Ag scientists with Montana State University Extension have some fresh nitrogen fertilizer information for producers.
Encouraging producers to cut back on ammonia volatilization loss from N fertilizers to the atmosphere, the researchers say they have recommended practices that can increase yields, be a financial boost for producers, and cut down on the release of ammonia gas, a pollutant that calls under the greenhouse gas class.
To help growers, MSU has two just-out bulletins: "Factors Affecting Nitrogen Fertilizer Volatilization," and "Management to Minimize Nitrogen Fertilizer Volatilization."
The first one explains various soil and climate factors that interact to affect volatilization. Understanding these factors, say authors, can help crop producers avoid applying urea and other nitrogen fertilizers in situations that may promote substantial volatilization.
The second bulletin presents best management practices to minimize volatilization loss and increase nitrogen use efficiency.
"Multiple and often unrelated factors make volatilization variable and difficult to predict under field conditions," says Clain Jones, an MSU soil fertility specialist and lead authors of the bulletins.
Conditions that affect volatilization are relevant across climates and regions. Regional examples are provided by the authors, including researchers Idaho and Oregon as well as Montana.
Until recently, volatilization loss from urea application in cool temperatures was thought to be relatively low. But new research reveals that at low temperatures ammonia can volatilize slowly over a longer period of time.
"Field trials in Montana found up to 44% of the applied nitrogen could be lost from urea broadcast between October and April," says co-author Rick Engel, who has conducted volatilization research in Montana for five years.
Regional results by Engel and others suggest that surface soil moisture at the time of application and rainfall or irrigation amounts after application play the biggest roles in affecting volatilization loss. The worst conditions were when urea was applied to a moist surface with not rain and only sprinkle use for the next two or three weeks.
The bulletins are available at www.musextension.org/store. Or call (406) 994-3273 for information.