Nitrogen management 101
By KRISS NELSON
What are the important factors that impact a fall nitrogen decision?
“There are a lot of different variables that can be important for a particular geography, for a certain weather pattern or a fall time frame,” said Matt Sweeney, digital farming agronomist for Adapt-N Solution. “The topic in general is very elusive and complex.”
During a webinar held last week sponsored by DTN, Sweeney went back to the basics when discussing nitrogen management challenges, the forms of nitrogen available to producers and other things to consider when evaluating a nitrogen program.
“What we’re really talking about today is a concept of a nitrogen management challenge,” he said. “There are many different sources of nitrogen, many forms, many lost pathways. We’ve all seen the nitrogen cycle is a very, very complex, a very highly dynamic system. There’s a lot of moving pieces and obviously it is very highly influenced by the environment – the weather, the soils – and management practices.”
Sweeney said there are many things to consider when evaluating a nitrogen program.
“Such things as significant rainfall events and how they affect the nitrogen you have already applied or are considering to apply, dealing with warm or cool weather patterns, evaluating stabilizers or whether they fit within a particular nitrogen program or operation,” he said.
Basics of nitrogen management
Organic nitrogen, Sweeney explained, is a source of nitrogen that needs to mineralize, or be broken down before a plant can utilize it.
Other forms of nitrogen, he added, are those that are readily available to the plant such as ammonium nitrogen and nitrate nitrogen.
Nitrification is the conversion of the ammonium to a nitrate.
“This process is very temperature-dependent and the speed in which it converts can differ from one soil texture to another,” he said.
Nitrogen loss can occur in three ways: leaching, denitrification or volatilization.
Leaching is where the nitrates are primarily lost.
“Once the nitrogen is applied in that nitrate form or converted to nitrates, it is subjected to leaching,” he said. “Leaching is going to be occurring in most soils. Try to minimize the amount of time your nitrogen is sitting in the soil without active growing crops to which weather can impact your nitrogen application and be subjected to loss.”
Denitrification happens when the nitrate is living in an environment without oxygen.
“Saturated soils and poorly-drained soils will experience high levels of denitrification at times,” Sweeney said. “Again, there is a great need to evaluate and minimize the time nitrogen is sitting the soil without actively growing crops.”
The form of ammonium nitrogen can volatilize. Sweeney said it is important to get those fertilizers either injected or incorporated if at all possible to avoid losses from volatilization.
“The nitrogen cycle is extremely complex,” he said. “Having a better understanding and working with your local agronomist can drastically improve the management of your nitrogen applications and the nitrogen cycle on your farms. Improving management will obviously lower your loss potential and help you improve the profitability within your operation.”
DTN Nitrogen
A tool that has become available to producers is DTN Nitrogen, which is powered by Adapt-N.
According to the company, in an independent study, the technology has demonstrated a $30 an acre boost in profits and a 35 percent reduction in nitrogen loss. It also won the 2017 global Tulane Nitrogen Reduction Challenge.
The solution provides science-based, nitrogen modeling for proactive alerts, diagnostics and recommendations. The program also allows producers to analyze five seasons of nitrogen loss by subfield, field or zone.
“Adaptive management is helping agronomists and helping growers to develop a nitrogen management plan, helping to implement that plan and after application has occurred, helping to evaluate that plan,” said Sweeney. “In the off-season, it is making adjustments for that plan.”
DTN Nitrogen, Sweeney said, will not only help to evaluate any changing nitrogen management practices, but it will help the agronomist or grower to make the determination on making that change.
“Not only does it have to make sense agronomically, it has to make sense environmentally and it has to benefit your pocketbook as well,” he said. “DTN Nitrogen is proven to be the best nitrogen model and nitrogen recommendation tool on the market. It’s adopting that adaptive management approach for your nitrogen on your fields with your weather patterns and your soils.”