nitrogen cycle

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nitrogen cycle

n.
The circulation of nitrogen in nature, consisting of a cycle of chemical reactions in which nitrogen from the atmosphere is fixed in compounds in soil or water, assimilated by plants and animals, released to the soil and water through decomposition, and returned to the atmosphere through denitrification.

nitrogen cycle

n
(Biology) the natural circulation of nitrogen by living organisms. Nitrates in the soil, derived from dead organic matter by bacterial action, are absorbed and synthesized into complex organic compounds by plants and reduced to nitrates again when the plants and the animals feeding on them die and decay. See nitrification, nitrogen fixation

ni′trogen cy`cle


n.
the continuous sequence of natural processes by which nitrogen in the atmosphere and nitrogenous compounds in the soil are converted, as by nitrification and nitrogen fixation, into substances that can be utilized by green plants and then returned to the air and soil as a result of denitrification and plant decay.
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nitrogen cycle

nitrogen cycle

The continuous process by which nitrogen is exchanged between organisms and the environment. Some of the atmosphere's free nitrogen combines with other elements to form compounds that are deposited in the soil. These are then converted by bacteria, in a process called nitrification, into nutrients that are absorbed by the roots of green plants. Nitrogen is then passed into the food chain and returned to the soil by the metabolism and decay of plants and animals.

nitrogen cycle

The natural circulation of nitrogen (including nitrogen compounds) from air to consuming organisms (plants, animals and bacteria) and back to air.
ThesaurusAntonymsRelated WordsSynonymsLegend:
Noun1.nitrogen cycle - the circulation of nitrogennitrogen cycle - the circulation of nitrogen; nitrates from the soil are absorbed by plants which are eaten by animals that die and decay returning the nitrogen back to the soil
biological process, organic process - a process occurring in living organisms
References in periodicals archive ?
The study has significant implications for common agricultural crop plants as there is a strongly held belief that only plants with root nodules can benefit from the symbiotic relationship with the nitrogen-fixing bacteria.
It is done by Nitrogen-fixing bacteria (Diazotrophs means di: two, azo: nitrogen, trophs: lovers).
Acacias are leguminous plants, and like most legumes they form a symbiotic relationship with nitrogen-fixing bacteria on the roots, and are a significant source of atmospheric nitrogen being fixed into the soil for the subsequent use of all maimer of plant species (although some recent research suggests that erioloba, in fact, obtains most of its own nitrogen from the groundwater).
Their biggest benefit is they release nitrogen gained from eating and digesting the nitrogen-fixing bacteria so it is available for the plant at their root zones.
It is considered that response to inoculation may be influenced by genetic characteristics of the plant, bacterial strain and environmental conditions (HUNGRIA, 2011), and that in recent years many efforts have been directed to the selection and study of nitrogen-fixing bacteria in grasses.
In the root nodules of legumes, such as clover and beans, nitrogen-fixing bacteria transform atmospheric nitrogen into forms that nourish plants and, in turn, animals.
However, there are few studies of the diversity of nitrogen-fixing bacteria in the Pantanal biome.
Research on fungus-farming ants has revealed the association with nitrogen-fixing bacteria as fungus fertilizers and the application of antibiotics produced by symbiotic bacteria to control garden parasites.