Iowa State part of wide-ranging study exploring links between health of soils, plants, humans

Woman in blue jacket in front of tall corn speaking to group at field day
Researcher Kathleen Delate speaking to a field day audience at the Long-term Agroecological Research (LTAR) site at Iowa State’s Neely-Kinyon Research and Demonstration Farm near Greenfield, Iowa.

AMES, Iowa — Iowa State University is part of a new study funded by the Foundation for Food and Agriculture Research (FFAR) to explore possible links between soil health, the nutritional value of plants and human health.

The overall goal of the four-year, $1 million project is to investigate how management practices may alter nitrogen-related nutritional content of grains, such as protein, amino acids and B vitamins, and affect indicators of chemical, physical and biological soil health.  

An important focus will be to look for relationships that help explain levels of the amino acid ergothioneine (ERG). Amino acids are building blocks of proteins. ERG, present in many foods, is gaining interest as an important antioxidant that may have human health benefits, including reducing the potential for development of dementia-related illnesses. Known to be biosynthesized by fungi and fungi-like bacteria in soils, ERG is transferred up the food chain to animals and humans via unknown mechanisms. This study is one of the first to explore influences on ERG levels in soils and crops.

Kathleen Delate, professor of horticulture and agronomy and extension organic specialist, will lead the Iowa State portion of the wide-ranging study. Delate oversees research at the Long-Term Agroecological Research (LTAR) study at the Neely-Kinyon Research and Demonstration Farm near Greenfield, Iowa. Established in 1998, it is one of the longest-running studies of organic cropping systems in the country.

Iowa State’s role will include providing samples of organic corn and wheat grain, plant tissue and soils from the long-term field plots to be analyzed. Scientists will examine the samples for nutrients in grain and plants, levels of beneficial soil microorganisms, and possible connections to crop management practices like cover crops, crop rotations, compost, fertilization and tillage. The LTAR will also provide similar samples from the same plant varieties managed conventionally. 

This project is a collaboration with other long-term research trials that also have organic and conventional management comparisons at West Virginia University, Pennsylvania State University, and North Carolina State University. Cooperators also include soil microbiologists from the University of Delaware, USDA-ARS, and Stroud Water Research Center, Avondale, Pa., and scientists from the Pennsylvania State University Hershey Medical Center. The team is being led by Rodale Institute, headquartered in Pennsylvania, with a new research site near Cedar Rapids, Iowa.

The project seeks to better understand declines in mineral, vitamin and protein concentrations in crops produced in the United States over the past 70 years, during a period when grain yields have more than doubled.

“I’ve wanted to study nutritional aspects of the LTAR cropping systems, but that kind of work tends to be very expensive,” Delate said. “We have done some baseline analysis of proteins, carbohydrates and oils from plants grown on our research area. Being invited to contribute to this large study provides an exciting opportunity to dig deeper into understanding nutritional differences between organic and conventional crops and what might influence such differences.”