Article Title: Global Population and the Nitrogen Cycle
Author: Vaclav Smil
- During the 20th century, the world population has quadrupled.
- This would not be possible without the synthesis of ammonia.
- World's population has enough to eat because of modern agricultural practices.
- Nitrogen fertilizer is to thank for the abundance of food.
- Nitrogen remains in the atmosphere but can be absorbed by plants, animals, and humans.
- Nitrogen is needed for DNA and RNA, to make proteins and structural components of plant and animal cells.
- Humans can only acquire through food.
- Rhizobium and cyanobacteria are bacteria that fix nitrogen.
- When there's a lack of nitrogen in the soil, farmers have to use a large quantity of human or animal waste.
- Farmers plant peas or beans because of the nitrogen-fixing bacteria in the roots that help enrich the soil with nitrogen.
- Scientists struggle to break the nitrogen barrier.
- Fritz Haber's plan to synthesize ammonia from nitrogen and hydrogen worked.
- During the 1950s, the use of nitrogen fertilizer was 10 million tons; by the 1980s, it rose by an eightfold.
- Synthetic fertilizers provide 40% of the nitrogen taken up by plants.
- 1/3 of the protein in a human's diet depends on synthetic nitrogen fertilizer.
- Problems caused by reactive nitrogen in soils and waters range from local growth and global changes.
- Nitrogen fertilizer that leak to lakes or oceans causes eutrophication, which enriches the waters and as a result, algae and cyanobacteria grow. These decomposers consume all the oxygen and reduce fish and crustacean species.
- Nitrogen-based compounds contributes to soil acidity
- Excess acidfication could lead to increased loss of trace nutrients and the release of heavy metals into drinking supplies.
- Increased use of nitrogen fertilizer sent more nitrous oixide into the atmosphere.
The world's population has been steadily increasing over the years and the biggest question is: Is there enough food for everyone? We had enough to eat because of the advances in modern agricultural practices but because of nitrogen fertilizer, we have an abundance of food. Nitrogen remains locked in the atmosphere but only a tiny amount can be absorbed by plants, animals, and humans. That's where Rhizobium comes in; it is the most important nitrogen-fixing bacteria. Plants and animals can not use free nitrogen, we can only use fixed nitrogen. The use of nitrogen fertilizer has been increasing throughout the 1900s and that of course, lead to many problems. In the oceans and lakes, nitrogen fertilizer caused europhication, which lead to hypoxia. It also caused soil acidity and sent more nitrous oixide into the atmosphere.
After reading this article, I was shocked that humans caused another environmental problem in the world. We thought nitrogen would be helpful farming but instead it turned out completely different than what we expected. The best hope for reducing the growth in nitrogen use is in finding more efficient ways to fertilize crops. Hopefully, scientists began to understand that too much nitrogen is not beneficial to the environment and will discover new ways to help with crop growth. Soil conversation and the recycling of organic wastes is a good place to start.