Why is volcanic soil so fertile?

Volcanic soils are fertile due to their non-crystalline mineral content that reacts favorably with growing organic matter. They are powdery in consistency and retain a high amount of water which is beneficial for plant growth.

Volcanic soils are also called andisols. They are the result of accumulated volcanic ash following an eruption. These soils bond well with organic materials, and may form a nutrient-rich layer that facilitates the growth of plants on the surface. The minerals in the soil form a chemical reaction when exposed to the atmosphere, allowing them to be utilized by plants as nutrients. Without proper management, physical weathering may strip the soils of their fertile layer.