institute. He has been working on breeding corn since 1989, when he started working with organic growers looking for high-quality corn with better nutritional value and taste without losing much yield.
Some of the varieties he is working with include a Mexican corn that has prop roots that produce a mucus that allows bacteria to live and fix nitrogen for the plant.
Conducting research similar to Goldstein’s, a public-private collaboration of researchers at UW–Madison, the University of California, Davis, and Mars Inc., in 2018 identified varieties of tropical corn from Oaxaca, Mexico, that can acquire a significant amount of the nitrogen they need from the air by cooperating with bacteria. The corn in that study, which was grown in southern Mexico in nitrogen-depleted soils using traditional practices with little or no fertilizer, secreted copious globs of mucus-like gel out of arrays of aerial roots along its stalk. This gel harbors bacteria that convert atmospheric nitrogen into a form usable by the plant.
“Nitrogen-fixing corn is a natural occurrence in Mexico and South America, the home of corn,” said Mike Travis, UW-Extension agriculture and natural resources educator in Pepin and Pierce Counties. “The challenge is most of those varieties are 12-month varieties and grow to be 10- to 12-feet tall, not something you can grow here.”
Other nitrogen-fixing varieties Goldstein is studying produce dense root systems in the top several inches of soil that draw microbes in a low-oxygen environment that may lead to nitrogen fixation, he said. There are also varieties that may grow a fungus on their leaves, which form lesions that then seem to heal, leading Goldstein to wonder if that fungus is aiding in nitrogen fixation, he said.
Goldstein is working with farmers in Illinois and Wisconsin, including Weiss Family Farms in Pepin County, trying varieties of nitrogen-fixing corn. The varieties being grown at Weiss Family Farms reach maturity between 102 and 108 days, he said.
Goldstein said his corn is showing promise on properties with very limited nitrogen. It is also returning a high protein content and provides a soft kernel, which improves digestibility, he said.
“We are working with corn and company, and the company is stuff that you usually don’t see; it’s microbes and fungi and so on, and it’s with what goes on in the soil and what goes on inside the plant,” Goldstein said. “The end point will be to get something that is very productive, very nitrogen-efficient, very nutritious and high in value.”
For more information, visit www.mandaamin.org.