Availability of Potassium and Secondary Nutrients from Polyhalite and Their Significance for Crop Growth.

Availability of potassium and secondary nutrients from Polyhalite and their significance for crop growth Polyhalite (K2SO4.MgSO4.2CaSO4.2H2O), being a natural mineral containing all secondary nutrients besides potassium, can be an alternative or complementary to other conventional fertilizers such as KCl (MOP), K2SO4 (SOP), MgSO4 (Epsom), K2SO4.2MgSO4 (SOPM), and CaSO4 (Gypsum). Differences in water solubility of polyhalite under lab conditions with other established fertilizers prompted us evaluating its nutrient availability for different crops. Sirius Minerals’ global agronomy program provided an opportunity to compile evidences from different field and green house agronomy experiments in various crops pertaining to the availability of nutrients from polyhalite and their influence on crop growth. Results are being analysed and will be presented.