January 4, 2023
Northwest Ohio Farmers Implement Subsurface Nutrient Placement On Their Farms
Subsurface nutrient placement places essential crop nutrients like nitrogen, phosphorus and potassium below the soil surface in the root zone so that the nutrients are more readily available for crop uptake. Subsurface placement is considered a best management practice (BMP) that helps protect surface water quality by dramatically reducing the potential for nutrient runoff.
“Broadcast fertilizer poses the greatest risk of dissolved phosphorus loss immediately after application because there is minimal contact between the fertilizer and the soil,” says Mark Williams, a USDA-Agricultural Research Service researcher. “Incorporating or injecting fertilizer into the soil increases the soil-fertilizer contact and, as a result, can decrease dissolved P losses up to 70% during storm events following application.”
With on-field research in hand, several farmers in northwest Ohio are using funding from both the H2Ohio water quality initiative and Natural Resources Conservation Service programs such as the Environmental Quality Incentives Program (EQIP) to voluntarily implement subsurface nutrient placement on their farms.
“As a no-tiller, I wanted to be able to understand where to place nutrients so that the roots can access it when needed the most,” says Austin Heil, a sixth-generation farmer in Kenton, Ohio.
Broadcasting fertilizer on the soil surface without being incorporated can potentially result in a stratification of nutrients in the top few inches of the soil, leaving fertilizer potentially exposed to rainfall that can wash off nutrients into bodies of water. Various tillage systems can help combat this.
Heil has found innovative ways to utilize the equipment he already owns to economically achieve subsurface placement on their 280-acre farm.
By equipping an eight-row planter with a hydraulic drive motor and calibrating it with rate-controlling technology, Heil says he is able to place fertilizer four inches underneath the soil surface and about two and a half to three inches from the corn rows—all without investing in new equipment or machinery.
Research shows that by placing fertilizer closer to the root zone, fertilizer is used more efficiently, reducing the amount of fertilizer needed to be applied. Along with applying the right fertilizer source, at the right rate and right time, this can result in significant cost savings for the producer.
Jan Layman, who farms over 5,500 acres of corn and soybeans in Hardin County, practices continuous no-till. He has always done subsurface placement for nitrogen, but through the H2Ohio program, he became interested in doing that practice with phosphorus as well.
“After a lot of studying, it looked to me like the least expensive and most efficient way was to do something with our sidedress machine, “ says Layman. He invested about $20,000 into plumbing and pump control modifications to saddle tanks. In comparison, Layman says new equipment to do this would have cost him $200,000 to $300,000.
Like Layman, Fulton County farmer Kevin Thierry outfitted fertilizer tanks to his strip-till machine in order to place fertilizer below the surface where he says the crops need it most.
“I’ve always liked the concept of putting fertilizer in the ground right underneath the plant where it needs it, instead of it being broadcasted, having to incorporate it into the soil, and then just hoping the plant can find it,” explains Thierry.
As a strip-till farmer, Thierry needed a machine that could give him the best of both worlds—the opportunity to clear the soil of debris through tillage and incorporate nutrients all in one pass.
The fertilizer component of Thierry’s strip-till unit includes a delivery system from Lynx Ag that contains potash in one box and phosphorus in another. The back of the implement is a combination of two Unverferth ripper strippers that were six-row, 30-inch units that he made into 12-row, 20-inch units. The machine uses grid-sampling rate controller technology.
To learn more about each of the subsurface placement units these Ohio farmers are using, a video series is available to watch here.