This time of year, you’re done with most of the necessary applications in your cornfields. At this point, you’re scouting for weed escapes, summer diseases and one of the most dreaded headaches a corn farmer can face: nitrogen deficiency.
As a farmer, you know how incredibly important nitrogen is for your crop. It’s one of your most expensive inputs each season, because it’s one of the most crucial nutrients corn needs to ensure a good yield. It can be difficult, however, to get the right amount of nitrogen to your corn each year to get the yield you want.
Mike Moechnig is a field scientist for Corteva Agriscience. He explains why, exactly, nitrogen is critical to corn yield.
“Nitrogen is generally needed in greater quantities — relative to other nutrients — because many components of plant growth require nitrogen. For example, nitrogen is a large building block of amino acids, which are necessary for proteins in cell growth, enzyme activity, DNA/RNA, chlorophyll and other growth components,” Moechnig says. “Slowing these functions due to nitrogen deficiency can have lasting effects on plant growth. Every day is an opportunity for plant growth, and each plant has a limited number of days to grow. If growth is slowed on any given day, the growth opportunity is lost.”
“Every day is an opportunity for plant growth, and each plant has a limited number of days to grow. If growth is slowed on any given day, the growth opportunity is lost.”
And once growth opportunity is lost, so is the opportunity for greater potential yield at the end of the season. That’s why it’s important to have a good idea of the amount of nitrogen your crop will need for the yield you want and to make a plan to ensure your corn gets that nitrogen.
Granular Agronomy offers precision tools, expert advice and custom prescriptions to help farmers pinpoint the correct inputs for their fields. This is a great option to help avoid nitrogen and other nutrient deficiencies.
Another tool to help estimate the right amount of nitrogen is the third-party Ag PhD Fertilizer Removal by Crop App. This app gives a more general estimate of the nitrogen needed. You select your crop and input the number of bushels you’re hoping to grow, and the app gives you an estimated amount of nutrients needed to achieve your goal. For example, if you type in 200 bushels, the app says you will need about 224 pounds of nitrogen.
When it comes to scouting for nitrogen deficiency, the symptoms you’ll want to look for depend on the stage of the corn plants.
“Young plants may not readily show signs of nitrogen deficiency, but if they do, it may be a slight reduction in green color, slight growth reduction or slight variation in height uniformity,” Moechnig says. “Nitrogen deficiency symptoms often become more apparent at later vegetative or reproductive growth stages.”
“Nitrogen deficiency symptoms often become more apparent at later vegetative or reproductive growth stages.”
In those later stages, signs of nitrogen deficiency include the “firing” of leaves, when they first turn a pale greenish yellow, which spreads into dry, brown tips and edges. Deficient corn plants can also have more spindly stalks.
If you find nitrogen deficiency after you’ve made your planned applications, you can go back and apply more nitrogen. This obviously becomes more difficult as the plants mature and the canopy starts to close. It really depends on the type of equipment you or your applicator are working with and whether you want to make another field pass.
Moechnig says, however, once you see the signs of nitrogen deficiency, it’s likely too late to completely save the yield. “It is best to avoid deficiency that causes negative growth responses, as there can be some yield loss even if additional fertilizer is added to correct the problem,” he says.
So, if you do discover nitrogen deficiency this summer, the best thing to do is to plan to avoid the problem next year.
Moechnig advises soil testing before future applications and keeping good records of those tests every season. He says, “Some helpful information may include soil tests to quantify carryover nitrogen from the previous year or nitrogen remaining from spring applications prior to a sidedress application.” You can use that information to dial in the right amount of nitrogen you need to apply.
Moechnig says it’s also important to make sure you consider other factors like soil type, historical weather patterns and the forecast to account for possible nitrogen losses during the season. He also advises working with your retailer to ensure appropriate application practices like applying at the right time and incorporating nitrogen when appropriate.
Finally, Moechnig says, it is imperative to stabilize your nitrogen applications with N-Serve® nitrogen stabilizer or Instinct NXTGEN® nitrogen stabilizer. “Even with proper planning, unexpected adverse environmental conditions can cause excessive N loss and reductions in crop yield,” he says. “Stabilizers can help reduce some of this variation to increase the crop yield response to nitrogen applications.”
Nitrogen is one of your most expensive inputs, and with fertilizer prices rising, it’s a very good idea to protect that investment.
So, watch for nitrogen deficiency in your corn this summer and, if you find it, work with your retailer to help make sure you don’t have to deal with it again next year.
Instinct NXTGEN® is 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.
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