What is the Difference Between Symbiotic and Nonsymbiotic Nitrogen Fixation?

The main difference between symbiotic and nonsymbiotic nitrogen fixation lies in the relationship between the nitrogen-fixing bacteria and the host plant or the absence thereof. Here are the key differences:

• Symbiotic Nitrogen Fixation:
• Occurs in plants that carry nitrogen-fixing bacteria within them, such as Rhizobium bacteria and leguminous plants.
• The bacteria fix nitrogen effectively only when they are symbiotic with plants.
• The process is beneficial to both the bacteria and the host plant, as it provides nitrogen for the plant's growth and a suitable environment for the bacteria.
• Nonsymbiotic Nitrogen Fixation:
• Free-living nitrogen-fixing bacteria carry out nonsymbiotic nitrogen fixation.
• These bacteria do not require a host plant and can fix nitrogen independently in the soil.
• Examples of aerobic, free-living bacteria include Azotobacter chroococcum, Azotobacter, and Beijerinckia.

In summary, symbiotic nitrogen fixation involves nitrogen-fixing bacteria that live in symbiosis with plants, while nonsymbiotic nitrogen fixation is performed by free-living bacteria in the soil. Symbiotic nitrogen fixation fixes nitrogen for its host, whereas nonsymbiotic nitrogen fixation makes nitrogen available for other plants and organisms in the soil.

Comparative Table: Symbiotic vs Nonsymbiotic Nitrogen Fixation

Symbiotic and nonsymbiotic nitrogen fixation are two different types of biological nitrogen fixation processes regulated by different bacteria. Here is a table comparing the key differences between them:

Both symbiotic and nonsymbiotic nitrogen fixation processes convert atmospheric nitrogen (N2) into soluble nitrogen compounds, such as nitrates, nitrites, and ammonia, which are essential for plant growth.