University of Minnesota Soil Fertility Specialist
Research on Iron Deficiency Chlorosis (IDC) has been identifying methods to manage the problem for soybeans. Since 2010 research has been conducted using strip trials within farmers' fields. Currently we are looking for a 5 acre area to conduct a field study looking at the effect of Soygreen and oat cover crops on areas of the field that range from no-IDC to severe IDC. Our goal is to determine the economic benefits of the treatments on varying IDC severity within fields planted with two soybean varieties with varying tolerances to IDC.
Four field trials have been conducted since 2010. At two of the locations there was severe yield reduction from IDC. In sever areas, in-furrow application of an EDDHA-Fe fertilizer such as Soygreen significantly increased yield by an average of 5 to 6 bushels across the entire trial, and by as much as 10 bu/ac or more in the severe areas. The oats cover has also shown some positive yield benefits in sever IDC field areas. When comparing varieties, there was a large yield benefit with the variety that was less tolerant to IDC, but the tolerant variety still overall produced a higher yield level when IDC was present. When there was no IDC the less tolerant variety out yielded the tolerant. This indicates that 1) planting a tolerant variety is still the best option and 2) the application of EDDHA-Fe fertilizer in-furrow is advisable if possible in areas moderately or severely affected by IDC. A summary of the current and past work on this subject is available in the new publication "Managing iron deficiency chlorosis in soybean".
The area needed for this study is about 5 acres preferably with some variability in the severity of IDC. Our current research studies have been located in western Minnesota between highways 212 and 12. Compensation for the study area is available and all plot work from planting until harvest has been completed by the soil fertility research group at the University of Minnesota. Planting and harvesting are completed using small plot research equipment. Our goal has been to provide information on site specific management of soil fertility issues around the state of Minnesota. Advancements in variable rate technology have made it easier to vary inputs and studies like these have been crucial in determining the how to approach these problems with variable rate technology and whether it is economic to do so.