Which term describes the transfer of nitrogen from the atmosphere to soil, to living organisms, and back to the atmosphere?

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The nitrogen cycle explains how nitrogen moves from the atmosphere into soil, into living things, and back into the atmosphere. Although nitrogen gas (N2) is abundant in the air, most organisms can’t use it directly. Specialized microbes fix N2 into usable forms like ammonium or nitrate, and some nitrogen also enters the system through lightning. Plants take up these forms, and animals obtain nitrogen by consuming plants or other animals. When organisms die or excrete waste, decomposers release nitrogen back into the soil as ammonium. Nitrifying bacteria then convert ammonium to nitrate, making it available again to plants. Denitrifying bacteria can return nitrogen to the atmosphere as N2, completing the cycle. The other cycles involve different elements or pathways and do not describe this atmospheric-to-biological-to-atmospheric loop.