Nitrogen Cycle

Nitrogen

An important element needed by living things.

Nitrogen is needed to build proteins.

Nitrogen is a key component in DNA (body's genetic program for life)

Nitrogen Cycle

The cycling of nitrogen between organisms, soil, water, and the atmosphere (Earth's spheres)

Nitrogen gas (N2)

78% of the atmosphere is made of nitrogen gas.

Plants and animals cannot get the nitrogen they need in this form.

Nitrogen Fixation

Process of converting nitrogen gas into nitrogen compounds, which are a usable form of nitrogen that plants can use.

Certain types of Bacteria and also Lightning can turn nitrogen gas into nitrogen compounds.

Lightning

converts nitrogen gas from the air into a usable form of nitrogen plants can use.

Denitrification

Process of converting nitrogen compounds into nitrogen gas, which is then released into the atmosphere.

Denitrifying bacteria carry out the process of denitrification.

Decomposition

A chemical reaction that breaks down compounds into simpler products.

When plants and animals decompose, nitrogen compounds are returned to the soil.

Bacteria

Microscopic living organisms that play an important role in the nitrogen cycle.

Nitrogen fixing bacteria change nitrogen gas to nitrogen compounds plants can use.

Denitrifying bacteria change nitrogen compounds to nitrogen gas to release back into the atmosphere.

Animals

Animals, including humans, get the nitrogen they need by eating plants or other animals that contain nitrogen.

When organisms die, their bodies decompose bringing the nitrogen into soil on land or into ocean water.

Animals also release nitrogen through their animal waste.

Plants

Plants take in the nitrogen they need through their roots. The nitrogen has to be "fixed" in a usable form.

Some plants (legumes) contain nitrogen fixing bacteria that live on their roots. The bacteria change nitrogen gas into nitrogen compounds the plants can use.

Soil

Nitrogen Compounds are found in the soil.

Nitrogen fixing bacteria change nitrogen gas to nitrogen compounds in the soil.

Denitrifying bacteria change nitrogen compounds in the soil to nitrogen gas.

Decomposers break down dead plants and animals and return the nitrogen to the soil.

Assimilation

The process by which plants take in and use nitrogen.

Feeding

How animals get nitrogen.

Algal blooms are caused by

High nutrient concentrations- typically caused by nitrate and phosphate runoff from fertilizer.