Water quality is a frequently overlooked factor that can adversely affect the performance of pesticides, especially herbicides. Besides pH, water “hardness” is a key concern, with much of the agricultural water sources across the U.S. exhibiting high concentrations of calcium, magnesium, iron, sodium, and aluminum. These hard-water cations — especially calcium and magnesium — can wreak havoc in a spray tank when not managed. Weak acid herbicides, such as glyphosate and 2,4-D, are most susceptible, but no herbicide chemistries are completely immune to the negative effects of hard water, including dicamba and sulfonylurea (SU) herbicides. Use of ammonium sulfate (AMS) in spray solutions only counters the effects of calcium hard-water cations, providing no protection whatsoever from magnesium and the others. Iowa applicator Jason Winegar of Nutrien Ag Solutions has been able to eliminate having to handle and pour 50-pound bags of ammonium sulfate into his sprayer while in the field. “When you do a good job of addressing hard water, the herbicides mix, blend, and apply much better,” says Jason Winegar, an applicator at Nutrien Ag Solutions in Dunlap, IA. “You get more uniform spray ...