Five Things to Consider about Nutrient Loss Management In-Season

Nitrogen management is a complex program and varies across each acre on the farm, according to Travis Kimmel, a Lead Agronomist with Advanced Agrilytics in Ohio. He says growers should be considering all of the variables that drive decision-making this time of year, when considering how to manage nutrient loss within their fields.

“I can’t change some variables of the field, but I can influence nutrients – and not just rate, but also timing,” says Kimmel. “I want to provide nitrogen recommendations that help a grower mitigate weather challenges and other situations I cannot control, so that we can capture the best performance and see the strongest return on investment.”

To achieve this success, Kimmel says knowing the soil types and a yield goal to generate prescriptive recommendations is not good enough. The recipe for performance comes from looking at the sub-acre environment and understanding, specifically, the degree of soil saturation on any given acre is a key difference; he also says that the best outcomes also require looking at additional nutrient needs, not just nitrogen.

Here are some tips from Kimmel for finding success in your farm’s nutrient success plan.

1. Consider timing along with rate of application: Every farmer has a different approach to bringing added nutrients to a corn crop through nitrogen application. Common applications might occur in the pre-planting window, or at planting, through side-dressing or perhaps split-up across a combination of these approaches. When you apply the nitrogen can be just as important as the how much N you’re applying in the field. Kimmel says that farmers need to be thinking about what has happened in the two weeks leading up to nitrogen application, as well as the forecast of what is ahead, to best understand conditions in the sub-acre environment. Armed with the knowledge of what’s happening down in the soil can help a grower be certain that they’re putting the nutrient where it is needed most – and also ensure that it’s staying there for optimal uptake in the roots.
2. Nitrogen stabilizer can make a significant difference: We all understand de-nitrification is not a farmer’s friend and preventing this process from degrading available nitrogen uptake within the root zone can be a huge step in nutrient loss management. Kimmel says many growers will benefit from a nitrogen stabilizer application to mitigate this risk, adding that some nitrogen stabilizers can make a significant difference when applied while the corn crop is still small. Again, though, he stressed the need to understand the locations across every acre where the greatest risk of leaching or de-nitrification exist – looking at water movement and organic matter, for example. Through a variable rate application of a stabilizer, growers can maximize their return and foster optimal nitrogen uptake by all plants in the field.
3. Get sulfur worked into your corn program: Maximizing the nitrogen use efficiency comes with maximizing sulfur use efficiency, too. Growers need to be mindful of the sulfur cycle that is taking place in the soil and the similarities between both N and S mineralization. “Remember, acres that are lower in organic matter and have lower mineralization rates, are working similarly for both nutrients and the same goes for the saturated environment. If we are at risk for leaching nitrogen, sulfur is being leached as well.” Kimmel says that changes in environmental practices over the last fifty years means that there is now less sulfur entering the soil profile through rainfall, so growers need to be proactive in managing sulfur as part of their holistic fertility programs.
4. Higher organic matter does not always equal higher net mineralization: Farmers with areas higher in organic matter need to take this effect into consideration when determining nitrogen rates. Kimmel says that those regions across a field with the highest organic matter levels may see more mineralization of nitrogen – because it is a natural side effect of the increased organic matter. “However, you must be able to quantify the impact of saturation, specifically if an acre is not adequately drained. We understand this piece and we create prerequisite layers allowing us to account for these dynamics within our prescriptions.” The nitrogen cycle is an incredible interaction that is continuously changing because we are dealing with so many variables within the soil profile. As agronomist we must make sure we are accounting for the complete cycle (including loss) to the best of our ability, not just portions of it.”
5. This year’s crop is a great place to plan for next year: It is not too early to be thinking of #plant2022 and the nutrient management plan that will maximize performance within each acre. According to Kimmel, walking your acres and evaluating the crop at various growth stages this year can be extremely valuable information for next year’s nitrogen decisions. He urges his customers to look beyond just year-end yield data when determining nutrient management plans, and that comes from considering performance correlation versus causation. Paying attention to what is happening within specific environments now can provide valuable insight when planning for next year.