More research required on enhanced fertilizers
Farmers and university researchers are trying to get the measure of what are being referred to as “enhanced efficiency fertilizers,” or EEFs, products that control fertilizer release or change reactions in the soil that lead to nutrient losses.
Most of the EEFs are nitrogen products. Richard Ferguson, University of Nebraska-Lincoln soils specialist, says that there are three basic groups:
Nitrification inhibitors suppress certain bacteria in the soil by slowing or stopping conversion of ammonium to nitrate. N-Serve is one such product that’s been around for years for ammonia. Instinct is a new product formulated for nitrogen solution.
At a glance
• UNL is studying several “enhanced efficiency fertilizers.”
• Some may be helpful if soils are prone to nitrogen loss.
• If not, the new products are no better than standard fertilizers.
Another group includes urease inhibitors, which are designed to reduce the loss of ammonia through volatilization, allowing time for rain or irrigation to move urea into the soil.
A third group consists of slow-release or controlled-release nitrogen fertilizers, with two basic categories — coatings and chemical formulations. The intent is to match release of nitrogen to the need of the crop.
For phosphorus, polymers are intended to maintain P availability from the fertilizer to increase its efficiency. One such product, according to Ferguson, is Avail, and only limited research has been done in Nebraska. “Results from other studies presented at national scientific meetings show no to limited response,” he adds.
Ferguson says most of the N products are higher in cost per pound of nutrient than current fertilizers. Some are being marketed; others are still being researched.
“The slow-release products and nitrification inhibitors are more likely to be beneficial if there is a high risk of loss from leaching and denitrification. If fertilizer is surface-applied, especially with heavy residue cover and on high pH soils, the nitrogen slow-release products and nitrogen volatilization inhibitors are more likely to be beneficial.
“If soil and climatic conditions are not conducive to N loss, the EEFs will be no better than standard fertilizers,” Ferguson says. “Where they can help, consider them as yield protection rather than as a yield booster.”
Ferguson encourages farmers to do their own strip trials with a split-planter design using several replications in a field or on more than one field. Well-calibrated yield monitors can be used to obtain the harvest data.
“Local UNL experiment station personnel or Extension educators can assist with design of the experiment and data analysis,” he says.
This article published in the April, 2011 edition of NEBRASKA FARMER.