Growing Knowledge

Read the latest insights from our experts as they cover agronomy issues that matter most to you and your operation.

Get Technical About Nitrogen Management

Mark Glady
Regional Agronomist
Nitrogen management in corn crops is challenging for a number of reasons, one of the main ones being nitrogen’s chemical properties: When in nitrate form, nitrogen is water-soluble, meaning it moves easily with water. If a field receives moderate to heavy rainfall and an abundance of water is moving down through the soil profile, nitrate can easily leach out of the profile along with that water. 
 
Since weather conditions and rainfall volumes are difficult to predict, one way to manage nitrogen is to collect data periodically throughout the growing season using various tests and technology. Here are some tools that can help you make sure your nitrogen is staying where you want it to and not moving off track.
 
1. Soil sampling
Using a pre-sidedress nitrate test (PSNT) soil sample is one tool that can provide insight into the level of nitrate present at the V5 growth stage. Work with your local trusted advisor to do this just prior to the grand growth phase of corn, when plants have a high demand for nitrogen. 
 
2. Tissue testing
Tissue testing provides a second piece of data to evaluate how much nitrogen is present in the plant at any given time. NutriSolutions® tissue testing lets you gauge the amount of nitrogen and other nutrients your corn plants are taking up. This lets you correct any deficiencies promptly and accurately.
 
3. Crop modeling
Crop models like the R7® Field Forecasting Tool provide insight into what nitrogen availability looks like for corn on any given field. Models are not perfect, but they do provide a look into the nitrogen sufficiency status of corn during the season. Postseason, the Field Forecasting Tool allows you to review the plant’s uptake throughout the year. Running different scenarios lets you know what you could have done differently during the past season and how to plan for the year ahead.  
 
4. Stalk nitrate test
A stalk nitrate sample is a kind of “nitrogen report card” you can get at the end of the season. It lets you know if your corn plants had enough soil nitrogen available to them, or if they were short and had to “rob” nitrogen from the stalk. This allows you to recalibrate your nitrogen management decisions for next season.
 
Better together
It’s hard to manage nitrogen throughout the season using just one of these methods. It’s when they’re used together that you derive the most benefit. The sooner you can detect whether your corn plants have adequate nitrogen, the sooner you can tackle problems. You can also have greater confidence in your nitrogen management strategy and more assurance in the recommendations your advisor makes, given test results.

A Better Way to Manage Nitrogen

Brad Roetman
Lab Director
Nitrogen is one of the most expensive inputs for crop productivity. Yet, it’s critical for healthy crops. That’s why finding better ways to manage it is crucial for farmers. At Solum, Inc., we’re working to develop new technology to characterize soil with the ultimate goal of helping farmers build more prescriptive nutrient management programs. We’re owned by WinField United, which gives us access to the latest technology and expert resources to make that goal a reality.
 
Keep track of your nitrogen
During corn’s rapid growth from about V10 to V18, plants can absorb up to 10 pounds per acre of nitrogen per day. If that nitrogen isn’t available in the root zone, it’s likely plants won’t reach their maximum yield potential. Spoon-feeding crops throughout the season helps ensure that mobile nutrients like nitrogen are available when plants need them most.
 
But how do you know how much nitrogen your crops need in-season? I recommend doing a soil test prior to side-dressing in order to understand baseline nitrogen levels in soil. Because nitrogen availability changes so quickly in soil, it’s necessary to get sampling results as close to that critical uptake period as possible. Armed with accurate soil nitrogen information, you’re better able to make in-season side-dress application decisions with confidence.
 
Timely soil sample results can also help save on nitrogen costs. If you know exactly how much nitrogen is available in soil, you can tailor a side-dress application to match your crop’s need. You won’t under- or overapply because real-time testing tells you exactly where you stand. That’s good news for your pocketbook and for the environment.
 
Solum offers a fast, easy soil nitrate test that generates lab-quality data at your local retail location. Our No-Wait Nitrate soil testing uses water and optical sensors to measure soil nitrate levels in just 3 to 5 minutes. The real-time results help you make a quick decision at a key time in the crop’s development.
 
Good nitrogen management helps realize a crop’s yield potential. For more information on how No-Wait Nitrate testing can help you plan your nitrogen applications, contact your local WinField United retailer.

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