The Response of UK Grown Silage Corn to Polyhalite Fertiliser.

Interest in potential usage of polyhalite [K₂SO₄.MgSO₄.2CaSO₄.2H₂O, K₂O (16%), S (21%), MgO (7%), CaO (19%)] as a fertilizer increased especially after the discovery of its huge reserve (13 million tons per annum) reserve at York, North Yorkshire in England.  An experiment was conducted at Univ. of Warwick, in 2014 in silage corn (Zea mays L.) on a loamy soil having a soil K content of 157 ppm.  Polyhalite, KCl (MOP), and K₂SO₄ (SOP) were compared in a randomized complete block design with four replications at 75, 150, 225, and 300 kg K₂O ha ^-1 in addition to control (No K and No S).  Another two treatments containing MOP and SOP blends at 67 and 33% and 33 and 67% , respectively of recommended 225 kg K₂O ha ^-1 were also evaluated for yield, yield as well as  quality attributes and post-harvest residual soil pH and EC.  Polyhalite, SOP and the two blends performed significantly higher than MOP and control in terms of total biomass, dry matter percentage, and N, P, K, Ca, Mg and S uptake.  No significant difference among treatments was observed for post-harvest soil pH and EC parameters.  Farmers can consider polyhalite as an option to supply K and S to the silage corn.