Fungi contribute to soil in which of the following ways?

• A. Aggregation and carbon storage
• B. Increases soil salinity
• C. Reduces carbon storage
• D. Degrades soil structure

Answer: (A)

Fungi strengthen soil by forming networks of hyphae that weave among soil particles, creating and stabilizing aggregates. These hyphae bind particles together and secrete sticky substances, with glomalin playing a key role as a glue-like glycoprotein produced by many soil fungi, including arbuscular mycorrhizal fungi. This aggregation improves soil structure, increases porosity, boosts water infiltration, and reduces erosion. The stable aggregates also shield organic matter from rapid decomposition, helping to keep carbon in the soil longer. In rangeland soils, this fungal activity supports plant health and contributes to soil carbon pools through continued plant inputs. Increasing soil salinity, reducing carbon storage, or degrading soil structure aren’t typical roles of fungi; salinity relates to salt balance and evaporation, while fungi predominantly build structure and promote carbon retention rather than degrade it.