Calmag Guaranteed Content % (w/w) Total Nitrogen: 13 Nitrate Nitrogen: 13 Water-Soluble Calcium (CaO): 16 Water-Soluble Magnesium (MgO): 6 Calcium and magnesium are present together in a form that can be easily absorbed by the plant. It is not subject to physical inhibition by ammonium or chemical inhibition by phosphate and sulfate, thus facilitating calcium uptake. It should not be mixed with other fertilizers. Calcium helps improve plant and fruit vitality, while magnesium enhances photosynthetic activity and helps keep leaves green.