Nitrogen Strategy #3 – Protect Your N Investment All Season

We’ve covered the value of building a plan for every acre based on your historical data, and the importance of taking all your application variables into account. But even the best-laid nitrogen plan must contend with the whims of Mother Nature. And without a crystal ball, the only thing you can do to protect your nitrogen investment is monitor and adjust as the season goes by.

Weathering the Storm

When your first seed is planted, there’s no telling what conditions it will experience throughout the growing season. Unpredictability is the new norm — from wetter springs and more intense rainfall and hail, to dryer summers and more frequent drought events, pests and disease. Whether it’s seed and soil loss from runoff, slower nitrogen mineralization, or reduced yield due to drought, the risks and results of extreme weather are forcing farmers to constantly think on their feet. 

“Weather has become a huge factor in N management,” explains Landon Spurling, a Granular Certified Services Agent (CSA) from southeast Nebraska. “Given how sporadic rainfall events have become, it’s essential to monitor N throughout the season and adjust your N model to reflect weather impact. For example, last summer, two of my local weather stations that are 3.5 miles apart recorded a 4-inch difference in rainfall.”

We can see the impact weather has on N in the chart below.

Same Field, Same N Source and Application, but Varying Nitrogen Needs.

The chart above shows estimated soil nitrogen in the top 2 feet throughout the year for a given soil type (each line represents a different year and its weather). Each year the same applications are made (100 lbs/ac before planting, 100 lbs N/ac as side-dress). As you can see, there was a 60 lb N/ac swing at VT on the same soil type from one year to the next (dot represents VT each year). If this grower hadn’t adjusted his N plan in-season, he would have left thousands of dollars of yield potential on the table.

React with Confidence

While you can’t control the weather, you can combat its effects and protect your N investment. Granular Agronomy CSAs partner with farmers to marry data science with deep agronomic education and hours of fieldwork to produce prescriptions designed to meet a grower’s yield goals without over-application of nitrogen. 

Using the Granular Agronomy Nitrogen model, your CSA can simulate the effects caused by the interaction of weather, soils and management, and provide you with a better understanding of what’s happening on every field.

Your CSA can answer critical in-season questions such as:

  • What effect did that 4” rain have on my nitrogen levels?
  • How has a cooler season affected nitrogen uptake?
  • With this dry snap do I need to apply N through my pivot?

Most importantly, you can use those scenarios and insights to adjust your nitrogen plan in-season, protecting your nitrogen investment and your yield. 

“While we may know what a field is capable of, we can’t guarantee a perfect growing season,” explains Spurling. “What we can do is factor in the impacts as they occur and adjust our nitrogen prescriptions based on agronomic science and modeling, not just a simple hunch or guess.”

Trial, No Error

Curious to see how your nitrogen plan stacks up against the Granular Agronomy model? Consider participating in the 2021 field trials.

In 2020, Granular conducted 36 trials across 8 U.S. states and Ontario, Canada, testing the nitrogen model on nearly 300 acres. “I joined a few of my growers in the trial,” said Alex Ballweg, a Granular CSA based in central Illinois. “It didn’t just validate the idea of right rate, rate place, but gave them confidence that the nitrogen model really works. They saw how accurately the model can simulate applied nitrogen scenarios, and how to use those scenarios to get most of every input and every acre.”

To learn more about 2021 field trials, contact Brett McArtor at [email protected] or 319-594-2417. 

Thanks for following along as we’ve talked through strategies to successful nitrogen management. If you want to learn more about Granular Agronomy or any of our agronomic and financial tools, call us at 888-435-4726 or schedule a demo at

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