Fertilizer Management to Reduce Nitrous Oxide Emissions

Agricultural fertilizer management strategies are essential in the reduction of harmful nitrous oxide emissions that contribute to climate change, according to a recently released bulletin by Michigan State University. Farmers are the ultimate stewards of our land and water resources, and they care deeply about their environmental impact. While great strides have been made to improve nutrient use efficiency, there are more opportunities to implement practices that deliver economic and environmental benefits. As the MSU bulletin illustrates, management strategies that reduce nitrous oxide emissions can save money for farmers while protecting soil, air, and water quality.

What is Nitrous Oxide? Why are emission reductions important?

Nitrous Oxide (N₂O) is an important greenhouse gas that contributes to climate change. The MSU bulletin notes that “because [nitrous oxide] has a long atmospheric lifetime (over 100 years) and is about 300 times better at trapping heat than is carbon dioxide, even small emissions of N₂O affect the climate.”

Nitrous oxide is produced by microbes in almost all soils. In agriculture, N₂O is emitted mainly from fertilized soils and animal wastes, where nitrogen (N) is readily available. The bulletin points out that “in the U.S., agriculture accounts for approximately 8% of GHG emissions, but about 75% of N2O emissions linked to human activity. Among these, N₂O is the most important GHG in nearly all field crops.”

Reducing Nitrous Oxide Emissions: Why proper fertilizer management makes sense

Farmers add N to fields either as synthetic fertilizers, such as urea or anhydrous ammonia, or as organic fertilizers such as manure. In this fertilizer application process, nitrogen from the fertilizer can be lost as nitrate to groundwater or as gases N₂O, dinitrogen (N₂), or ammonia. Typically, only about half of the fertilizer N applied to a crop is taken up by the crop during that growing season. Improved fertilizer management practices can save money for farmers, reduce N₂O emissions from crop fields, and improve overall efficiency at the field scale.

Four Fertilizer Management Strategies

Practices that reduce N₂O emissions increase N use efficiency by keeping more of the added N in the crop. This factsheet identifies the four main management factors that help reduce N₂O emissions from applied N fertilizer, commonly known as the 4 R’s: Right N application rate; Right formulation (fertilizer type); Right timing of application; and, Right placement.

Delta Institute’s Nitrogen Credit Program (NCP) is an opportunity for farmers to achieve cost-savings by reducing total nitrogen fertilizer applied to their corn crops and to generate additional revenue without sacrificing crop yields. The Nitrogen Credit Program is based on research conducted by Michigan State University. Read the MSU bulletin to learn more about these management strategies targeted toward reducing nitrous oxide emissions.