This is recycling of nitrogen compounds in nature; Tree nitrogen in the air cannot be used by plants; but has to be
converted into ammonium compounds; and nitratesin order to be reabsorbed; It is done in the following ways.
- The atmospheric nitrogen and oxygen combine to form nitric and nitrous acids; The acids combine with minerals in the soil;
to form nitrates that are absorbed; Fixation of nitrogen is done by nitrogen fixing bacteria; called Rhizobium; This bacteria
lives in root nodules; of leguminous plants; These bacteria absorb the nitrogen and convert it into nitrates; which are used by
the plants; other free living bacteria in the soil; like Azotobacter absorb nitrogen and then it is absorbed by the soil; Nitrifying
bacteria; like nitrosomonas; and nitrocucous are also nitrifying bacteria; when plants and animals did; they decompose;
releasing the ammonium compounds which are converted by nitrifying bacteria into nitrates and then nitrites; which are then
absorbed by the plants; which are then absorbed by the plants; However there are some bacteria that, convert
nitrates into nitrogen gas; which escapes back into the atmosphere; These are known as denitrifying bacteria; examples are
pseudomonas and dentrificans; They reduce the nitrates to obtain oxygen gas. (Accept the diagram to cycle for
nitrogen whose arrows are properly pointed
gregorymasila answered the question on February 23, 2018 at 12:09
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