The Nitrogen Cycle Nitrogen is extremely abundant in the atmosphere. However, it is not easy to acquire directly from the abiotic environment. Nitrogen enters and leaves the atmosphere through a...

Summarize the Nitrogen Cycle attached in points.

Extracted text: The Nitrogen Cycle Nitrogen is extremely abundant in the atmosphere. However, it is not easy to acquire directly from the abiotic environment. Nitrogen enters and leaves the atmosphere through a complex biochemical pathway in the nitrogen cycle (Figure 6, next page). es ed Most of the nitrogen used by living things is taken from the atmosphere Dent by certain bacteria in a process called nitrogen fixation. These micro- organisms convert nitrogen gas into a variety of nitrogen-containing compounds including nitrates, nitrites, and ammonia. Lightning and ultraviolet light also fix small amounts of nitrogen. In addition, humans add nitrogen to the soil as fertilizer. Once in the soil ecosystem, the nitrogen-rich compounds are available to producers. After the nitrogen is albsorbed, it is passed from producer to consumer and on up the food chain. Many animals consume more nitrogen than they can use and excrete the excess in the form of urea or ammonia. A dead organism's nitrogen-rich compounds are taken in by decomposers or are released back into the environment. These compounds are either recycled again by soil micro-organisms or they are converted by denitrifying bacteria back into nitrogen gas which then re-enters the atmosphere.