Nitrogen's Dark Side


Nitrogen is one of the most important nutrients for plants. It is an essential ingredient of proteins which 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 fact, right now, a worldwide glut of nitrogen is a threatening ecosystems around the world.

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. It's not that there isn't enough nitrogen; the earth's atmosphere is 78 percent nitrogen gas. However, plants can't use nitrogen gas. They must wait for nitrogen to be "fixed", that is pulled from the air and bonded to hydrogen or oxygen to form a compound they can use.

In recent decades, humans have been "fixing" nitrogen for use as a fertilizer at an enormous rate. Between 1980 and 1990 the amount of industrially produced (synthetic) nitrogen applied to crops was greater than all industrial fertilizer applied previously combined.

Synthetic nitrogen fertilizer is water-soluble and much of it runs off gardens, farms and lawns into lakes and streams or into groundwater. In addition, the burning of fossil fuels releases more soluble nitrogen into the atmosphere which then falls to earth in rain.

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

7 Ways You Can Reduce Nitrogen Pollution
1. Use Organic Fertilizers
Organic fertilizers do not contribute to the nitrogen glut because they use "recycled" nitrogen. Also, the nitrogen in organic fertilizers is insoluble and is released to the plants 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 your soil already has. Follow the soil test recommendations, using organic fertilizers. Call your local extension service to find out how to test your soil.

3. Apply Small Amounts of Fertilizer Frequently
When smaller amounts of nitrogen fertilizer is applied throughout the growing season (instead of one large application), plants will use more of the nitrogen and less will wash off of the field. Also, never apply fertilizer to frozen ground, it will wash away when the ice melts.

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. And when it’s grown locally, a lot less fossil fuels are burned in transport.

5. Eat More Vegetables
With a typical American diet, rich in meat, it takes 120 pounds of nitrogen a year to feed each person. A diet primarily composed of vegetables and grains takes about 70 pounds of nitrogen per person.

6. Drive Less
Vehicles and power plants contribute about 35 percent of the nitrogen found in coastal streams, according to a study last year by the U.S. Geological Survey.

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. Water will be trapped by the vegetation and less will wash into the lake or stream.

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