Which factor does NOT influence soil formation?

Soil formation is influenced by several key factors, among which climate, time, and topography are crucial. Climate affects the weathering of parent materials and the types of vegetation that can grow, which in turn impacts soil organic matter levels and nutrient availability. Time is significant because soil processes need time to build up layers and develop characteristics; younger soils will generally differ from those that have been forming for thousands of years.

Topography has a direct influence as well because the landscape's slope and elevation can affect water drainage, erosion, and microclimates, all of which contribute to how soils develop over time.

While plant growth does contribute to soil development by adding organic matter and influencing soil structure, it is not a primary factor in the initial formation of soil. Plant growth is often a result of the existing soil characteristics rather than a direct influence on the very process of soil formation itself. Thus, it doesn't play the same foundational role as climate, time, or topography.