Iron Deficiency Chlorosis (IDC) affects growers across the Upper Midwest, including Minnesota, and parts of North and South Dakota. This yield-robbing condition should be top-of-mind for growers knowing that its effects have the potential to be devastating. However, it’s important to remember that IDC is avoidable. Growers can take steps today to identify and prevent IDC in their soybeans tomorrow.

What Is Iron Deficiency Chlorosis?

Iron Deficiency Chlorosis occurs when crops are unable to access adequate amounts of soluble ferrous iron (Fe2+) for normal crop development processes. In some cases, enough ferric (Fe3+) iron may exist in the soil, but plants are not able to use the iron unless it is reduced to ferrous (Fe2+) form.

The plant’s inability to uptake the appropriate amount of iron creates a chlorophyll imbalance that can lead to the visual symptom of the yellowing leaves and can result in dramatic yield loss.

Soil characteristics and weather conditions can also increase the instances and severity of IDC in soils that are prone to developing these symptoms.

What Causes Iron Deficiency Chlorosis?

IDC is rarely caused by a lack of iron in the soil, but rather a lack of available iron, due to nutrient tie-up in the soil. However, in some areas, plants are not able to reduce and uptake iron in a usable form, usually due to one of three main causes:

High levels of calcium carbonate (CCE) in the soil 
Calcium carbonate particles can come in contact with the crop’s roots and neutralize the excreted acid (which helps with iron uptake by the plant) and can result in the plants’ inability to have access to adequate levels of iron.

High salinity 
Soils with a high salt content should be a major concern for anyone trying to predict and combat iron deficiency chlorosis since IDC conditions are the most severe in saline soils.

Soil pH levels above 7 
The pH of the soil also has a major impact on the availability of iron for the plants’ uptake. When the soil pH is more than 7.5 it is considered alkaline. When this happens, plants have a difficult time reducing the iron to the soluble form (Fe2+) needed to develop a healthy and high yielding crop.

What Are the Symptoms of Iron Deficiency Chlorosis in Soybeans?

• Yellow leaves and dark green veins (interveinal chlorosis),
• Less plant vigor
• Growing point and leaf death

Soybeans are affected by IDC when they are unable to access optimal amounts of soluble iron. Without a healthy amount of iron uptake, the plants often develop chlorotic yellow leaves and dark green veins often referred to as interveinal chlorosis. The plants have less vigor, leading to issues with growth and yield.

These symptoms will typically first manifest on the youngest of the top leaves.

When IDC is severe, the leaf edges may die. This necrosis may advance to the point where the leaves fall off the plant and the death of the growing point, decreasing the tissue available for photosynthesis.

If IDC is left untreated or without preventative action, yield loss can be devastating and leave the field prone to IDC in the future. Although there may be ample iron in the soil, soil conditions can make it inaccessible to the developing plant.

3 Ways IDC Negatively Impacts Uniform Soybean Development

1. Often, the symptoms from IDC simply kill the plants in the affected soils because they do not have adequate amounts of iron for normal development processes. In cases where IDC does not kill the soybean plant, it can impact the developing crop and a grower’s operation in several ways. The lack of soluble iron keeps the plants from developing uniformly, stunting the soybean plant’s normal development stages and causing affected plants to mature later than other soybean plants in the same field.
2. When a field has variability in crop maturity stages, growers have the potential to lose yield since they are not able to harvest the field until all the beans are ready. While the grower waits for the slower maturing beans to be ready for harvest, they risk losing yield in the areas where the beans matured earlier and remained in the field past their peak harvest timing.
3. If the IDC-affected areas of the crop are large enough, a grower might be able to run the combine in the earlier maturing areas first and then come back later when the slower maturing beans are ready to be harvested. This scenario is still not an ideal situation since having to make two trips to harvest the same field not only impacts yield, but also adds inconvenience, increased labor and equipment costs. In both scenarios, IDC negatively impacts the grower’s overall profitability.

How to Prevent IDC

These are the ways to prevent Iron Deficiency Chlorosis in soybeans:

• Determine whether your field is at risk or has previously suffered from IDC
• Apply iron-chelated fertilizer in-furrow
• Choose a soybean variety that is tolerant to IDC
• Consider planting a companion crop to optimize soil conditions
• Apply proper herbicides
• Avoid soil compaction
• Use an iron chelate product

Soygreen

Chelated with the purest ortho-ortho EDDHA that exists, Soygreen brands are the leading micronutrient for overcoming iron deficiency chlorosis in soybeans. Exclusively distributed by CHS Agronomy, Soygreen is an iron (Fe) formula developed for soybeans and other crops suffering from iron deficiency chlorosis. It has the purest and highest concentration of ortho-ortho EDDHA chelate compared to other premium micronutrient products. This chelating agent keeps the iron (Fe) soluble for uptake and even makes other nutrients in the soil available to the plant.

Soygreen is available in three different formulations to better fit your application needs. A dry water-soluble powder that is easy to mix and apply, a convenient liquid solution for ease and convenience, and a granular blend that is designed for the air seeder market.

Soygreen® is a powder iron product chelated with Levesol's ortho-ortho EDDHA, making it the most effective and proven IDC product on the market.

Soygreen® AST is a liquid ortho-ortho EDDHA chelated iron solution designed to minimize leaching and allow the product to be available in the root zone longer.

Soygreen® Granular 2.4 is a superior granular iron product containing Levesol’s ortho-ortho EDDHA chelate and is designed for air seeder application.

IDC does not have to be a death sentence for soybeans. With a keen eye on potential warning signs and preventative measures in place, such as utilizing Soygreen®, growers can mellow the yellow in their crop or avoid IDC altogether.

To learn more about Soygreen, visit chsagronomy.com/soygreen or contact your local CHS representative.