Variety selection should not be overlooked as a management practice for the control of iron chlorosis. If iron chlorosis is observed, the grower can attempt to apply iron as a foliar treatment or use cultivation as a remedy. The foliar application should be made at the 2nd trifoliate stage of development. The iron should be applied in the chelated form for best results. This treatment is expensive and there is no guarantee that the soybean plant will recover from the chlorosis condition.
Cultivation is the more practical option.
This tillage operation allows for more rapid movement of oxygen into the rooting zone. Soil iron is then converted to a form that is more readily absorbed by plants and chlorosis frequently disappears. Row spacing for soybean production should be planned to allow for cultivation in fields where chlorosis has been identified as a production problem in previous years. Other Possible Nutrient Needs Research trials conducted at several sites in Minnesota over a number of years have shown that soybeans do not respond to the application of sulfur, magnesium, zinc, manganese, copper, and boron applied in a fertilizer program. Therefore, additions of these nutrients to a fertilizer program are not suggested.