Row Crop Recipe: Practices to Help Agriculture Reduce Nitrogen Loss, Cut Carbon Footprint

Farm fields planted in the middle of Manhattan, Kan., are releasing secrets within the soil.

“It's all about the soil,” says Dr. Charles Rice, Kansas State University Distinguished Professor at Kansas State University in the department of agronomy. “We're finding some unique things, we're getting carbon sequestered in the soil,” says Rice.

Rice, a microbiologist by training, is talking about his research while standing in front of a  32-year continuous corn plot to his left and a field of seven years continuous no till on the right.

“What we're trying to do is understand the sustainability or the environmental footprint,” Rice adds. “So, we're focused on carbon on the left, but this one's more focused on the nitrogen.”

And while some of his research is showing broad findings (ex: no-till is the best way to sequester carbon), it’s what’s happening underneath that’s harvesting valuable results.

“No till sequesters about twice as much as tillage,” Rice says. “We've been doing this research long enough now that we're starting to see carbon sequestered not only in the top 2", but that's moving down into the next layer 2" to 6" down into the soil.”

Rice and a team of researchers at Kansas State are exploring how to manage nitrogen in order to reduce greenhouse gas losses.

“Particularly nitrous oxide, which is a potent greenhouse gas, it's about 300 times more potent than a molecule of CO2,” he says.

The Kansas State University research is showing not only what type of tillage practices could be beneficial, but how improving nitrogen applications could benefit farmers’ bottom lines and the environment simultaneously.

“Environmentally, it's important not to have those greenhouse gases released, but economically it’s important because that loss means less fertilizer available for the corn plant, which the farmer nitrogen is a key component of car production. And so we don't want to waste that nitrogen.”

Keys to Keep Nitrogen in Soil

The right time, placement and rate of nitrogen applications are important, and Rice is also digging deeper to learn how to manage the introduction of nitrogen into the soil in order to reduce losses.

“What we found is that by using nitrogen inhibitors, and putting it on when the corn really needs it, which is about a foot high or V6 state, then we get a 50% reduction in nitrogen losses,” Rice says.

He says the fields are also testing how some inoculants on plant roots supply nitrogen through bacteria, rather than fertilizer.

“It's a unique opportunity, and hopefully in the future, we're going to see more inoculants developed to help reduce, manage it and help reduce the nitrogen fertilizer inputs for the farmer,” Rice adds.

As the financial savings from preventing nitrogen running off can be huge, the environmental piece is also key.

“We're trying to understand the diverse microbial soil microorganisms in the soil, take advantage of their ability to transform nitrogen and make it available for the plant without putting it into the atmosphere,” says Rice.

The research is transforming not only the way nitrogen is applied, but also accepted by the soil.

“The first six weeks from planting until the corn really needs nitrogen, that's when our soils are the wettest, and you create the environment for gas losses or leaching,” he says.

Rice says some of the work done at Kansas State suggests agriculture can reduce nitrogen loss by 50%, just by changing the way it’s managed.

“If you apply no till and cover crops that we can call a sequester carbon, that would reduce the emissions by another by 50%,” Rice says. “The No. 1 thing is minimal disturbance; no till is the prime optimum example and then instituting cover crops, as well.”

Carbon Negative Agriculture

The efforts to reduce tillage, while coupled with changing up what crops farmers plant today, could also significantly reduce the environmental footprint of farmers.

“You really want to diversify,” says Rice. “And I would argue a corn, soybean rotation is not really a good rotation. You want to add in more complexity. So adding wheat as a cash crop or cover crops, diversifies that rotation has many benefits for the crop, but also the soil and the production system.”

A visionary within agriculture, Rice already has a Nobel Peace Prize for his climate work within agriculture. As his quest is producing lofty goals for agriculture.

“Our hope is that we can make agriculture carbon neutral, if not carbon negative,” he says.

Rice is cultivating change as the Nobel Peace Prize winner thinks agriculture can be the solution to climate challenges.

Future Research 

Just this week, a collaboration was announced between K-State's Rice and Valent BioSciences. The new program will take an even deeper dive into the complex interactions that control soil carbon stability, as well as the role nitrogen plays. By stabilizing nitrogen and carbon, the research could continue to unlock key insights into soil conservation management practices that influence soil health, as well as the environment. 

"This collaboration with Kansas State University marks the next important and exciting step in our commitment to soil health in agriculture," says Warren Shafer, vice president, Global R&D and Regulatory Affairs at Valent BioSciences. "The specific projects being conducting with the university will help us remain the thought leader in the fields of carbon and nitrogen cycling, as influenced by the soil microbiome. These projects are part of a larger initiative led by our parent company, Sumitomo Chemical Company, to mitigate climate change by reducing carbon dioxide in the atmosphere."

"This private/public partnership leverages global strengths for both organizations to address significant climate change research needs," adds David V. Rosowsky, K-State vice president for research. "Dr. Rice's unmatched expertise in soil health will be invaluable to this initiative, as will the tremendous assets our corporate partners can provide. This is a model for how the nation's land-grant universities can address global issues."
 

According to Kansas State, the soil cores from the K-State studies will be evaluated and analyzed at the Donald Danforth Plant Science Center in St. Louis by using state-of-the-art imaging technologies. According to the outlined collaboration between Rice and Valent, "the Danforth Center are using X-ray imaging equipment and computer learning to pioneer new techniques that shape the way we observe interactions between plant roots and beneficial soil microorganisms within the rhizosphere."