Nitrogen on Corn
Fertigation Has Advantages
Nitrogen is a key factor in maximizing corn yield. In addition to being the fertilizer ingredient needed in the greatest quantity, timing is also important. Don’t forget that if available N isn’t the limiting factor, it really won’t matter how much extra is applied. Work closely with your agronomist and keep monitoring throughout the season. The farther ahead you apply your nitrogen before it is needed, the greater the probability it may not be available when the plant needs it. This is a key advantage of fertigation. Pivots can run through the entire season and nitrogen is being applied with water. This has two advantages. It will permeate the soil surface as a liquid, minimizing volatilization associated with top dressing dry fertilizer. Nitrogen is primarily absorbed by the roots in solution which is how it is delivered in fertigation.
Different Nitrogen Demands by Growth Stages
During the first 35 days after planting, a corn crop needs slightly less than 2 lbs. of N per acre per day.
From V6, N Uptake nearly doubles to 4 lbs. per acre per day.
Between V10 and V14 N demand may go as high a 8 lbs. of N per acre per day.
At silking or R1 requirements for available N decreases to 4 to 5 lbs. per acre per day.
From late reproductive stages through black layer, the requirement drops back to mirror the young plant needs of 2 lbs. acre per day.
Many products, forms of Nitrogen and application systems are available: From anhydrous to dry urea and slow-release products to liquid 28 and more. Knifing in, broadcasting, band applying, Y drop liquids and fertigation through pivots can all have a place in your system. What gives you the most control, best placement and affordable system for the fields on your farm. More than likely it will be some combination of products and application methods.
It is important to have season-long N availability. Typical ground applicators can be disrupted by weather issues that may cause gaps to be created, often leaving plants short of their current needs. Pre-season or early season applications designed to carry your crop through the entire season may be lost through leaching or volatilization. While some farmers anticipate a portion of this occurring, they spend money on more than an adequate amount of fertilizer to create a safety net. Having the majority of your Nitrogen applied in a timely, as needed manner through fertigation, you can often reduce the total applied each season and still benefit from achieving your target yields.
Don’t forget sulfur with your in-season nitrogen applications, especially if you are farming for higher yields. Sulfur helps corn metabolize N more efficiently.
Work hard at planning and testing so you have adequate, accurate information and utilize a good agronomist. Fertigation through pivots is one more available tool for your toolbox. The nice part is that it is a small step when you have invested in pivots to provide adequate water to reach your targeted yield goals. If you haven’t taken that initial step, fertigation is one more reason to consider the value of center pivot irrigation for your crops. Managing your water is another piece in a successful plan. Success is the result of good management, solid data and well-tuned equipment. Once you find and fix the limiting factor in obtaining higher yields, begin to tackle the next limiting factor you can control. Water is one of them!
Credit to Farm Journal / Ag Web for much of the content in this article.
ABOUT THE AUTHOR
Pete is the marketing manager for Michigan Valley Irrigation, having joined the company in 2016. He was raised on a dairy farm in western New York and graduated from Cornell University with a B.S. in agricultural economics. His entire working career of over 37 years has been involved in agriculture. A farmer helping farmers. When away from Michigan Valley he operates, Joyful Noise Farm, a small livestock and produce farm and spends time with his family.
