DOWNS, Ill. — Corn growers have a myriad of management options beyond hybrid selection, and a broad range of in-field studies are conducted by companies to assist in that decision-making.

Many of these studies were highlighted when Beck’s Hybrids hosted its annual field day at the Central Illinois Practical Farm Research site.

Clayton Stufflebeam, Central Illinois PFR assistant, and Brian Arteman, an intern at the Downs site, were among the tour guides who described some examples of about 60 studies at the facility.

The ongoing studies include finding the optimum nitrogen rate for corn after soybeans.

According to four years of data collected from all of Beck’s PFR locations, 183 pounds of nitrogen per acre is the optimum economic rate for nitrogen in corn after soybeans and 215 pounds of nitrogen per acre for corn after corn.

“Corn after soybeans is much lower than corn after corn is because of carbon tie-up,” Stufflebeam said. “It takes nitrogen to break down that carbon load in the corn residue, and once that nitrogen is available after that carbon is broken down, it is ready to be used by the plant.

“Soybean residue is much more delicate, breaks down quickly and we don’t have to use nitrogen as an energy source for the microbes to break down that carbon.”

The nitrogen rates in the field tests ranged from zero to 250 pounds per acre.

“We can achieve higher yields with more nitrogen, but net return-wise ($183 and $215) are our best,” Stufflebeam said.

There are several nitrogen stabilizers in the market, and the PFRs examined their impacts on yields.

“For those who use liquid nitrogen, there is a great possibility that you could lose some of the nitrogen, whether it is in the air through volatilization or in-soil and eventually into the air through denitrification,” Arteman said.

“So here at PFR, we test nitrogen stabilization products, Nutrisphere-N and Agrotain Plus, both of which control both denitrification and volatilization.

“We also test Instinct, which contains the same active ingredient as N-Serve and it only controls denitrification, and we test Factor, which offers volatilization protection.”

The four products are used in separate trials.

“We also put Instinct and Factor together because they only do one or the other, so we can see if we can get added control,” Arteman said.

“In the past three years here at the Central Illinois PFR, we’ve seen a $41 average net return per acre increase over our control plots with no nitrogen stabilizer, just from using those nitrogen stabilizers. That’s pretty substantial.

“Last year at the Central Illinois and Central Indiana PFRs, it averaged about a $45 per acre increase on average.

“Nitrogen is one of our most important and most expensive inputs on our corn crop and so we definitely need to control the loss of that somehow.

“These four products have all done an excellent job for us here. It is definitely a good investment to make, just to add that little bit and help keep that nitrogen where we want it.”

Finding just the right corn planting population also is a part of the ongoing PRF research.

“We are testing four hybrids with five populations ranging from 24,000 to 44,000 with 4,000 population increments. We also have increments of 30-inch rows, 20-inch rows and twin-rows for each hybrid,” Stufflebeam said.

According to data collected the past four years over all of Beck’s PFR locations, optimum planting population for 20-inch is 34,000 and the optimum planting for 30-inch rows is 33,000, resulting in a $2 per acre advantage using 20-inch rows.

“Is that a big enough gain to go with a 20-inch row system? Definitely not as the corn planter, corn head, tires on everything has to be changed,” Stufflebeam said.

“I also don’t see twin-row having much of benefit at this time. Eventually 20-inch rows are probably the way of the future, but not until the genetics get there.”

Planting cover crops is gaining interest among growers, and a corn after cover crop study has been conducted at the Central Illinois PFR the last several years.

This past year the field tests included looking at various nitrogen rates applied on corn after cover crops. The rates ranged from 100 percent of the recommended rate of 180 pounds to 75 percent and 50 percent of the suggested rate.

The control plot yielded 135 bushels per acre in 2012 with 180 pounds per acre of nitrogen.

“All cover crop scenarios out-yielded the cover crop control at each nitrogen rate. The ryegrass with a 50 percent nitrogen rate yielded 148 bushels,” Stufflebeam said.

“There was a substantial gain by using ryegrass as a cover crop last year. I don’t know if it will hold true this year, but with last year’s drought we think the thick root mass of the ryegrass held on to quite a bit of moisture and it saved it for later on in the season when the drought hit.”

The highest net return in the study was more than $800 per acre using the ryegrass and a 50 percent nitrogen rate of 90 pounds per acre.

“Using half of the nitrogen recommended, we’re helping the environment and making some money at the same time,” Stufflebeam said.

“That will be pretty exciting if that holds true this year. We want to learn more about these cover crop mixes and the advantages of cover crops in general.”