Which soil structure enhances water infiltration and air movement in the topsoil?

• A. Blocky structure
• B. Platy structure
• C. Granular structure
• D. Prismatic structure

Answer: (C)

Water movement and gas exchange in the topsoil thrive when the soil has a granular structure. Granular soil forms loose, crumb-like aggregates with many interconnected pores, creating a network that lets water infiltrate quickly after rain and allows air to move through the surface layer. This combination supports drainage and root respiration in the topsoil. In contrast, plat y structure tends to form flat layers that hinder vertical flow and aeration; blocky structure with angular blocks slows infiltration and can restrict pore connectivity; prismatic structure creates vertical columns that drain well but often reduce the surface pore network needed for rapid infiltration. So the granular structure best promotes infiltration and air movement in the topsoil.