Final answer:
The proportion of larger particles in the soil makes the soil less porous.
Step-by-step explanation:
The proportion of larger particles in the soil makes the soil less porous. Soil texture, which is influenced by the size of particles in the soil, plays a crucial role in determining the porosity of the soil. Sandy soils, composed primarily of larger particles, have fewer spaces for water to reside, leading to less porosity compared to soils with smaller particles.