Which characteristic enables clay to retain more water?

Clay retains more water primarily due to its higher surface area. The particles of clay are very small, often less than 0.002 millimeters in diameter, which results in a significantly greater total surface area compared to larger soil particles like sand or silt. This extensive surface area allows clay particles to form strong attractions with water molecules, creating more pathways for water retention.

Additionally, the fine texture of clay means that the spaces between the particles, known as pores, are also very small. These small pores can hold water more effectively than larger pore spaces found in sandy soils, which tend to drain quickly. Therefore, the combination of higher surface area and the smaller size of pores allows clay to absorb and retain more water, making it an important component in water-holding capacities of various soil types.