From 1999 to 2004, Illinois State Water Survey scientists created a web site about the nitrogen cycle as an educational tool.
The site is no longer actively maintained and some of the quantitative data may be out of date, but the basic
discussion of principles and processes is still accurate and relevant.
For further information on nitrogen in various reservoirs, please contact the following people:
Groundwater: Walt Kelly
Surface Water: Laura Keefer
Atmospheric: David Gay
Soils and crops: UI Agricultural Extension