Which organism is most associated with rapid nutrient cycling in soils?

• A. Bacteria
• B. Fungi
• C. Nematodes
• D. Archaea

Answer: (A)

Rapid nutrient cycling in soils is driven by bacteria because of their high growth rates, abundance, and broad metabolic capabilities that quickly mineralize simple organic matter into inorganic nutrients like ammonium and nitrate. This rapid turnover makes nutrients readily available to plants and other soil organisms. Fungi, by contrast, excel at breaking down more complex substrates such as cellulose and lignin, which tends to release nutrients more slowly and supports long-term carbon turnover and soil structure rather than rapid mineralization. Nematodes mostly influence nutrient release indirectly through grazing on microbes and other soil organisms, so they aren’t the primary drivers of fast mineralization. Archaea participate in some nitrogen and carbon transformations, but in many soils, bacterial processes dominate the rapid nutrient cycling observed.