Nitrogen cycle

The Nitrogen Cycle is one of our planet's most important nutrient or biogeochemical cycles.There is no shortage of the element nitrogen here, it makes up 78-79% of our worlds atmosphere. The atmosphere's nitrogen, N2, has a very strong triple bond between the two atoms and it shows.As plants need fixed nitrogen and we rely either directly, by eating plants, or indirectly, by eating animals that have eaten plants, on them for our lives, fixed nitrogen is critical to life and all the things around it.Nitrogen fixing bacteria are able to fix nitrogen by breaking apart the triple N bond and reworking it to make plant friendly compounds that are ammonia or nitrates. They fix around 120 million tons of nitrogen per year around the world waste.

http://www.the-compost-gardener.com/nitrogen-cycle.html

http://whatcom.wsu.edu/ag/compost/fundamentals/needs_carbon_nitrogen.htm

http://ag.arizona.edu/yavapai/anr/hort/byg/archive/nitrogencycling2010.html