Samantha MillerDanielle TombleyNatalie GerlachPeriod 4

NITROGEN CYCLE

Natural Process

• Natural nitrogen fixation- a special type bacteria converts nitrogen gas to ammonia this new gas is used by plants . An example of natural nitrogen fixation would be lightning.  

• Nitrification- when ammonia is converted into nitrite ions that plants use as nutrients. 

• Ammonification- when decomposing bacteria starts to convert waste that has a large amount of nitrogen into simpler compounds

• Denitrification- this is where bacteria starts to convert simple nitrogen compounds to nitrogen gas and returns the gas back to the atmosphere to restart the cycle

Natural Reservoirs

• Water in the soil• Groundwater in the ocean• Living and dead plants (nitrogen is a limiting factor

in plants)• Organic and inorganic reservoirs: amino acids,

proteins, fertilizers, ammonia (urine)

Why is the Nitrogen Cycle Important?

• Every living organism uses nitrogen; it is the basis of life. • It is used in amino acids and nucleotides. • Nitrogen is found in abundance and is seemingly unusable

in our atmosphere. • Component for plants to make chlorophyll• A major problem occurring is eutrophication, which is

when there are too many nutrients in the water. • Occurs when fertilizers are packed with nitrogen and the

runoff goes into bodies of water, increasing the amount of nitrogen in the water.

HUMAN IMPACT

How

Humans have an impact on the nitrogen cycle from many different practices, especially fossil fuel combustion and

when we use nitrogen-based fertilizers. It can also be increased through deforestation and the growth of human population. The main increase of nitrogen from humans is

from fertilizer usage; the nitrogen from this process is added much faster than the natural increase on nitrogen.

The nitrogen in fertilizers is added to improve plant growth.

MDCs vs. LDCsMDC

Germany• Germany has factories and cars so

they emit nitrogen from burning fossil fuels, but not nearly as much as the US nor India does.  

USA• Being more developed means that it

adds the most nitrogen to the atmosphere. More attention is being drawn to the negative affects of too much nitrogen, so more people are putting in effort to try to put a stop to the pollution.

• Some ways that the US affects the nitrogen cycle are by having a power plant, cars, factories and home fireplaces. All of these produce emissions of nitrogen into the atmosphere which adds to the breakdown of the hole in the ozone layer. 

LDCIndia• India has a large population so

they use more cars and need more food adding to the excess nitrogen issue. Being an LDC means that there is little concern for the environment, and it is not likely that they will try and cut down on nitrogen emissions.

Mexico• Mexico produces the most corn

in the world which means they need a lot of fertilizers to grow at the rate production needs them to.

Pathway Affected by Human Activities• Nitrogen is a limiting factor in plants, and humans are putting a lot of nitrogen into the atmosphere through burning fossil fuels and nitrogen-based fertilizers (industrial nitrogen fixation.) This causes alterations of the nitrogen cycle in order to compensate for the abundance of nitrogen.• The added nitrogen can negatively affect biodiversity.• The nitrates in nitrogen-based fertilizer leaves the soil through runoff and begins the process of eutrophication.• Eutrophication speeds up the aging of lakes and causes algal

blooms.

• In response, some farmers are changing the amount of fertilizers they use and they do so right when it is needed so they don’t over fertilize.• The U.S. put in regulations and laws to protect air and water from excess nitrogen pollution