Physical Description:
Dolomite is a naturally occurring material containing 39% magnesium carbonate (of which 11% is elemental magnesium) and 57% calcium carbonate (of which 24% is elemental calcium). It is sourced from Golden Bay in the Nelson region and is ground to a yellow-brown powder.
Uses:
Primarily used for dairy farming as both a magnesium source and liming source. It is also used in some horticultural situations where magnesium and calcium inputs are required.
Benefits:
Where both magnesium and lime are required, dolomite is often more cost-effective than applying magnesium oxide and lime separately in the upper South Island and lower North Island. Even when the liming value is not considered, dolomite is often used as a source of magnesium, as the availability of the magnesium is increased, relative to Magnesium Oxide, by its finely ground nature.
Application:
Dolomite is typically applied at rates of about 100-300kg/ha. However, rates of up to 1000kg/ha may be warranted, depending on the amount of capital Magnesium required. Dolomite is often mixed with RPR, Sulphur Super, and Potassium Chloride (Potash).
Storage & Handling:
Dolomite is safe to store - ensure it is kept dry.
Source:
Omya/Ngarua Lime near Nelson - it is then freighted around the country to Ravensdown stores.