Growers should deduct the amount of nitrogen and phosphorus used in a starter fertilizer from the total nitrogen and phosphorus needed for the season, says Harris. However, total phosphate requirements of the corn crop often can be supplied in the starter fertilizer. Since nutrients applied in starter fertilizers are a part of the total fertilizer program, using this recommended practice is not very costly.

“We do not recommend putting anything in the furrow,” he says. “There are products that are recommended for putting in the furrow, but they make me nervous at this point. We’ll continue to look at them.”

As for poultry litter applied as fertilizer, it’s important to know the amounts of nutrients contained in the manure prior to making a decision to use it as your main source of phosphorus and potassium, says Harris.

“The majority of the nutrients contained in the manure are readily available in the season. If you are using poultry litter, in general, you should be able to use about 65 percent of the nitrogen and 80 percent of the phosphorus and potassium contained in the litter the first year.”

For example, if your analysis is 50-50-50 per ton, and you apply 2 tons per acre, then credit your fertility program 65 pounds of nitrogen, phosphorus and potassium the first year. At least 25 percent of the nitrogen should be available within the first two to three weeks after application and the remainder throughout the season.

“I like to see it put on preplant and then still side-dress with commercial nitrogen,” he says.

Other nitrogen materials are available that are known as enhanced efficiency (EE) fertilizers, says Harris, and these are being tested.

“I had this conclusion two years ago, and I still stand by it. They are not silver bullets. Some will play a role, depending on the product and how we use them. We still need to further test them. At this point, one that is working pretty well is Agrotain, which is a urease inhibitor. Where I think a urease inhibitor really comes into play is when dry urea, a 46-percent nitrogen material, is used in a dryland, strip-till situation.”

phollis@farmpress.com