Make no mistake, Kip Cullers is out to hit the highest yield possible on soybeans — at whatever the cost. “We are not worried about making money on our contest acres. Although 100+ bu./acre soybeans are quite profitable, we're more interested in what we learn. What we learn from our yield contest acres we then apply to our normal acres,” says the Purdy, MO, farmer who for the second year in a row has grown the highest soybean yields in the world — 154.7 bu./acre.
What's more, this is only the second time he's entered the contest. “This is an example of how intensive crop management results in high returns and unprecedented soybean yields,” says Dale Ludwig, executive director of the Missouri Soybean Association.
Cullers, from southwest Missouri, grows about 7,000 acres of corn and 600 acres of soybeans, along with more than 3,000 acres of green beans and greens such as spinach, collard, kale, mustard and turnips. He also has a beef and poultry enterprise.
Last year, Cullers hit 139.39 bu./acre on the same 40-acre sandy loam soil field using irrigation and conventional tillage. Ten acres were selected for the actual test. But even on his dryland acres and planting soybeans as a double-crop behind green beans, he averaged 60 bu./acre this year. The previous high is believed to be 118 bu./acre, set in 1993.
Cullers planted Pioneer 94M80 soybeans at 250,000 seeds/acre, ending up with a 220,000-plant stand at 6 in. tall. “That's a little higher than what universities recommend,” he admits. The Roundup Ready 94M80 is a late Group IV soybean that's rated with excellent harvest standability and tolerance to soybean sudden death syndrome, and is resistant to soybean cyst nematode.
Although he planted the winning variety on May 7, he is a believer in early planting. Two other varieties were planted on April 22 and 29. “If you can extend flower and grain fill, that's positive and has to help,” he says.
He planted in twin rows, 9 in. apart on 30-in. centers with a precision Monosem planter he regularly uses for his vegetable crops. “We need to plant soybeans and take care of them like they're a corn crop,” he says.
In addition, he applied 3 tons of turkey litter/acre and supplemented that with ammonia sulfate and potassium sulfate. He also made two 9-oz. Headline fungicide applications at first pod set and then three weeks later. Plus, he applied 3 oz. of Respect insecticide to control stinkbugs.
“When you're watering like we do here in the South, you're going to have some disease and plant health issues,” he says.
“I also used Optimize, a soybean growth promoter, to improve the size of my roots,” he says. “In a size-by-side test with and without it, the root mass was twice as big with the Optimize.”
On tillage, Cullers chops corn stalks and disks about six times. “We even sprayed a residue blend to help eat the stalks and make them decompose faster. It's basically sugar and nitrogen with microbes that help decompose stalks,” he says. “Then we disk rip and moldboard plow, burying all the stalks. It's a massive amount of tillage.”
Admittedly, Cullers takes a total system's approach to his crops and pays close attention to detail.“I learned that raising vegetables,” he says. “I scout my contest field beans three to four times a day.”
Cullers insists that if you expect peak soybean yields, you've got to pay close attention “and you'd be surprised at what you could do with yields.
“The easiest thing you can do is to be sure you're planting the right genetics for your area,” he says. “Next, experiment with fungicides and insecticides. Try them on a small scale and see what works for you. If you don't try new things it's hard to get ahead. And try it on at least 20 acres to get a good test.”
The obvious question: What's ahead for next year? “I think I can hit 200-bu. beans, but it depends a lot on the weather,” Cullers says.
Palle Pedersen, Extension soybean specialist from Iowa State University, believes Cullers can hit a higher yield mark.
“Compared to Iowa, Cullers has a longer growing season with more sunlight in addition to irrigation,” Pedersen says. “Harvestability is going to be his limiting factor, however. Plants are lodging because they're so big.”
Farmers everywhere can learn from a yield winner like Cullers. “You can learn to intensively scout and observe your plants,” Pedersen says. “Challenge yourself. We shouldn't be satisfied with what we're doing and should always explore new management areas.”