Cordoned off and scattered with aquamarine pellets, campus lawns are being given time to grow, bolstered by recent rain. Dartmouth budgeted spending $22,640 on fertilizer this year, according to turf manager John Buck.
About 41,000 pounds of fertilizer, including 23,000 pounds of Nature Safe organic fertilizer, are used on the campus and athletic fields, Buck said.
Timing is crucial for grass development, Buck said. The first round of fertilizer was laid at the end of April, and placement will likely continue until the end of this month.
Harrell’s Polyon, the round polyurethane capsules visible across the Green, are a non-natural fertilizer scientifically engineered to release nitrogen and other nutrients over time.
Nature Safe, made from chicken byproducts and fishmeal, proved ineffective due to the harsh winter that lowered soil temperatures, Buck said.
While the fertilizer poses no danger to humans, it is not meant for human consumption, Buck said.
“I mean, you don’t want to eat this stuff or drink it,” he said.
As the grounds crew prepares for Commencement, certain areas, including the Green, Baker-Berry Library lawn and the lawn in front of Dartmouth Hall, receive more attention than others, Buck said.
“We try to be everywhere and try to do the best job we can, but some areas don’t receive the level of care that others do, and appropriately so,” Buck said. “A lot of areas are natural — we mow and don’t use any fertilizer on them, and for the use that they get, they do just fine.”
The University of Rhode Island, which has one of the oldest turfgrass research programs in the country and spends $15,000 to $20,000 on fertilizer annually, uses liquid fertilizer as well as granule fertilizer, turfgrass manager Brian Boesch wrote in an email.
To Boesch, granule fertilizer is safer to apply near pedestrians and easier to use on oddly shaped lawns. The University of Rhode Island does not use organic fertilizer because of unpredictable results and its potential to emit foul odors, Boesch said.
The fertilization process is long and allows little room for error, Buck said. First, the staff aerates the soil, allowing air and water to enter. Hollow tubes drilled four to six inches into the ground remove a column of soil, leaving a plug on the surface.
Next, slice seeding and verticutting are used to replace turf lost in the winter, opening the soil and inserting grass seeds into the topsoil.
Buck said a critical element of fertilization is balancing the soil elements. Necessary for growth, an abundance of either phosphorous or potassium could be damaging.
In 2013, the grounds staff used about two pounds of nitrogen per 1,000 square feet annually, “a pretty reasonable amount,” Buck said. Additionally, they used about 0.7 pounds of potassium per 1,000 square feet.
“Potassium helps to build a resilient kind of stemmy plant, which we’re trying to encourage,” he said.
One environmental concern that accompanies the use of fertilizer is runoff, Buck said. Though Boesch also acknowledged the concern, products applied in a safe and reasonable manner pose threat, he wrote in the email.
Malcolm Salovaara ’17, an EcoRep, said the use of fertilizer is inherently unsustainable because it creates an “open-loop ecosystem,” in which the grass begins to rely on human action for its existence.
“There are ways for there to be nutrient cycles that would be closed loop in a lawn system, but those don’t include pure green, lush grass,” Salovaara said. “It wouldn’t look like a perfect lawn.”
