Being efficient with nitrogen applications is not a new concept in the ag industry. Whether the producer’s motive is to reduce nitrates in groundwater or to decrease fertilizer expenses — or a combination of both — research studies are looking at increasing the efficiency of nitrogen application.

Looking at where the industry has been in the past and where the industry is headed is important when understanding the optimal management strategy.

At the recent 4Rs Nutrient Stewardship Field Day at the Eastern Nebraska Research, Extension and Education Center near Mead, past management strategies and future concepts were on display. Richard Ferguson, soil and water sciences professor at the University of Nebraska-Lincoln, discussed where we have been as an industry and where nitrogen management is headed.

Blast from the past

Professor Robert Olson was one of the first researchers to spearhead nitrogen studies from the 1960s into the 1980s. During his time at UNL, he published many articles about nitrogen utilization.

“So, think back to 1964 — this is all a decade or so after nitrogen fertilizer became available in the state, so farmers are still learning how to use this new resource,” Ferguson said.

Ferguson shared a quote from one of Olson’s bulletins called “Using Fertilizer Nitrogen Effectively on Grain Crops” that he still found relevant today: “Summer side dressing of fertilizer nitrogen for row crops, regardless of chemical form, has usually proved superior to fall or spring applications. Thus, losses are minimized by delaying application to a time when crop roots are actively absorbing nitrogen from the soil.”

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Almost 60 years ago, the recommendation coming from the Extension was to side dress and be conscious of nitrate contamination. The big takeaway from where the industry was back then was the push to optimize profit rather than maximizing yield.

“Those approaches, when adequately calibrated, promise the surest method of achieving most economic yields while conserving nonrenewable resources and preserving environmental integrity,” Ferguson said.

WHERE WE HAVE BEEN: Understanding where the industry has been gives producers a starting point to know where the industry should go when it comes to nitrogen use. Here, Richard Ferguson, a soil and water sciences professor at the University of Nebraska-Lincoln, explains where the industry has been for nitrogen application dating back to the 1960s.

Ferguson said the university was receiving a lot of backlash from farmers for being too conservative during those times. However, during the 1970s, there was an energy crisis that increased the price of gasoline, so there was a large emphasis on conserving resources.

Fast forward to around 2002, and there was a switch from using a predictive nutrient strategy to a reactive strategy. Ferguson said this switch emphasized that farmers should let the crop tell them what it needs instead of predicting future needs.

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Nitrogen of the future

There still is a public concern with the number of nitrates in the groundwater. However, once regulation and education were enacted and best practices began to be adopted by farmers, groundwater nitrates slowly declined or at least leveled off in many areas.

“So, our approach was to go out and grid sample the field, generate a fertilizer rate based on the organic matter and precision nitrates, and then generate a fertilizer application,” Ferguson said. “We started to have access to GPS, and that certainly helped us do a better job of how we implemented those treatments.”

With the introduction of precision agriculture, farmers now have the tools to better apply nitrogen and make changes to be more efficient.

Based on different technologies that Ferguson has seen, there are three that he predicts the industry could adapt to for the future.

Green ammonia. This is where, using water, nitrogen from the atmosphere is converted to ammonia through renewable resources such as wind or solar power. This will encourage producers to move away from using natural gas or other fossil fuels for synthetic fertilizer.

Variable rate fertigation. One fertigation system, Sentinel, is based on research from UNL. With this precision ag technology, producers can gain data telling them the time and place to fertilizer and irrigate in the field. Ferguson reported that, on average, there has been an increase of $24 per acre in profitability due to increased efficiencies from the use of this platform.  

VISION FOR THE FUTURE: Autonomy might be a scary word in the industry, but it doesn’t have to be. Whether mapping fields or applying fertilizer, drones and autonomous machinery can increase efficiency and profitability on the farm, as demonstrated here at a recent field day near Mead, Neb.

Autonomous fertilization. Although some producers are hesitant to start incorporating the use of autonomy on the farm, this technology, Ferguson says — whether drone or on the ground — has assisted in improving efficiency and precision.

You can learn more about the four R’s at agronomy.unl.edu.