Iron deficiency chlorosis Iron deficiency chlorosis (IDC) is a technical phrase for plants that have yellow leaf tissue between veins because they have not been able to take up enough iron ( Figure 1 ). Iron is needed for plants to make chlorophyll - the green pigment that plants use to capture the sun's light energy. Through photosynthesis plants use this energy to combine carbon dioxide from the atmosphere and water from the soil to make carbohydrates. IDC is favored by saturated soils with high calcium carbonate and soluble salt (and sometimes nitrate) contents. Figure 1. Iron deficiency chlorosis (IDC) symptoms on soybean (photo: Angie Peltier) Each spring, after that period of poor growth and development caused by IDC, soybean plants in northwest Minnesota typically outgrow all but the most severe IDC symptoms. Provided that there aren't too many factors other than IDC contributing to lower yield, a careful review after harvest of yield maps may help one to pick
