A clear presentation of the movement of nitrogen through an ecosystem from the University of Missouri at Columbia Extension Service. Page includes both simplified and more detailed illustrations of the cycle that would be useful at different grade levels from elementary to freshman in college. There is also a description of how nitrogen is added to and lost from the cycle as well as impacts on the environment as excess nitrogen moves into the watershed. Two figures are provided along with links from the water quality initiative as well as links to education, research, and services published by MU Extension. There are several links to more detailed information on specific aspects of the basic cycle such as denitrification, immobilization and leaching. The site meets the needs of the expected users.