Here's why:

* Rock and mineral fragments: These provide the basic structure and nutrients for plants.

* Organic matter: This comes from decaying plants and animals, adding nutrients and improving soil structure.

* Air: Necessary for the roots of plants and for the organisms living in the soil.

* Water: Essential for plant growth and for dissolving nutrients that plants can absorb.

Let me know if you'd like to explore any of these components in more detail!