Two of these trials on pumice soils in Kaingaroa Forest have shown that calcined magnesite (calmag) applied as 2-5 mm chips at a rate of 150 kg Mg/ha is very effective in increasing soil exchangeable Mg concentration within 2 years of application (Mitchell et al.
1), have shown that the rate of dissolution was in the sequence: Epsom salts [is greater than or equal to] fine calcined magnesite [is greater than] coarse calcined magnesite, coarse granmag (partially acidulated and granulated calcined magnesite), fine dolomite [is greater than] fused magnesium phosphate (Loganathan et al.
Calcined magnesite (calmag, MgO) is made by calcining magnesite (Mg[CO.
radiata the rates of Mg fertiliser dissolution within 27 months follow the sequence: Epsom salts [is greater than] calcined magnesite (1-2 mm) [is greater than] granmag [is greater than] calcined magnesite (2-4 mm) [is greater than] forestry grade dolomite (0.
Heming SD, Hollis JF (1995) Magnesium availability from kieserite and calcined magnesite on five soils of different pH.