We have always believed in being good stewards and constantly looking for ways to improve our management decisions year after year. This past fall, we worked with The Ohio State University Extension Water Quality Team on their End-of-Season Residual Nitrogen Study.
With input costs continuing to rise and environmental pressures growing, we wanted to find out: Is our corn nitrogen management program holding up under real-world conditions?
The short answer? Yes. But here is more information about what Ohio State Extension found.
What the Study Found
We had two fields tested this fall, following 2024 corn harvest, to see what residual nitrogen levels were left in the soil following the end of the crop year. The residual nitrogen levels came back at 14.7 ppm and 23.7 ppm, both well below OSU’s threshold of 30 ppm. That puts us either at or below the average compared to all other farms in the study, which tells us that the nitrogen we applied throughout the growing season was effectively taken up by the crop, even in a drought-stressed year.
As Heather Torlina, Water Quality Extension Associate with Ohio State University Extension, noted:
“Your results were either average or below average for residual nitrogen! This is good. Your corn nitrogen management program seems well thought out.”
That was encouraging feedback to hear. It confirmed that our intentional approach of focusing on timing, rate, and placement is delivering results both agronomically and environmentally.
Why This Matters
According to the summary data from the broader study, some Northwest Ohio fields had a range of 16-290 lbs of residual nitrogen per acre remaining after harvest. The higher levels of residual N could have been tied to farms utilizing manure applications.
The Role of Manure in Corn Nitrogen Management
Manure is a valuable nutrient source. It provides nitrogen, phosphorus, potassium, and organic matter—key ingredients for long-term soil health. Manure supports organic matter buildup, enhances soil structure, and feeds microbial life. From a sustainability standpoint, it’s an important tool to reduce dependence on commercial fertilizers.
But like any input, manure requires thoughtful management. Its nutrient availability isn’t always immediate or consistent, which means it’s possible to apply more than the crop can use in a single season. Depending on your application method, surface applied and then later incorporated versus injection, timing, and rate are still critical. We are by no means saying manure isn’t effective or a bad option; like all other fertility inputs, it simply needs to be managed with the same level of precision.
Adapting to Drought Conditions
On the flip side, some fields showed very low levels of residual nitrogen, less than 30 lbs per acre. In many of those cases, crops may have drawn down most of what was applied, or it may reflect tighter nitrogen programs with little room for loss or surplus. Then there are the middle-of-the-road fields, with 60 to 120 lbs of residual N, which might reflect average rates that didn’t quite get fully utilized—possibly due to timing, placement, or dry weather.
Drought is another wildcard. When crops don’t get enough water, they can’t take up nutrients efficiently. Even well-planned applications—whether commercial or organic—can result in leftover nitrogen simply because the crop couldn’t use it.
It’s a reminder that effective nitrogen management isn’t just about how much is applied. It’s about knowing your soil, understanding your sources, monitoring your weather, and adjusting your approach accordingly.
What We’re Doing
This study confirmed that our intentional approach to corn nitrogen management—focusing on timing, rate, and placement—is working. One major factor is our focus on soil health. The farms that took part in this study have decent organic matter. We are trying to build organic matter, specifically on the more challenging acres. Organic matter plays a big role in nitrogen availability, and this study confirms that. OSU reminds us that for every 1% of organic matter, soils can supply up to 20 lbs of nitrogen, which is often overlooked. We’re also committed to avoiding excessive application. Our goal is to apply what’s needed, when it’s needed—no more, no less.
In the image to the right (or below on mobile), we were fixing a drainage tile washout this past spring and had to dig a trench. This part of the farm was mined for the Ohio Turnpike many years ago. Looking at the image, you can tell where the mining process stopped. Over the years, we have been very intentional in building back the organic matter in the soil by utilizing cover crops and nutrient management.
Cover crops are another part of our farming practices. We have utilized cover crops since the 1990s and are grateful for the H2Ohio program incentivizing others to implement this practice. Cover crops help us retain and cycle nutrients during the off-season, especially valuable as we try to make every pound of nitrogen count. And we don’t just set it and forget it—we evaluate and manage our crops during the growing season to make changes and adjust on the fly if a crop needs help in one area or another.
Where We’re Headed Next
As the 2025 growing season is officially underway, we’re exploring ways to dial in our nitrogen management even more. One tool we’re looking at is OSU’s Corn Nitrogen Rate Calculator to help find the Maximum Return to Nitrogen (MRTN) for each field — balancing yield goals with profitability and stewardship.
Beyond that, we’re evaluating how other factors like hybrid selection, planting date, and soil variability can impact nitrogen efficiency. We’re also keeping an eye on emerging technologies, such as in-season tissue testing, aerial imagery, and aerial applications. We walk our farms throughout the growing season to help us spot deficiencies earlier and make more targeted applications, weather by ground rig or drone.
At the end of the day, this is about more than just numbers. It’s about being intentional, making informed decisions, and continuing to improve how we farm the same ground our family has cared for for generations.
Key Takeaways From the Study
We volunteered the two farms for this study because we wanted to better understand how much of our applied nitrogen was actually being used by the crop, especially after a tough growing season like we had in 2024. It’s one thing to build a corn nitrogen management plan on paper, but testing it in the real world gave us insights we couldn’t get otherwise.
This study helped confirm that our nitrogen program is working. We’re applying what’s needed, and the nutrients are staying where they should. That’s a win for both our bottom line and the Lake Erie Watershed.
We’re grateful to Heather Torlina and the OSU Extension team for including us in this project. Heather recently returned to pull spring soil cores from the same farms, and we’re looking forward to comparing the results and learning how winter weather may have impacted residual nitrogen.
At the end of the day, we’re always trying to learn. No two years are ever the same, and no two fields are either. That’s why we value opportunities like this—working with OSU Extension to gather real, on-farm data that helps us make better decisions for our operation. It’s not about proving we have it all figured out, because we don’t; it’s about staying curious, asking the right questions, and being open to adjusting how we farm so we can keep doing it better year after year.