Pumice

Origin

Pumice is produced as volcanic lava cools. The escaping steam and gas contribute to its porous nature. This alumino-silicate material contains potassium, sodium, magnesium, calcium, and slight amounts of iron.

Characteristics

Pumice can absorb K, Mg, P, and Ca from the nutrient water making it available for plant absorption later (Bunt, 1988)
 

Durability

Pumice is a natural product which can be crushed over extended use. It is a natural soil amendment and can be used with compost to enrich soil