Leopold Center - Leopold Center grant leads to new fertilizer technology


This research team developed a prototype for a new fertilizer manifold. Members are (left to right) Paul Boyd, Mark Hanna, Tom Colvin, Kyle Baumgartner and Michael White.


This is the Impellicone, which is licensed to CDS-John Blue and based on the ISU prototype. It went on the market in December 2003.

Maybe they couldn’t build a better mousetrap, but a team of Iowa State University researchers definitely knows how to build a better fertilizer applicator.

A new technology, known as the Impellicone and fostered at Iowa State, has the potential to reduce the amount of nitrogen fertilizer typically used on crops. It was named a top new agricultural equipment design in 2004 by the American Society of Agricultural Engineers (ASAE).

“This is an example of something that could make the world a different place, all because the Leopold Center was willing to look at a problem,” said researcher Mark Hanna, ISU Extension agricultural and biosystems engineer.

“This technology allows people to more uniformly apply fertilizer, and if rates of application are reduced to take advantage of this uniformity, it’s a win-win situation for everyone,” he added.

Grant funds background research
Although preliminary tests were conducted earlier, work on the project began in earnest with the start of a three-year grant from the Leopold Center in 2000. The grant funded background research into a problem inherent in the application of anhydrous ammonia (NH3) fertilizer: uneven distribution which can be one possible cause of over-application of nitrogen.

The Impellicone is a self-powered manifold or flow-divider system that more uniformly mixes and distributes the liquid and gas phases of NH3 to multiple outlets across an applicator. The equipment gets its name from the cone-shaped impeller (rotor) that mixes and distributes the NH3.

The Impellicone is licensed to CDS-John Blue Company, a manufacturer of agricultural equipment in Huntsville, Alabama. According to a company official, about 400 units, which cost between $375 and $500, have been sold since they went on the market in December 2003.

Hanna’s “conservative estimate” is that the technology could result in a 5 percent reduction in applied NH3. In Iowa, that’s 50 million fewer pounds of applied NH3 for a savings to producers of approximately $9 million.

Working with Hanna on the Leopold Center grant were Tom Colvin, professor and USDA collaborator at the National Soil Tilth Laboratory; James Baker, ISU professor emeritus of agricultural and biosystems engineering; Michael White, ISU Extension crop specialist in Warren County; former agricultural engineering graduate student Paul Boyd and Kyle Baumgartner, a junior in agricultural engineering from Strawberry Point.

Hanna said the team tested existing equipment in the field, measuring the amount of NH3 coming from each outlet supplying a 28-ft. long applicator tool bar. They found that application using conventional equipment could under-apply by as much as 32 percent, which is one reason why farmers may be tempted to over-apply – to guarantee that individual plants receive the minimum recommended amount of nitrogen.

Alternative solutions more costly
Other solutions to the distribution problem are either more complicated (one model requires changing parts to adjust rates) or more expensive, such as a second pump to re-pressurize the anhydrous ammonia between the nurse tank and the application toolbar (at a cost of $6-$10,000).

“We knew we needed to keep the cost low so that it would be used over a wide range of applications,” said Boyd, now employed by the U.S. Army Corps of Engineers in Omaha. “Dr. Hanna challenged me to come up with an alternative design that we could test.”

After several designs and months of testing – all funded by the Leopold Center grant, Hanna and Boyd had a prototype. Iowa State’s Office of Intellectual Property and Technology Transfer and the ISU Research Foundation helped them identify an industry partner and apply for a patent.

The ISU team then worked with engineers from CDS-John Blue to refine the commercial design. The equipment was tested in the field last summer.

Favorable response
“All of our customers are really excited about it,” said Seth Ferguson, CDS-John Blue engineer. “They’re looking at the benefit of better accuracy so there will not be as much streaking in their corn and more uniformity in their crops.”

“We think that a typical corn grower will usually pay for this in 500 to 600 acres in one year,” he added.

Denny Bell, who manages Fertilizer Dealer Supply in Jesup, said he sold several Impellicones last spring and has heard no complaints. The units went to individual farmers, rather than fertilizer dealers, but some people are taking a “wait-and-see” approach before purchasing the device.

Jerry Dove said he had read about the Impellicone in a farm magazine and decided to try it on 550 acres he farms near Janesville. Successful Farming followed the research and was an early partner in the ISU project. Dove said he won’t know how it helped until he checks his fields for nitrate levels after harvest.

“There are a lot of specialized ways to distribute and monitor anhydrous ammonia but the weak point has always been the manifold,” Dove said. “This system seems to make a lot of sense. I’m anxious to do the stalk testing. I think we’ll be pleased with the results.”

Results of the Leopold Center research project, Reducing anhydrous ammonia application by optimizing distribution, summarized in the 2003 Center Progress Report, available from the Leopold Center.

Read more about the project in Successful Farming magazine. Crop editor Rich Fee followed this project’s development and the Meredith Corporation also contributed funds for the early work.