Manganese deficiency in soybean can be expected on Wisconsin soils with high pH (>7.0) and/or higher soil organic matter (OM) contents (>6.0). Soils that meet these criteria are typically, but not exclusively, found in Eastern Wisconsin. In the 2005 and 2006 growing season, Dr. Laboski did not receive any calls/emails regarding suspected Mn deficiency in soybean. However, in the 2007 growing season, Dr. Laboski received many inquiries. Manganese was confirmed to be deficient in many fields over an area from Eastern Waupaca Co. south to Jefferson Co., and mostly east of Lake Winnebago. In every case that was confirmed with soil and tissue analysis, the soil had high pH and/or higher OM content. In most cases, glyphosate resistant (GR) soybean varieties were planted in the field.