Reduce Harvest Loss From Lodged Or Green Stemmed Soybeans

When you have lodged or green stem soybeans you are not operating business as usual. Be prepared to slow down to minimize harvest loss. ( Sonja Begemann )

As you enter harvest season, it's important to have a game plan for handling any challenges you encounter. That's particularly true if you have green stems or lodging in your soybean fields--you'll want to prioritize those fields and be extra mindful at harvest.

Here's what you need to know:

When you have green stems, check the pods. If they are still green, you will want to let them dry in the field. But if the pods and soybeans are dry, waiting an extended period could put you at risk of pods opening and losing soybeans.

“Recognize it’s not business as usual,” says Mark Hanna, Iowa State University Extension agricultural engineer. “Have the right attitude.”

Here are several steps you can take to reduce soybean loss:

  1. Consider adjusting your rotor speed to increase threshing action. Since beans have more green material alongside them, they don’t get knocked around as much as drier plants. Walk behind your combine and check the grain tank for unthreshed beans to decide if increasing speed could be helpful.
  2. Make sure your cutter bar is good to go. When it comes to the cutter bar, look at all aspects. Check to make sure the blades are sharp and in good register with the guards, close enough to get the job done.

Scout fields to determine where you have lodging and what fields you need to combine earlier. If it’s too late--or you decide to let them fall to help them dry--use these tips to maximize your harvest.

  1. Get the head and cutter bar as low as possible without getting it in the dirt. Scoop low to get as many of those pods near the ground as you can.
  2. Make the following adjustments to the combine reel:
    1. Change the reel index, the speed of the reel compared to ground speed. When lodged, it may be beneficial to increase reel speed from just slightly more than ground speed to nearly two times ground speed. It’s probably counterproductive to go faster than that.
    2. “If you start to see plants going all the way around the reel and pushing them out, that’s probably too fast,” Hanna advises. Keep an eye on the head and walk behind to see if losses suggest that reel speed needs to be faster or slower.
    3. If you lower the reel to help pick up lodged plants, make sure you don’t lower it too far. The reel should be low enough to pick up lodged plants, but not so much that the pick-up fingers on the reel bats can be clipped by the cutter bar.

When it comes to harvesting green stems or lodged beans, you’ll need to be vigilant to ensure your methods are working.

Why? Unfortunately, the loss monitor on your combine isn’t good enough when 90% of losses happen at the head. The loss monitor shows losses out the back end, which is only 10% of the problem.

Losing four soybeans per square foot equal a loss of one bushel per acre, so take the time to get out behind the combine and make sure your harvest method is minimizing loss.

“You’ll be time and money ahead if you double check,” Hanna says. “Have the right attitude and be safe."

*This story was originally posted in Sept. 2016, Hanna has since retired.