Biogeochemical Cycles
  Spheres of B. Cycles
  Nitrogen Properties
  Simple Nitrogen Cycle
  Human Influences
  Spheres of the N Cycle
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Graph of the four spheres of the N Cycle. Choices 
				include Atmosphere, Biosphere, Geosphere, and Hydrosphere
A pictorial view of the N spheres showing some of the major transfers between the spheres and reservoirs of N within the spheres.

Choose a sphere: Atmosphere Biosphere Geosphere Hydrosphere

Overview w B. Cycle w Spheres w N Props w N Cycle w Influences w N Spheres

Atmosphere Biosphere Hydrosphere Geosphere