Reactive nitrogen (Nr) levels have increased dramatically worldwide due to anthropogenic activities, particularly Nfertilizer production and use as well as fossil fuel combustion (Galloway et al. 2004). As a consequence, environmental Nr is accumulating at local, regional, and global levels and the excess of Nr can have negative impacts on the environment, such as the greenhouse effect, destruction of the ozone layer, acid rain, nitrate pollution in groundwater, eutrophication of lakes, and offshore water (Vitousek et al. 1997).