This is an image of nitrogen cycle taken from this [http://www.epa.gov/maia/html/nitrogen.html] EPA website. |Source=Originally from [http://en.wikipedia
is a derivative work of the following images: File:Cicle_del_nitrogen_de.svg licensed with Cc-by-sa-2.0-fr, Cc-by-sa-2.5,2.0,1.0, Cc-by-sa-3.0-migrated
DescriptionLocalFregMaia-Maia.svg Mapa da Freguesia de Portugal Date 20 January 2007, 19:27 (UTC) Source Own work Author Permission (Reusing this file)