This summer, the University of Minnesota partnered with organic farmers on a project that helped boost the efficiency of crop growth and reduce pollution, according to the College of Food, Agriculture and Natural Resource Sciences.

The University is working on the project with around 64 farms to research the use of cover crops to replace the use of traditional fertilizers, said Gigi DiGiacomo, a research fellow at CFANS and research contributor. The project, funded by USDA, aims to improve efficiency for farmers growing some of the nation’s most valuable crops.

Recently, the practice of using high tunnel greenhouses has grown increasingly popular among organic farmers. High tunnels are plastic-covered structures that provide a good level of environmental protection, especially in colder climates, according to the U.S. Department of Agriculture.

Now, researchers are trying to use these tunnels to reduce pollution and benefit farmers across the U.S.

Typically, manure is a common crop fertilizer due to its nitrogen content, but it also contains phosphorus, said Julie Grossman, associate dean of undergraduate programs and soil scientist at CFANS.

Grossman said phosphorus can be dangerous in excess, as runoff can lead to water pollution and algae.Algae pollutes water and makes it hard for many organisms in bodies of water to survive due to low oxygen levels, according to the United States Environmental Protection Agency. 

That’s exactly why researchers are focusing on using cover crops as fertilizer in high tunnels as an alternative to manure. 

According to CFANS, cover crops are crops that are grown not to eat but to help soil fertility and create a more balanced ecosystem. In this project, researchers focused on legumes with nitrogen-fixing qualities to replace the role of manure.

The legumes take in nitrogen from the air and eventually die, returning nitrogen to the soil, Grossman said.

Now, researchers are trying to find cover crops that are able to last through the cold Minnesota winters.

“It’s a very research-heavy project, but I think to me the most important part is that the farmers are getting to be involved in the data collection and observe what works for them,” Grossman said.