Nitrogen

Nitrogen is all around us.

Key Facts

  • Nitrogen gas (N2) makes up about 78% of the atmosphere by volume.
  • Nitrogen is found in amino acids that make up proteins and genes in humans, animals and plants.
  • Ammonia (NH₃) is found in urine.
  • Nitrate (NO₃) is the main source of nitrogen for plants.
  • Too much nitrate can cause serious health problems in humans, especially children.
  • Nitrogen is found in soil.
  • Nitrogen is one of the main ingredients in fertilizers.

Did you know?

Like the water cycle, there is a nitrogen cycle in nature.

The Nitrogen Cycle in Freshwater

  • In freshwater, the nitrogen cycle begins with microscopic floating plants (phytoplankton) and rooted aquatic plants. They absorb nitrogen in the form of nitrate, (NO₃).
  • Microscopic animals (zooplankton) and other plant-eating aquatic organisms feed on these aquatic plants and consume the nitrogen in them.
  • Then the aquatic animals release waste products containing ammonia (NH₃).
  • Bacteria in the sediments turn the ammonia to nitrite and then to nitrate. Decomposing plants and animals also release nitrate back into the water.
  • Nitrate becomes food for plants, and the cycle begins again.

Image: Tropical Fish Centre

The Nitrogen Cycle on Land

  • On land, dead organisms and waste from live organisms decompose and release nitrate.
  • Some nitrate soaks into the soil and down into groundwater.
  • Some nitrate is absorbed by plant root systems.
  • When organisms eat plants or drink the water, the cycle begins again.

NOTE: When nitrogen combines with other elements, the process is called fixation.

Image: Australian Environmental Institute

Show
You Care

We know you want to enjoy the lake for many years (and generations) to come. So, we’ve put together a list of simple steps you can take to reduce the nutrients, sediments and toxins flowing into the lake and its streams.

Pump your septic tank every 3 years

Plant Natives

  • Keep the natural landscape of northern Michigan around your home.
  • Limit the size of your lawn.

Replant Trees

  • Trees take up nutrients so they don't reach the lake.
  • Tree roots hold soil that contains nutrients from eroding away into the lake.

Use Natural Lawn Fertilizers

  • Too much chemical fertilizer is applied to lawns and ends up making the lake green.

Plant Rain Gardens

Plant Buffer Gardens along shorelines

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