National environmental sustainability organizations Re:wild Your Campus and Beyond Pesticides are collaborating with Grinnell College to pilot an organic land management project on MacEachron (Mac) Field. The project, which began in the spring of 2024, aims to improve soil health without the use of synthetic chemicals, said Chris Bair, environmental and safety manager.
The effort to eliminate herbicide use started in 2019, when Grinnell alumni Tommy Hexter `21, Jacy Highbarger `22 and Grace Duffy `22 worked with Re:wild Your Campus to implement a prairie restoration project next to the Harris Center.
Sheina Crystal, co-director of Re:wild Your Campus, said that organic land care is an alternative to conventional land care, in which chemicals like herbicides are used to maintain green spaces. Bair said that before the project started, the College used pre-emergent herbicide to prevent weeds from germinating and synthetic fertilizer on campus lawns about once a year.
“It’s a bit of a mindset shift, going from treating a weed with a chemical when it pops up with conventional land care, as opposed to … managing soil health and growing healthy grass to minimize weed pressure generally,” Crystal said.
Jay Feldman `75, executive director of Beyond Pesticides, said that treatments include inputting organic nitrogen, conducting soil aeration and overseeding, a process in which more grass seed is added to fill in bare areas. These treatments will build up crucial microbes in the soil, some of which Feldman said were inactive in Mac Field with conventional land care methods.
“We’re trying to enhance the growth of the turf to compete out any weeds,” Feldman said. “We’re also … trying to increase resiliency, so that we have a stronger root structure, so that … the turf system is able to withstand that wear and tear and bounce back when there is a lot of stress on the turf, which there is on this site.”
Natural Grocers, a national organic foods store chain, funded the consultation for this project, which included a lab analysis of Mac Field’s soil health. Bair said he appreciates the help that the College received from outside organizations.
“We certainly had no one on staff that had any experience [with organic land management],” Bair said. “A consultant that knew how to do this could hold our hand and walk us through it.”
Bair said that the College covered the additional expenses for the 3.5 acres of Mac Field, which totaled about $10,000. Bair and Feldman said that organic management makes fiscal sense — Bair said that the amount of money put towards organic management will go down over time.
“You get an economic return because we can effectively cycle nutrients instead of pouring fertilizers on a particular plant or property,” Feldman said. “That’s what we’re doing at Grinnell.”
Crystal said that the new land management methods should not cause any visible changes to Mac Field.
“The idea with the kind of organic land care that we’re doing on Mac Field is that it should yield the same high-quality turf that students are used to,” Crystal said. “Lots of folks associate organic land care with an ugly lawn and think that you need the chemicals to maintain a good-looking campus.”
Additionally, Crystal said organic land care is important for increasing biodiversity.
“We’re seeing a huge loss in biodiversity and insect populations,” she said. “Synthetic pesticides often contain a lot of ingredients that are really toxic for both wildlife and insects and pollinators, and in employing organic land care, we’re eliminating the use of these toxic chemicals.”
Organically-managed land is able to better retain moisture, which increases an area’s resilience to climate change, Crystal said. Feldman said that herbicide use can cause negative health effects, including respiratory issues and damage to the endocrine system.
Crystal said she hopes that organic land care will eventually reach the entirety of Grinnell’s campus.
“The goal is that the Grinnell facilities management staff feels confident in their ability to implement organic land care and feels confident in the efficacy of organic land care and expands the practices to the rest of campus,” Crystal said.
Feldman said that it will take a while to evaluate the results of the project because it typically takes two to three years to completely convert to an organic land management system.
“The second half of the growing season was fairly dry,” Bair said. “It’s hard to say how well it’s doing. … They told us ahead of time not to expect huge gains the first year. This is going to be a multiple-year effort.”
Grinnell land steward Sara Garcia `25 said she hopes to set up more soil tests of prairie and turf on campus.
“I’m … trying to understand how planting a prairie impacts the soil health, the microbes there, the biology within the soil, and comparing that to the land that’s treated with pesticides and herbicides on campus,” Garcia said.
Garcia is also starting a petition to plant a prairie next to South Campus, possibly in front of Loose Hall.
“I’m really excited about that,” Garcia said. “We want students to be able to walk by a prairie on their way to class.”
Bair emphasized the impact that student advocacy can have on environmental projects.
“I think one of the reasons it was successful, not only was there student pressure, but it was students saying, ‘We’d like to try this. How can we help?’” Bair said. “That makes a big difference, any time students are asking for change and then are part of the solution.”
