Characteristic Features of POLY4 As a Multi-Nutrient Fertilizer.

One of the main concerns for the fertilizer industry is the hydroscopic nature of fertilizer products. Absorption of water by fertilizers leads to products caking resulting in a poor shelf life. Understanding the characteristics of fertilizers is important when bulk mixing to create NPK fertilizer blends. Polyhalite is an evaporate mineral with the chemical formula of K₂Ca₂Mg(SO₄)₄·2H₂O that can be used in NPK blends. For this presentation, the compatibility of granulated polyhalite, formulation marketed as POLY4, with other fertilizer materials was tested using accelerated caking tests and IFDC fertilizer testing procedures.

Initial work with the University of Limerick assessed a range of 17 simple 50:50 mixtures of POLY4 and other fertilizers using an accelerated caking test to assess compatibility. Building on these results, NPK blend ratios were assessed with and without POLY4 to assess caking propensity of the blends. Finally, work has been up scaled to widely recognised industrial methodologies developed by IFDC to further demonstrate the characteristics of POLY4 for the fertilizer industry.