The Future of Nitrogen Fertilization

Study Reveals Nitrogen Rates on the Rise

An Iowa State University study analyzing data from multiple research projects conducted over three decades all aiming to understand optimal nitrogen fertilizer rates reveals that nitrogen rates of use are on the rise. It makes sense considering food security goals are ever striving to produce more food using less land. Far from a simple math equation, calculating optimal nitrogen rates involves identifying how much nitrogen is needed for favorable crop yields, how little a farmer can spend and still maintain predictable yields and how lost nitrogen affects environmental health. A positive in one column can equal a negative in another.

Calculating Nitrogen Efficiency

The University study examined the corn belt of the Midwest where nitrogen fertilization is necessary in producing a crucial food source for humans and livestock as well as ethanol fuel. All three destinations for the commodity are expected to experience increased demand in the next decade making efficient use of nitrogen a priority.  As mentioned above, optimal rates vary depending on the lens you use. A farmer budgeting inputs and calculating a workable ratio of nitrogen pounds per acre to bushels yielded per acre might come up with a different ideal ratio than an environmental scientist determining acceptable seepage of lost nitrogen into groundwater.

Prior to this research study it was generally believed that rates held steady when accounting for trade offs between wet and dry years, crop rotation practices and the corn belt’s commitment to steadily chip away at inefficiencies in their sector.  If in one year more nitrogen was lost into the air or swept into groundwater perhaps the following year had ideal conditions for maximum plant absorption, in theory, rates would have ebbed and flowed without climbing sharply. Knowing that rates are increasing approximately 1.2% every year, confirming what many individual farms were experiencing, underscores the need to continue recalibrating our formulas for nitrogen optimization.  

Roughly 87 million acres were used to produce corn in 2024, up from approximately 79 million acres in 2005, testament to demand increases on U.S. arable land. Continuing to fine tune nitrogen use stands to benefit a farmers bottom line just as much as it does environmental health. And, in recent years ideal rates proposed by both parties have gotten more similar.

Removing Inefficiencies in Nitrogen Use

Nitrogen fertilizer use rates have direct ties to the protein content of corn. The more protein produced in the plant, the more it needs nitrogen. Current research in plant genetics is taking a closer look at corn varieties that are lower in protein. Fuel production does not call for high protein corn. And livestock feed primarily values corn for its carbohydrate qualities in favor of soy for protein for animal digestion. Could we decrease nitrogen rates by leveraging low protein varieties? Many scientists believe this is the best place to build in nitrogen efficiency.

A University of Wisconsin study found that the average farmer uses 180 pounds of nitrogen fertilizer and removes 130 pounds of nitrogen through harvest yields leaving 50 pounds , or 28%, of nitrogen in the ground. The use of nitrogen fertilizer offers a measure of predictability in crop yield for farmers. Skimming on it can have catastrophic effects for a bottom line leaving farmers little choice but to carry on with methods they know have proven results. While producers may want to reduce their use, especially as fertilizer prices climb, transitioning to precision technology also requires a significant financial investment. 

Sensor based fertilization systems could be the future of nitrogen efficiency with farmers who invest now seeing the benefits of both fewer dollars spent on inputs and increasing environmental health. Innovations in precision technology continue to decrease the amount of nitrogen used, shaving off excess application. Advancements also target time of application to ensure minimal nitrogen is lost between fertilization and planting. Like so many aspects of agriculture, nitrogen fertilization has long depended upon frontloading acreage with the nutrient as a surefire guarantee of crop yields, rather than adjusting methods to give plants what they need exactly when they need it. 

Precision technology and genetic research offer promising solutions to financial obstacles faced by farmers in the corn belt who play a crucial role in producing more commodity crops on existing ground. The combination of innovative approaches could also continue to narrow the gap of ideal nitrogen ratios between farmers and environmentalists; a feat that has long felt elusive in the ag sector.