Which pair of materials can help mitigate evaporation?

• A. Mulch
• B. Mulch and Humus
• C. Humus
• D. Irrigation

Answer: (B)

Mitigating evaporation hinges on cutting water loss from the soil by protecting the surface and boosting the soil’s ability to hold moisture. Mulch acts as a protective blanket over the soil, shielding it from direct sun and wind, and dampening soil temperature swings. This reduction in surface evaporation is a direct, immediate win for conserving soil moisture.

Humus, a form of decomposed organic matter, improves soil structure and increases the soil’s water-holding capacity. By adding organic matter, it enhances porosity and moisture retention within the rootzone, helping the soil store more water for plants between irrigations or rainfall.

Using both together gives the best result: mulch provides a surface barrier to evaporation, while humus strengthens the soil’s long-term moisture storage. Irrigation, on the other hand, delivers water but does not reduce the rate at which water is lost from the soil; it can even increase evaporation if not managed properly, so it isn’t a material that mitigates evaporation by itself.