Nitrogen Applications For 2012 Corn Crop

While soil temperatures were warmer than normal last winter, the dry soil conditions have resulted in very little nitrogen loss this spring.

According to University of Illinois assistant professor of crop sciences Fabian Fernandez, soils in the state were dry at the beginning of autumn 2011, with above-average precipitation levels only during November and December.

“In March, I predicted that the risk of nitrogen loss would increase only if the spring became too wet,” said Fernandez. Precipitation thus far this year is, overall, below average in the state. Thus, so far, the likelihood of nitrogen loss this year is very low.

Taking a look at soil nitrogen also provides evidence that applied nitrogen remains in the soil.

“Nitrification has proceeded quickly this spring,” Fernandez said. In central Illinois, a field with anhydrous ammonia plus NServe applied in November 2011 contained 80 ppm ammonium in the top 12 inches of soil at the end of February. Now, in mid-May, the concentration is 27 ppm. During the same time interval, nitrate concentrations have increased from 10 to 31 ppm. Although ammonium has transformed to nitrate, there is still a considerable amount of ammonium in the soil, probably because not all of it has been nitrified and also because organic nitrogen in the soil is being mineralized to ammonium.

Last week, samples were also collected for the 12- to 24-inch depth. As expected, there has not been sufficient water to move nitrate down the profile and nitrogen concentrations were low: soil nitrate was only 9 ppm and soil ammonium was 3 ppm.

At this time, most corn is growing rapidly and starting to take up nitrogen. “If all the nitrogen has already been applied, I do not anticipate a need to apply additional nitrogen for this crop,” Fernandez said. “If no nitrogen or only a portion of the nitrogen was applied, now is the time to start applying the balance of the application.”

The nitrogen needs of the corn plant are low from the early vegetative development stages until about V5 (fifth-leaf stage). Most nitrogen is taken up during the V8 to VT (tassel) stages. Soon after pollination, nitrogen uptake is essentially completed.

Because the potential for nitrogen loss by leaching or denitrification at this time of the growing season is very low and corn plants will soon enter a rapid nitrogen uptake phase, Fernandez recommends not delaying the application. However, if farmers are not quite ready, research has shown that the chance for yield loss due to nitrogen stress is very low, even when applications are done as late as the V6 development stage, because in most soils in Illinois, mineralization of soil organic nitrogen provides ample nitrogen for early crop demands. Moreover, if part of the total nitrogen was already applied, a delay in applying the remaining nitrogen is not likely to cause plant nitrogen stress.

In fields with low nitrogen-supplying power (soils with low organic matter) or where no nitrogen has been applied, early application (before the V6 development stage) is recommended to avoid loss of yield potential. Another reason not to delay application, especially because of the dry conditions this year, is that the sooner nitrogen is applied, the greater chance it will have to be moved into the root zone by rain.

“In my opinion, the best options to sidedress nitrogen are to inject it into the soil or dribble it between rows,” Fernandez said. If anhydrous ammonia is used, make sure the knife track gets properly sealed to avoid crop injury from free ammonia escaping to the atmosphere.

While most fields look very dry on the surface, adequate moisture is still present below the surface to retain the ammonia. According to Fernandez, “If the application is done at least 6 inches below the surface in fine-textured soils or at least 8 inches below the surface in coarse-textured soils, there should not be problems with ammonia volatilization.”

The advantage of dribbling nitrogen between crop rows over broadcast applications is that dribbling reduces the potential for volatilization of urea-containing fertilizers (urea and UAN) and reduces fertilizer contact with the foliage, thus reducing foliar damage.

If injection or dribbling options are not available, Fernandez recommends broadcast urea. This product has the least impact on leaf burn when compared to UAN, ammonium nitrate, or ammonium sulfate. If the canopy is wet, it is best to wait until it dries to minimize dry fertilizer adhesion to the leaves.

If there is not a high likelihood of rain, Fernandez suggests applying urea with a urease inhibitor (such as Agrotain) to minimize nitrogen volatilization. When urea is broadcast on the soil surface without a urease inhibitor, nitrogen losses start to increase 3 to 4 days after the application if there is no rain to incorporate it. After 10 days without rain, as much as 30 percent of the application can be lost. By contrast, ammonium sulfate and ammonium nitrate are not subject to volatilization losses if left on the soil surface.

The least desirable option is to broadcast a UAN solution because this application is most likely to injure the crop. If no other options are available, the application should be done as soon as possible because the smaller the plant, the less chance for fertilizer to make contact with it.

Some studies have shown that there is little damage if a UAN solution is broadcast when plants are about 6 inches tall. Similarly, for bigger plants (V4 stage), an application of up to 100 pounds of nitrogen per acre is unlikely to cause substantially reduced yield. This kind of application is best done a few hours before rain so the fertilizer can be washed off the leaves, although this is not advisable if a herbicide is combined with the UAN application (read the label to ensure this is allowable). Also, be aware that including a herbicide with UAN can intensify leaf burn damage.

Leave a Reply

Fertilizer Stories

FertilizerThe Fertilizer Institute: New President, Renewed Energy
February 3, 2014
Chris Jahn relishes the opportunity to lead the organization through the challenging times ahead. Read More
FertilizerA New Cycle For Fertilizer Demand
January 2, 2014
Changes in the corn market could have a major impact on the crop nutrients sector in 2014, say experts. Read More
FertilizerOSHA Hammers West Fertilizer With Over $100K In Fines For April Explosion
October 10, 2013
The Occupational Safety and Health Administration is fining the parent company of the West Fertilizer plant, Adair Grain Inc., $118,300 for 24 violations. Read More
FertilizerTFI Appeals Chesapeake Bay TMDL Ruling
October 10, 2013
The Fertilizer Institute joined a coalition appealing a U.S. District Court ruling on the Chesapeake Bay Total Maximum Daily Load (TMDL) for nitrogen and phosphorus. Read More

Trending Articles

Green Valley Ag facility
Retail FacilitiesGreen Valley Ag Adopts A.J. Sackett’s Precision Fertilizer Blending® Technology At New Facility
July 8, 2014
Sackett's Precision Fertilizer Blending® Technology is making huge strides around the world. Green Valley Ag adopts the technology at its new facility to support its advancing agronomic needs. Read More
Retail FacilitiesWaconia Manufacturing Builds Facility Designed For Speed, Efficiency
July 7, 2014
To make its new hub facility more efficient, Cooperative Elevator enlisted the aid of Waconia Manufacturing. Read More
EquipmentSummer Show Preview 2014: Superior Sprayers Take The Field
July 3, 2014
In this final installment of our coverage of the major categories of Big IRON that retailers can expect to test-drive at this summer’s events, here is a look at 19 sprayers. Read More
Scouting a soybean patch at Green Valley Ag.
EmployeesCropLife Compensation Survey: Battling Talent Drain
July 2, 2014
Retailers too often lose employees to companies outside of agriculture, while recruiting efforts are most often limited to competitors and other ag-focused organizations. Read More
HerbicidesDow AgroSciences Introduces SureStart II Herbicide
June 16, 2014
The enhanced formulation has improved viscosity and increased stability under heat and controls more than 60 high-anxiety grasses and broadleaf weeds found in corn fields. Read More
HerbicidesBASF Investing $270 Million To Expand U.S. Herbicide Production
June 11, 2014
BASF has invested more than $270 million to expand herbicide production capacities in the U.S., including more than 20 new products to be launched over next two years. Read More

Latest News

HerbicidesWillowood To Market Glufosinate
July 28, 2014
Willowood USA recently announced that Federal EPA has approved its technical registration for glufosinate. Read More
InsecticidesHow To Scout For Corn Earworms In Corn
July 28, 2014
In her weekly report, University of Missouri Agronomy Specialist Jill Scheidt discusses what to look for when scouting for corn earworm. Read More
Crop InputsDuPont Pioneer, Weyerhaeuser Enter Technology License A…
July 28, 2014
The agreement brings together agricultural and forestry know-how to sustainably improve crop productivity for corn growers around the world. Read More
EquipmentAGCO Launches Global iPad App
July 28, 2014
The free AGCO Global iPad App can be downloaded from the Apple iTunes Store and features the full family of RoGator self-propelled sprayers and TerraGator high-floatation spreaders. Read More
Eric SfiligojYuma Centennial Ag Supply Earns 2014 National Environme…
July 28, 2014
Colorado-based ag retailer receives top trophy in 24th annual DuPont Crop Protection/CropLife ceremony. Read More
CropLife 100Pinnacle Forms Alliance With Wildlife Managment, Seed O…
July 25, 2014
The strategic alliance will provide Tecomate with key wildlife products, processing facilities, distribution centers and sales through Pinnacle’s ever-growing retail network. Read More
ManagementFranken Presses White House On RFS Support
July 25, 2014
Al Franken and a group of Senate democrats recently met with senior White House official John Podesta to urge the administration to change its position on an EPA proposal. Read More
ManagementASA, FarmLink To Launch ‘Operation Benchmark̵…
July 25, 2014
The American Soybean Association (ASA) and FarmLink are teaming up to help farmers close the $11 billion gap between what they harvested in 2013 and what they could harvest annually. Read More
StewardshipNorthey: Farmers Commit $1.4 Million to Try New Water Q…
July 25, 2014
The practices that are eligible for funding include cover crops, no-till or strip till and using a nitrification inhibitor when applying fall fertilizer. Read More
Precision AgFarmers Learn How Changing World Will Impact Iowa
July 24, 2014
Technology and understanding global consumer demand for Iowa farm products brought hundreds of farmers and agribusiness leaders to Ames recently for the annual Iowa Farm Bureau Federation Economic Summit. Read More
HerbicidesPurdue: Late Season Weeds May Require Manual Removal
July 24, 2014
Hand-rouging and pulling late season weeds by hand may be the best way to remove them, more so than using a herbicide, a Purdue Extension weed scientist says. Read More
Soybean Field
InsecticidesTransform WG, Closer SC Insecticides Receive R&D 10…
July 23, 2014
Dow AgroSciences has received the award from R&D Magazine for Transform WG insecticide and Closer SC insecticide with Isoclast active. Read More
EquipmentKinze, Raven Team Up On 4900 Planter Monitor
July 23, 2014
Kinze Manufacturing announces a partnership with Raven Industries to develop a standalone monitor solution for the Kinze 4900 series planter. With this new Read More
LegislationNew Farm Bill Continues To Confuse As Growers Await USD…
July 23, 2014
The new five-year Farm Bill eliminates many of the direct payments previously payed to growers and could benefit from USDA clarification, reports a Toledo Blade columnist. Read More
EquipmentPrecisionAg.com Relaunches With Responsive Design For M…
July 22, 2014
PrecisionAg, the worldwide leader in precision agriculture information and analysis, announces the launch of its completely redesigned website, PrecisionAg.com. Read More
FungicidesEPA OKs Two Willowood Fungicides
July 21, 2014
The EPA has approved Willowood Azoxy 2SC and Willowood AzoxyProp Xtra. two widely used broad spectrum, preventative fungicides with systemic and curative properties. Read More
Precision AgFarmers Learning Fast As UAVs Take Off
July 17, 2014
Farmers and others interested in how UAVs can be used in agricultural applications were able to learn more about the technology during the recent Precision Aerial Ag Show. Read More
CropLife 100Bobby Knight, Richard Petty To Highlight Ag PhD Field D…
July 17, 2014
Attendees at the July 24 Ag PhD Field Day at Hefty Farms will learn about the latest agricultural technologies, and get a chance to meet legendary sports figures Bobby Knight and Richard Petty. Read More