How does residue management influence soil temperature and moisture retention in arid-range soils?

• A. Residue cover increases evaporation.
• B. Residue cover moderates soil temperature, reduces evaporation, and increases soil moisture retention and infiltration.
• C. Residue cover has no effect.
• D. Residue cover prevents infiltration.

Answer: (B)

Residue on the soil surface acts like mulch, shading and insulating the soil while also easing the movement of moisture. By shading, it lowers daytime soil temperatures and smooths temperature swings, which slows the rate at which soil water evaporates. The cover also blocks some of the energy driving evaporation and reduces wind speed at the surface, further decreasing moisture loss. When rainfall comes, a protected surface is less prone to crusting and runoff, so water infiltrates more readily and stays in the root zone longer. Over time, the organic residue can improve the soil’s water-holding capacity, enhancing overall moisture retention. This combination of cooler, more stable temperatures and reduced evaporation with better infiltration is why residue cover has the described positive influence in arid-range soils.