What is the most significant factor that controls the development of soil?

There are five factors of soil formation, these are:
1) Parent Material
2) Topography
3) Biota
4) Climate
5) Time

The parent material of soil is the material that soil develops from. It is where the soil acquires its inherent characteristics or attributes that will influence the direction, timing, and nature of soil as it develops over time.

Though Topography, Time, and Climate are factors of soil development, they are rendered unimportant when parent material is not present.

The most significant factor that controls the development of soil is the climate.

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