https://www.beckshybrids.com/resources/agronomy-talk/weed-management-brief-importance-of-ams-with-liberty-and-glyphosateBasically 28% isn't going to condition hard water like AMS does. The sulfate is what binds with the hard water ions.If you want good results with Liberty follow the label. If you don't care if you kill the weeds, do whatever is easiest.
Why not use 28% instead of AMS in Liberty on soybeans?
