Today’s modern agricultural practices are dependent on the use of commercial fertilizers to boost productivity levels to new heights. Some call nitrogen the transformational nutrient for its contribution to the dramatic increase in productivity that has occurred since the 1950s.

Nitrogen is essential for the growth of both crops and animals. Nitrogen in its stable form, N₂, makes up the largest percentage of our atmosphere, but is unavailable for plant and animal growth. Once N₂ is converted and available for living functions, it exists in many forms in soil and water systems and has unique and important chemical, biological and environmental properties. 

These forms of nitrogen are referred to as reactive nitrogen (N_r) and include: ammonia (NH₃); ammonium (NH₄); nitrite (NO₂) and nitrate (NO₃); nitric oxide (NO); and nitrous oxide (N₂O). Although nitrogen is essential for living functions, in its reactive form it has the capacity to have adverse environmental consequences if it escapes into the groundwater, surface water or the atmosphere.

The primary route of N_r losses into ground and surface water systems are through leaching and runoff. Reactive nitrogen is lost to the atmosphere through nitrification/denitrification and volatilization. 

For more detailed information about the fate and impacts of nitrogen in the environment, see the Michigan State University Extension article “What is reactive N and why should I care?” Managing nitrogen to minimize nitrogen losses and increase nitrogen use efficiency can be accomplished with known strategies.

To better understand some of the strategies associated with efficient nitrogen management, the MSU Extension Nitrogen in the Environment Project Group, a committee of MSU Extension educators and specialists, have developed a set of PowerPoint slides that can be used by farmers, agribusiness professionals, teachers, educators and others interested in the stewardship of nitrogen. The short presentation is intended to help educate others about the nitrogen cycle, forms of reactive nitrogen (N_r), risks associated with N_r losses, the 4R Best Management Practices (right rate, right time, right place and right form) and the benefits of using management strategies to increase nitrogen use efficiency.

The presentation is available at: Don’t Lose it…Use it! Keeping nitrogen in the root zone in agricultural fields.