Sources of Nitrogen from the Landscape

Nitrogen in Urban & Suburban Areas

There are two major inputs of nitrogen into urban areas and two minor inputs. The two major contributors are atmospheric deposition and nitrogen fertilizer applications. Pet waste and animal waste are minor contributors.

1. Atmospheric Deposition
   Cars produce nitrogen compounds that are released into the air. These nitrogen compounds can be returned to the ground attached to dust particles or through rain events, which adds nitrogen into urban areas.
   
   
2. Nitrogen Fertilizer
   Another major source of nitrogen in urban areas is nitrogen fertilizers. Fertilizer additions to lawns in urban and suburban areas can be significant. For example, in one urban community within the Neuse Basin, 90% of all homeowners apply or hire lawn care companies to apply fertilizer. On average, homeowners in this community of approximately 80,000 residents apply about 500,000 pounds of nitrogen fertilizer of their lawns every year. The 500,000 pounds of nitrogen does not include the fertilizer applied to multiple dwelling residents, businesses, recreational facilities, golf courses, or schools.
   
   Fertilizers left on hard surfaces is a big concern. When rains fall, this fertilizer is washed into the storm drain system. Since most storm drain systems drain directly into streams, the dissolved fertilizer in stormwater enters directly into streams.
   
   
3. Pet Waste
   Pet waste, as it breaks down, contributes nitrogen to the system. Pet waste is considered to be a minor source of nitrogen.
   
   
4. Wildlife
   Wildlife, such as squirrels, raccoons, birds, and even deer, add nitrogen to the urban environment. Wildlife is considered to be a minor source of nitrogen.