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

FertilizerFall Fertility 2014: Forecasting Fertilizer Use
September 7, 2014
Great crops this year have tapped the soil, and fall work is definitely called for, but how challenging will that get? Read More
Aerial view of the West Fertilizer explosion site
FertilizerFertilizer Companies Blame City For West, TX, Explosion
August 6, 2014
El Dorado Chemical Co. and CF Industries contend the city failed to properly train the first responders and had insufficient protocols in place to battle the April 17, 2013, blaze at West Fertilizer Co. that triggered the explosion. Read More
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

Trending Articles

Matt Hopkins15 Best New Agriculture Apps Worth Downloading In 2014
December 16, 2013
These latest agriculture apps are sure to help ag professionals do their jobs more efficiently in 2014 and beyond. Read More
Seed/BiotechMonsanto Offers New Support For Ferguson, Area Communities
October 8, 2014
Monsanto Co. has committed $1 million in new support for several collaborative efforts in Ferguson, MO, and surrounding communities in North St. Louis County. Read More
Seed/BiotechUnapproved Genetically Modified Wheat Found In Montana
October 3, 2014
USDA reports that one year after discovery of Monsanto's unapproved wheat in a single Oregon field disrupted U.S. wheat export sales, the GMO wheat has again been found in Montana. Read More
Equipment2014 Product Of The Year Voting
September 19, 2014
Many new products were introduced to the ag retail marketplace this year. From this group, CropLife IRON and its consulting partners have selected five finalists for the Product of the Year award. Please cast your vote today to help us determine the winner. Read More
FertilizerFall Fertility 2014: Forecasting Fertilizer Use
September 7, 2014
Great crops this year have tapped the soil, and fall work is definitely called for, but how challenging will that get? Read More
CropLife 100CHS To Build $3 Billion Fertilizer Plant In North Dakota
September 5, 2014
The fertilizer plant in Spiritwood will be the single largest investment in CHS history, as well as the single largest private investment project ever undertaken in North Dakota. Read More

Latest News

Seed/BiotechSyngenta Ranked A Top 10 Biotech Employer For Third tim…
October 20, 2014
Syngenta ranked in the top 10 among the world’s top biotech employers, according to an annual survey conducted by Science magazine. Read More
CropLife 100Wheat Growers Break Ground For New Facility At Kennebec
October 20, 2014
Wheat Growers has broke ground for a state-of-the-art shuttle loader grain handling, fertilizer and agronomy facility in Kennebec, SD. Read More
FertilizerVerdesian Life Sciences Signs Agreement With Los Alamos…
October 20, 2014
Verdesian Life Sciences has signed a licensing agreement with Los Alamos National Laboratory to develop and market LANL’s latest nitrogen enhancement technology for plants. Read More
MicronutrientsStoller Group Announces Groundbreaking At New Office Bu…
October 20, 2014
Jerry Stoller, founder and president of Stoller Group, announced the groundbreaking at the site of the company’s future headquarters in Read More
Crop InputsBioSafe Systems Opens New Production Facility In Nevada
October 20, 2014
BioSafe Systems has completed construction of a state-of-art production facility in Sparks, NV, for its line of activated peroxygen products. Read More
Crop InputsPlatform Specialty Products To Acquire Arysta LifeScien…
October 20, 2014
Once the acquisition is complete, Platform Specialty Products will combine Arysta LifeScience with previously acquired companies Agriphar and Chemtura Crop Solutions. Read More
Seed/BiotechEPA Approves Dow’s Enlist Duo Herbicide
October 15, 2014
The Enlist Weed Control System, breakthrough technology to fight resistant and tough weeds, has received the long-awaited green light from federal regulatory authorities. Read More
MicronutrientsGypsum On Farms Could Help Keep Water Clean, Not Green
October 14, 2014
Gypsum, which has roots in the past as a farm soil treatment, also may have a bright future, and not just as a booster of crops but also as a protector of water. Read More
Photo credit: The United Soybean Board/The Soybean Checkoff.
Crop InputsVerdesian Grows Sales Staff
October 14, 2014
The new account managers will drive sales growth and support relationships with key customers in the plant nutrition and seed treatment and inoculants product categories. Read More
WebinarsUpcoming Webinars
October 14, 2014
Register for one of our upcoming Webinars or access our archive of past Webinars to view recordings of presentations that may be of interest to you. Read More
CropLife 100The Andersons Purchases Six Grain Elevators, Four Agron…
October 14, 2014
The Andersons has acquired Auburn Bean and Grain of Auburn, MI, which will increase the storage capacity of its Grain Group by about 13%. Read More
StewardshipThree Ohio Ag Retailers Honored With 4R Certification
October 13, 2014
The 4R Nutrient Stewardship Certification Program has announced its first three agriculture nutrient service providers to achieve certified status. Read More
Eric SfiligojEntering Agriculture’s New Phase
October 13, 2014
The market’s giddy ride the past few years might be coming to an end in 2015, warns one industry insider. Read More
Eric SfiligojWar And Green Peace
October 11, 2014
A one-time member of Green Peace recently explained why he left the organization after 15 years. Read More
StewardshipCover Crops Add To Farm Sustainability
October 10, 2014
Farmers nationwide find cover crops to be a tool that helps groundwater, prevents erosion, builds soil quality and complements existing best management practices. Read More
EquipmentMeeting Changing Liquid Storage Needs
October 10, 2014
Tank and containment choices are expanding with shifts in farming practices and the economy. Read More
StewardshipEDF Launches Initiative To Reduce Fertilizer Pollution …
October 9, 2014
The effort will engage farmers and businesses throughout the supply chain to transform the way fertilizer-dependent grain crops are grown and sourced. Read More
ManagementMACA 2014: The State Of The Agricultural Industry, And …
October 9, 2014
The trade association’s annual gathering featured speakers from across agriculture and beyond. Read More