Incremental improvements in the water quality of Lake Erie – Ohio Ag Net

By Dusty Sonnenberg, CCA, Field Leader, a project of the Ohio Soybean Council and Soybean Check-off

The improvements in water quality in Lake Erie have been noteworthy in recent years. Ever since the Toledo water crisis of 2014, farmers and the agricultural industry have been under a microscope, both literally and figuratively. Greg LaBarge, field specialist, agronomic systems with OSU Extension, has been studying nutrient management impacts on crop production and water quality.

“We have good news in that things are improving,” LaBarge said. “We are seeing that the dissolved reactive phosphorus going into the lake is down about 10%. Our goal is a 40% reduction, so we have not gotten all the way to our goal yet.”

While the dissolved reactive phosphorus level in the lake still has room for improvement, the toxic component of the harmful algal bloom has decreased.

“We have also seen the cyanobacteria, which is the harmful part of the algal bloom, has decreased in intensity,” said LaBarge. “The goal is 9 out of 10 years to have a level that is less than a three on a zero to 10 scale, with zero being ideal. At this point, we are at 5 out of 10 years.”

Farmers have been paying attention to the water quality issue and are doing their part to implement best management practices to reduce these levels.

“I think from a nutrient management standpoint, we are doing really great work reducing the amount of phosphorus that is applied to the fields,” LaBarge said. “By cutting back our rates, we are reducing one source of potential loss when we make those fertilizer applications. The second thing we accomplish is that we are now removing even more phosphorus from the grain because we continue to increase yields. By reducing the amount of phosphorus going on, and continuing to increase our yields, we result in a net reduction in the amount of phosphorus that is being stored in the soil. Less phosphorus in the soil leads to less phosphorus losses when we have the rainfall events that lead to drainage flows in the watershed, so now we have less phosphorus coming off the fields.”

Given the current cost of fertilizer, reducing fertilizer applications and rates is also an economic win for farmers.

“At $850 a ton, MAP is one of our more expensive nutrients. From an economic standpoint, it makes sense to put less phosphorus down. Agronomically, we see that we have been able to manage that and see that soil test phosphorus will stabilize in the soil, and we have a good buffering capacity in that case,” LaBarge said. “We also see that there is not necessarily a crop response all the time when we apply fertilizer. We are starting to understand where the sweet spot is in relation to economics and understanding crop yield increases from phosphorus and how we go about achieving better economics for nutrient management.”

Research will continue in fertility management and water quality as it applies to Lake Erie.

“In 2026, we are going to start focusing more on what is in the soil as far as the phosphorus. The idea of water management is to try to keep water contained in the field or filter it before it leaves. This is going to be important as we try to deal with the chronic source of phosphorus in any basin across the state of Ohio,” said LaBarge. We are going to see practices like wetlands needing to be put in place, and possibly drainage water recycling, two-stage ditches, and anything that will start to slow down water, so it infiltrates into the soil.”