When Corn Needs Nitrogen Most During the Growing Season

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Young green corn

Nitrogen is one of the most important nutrients for growing high-yielding corn. It is a critical component for nearly all the building blocks needed for healthy corn growth — including amino acids, proteins, nucleic acids and the production of chlorophyll. 

You and your customers know just how essential it is to have the right amount of nitrogen in the root zone for maximum yield potential. However, while corn uses this nutrient throughout the growing season, there are certain growth stages when corn requires more nitrogen than others. Knowing when these stages occur can help your customers dial in their management practices to make the most of their nitrogen investments.

When Corn Takes Up Nitrogen

Generally, corn takes up most of the nitrogen it needs for the season prior to tassel. Let’s break down the numbers:

  • 60% to 70% of the nitrogen required is taken up by the VT stage.
  • 30% to 40% of the remaining nitrogen required is taken up post-tassel between the R1 and R6 stages.

Drilling down even further, corn uses about half of the necessary nitrogen between the V8 and VT stages. This is a period that only lasts about 30 days.

The chart below offers a look at nitrogen uptake throughout the growing season. You can see which parts of the corn are using the bulk of the nitrogen during each particular growth stage. You also can see how uptake sharply increases around that V8 stage until it reaches 100% uptake at R6.

The chart also shows, on average, how much applied nitrogen is still available in the root zone during each of those corn growth stages. The red line shows the average amount of nitrogen available on unstabilized acres, while the blue line shows the average amount of nitrogen available on stabilized acres.

In-crop Applications

Knowing that the V8 to VT time frame is especially important for corn nitrogen uptake, you and your customers can take measures to ensure the nutrient is in the root zone during that period. 

Protecting their nitrogen applications with a proven stabilizer is one great way to help make sure nitrogen is there when it’s needed. Splitting up nitrogen applications — applying some in fall or early spring and then some again at sidedress — also can be an effective strategy, when possible. 

If you’re going to help customers with sidedress applications this season, we recommend making those applications sometime between the V3 and V6 stages. We also recommend using a nitrogen stabilizer to protect that investment. Here are options from Corteva Agriscience:

  • N-Serve® nitrogen stabilizer and Instinct NXTGEN® nitrogen stabilizer are both powered by Optinyte® technology, which is proven to protect nitrogen below ground, where up to 70% of loss happens from leaching and denitrification. N-Serve works with anhydrous ammonia, and Instinct NXTGEN works with UAN, urea and liquid manure. Both solutions are shown to extend nitrogen availability in the root zone up to eight additional weeks. 
  • PinnitMax® TG nitrogen stabilizer is a new above-ground solution. PinnitMax TG prevents volatilization of UAN and urea for up to 14 days. This new product will be available on wide release in 2023.

You and your customers also can consider an in-crop biological application to help enhance their nitrogen management. Utrisha N nutrient efficiency optimizer is an alternative sustainable nitrogen fixation product. The active ingredient in Utrisha N is a bacterium, which captures nitrogen from the atmosphere, supplying it to crops for enhanced plant growth and optimum yield potential. This biological should be applied sometime during the V4 to V8 time frame in corn to help ensure the bacteria can start supplying nitrogen to the crop ahead of that critical rapid uptake period.

Your customers are undoubtedly facing some challenges with current nitrogen fertilizer costs. However, by helping them find smart ways to manage that investment, you can help them overcome those challenges. Knowing when corn needs nitrogen the most is just one piece of information to help dial in the right practices to get the best possible ROI. 

If you have any questions, you can always reach out to your Corteva Agriscience territory manager to find the best solutions for your customers’ farms.

Instinct NXTGEN®, PinnitMax® TG and Utrisha N nutrient efficiency optimizer are not registered for sale or use in all states. Contact your state pesticide regulatory agency to determine if a product is registered for sale or use in your state. Do not fall-apply anhydrous ammonia south of Highway 16 in the state of Illinois. Always read and follow label directions.