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Don’t Make Your Soybeans Wait for Manganese

May 20, 2014

By Paul Reising, Wolf Trax

I’ve seen in recent years the growing popularity of in-season foliar applications of manganese fertilizer for soybeans. Part of the reason why the foliar fertilizer practice has grown is the obvious visual response that many farmers see after an application. The soybean plants take on a greener color. That’s because manganese is important for photosynthesis.

But what if I told you that the visual response – that greener color after a foliar application – is a bad thing?

Avoid Crop Stress
Seeing a difference in your field means the soybean plants did not have enough manganese before the foliar application. During the time you were robbing your soybean crop of this important micronutrient, you were also losing yield.

At Wolf Trax we advise our customers to deliver nutrients before they are needed by the plant. You can do this by coating your dry fertilizer blend with Manganese DDP™ (Mn DDP) or mixing Manganese DDP with your starter fertilizer.

Optimize Mn Application Timing
Foliar fertilizers aren’t always bad – as long as you make sure your soybeans have the manganese they need early.

At Purdue University Dr. James Camberato conducted research on timing of manganese fertilizer applications in soybeans. For applications at planting, he added Manganese DDP at a rate of 0.5 lb/acre to 10-34-0 starter fertilizer. And for in-season foliar applications, he added Manganese DDP at a rate of 3 oz/acre to glyphosate. The trial’s check received no starter fertilizer or manganese.

I’d also like to note that adding just a starter fertilizer with no manganese provided almost no difference in yield, only half a bushel more. This treatment highlights just how important manganese can be for soybeans.

Here is how much each treatment boosted yield over the trial’s check:



The best result came from a programmed approach: including Manganese DDP with a pre-plant/at-plant fertilizer application and again in a foliar spray.

But the next best option was NOT spraying just an in-season foliar application of manganese fertilizer. Instead, the second best option was applying Manganese DDP at planting.

Provide Mn to the Whole Soybean Plant
Besides making sure that the plant has access to the nutrient when it’s needed, a soil application also ensures that the whole plant benefits from the fertilizer application. Manganese is immobile in the plant. A foliar application supplies the important micronutrient to the part of the plant that is sprayed. Manganese will not redistribute itself to new growth.

When roots take up soil-applied Manganese DDP, however, the micronutrient is distributed throughout the whole plant. 

Choose Highly-Available Manganese DDP
If you are interested in including manganese in your dry fertilizer blend, be sure to ask for Manganese DDP. Traditional granular manganese fertilizers tend to get locked up in soil quickly. Manganese DDP features the patented PlantActiv™ Formulation that helps the nutrient resist soil tie-up and remain plant-available.

Source: wolftrax