Bringing Up Beans

ST. LOUIS (DTN) -- It's a jungle out there for some soybean growers.

In states that saw abundant rainfall and late planting this year, some farmers are facing overgrown soybean fields where spindly plants have toppled over into a tangled mess just in time for harvest.

Of his 900 acres of soybeans in western Michigan, Ken Zahm estimates 30% have fallen over and promise to complicate harvest efforts next week.

"Lodging does seem more prevalent this year," the Marne, Mich., farmer told DTN. "We had plenty of moisture but cooler temperatures which caused the beans to grow a thinner stalk."

His weak-stemmed beans have been no match for the strong winds that visited his area recently, he added. "Just this morning, the wind was blowing at 35 to 40 miles per hour," he noted. "We don't need that!"

HARVEST TIPS

Harvesting fallen beans can be tricky, so growers should experiment to figure out the most effective combination of adjustments to their equipment.

Adjusting your ground and reel speed is the most important factor, said Michigan State University senior soybean educator Mike Staton. "Slowing down is really critical," he told DTN. "Typically, you have to be more aggressive with the reel speed and position. One of biggest things that I see is the reel is not going fast enough in relation to groundspeed to pick up the plants."

This adjustment can be sensitive and tricky, Staton explained in an MSU Extension article. Typically, your reel should run about 25% faster than the ground speed, but in lodged conditions, inching it up as far as 50% can help. Watch for shattering and slow down the reel if you spot it, Staton added.

Growers can also tweak the angle of the reel's pickup fingers and run the reel axle up to a foot away from the cutter bar. "You want the reel as low as you can and as far forward as you can; it takes some experimentation," Staton said.

Dropping the cutter bar as low as possible and harvesting at a 20 to 45 degree angle to the direction of the lodging can also help catch particularly flattened beans. Auto steer is critical if you choose to do this, Zahm noted.

Zahm also uses an AWS wind system on his soybean head to help draw in low-lying stems. "This blows high velocity air on the cutter bar to help with feeding the crop into the combine," he explained.

In extremely lodged fields, growers should consider installing vine lifters on the cutter bar, Staton added.

Ultimately, experimenting and adjusting to your particular lodging conditions will take time and patience, Staton concluded. "Make one adjustment at a time and stop frequently to evaluate your progress towards reducing gathering losses," he said.

For more details on harvesting lodged soybeans, see Staton's article here: http://goo.gl/….

PREVENTION STARTS AT PLANTING

While environmental conditions did contribute to lodging this year, controllable factors like planting populations, irrigation timing, variety selection, nitrogen levels, and potassium deficiencies may have also played a role, Staton said.

"Management for this starts now because [farmers] can look and try to analyze which management practices maybe contributed to lodging," Staton told DTN. Growers who are dealing with this for the first time should also take time to develop a harvest plan for scooping the toppled beans off the ground, he said.

A soggy spring and rainy June allowed soybean plant growth to take off during vegetative stages, Staton said. Growers new to irrigation might have also discovered that heavy watering during this period led to the same problem, he added.

No matter the cause, abundant moisture gave many growers "this lush, jungle of beans with long internodes and tall, gangly plants" that didn't yield any better but were more prone to toppling over before harvest, Staton explained.

Planting date also played a role. "At least in the north-central region, typically our tallest plants do result from a little bit later planting date," Staton noted.

Growers like Zahm, who was forced to plant in late May through early June, were more susceptible to tall, gangly beans, Staton said.

TAMING YOUR BEANS

The primary contributor to lodging that growers can control is planting population, Staton said.

Over-populated fields can force soybean plants to fight for resources, resulting in weakened stems. Too high of a planting population can also waste your own resources, Staton added.

"If you end up with 100,000 plants per acre [at harvest], you've reached your maximum economic return on seed investment anyway," he said.

Zahm said over the years he has dropped his planting population from 220,000 seeds per acre down to 150,000. That puts his harvest populations closer to 130,000, which has helped him control lodging most years.

University of Illinois scientists have developed a seeding rate calculator to help growers determine their planting population. You can read more about the calculator here: http://goo.gl/…, and access it here: http://goo.gl/….

Growers can also select varieties with good lodging-resistance scores and shorter plant height predictions, Staton said.

Too much nitrogen can also lead to overly leggy legumes. Nitrogen from manure applications can remain accessible in a field for two years, Staton pointed out. "Growers do have to be careful with manure applications on ground that will go to soybeans," he said.

Proper potassium levels help soybeans build a stronger stem, both Zahm and Staton noted. Zahm is now careful to apply potash to his bean fields each year as needed.

Emily Unglesbee can be reached at emily.unglesbee@dtn.com

(PS/GH/CZ)

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