Can we use rock wool (slag wool) for soil amendments?

Asked December 27, 2015, 3:24 PM EST

slag wool is sufficient of soluble silica (30%) and porosity, infiltration of water is good, and Cao can neutralize the acidic earth.

can we use this for soil amendments or soil conditioner in organic agriculture?

chemical composition
SiO2 :36~47 CaO: 24~35, Fe2O3:2~8, MgO:2~6 Al2O3 10~16

Hello ! sir/madam

Thank you for accept my question.

I would like to review and edit my question.

  1. Question keep point is that slag wool (stone woo, rock wool, mineral wool) can be used in soil conditioner or fertilizer for organic agricultural products?

    Because, slag wool is made of basic slag from smelting and basic slag powder is a kind of fertilizers (Silica fertilizer) and useful material in organic agricultural products in Korea law.

    Slag wool is more useful soluble silica SiO2, than basic slag: slag wool is made of melting basic slag plus lime stone (flux) and basalt (silica source) co- melted.

Many Korean avoid rock wool as like Asbestos man till now.


Outside United States

1 Response

The National Organic Program Standards (NOP) has listed Basic Slag as a prohibited input in their draft guidance document NOP 5034-2:

Calcined and fluxed minerals are usually prohibited with the exception of Hydrated lime (calcium hydroxide / slaked lime) which is restricted to use for plant disease control only and not as a fertilizer.