"The nitrogen cycle is the biogeochemical cycle by which nitrogen is converted into multiple chemical forms as it circulates among atmospheric, terrestrial, and marine ecosystems."
The cycle of nitrogen through various geological and biological process.
Biogeochemical cycles: The Nitrogen cycle is one of the biogeochemical cycles in which nitrogen compounds are converted into different forms by various biological, geological, and atmospheric processes.
Nitrogen fixation: This is the process by which atmospheric nitrogen (N2) is converted into ammonia (NH3) by nitrogen-fixing bacteria. This ammonia can be used by plants as a source of nitrogen.
Nitrification: This process involves the conversion of ammonia (NH3) to nitrite (NO2-) and then to nitrate (NO3-) by nitrifying bacteria. Nitrate is the main source of nitrogen used by plants.
Denitrification: The inverse of nitrogen fixation, this process converts nitrate to atmospheric nitrogen (N2) by denitrifying bacteria.
Plant uptake: Nitrogen is taken up by plants in the form of ammonium (NH4+) or nitrate (NO3-) ions through their roots.
Ammonification: The process by which organic nitrogen is converted into ammonium (NH4+) by decomposers.
Decomposition: Once plants and animals die, the nitrogen compounds in their bodies enter the soil where they are decomposed by microorganisms.
Mineralization: This process involves the conversion of organic nitrogen to inorganic nitrogen by microorganisms in the soil.
Nitrogen cycling in aquatic ecosystems: Nitrogen cycling in aquatic ecosystems is similar to that on land, but with some specific adaptations to the aquatic environment.
Human impacts on the nitrogen cycle: Human activities like agriculture, industrialization, and urbanization have significantly altered the nitrogen cycle, leading to environmental problems such as eutrophication and acid rain.
"The conversion of nitrogen can be carried out through both biological and physical processes."
"Important processes in the nitrogen cycle include fixation, ammonification, nitrification, and denitrification."
"The majority of Earth's atmosphere (78%) is atmospheric nitrogen, making it the largest source of nitrogen."
"Atmospheric nitrogen has limited availability for biological use, leading to a scarcity of usable nitrogen in many types of ecosystems."
"The nitrogen cycle is of particular interest to ecologists because nitrogen availability can affect the rate of key ecosystem processes, including primary production and decomposition."
"Human activities such as fossil fuel combustion, use of artificial nitrogen fertilizers, and release of nitrogen in wastewater have dramatically altered the global nitrogen cycle."
"Human modification of the global nitrogen cycle can negatively affect the natural environment system and also human health."
"Nitrogen is converted into multiple chemical forms as it circulates among atmospheric, terrestrial, and marine ecosystems."
"Fixation is an important process in the nitrogen cycle as it converts atmospheric nitrogen into forms usable by plants and other organisms."
"Atmospheric nitrogen, which is not directly available for biological use, is converted into forms like ammonia through processes like fixation and ammonification."
"Nitrogen availability can affect the rate of key ecosystem processes, including primary production and decomposition."
"The use of artificial nitrogen fertilizers is one of the human activities that have dramatically altered the global nitrogen cycle."
"Denitrification is an important process in the nitrogen cycle as it reduces nitrates back into atmospheric nitrogen, completing the cycle."
"The majority of Earth's atmosphere (78%) is atmospheric nitrogen."
"The global nitrogen cycle has been dramatically altered by human activities such as fossil fuel combustion and release of nitrogen in wastewater."
"Nitrogen availability can affect the rate of key ecosystem processes, including primary production and decomposition."
"Human modification of the global nitrogen cycle can negatively affect human health."
"Nitrogen availability is crucial for primary production, which is the process of converting sunlight into organic compounds through photosynthesis."
"Ammonification is a process in the nitrogen cycle where organic nitrogen is converted into ammonia, which can then be further transformed through nitrification."