Sunday, February 27, 2011

Too Much of a Good Thing?

An excess of nitrogen, a naturally occurring element essential for growth, has been increasing in concentration in waterways. Through the combustion of fossil fuels, nitrogen gasses are released into the atmosphere and then fall again to the earth as acid rain rich in nitrogen compounds. Nitrogen is also added to agricultural fields through chemical fertilizers. Nitrogen is put into an ammonia rich compound and prayed or spread across agricultural fields. When heavy rains fall, the excess nutrient not used in growth is picked up by the water and taken into larger collections of water which eventually lead to streams, rivers, or lakes. The increase in livestock around the world also adds to the increase of nitrogen in water. Animal and human waste contains high amounts of nitrogen that can be swept into waterways because of heavy rains or sewage problems. The nitrogen from all of these sources ultimately travels to water ecosystems.

Due to the excess of nitrogen in these water ecosystems, a process called eutrophication occurs. Eutrophication is when algae suddenly grow out of control because there is a large amount of their essential grown nutrient. This extreme excess of growth causes pipes to clog, all of the oxygen to be use up in the system, and the high concentration of organisms blocks the light from those that live deeper in the water system. Jill Baron, a scientist with the USGS, is currently participating in a study of limiting nutrients in alpine lakes in locations such as Colorado, Norway, and Sweden. These ecosystems are ideal to study because they are secluded from humans and have no immediate drainage from polluted watersheds. Before the industrial revolution, organisms in the water ecosystems in these locations has an abundance of phosphorus and were limited in growth because a lack of nitrogen. After the shift to a more urban society with more pollutants, there was so much nitrogen present in the alpine lakes that organisms were not missing phosphorus to continue their growth. This discovery shows that there has been a significant increase of nitrogen in the atmosphere due to the increase of technology and burning of fossil fuels from the time after the industrial revolution until now.

The pollution of water due to agricultural practices, industry, urbanization, and the burning of fossil fuels could prove to be devastating to the world in the next 50 years. There has been a prediction that water will be the most essential natural resources to protect as the world population continues to climb. If waterways continue to be polluted with nitrogen, they will become less productive for providing food resources and drinkable water to humans and animals. It is important that the agricultural practices of spreading excess ammonium fertilizer and the extreme burning of fossil fuels stops in order to preserve the potable water that the world currently has access to in order to benefit future generations.

1 comment:

  1. This is a serious issue that will have increasing effects in the future. There are some things that can be done such as planting buffers by drainage areas so the nitrogen is taken up by plants before entering water systems, and fertilizer applications can be dosed better according to need (though this may already be done to some extent by many farmers to reduce their fertilizer cost). It may be possible for breeders/ plant biotechnologist to improve nitrogen use efficiency, but other solutions will have to be looked at.