Soaring gas prices are having an obvious impact on everyone's pocketbook. But there's a not-so-obvious impact that higher fuel prices are having on the cost of fertilizers.

“Nitrogen fertilizer is close to $400 a ton, which is higher than I've ever seen it,” said Dennis Gardisser, professor/associate department head, Biological and Agricultural Engineering, for the University of Arkansas Cooperative Extension Service.

He said the price of fertilizer has increased because fuel is used in the manufacturing process.

“This will be a year everyone wants to get the maximum from every dollar spent,” Gardisser said. This means growers should make sure they're getting the most bang for their buck when applying fertilizers.

“Farmers need to be as efficient as possible in applying fertilizers so as not to waste money. That means spreading the fertilizer evenly at the correct rate.”

Gardisser said many farmers use fertilizer “buggies” from agricultural dealerships. The typical buggy isn't always well-calibrated, and it can streak fields, he said. Streaking is the uneven distribution of fertilizer. Some areas can get too much while other areas receive too little. The effects can easily be seen from the air, “but where you don't want to see it is in your yield monitor when you start harvesting the crop. We've seen losses of up to 20 percent.”

If you're going to use buggies, he said, you should take time to calibrate them.

“I know when we've calibrated some of these buggies, the settings were never changed much. One setting may be set perfect for urea. But it won't be set perfectly for 100 pounds per acre or for 200 or 300 pounds.

“We've seen coefficient of variations of up to 50 percent. That means half the field is getting twice as much fertilizer as other parts. It happens a lot. A lot of times you don't gain a lot of yield with too much fertilizer. Too little fertilizer will make the crop suffer.”

But the engineer says producers should consider hiring a professional ground or aerial applicator “to be sure that products are applied in a timely, uniform manner so that the expensive dollar spent on fertilizer is effective and gets the return producers want.

“We use airplanes a lot in Arkansas, and many of them are calibrated to do a good job,” he said. “The university program helps applicators evaluate the accuracy of their systems. But not all applicators participate in the program.”

Gardisser expects farmers to be busy soon fertilizing wheat. He said warm weather and recent moisture will kick off a growing spurt. He said the same advice about fertilizer efficiency will also apply later in the season when farmers are raising rice.

The university has several calibration workshops to show both ground and aerial applicators how to adjust and calibrate. The fertilizer companies in the state have been good to support the program.


Lamar James is an Extension communications specialist with the University of Arkansas.