February 2020

K-Mag® Corn Blend Study


Evaluate corn yield response to MOP (0-0-60) and K-Mag® Premium (0-0-21.5-10.5Mg-21S).


  • Muriate of Potash (MOP) is a common potassium (K) fertilizer used in corn production.

  • Higher corn yields combined with lower atmospheric sulfur deposition has accelerated the need for sulfur (S) on corn.

  • Soluble magnesium (Mg) has been documented to improve photosynthesis, enzyme activation, and grain yield.

  • K-Mag® is a unique 3-in-1 nutrient source that features low chloride, water soluble nutrients, and does not affect soil pH; regardless of rate.

Trial Details

Locations and Crop Management:

CROP: Corn (Zea mays)

YEARS: 2018-2019

DATA SOURCE: Field studies conducted by third-party, independent researchers.

EXPERIMENTAL DESIGN: Small-plot RCBD with 4 replications.


N Rate: Applied according to local recommendations

P Rate: 80 lbs P₂O₅/ac applied as DAP (18-46-0) or MAP (11-52-0)

K Rate: 60 lbs K₂O/ac as either MOP or a blend of MOP (50 lbs K₂O/ac) + K-Mag® (10 lbs K₂O/ac)

Application Timing: Preplant

Application Method: Broadcast Incorporated

Corn Blend Study Results


  • Replacing a small amount of MOP with K-Mag® increased corn yield by 4.5 bu/ac over MOP when averaged across 23 trials (2018 and 2019).

  • These results demonstrate the value of K, Mg, and S for current yield levels and corn production systems.

  • Access additional yield data, ROI calculators, and resources at K-Mag - Performance.

©2020 The Mosaic Company. All rights reserved. AgriFacts® and K-Mag® are registered trademarks of The Mosaic Company. Individual results may vary, and performance may vary from location to location and from year to year. This result may not be an indicator of results you may obtain as local growing, soil and weather conditions may vary. Growers should evaluate data from multiple locations and years whenever possible.