Plant Health Initiative

Soybean field showing symptoms of iron deficiency chlorosis. Photo credit: R.J. Goos, North Dakota State University

Iron Deficiency Chlorosis - Management

Variety selection

The most successful management of iron deficiency chlorosis is the selection of soybean varieties with greatest resistance. There have been major improvements in soybean varieties that are tolerant to the soil and environmental conditions that lead to iron chlorosis. Most public and private soybean varieties have been rated for IDC tolerance.

Soil management

Researchers in Minnesota have observed that a combination of free calcium carbonates and soluble salts makes the IDC problem most severe. It appears at this time that free calcium carbonate in excess of 10% and soluble salt levels in excess of 1.5 lead to severe chlorosis. These numbers may change as more observations are made.

Manure applications can help to improve soil chemistry. Application of iron on foliage is rarely effective. A EDDHA iron chelate product, called SoyGreen, has been shown in some consistent results in cases of severe iron deficiency chlorosis..

If overwatering or poor drainage are possible causes, they should be corrected.

Plant a competition crop

Researchers in Minnesota report that planting oats as a competition crop just ahead of planting soybeans then killed with Roundup at a height of 10 to 12 inches proved to be a very effective management practice. The oat crop absorbed nitrate-nitrogen thereby reducing the amount available to the soybean crop.

 

Resources: Update on Iron Deficiency Chlorosis, Minnesota Farm Guide, 2008