With bigger farms and unpredictable weather, getting nutrients to the plant at the right time and place has become trickier than ever. Now add in the threat of fertilizer regulations and you can see why the time may be right for slow release nitrogen. Anywhere you have potential for nitrogen losses, this technology will shine.
"If we’re going to have to work under new regulations, chances are we’re not going to be able to apply an excessive amount of nitrogen to make sure crops make maximum economic yield," says Eric Ellison, agronomist with Agrium, a fertilizer company specializing in controlled release fertilizer.
Slow release fertilizers, or "Enhanced Efficiency Fertilizers" (EEFs) cost more than conventional fertilizers. They have been around over 25 years, but only a few have moved into large scale commercial use. That may be changing. As protecting water sources takes center stage, regulators and concerned citizens have become more sensitive to nitrogen losses. You should be sensitive too: every pound of N that goes into the water is a pound of N you paid for and lost.
That's where EEFs come in.
The Association of American Plant Food Control Officials defines EEFs as “fertilizer that increases nutrient availability or uptake and decreases nutrient losses to the environment compared with a reference soluble fertilizer.”
What's on the market? An EEF nitrogen product may be an inhibitor, a chemical added to standard fertilizers to slow conversion of urea or ammonium ion; others may be nitrification and urease inhibitors.
Important commercial inhibitors include Agrotain (Koch), Instinct and N-Serve (both from Dow), Guardian (Conklin), Agrotain Plus and SuperU, made by Koch.
All inhibitors with demonstrated efficacy have a limited lifetime in soil. How long? Typically they are very effective at temps below 41 degrees F; so, for fall anhydrous or urea applications, they can be very effective to carry you through to spring.
Slow and controlled release fertilizers are another effective way to control nitrogen losses. Next week we'll talk about how polymer-coated fertilizer works and its potential impact on yield.