By Darren Hefty

What’s the “silver bullet” for achieving higher yields? That’s a question I get all the time. Usually I would just say there isn’t a silver bullet.  This year for one farmer I know manganese was the single answer for a large yield gain.  Let me explain.

A farmer who applies a good amount of hog manure as a majority of his fertility program attended an Ag PhD Soils Clinic in 2015.  It inspired him to take a new look at his soil.  With a complete soil analysis he learned that the only nutrient he was short in (in other words, his yield-limiting factor) was manganese.  So for 2015’s corn crop, he applied only manganese and left two check strips.  He saw yield gains of 31 bushels per acre and 38 bushels per acre where he applied the manganese.  It was his “silver bullet” this year.

We target a soil test level of 20 to 40 ppm on a Midwest Labs 6-inch soil test as a minimum level where manganese should be.  Crop removal on corn, soybeans, wheat, and most other crops is far less than a pound per acre per year.  Once you build it up to the critical level so it won’t hurt your yield, you’ll only need maintenance levels applied each season for the rest of your farming career.

Nutrients Can Be Synergistic

One trial we ran on a field this past growing season was to apply a large rate of potassium (1400 pounds of potash per acre to be exact) to see how quickly we could build the base saturation of K up to 4 percent.  We took soil tests at the end of the season to see where the K levels were to evaluate the study in addition to the yield monitor data we took off the combine.  The other thing we did was to run weekly plant tissue analysis to see what nutrients were effectively getting into the plants to see if we were causing any positive or negative effects to the crop with our high rate of potash.  We found an interesting synergy.  All through the season, where we applied the potash we saw more manganese in the plant compared to where we didn’t apply the high rate of potash.  There is a definite synergy between potassium and manganese.

Why is Manganese Important?

There are many things that manganese helps in your plant.  In fact, it’s often referred to as “the element of life.”  Here’s a short list of functions it is involved with:

  • Chlorophyll production
  • Lignin building (meaning less lodging)
  • Disease prevention
  • Pollen
  • Kernel Weight

It’s also important for even emergence in your crop.  Another quick story from this year is from the Field Day site on our farm.  Neal Kinsey, a well-respected soil fertility expert, was walking along our high-yield contest plots with me.  He remarked that our manganese levels must be low.  I asked him what he noticed that made him believe that to be the case.  Neal said the ear placement on our corn was up and down, leading him to believe that emergence was uneven and that manganese could be part of the issue.  He was absolutely right, as the manganese in some of the plots was less than 10 ppm (far below the 20 to 40 ppm target).

I’m not saying manganese is the yield limiting factor across your entire farm, but it definitely pays to look with a good soil testing program.  I’d also recommend following up with plant tissue analysis on a weekly basis during the growing season to see if manganese is getting into your crop.