ATLANTA - (MARCH 30, 2009) Georgia-Pacific Plant Nutrition is ramping up its field research program in corn this year after two years of results showing yield increases of up to 29 bushels per acre (bu/A) and improved nitrogen efficiency in university and company field trials with its soil- and foliar-applied Nitamin® Steady Delivery® technology.
“Now more than ever, growers are looking for ways to maximize nitrogen efficiency in corn,” says John Kruse, senior agronomist with Georgia-Pacific Plant Nutrition, manufacturer of Nitamin Steady Delivery plant nutrition technology. “Research results from the past two years show that Nitamin soil- and foliar-applied continuous-release nitrogen can be an effective tool in a planned program to optimize N efficiency and consistently increase yields.”
Soil-applied Nitamin Nfusion fertilizer and foliar-applied Nitamin 30L fertilizer are manufactured by Georgia-Pacific and distributed by Wilbur-Ellis and others. The patented polymer technology in Nitamin fertilizer provides an effective slow-release nitrogen source for crops.
“The trial work we have seen to date on corn looks very promising,” says Beth Myers, regional nutrition agronomist for the Great Lakes states, Wilbur-Ellis. “Even at reduced N rates, we are seeing increased yields with a Nitamin fertilizer-powered program compared to conventional N applications.”
Soil-applied Nitamin NFusion
Nitamin Nfusion soil-applied liquid nitrogen fertilizer is completely water soluble and contains 22 percent nitrogen, of which 94 percent is slowly available N in the form of polymer urea. Nitamin Nfusion fertilizer can be blended with quick-release liquid fertilizers such as urea ammonium nitrate (UAN), urea solution or ammonium nitrate solution in various ratios to provide a flexible nitrogen release pattern that matches the nutritional requirements of the crop.
Wilbur-Ellis field trials conducted in Wisconsin last year compared a standard UAN side-dress application to an 80 percent UAN/20 percent Nitamin Nfusion fertilizer blended at a 20 percent reduced overall N rate. Both fields had received 20 lbs/A of N as a starter fertilizer and the side-dress N application was made about 35 days after planting. The Nitamin Nfusion fertilizer field received 117 lb/A total N and the UAN-treated field received 140 lb/A total N. Agronomists noted that the Nitamin Nfusion fertilizer field yielded 9 bu/A higher than the field that received a higher standard UAN application.
In 2007 and 2008 irrigated corn trials at the University of Nebraska, Nitamin Nfusion fertilizer was mixed in a 30:70 ratio (percentage N basis) with UAN/32 and compared to straight UAN/32. In plots where Nitamin Nfusion fertilizer was soil-applied, the corn produced yield increases of up to 29 bu/A when compared to standard UAN in single- and split-application trials. Also, stalk tests confirmed that Nitamin Nfusion was absorbed more by the corn plant when compared to the same N rate in UAN-only applications.
“If you have conditions where you might get nitrogen loss through leaching, whether it’s sandy soils or heavy rainfall, then a slow-release product such as Nitamin fertilizer will give you a nitrogen efficiency benefit,” says Dr. Charles Shapiro, University of Nebraska soil fertility researcher. “In both years of the studies, we found that the Nitamin stayed where it was applied, so it was readily available for the corn plant.”
Foliar-applied Nitamin 30L
Nitamin 30L fertilizer, a blend of methylene urea, urea and triazone, contains 30 percent N, of which 60 percent is slowly available. The remaining 40 percent is urea, which provides a readily available N component. Nitamin 30L fertilizer has a lower salt index and biuret content than urea, making it ideal for foliar applications.
Dr. Kelly Nelson, research agronomist at the University of Missouri, reports that studies last year showed yield increases of up to 28 bu/A when 4 gallons per acre of foliar-applied Nitamin 30L fertilizer was applied at the VT stage. When tank-mixed with Headline (pyraclostrobin) fungicide for a foliar application, Nitamin 30L fertilizer was generally more effective at lower rates. At one gallon per acre with Headline fungicide at 3 oz./A, the corn yields increased by 23 bu/A when compared to the non-treated control. At higher rates, researchers saw some compatibility issues, Dr. Nelson reports.
“A lot of farmers are in high-yield environments, and it would make a lot of sense to utilize a fertilizer as a carrier on a fungicide application,” Dr. Nelson says. “We’re researching this practice further to find out what goes on in the spray mix, optimum application timings and the best application rates.”
University of Arizona research shows that rapid uptake of nitrogen by corn occurs between 35 and 60 days after planting, peaking at the 12-leaf stage. Factors such as inadequate soil moisture, restricted root growth and N leaching mean the plant may not have access to all of the soil N it needs to maximize yield during that time period.
“A foliar application of Nitamin 30L fertilizer just prior to this phase of development can be ideal for plant growth and health,” Kruse says. “It also coincides with most herbicide applications, so a tank mix combination of nutrients and crop protection products eliminates the need for extra applications.”