New nitrogen stabilizer likely for 2009
Farmers will have a new option to halt nitrogen (N) losses next year. Dow AgroSciences expects federal registration in 2009 for Instinct, an N stabilizer designed for urea ammonium nitrate (UAN) and manure applications. Instinct currently holds a federal 24 (c) registration in Iowa.
Farmers have used an N stabilizerâ€”N-Serveâ€”for anhydrous ammonia for over 30 years. However, little liquid fertilizer was stabilized with N-Serve due to incorporation issues.
Like N-Serve, Instinct will help prevent N losses in 28 and 32% UAN fertilizers due to denitrification and leaching. Unlike N-Serve, though, immediate incorporation is not required.
"When applied to the soil, Instinct allows up to 10 days for incorporation," says Adam Manwarren, product manager for Dow AgroSciences.
Instinct is designed for spring fertilizer applications. Incorporation can occur via rainfall or by mechanical means. One-half inch of rainfall within 10 days is recommended for Instinct incorporation. If this rainfall amount doesn't occur within 10 days, a minimum of a rotary hoeing is recommended.
N goes through a three-stage conversion process in the soil from ammonium to nitrite to nitrate. Nitrate-N is the N form prone to denitrification and leaching.
Like N-Serve, Instinct is a nitrapyrin product. Nitrapyrin helps prevent N losses by blocking the nitrosomanas bacteria that convert ammonium N to nitrite N and ultimately nitrate N.
Sam Ferguson, Dow AgroSciences field scientists, says Instinct will have a good fit in preventing early-season N losses.
"N losses tend to occur in May and June, when the corn is small," he says. That's particularly true in a spring like 2008, when prolific rainfall set the stage for N losses that could transfer into yield reductions come fall.
"Most yield reductions come from one or two N loss events," Ferguson adds.
N losses due to saturated soils add up quickly, regardless of soil type. Heavy soils can lose between 15-50 pounds per year of nitrate-N through tile lines, while an inch of rain can move nitrate-N one foot in sandy soils.
Meanwhile, denitrification can lead to a 10% N loss if soils are saturated for three days. Denitrification losses can increase 10% for each additional saturated day.
"If you have saturated soils for four days, you can lose 20% of your N," says Ferguson.
N-Serve can stabilize N in incorporated liquid manure applications. However, it doesn't work for most liquid manure applications that are broadcast and later incorporated. Instinct will fit better with these manure applications.
Dow officials say Instinct's cost will be comparable to that of N-Serve.
Yield response will likely hinge upon the rate of N loss. In 2007, for example, Dow trials with four Midwestern retailers showed Instinct increased corn yields five bushels per acre when added to UAN versus UAN alone.
University of Illinois (U of I) research showed similar findings.
"We're seeing some benefits, but in 2007, they weren't that big," says Bob Hoeft, U of I crop science department head and soil fertility specialist. "However, it was a dry year in 2007. There was not much N loss that year. There might be more response in 2008, but we wonâ€™t know until the combines roll in the fall."