How to Help Reduce Nitrogen Pollution

Nitrogen is one of the most important nutrients for plants. It is an essential ingredient in the proteins that are the building blocks of growing plants. It is necessary for the production of sugars and, subsequently, of ripe fruit. In fact, all soil life and all plants require substantial amounts of nitrogen. As a result, most farmers and gardeners apply some form of nitrogen fertilizers to their crops.

However, nitrogen also has a dark side. Too much nitrogen can damage plants and cause serious problems in the environment.

In many ecosystems, nitrogen is the limiting factor controlling the nature and diversity of plant growth. This is true in "wild" areas and also on farms and in gardens. Though the earth's atmosphere is 78 percent nitrogen, plants can't use nitrogen in a gaseous state. They must wait for nitrogen to be "fixed" in the soil—pulled from the air and bonded to hydrogen or oxygen to form a compound they can use.

In recent decades, humans have been producing huge amounts of synthetic nitrogen for use as fertilizer. This synthetic nitrogen fertilizer is water-soluble and much of it runs off gardens, farms and lawns into lakes and streams or into groundwater. The burning of fossil fuels also introduces into the atmosphere large amounts of nitrogen, which then falls to earth in rain.

A scientific panel of the Ecological Society of America found that excess nitrogen causes many environmental problems, including the pollution of estuaries and coastal waters; acidification of soils and streams and lakes; increased global concentrations of the greenhouse gas nitrous oxide; loss of important soil nutrients; and loss of plants adapted to low-nitrogen soils.

1. Use Organic Fertilizers
Organic fertilizers do not contribute to the overproduction of nitrogen because they typically contain "recycled" nitrogen, such as animal manures and crop residues. The nitrogen in organic fertilizers is also in an insoluble form, so it is released slowly over time. Synthetic fertilizers are water-soluble and can be easily washed away into lakes and streams.

2. Test Your Soil
Find out what level of nitrogen and other nutrients already exist in your soil. Follow the soil test recommendations, using organic fertilizers. Your local extension service or garden center will have information about how to test your soil.

3. Apply Small Amounts of Fertilizer Frequently
When you apply smaller amounts of nitrogen fertilizer throughout the growing season (instead of one large application), plants will use more of the nitrogen and less will be leached away with rain and irrigation. Also, never apply fertilizer to frozen ground; it is likely to wash away when the ground thaws.

4. Buy Local, Organic Produce and Meat
Or better yet, grow your own. Organic produce is grown without synthetic fertilizers that contribute to the nitrogen glut. When your food is grown locally, a lot less fossil fuel is required for transportation.

5. Eat More Vegetables
The typical American diet includes a large amount of meat. It takes 120 pounds of nitrogen a year to feed a typical American carnivore. A diet primarily composed of vegetables and grains takes about 70 pounds of nitrogen per person.

6. Drive Less
A study by the U.S. Geological Survey found that vehicles and power plants are responsible for about 35 percent of the nitrogen found in coastal streams. Do your part to reduce the amount of nitrogen in our air and water.

7. Create a Buffer Zone
If you live near a lake or stream, allow a buffer zone—a strip of grass or other vegetation—to grow along the shore. Runoff from storms or snow melt will be trapped by the vegetation and less will wash into the lake or stream.