system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: Why is volcanic soil so fertile?
gpt
The lava that comes out of a volcano is full of minerals containing phosphorus, potassium, etc. The things that plants need to grow.

As the lava rock gets broken down and mixed with organic material, it creates a nutritious soil for plants.

Over time, nutrients get washed or blown away by rain and wind, returning nutrients to the sea or other areas. The soil becomes less fertile as the nutrients are lost.