Which mulch type is less likely to add nutrients to the soil but can improve moisture retention?

Which mulch type is less likely to add nutrients to the soil but can improve moisture retention?

• A. Organic mulch
• B. Mulch mats
• C. Inorganic mulch
• D. Compost

Answer: (C)

The main idea is how mulch interacts with soil nutrients and moisture. Mulch that is inorganic stays essentially the same over time and doesn’t break down to feed the soil, so it’s unlikely to add any nutrients as it sits on the surface. At the same time, it can help keep soil water from escaping by shielding the soil from sun and wind, or by blocking evaporation, which improves moisture retention. In contrast, organic mulches—like bark, straw, or compost—decompose and release nutrients into the soil, boosting fertility, and compost even adds nutrients directly. So, inorganic mulch fits the description of not supplying nutrients while still helping conserve soil moisture.