Drive for 100 - 7

Break the Yield Limit

Scott McKee makes two passes across a field each time he scouts for pests. (DTN/The Progressive Farmer photo by Greg Latza)

Scott McKee can still feel the combine engine pulling down as it gobbled his 2014 South Dakota Soybean Association yield contest entry.

"The combine had to creep along. The stems were still green because we didn't have a hard frost by harvest. We didn't realize we were harvesting more than 100-bushel beans. It didn't really sink in until after we finished weighing," McKee said.

Still, he knew it was going to be a big crop. "There were 70 to 130 pods per stem with four pods [at each node] all the way up the stem, and every pod was full. The test weight was almost 60 pounds per bushel at 12% moisture," he said. When the final statewide yields were tallied, he broke the South Dakota soybean yield record at 103.7 bushels.

McKee is a third-generation farmer near Alcester, South Dakota, located in the far southeast corner of the state. His 83-year-old father, Paul, still lends a helping hand on the farm.

Scott has been involved with corn yield contests on his 400-acre farm since 2000, placing or winning 13 of the 15 years. Last year was the second year he's entered the soybean yield contest.

"Yield contests challenge what you can do, and it helps me make improvements in the rest of the operation," he noted. "I share a lot of information about my operation with others, but not everything. What works for me may not work for the next farmer," he added.

The two 12-acre fields he uses for yield contests are divided into two sections: one with east/west rows, and the other with north/south rows. Like on the rest of his farm, he follows a corn/soybean rotation for yield-contest ground.

The silty clay loam soils in the fields are not tiled. The ground was used as pasture until the 1980s and received heavy applications of hog, cattle and chicken manure. "It's part of the bottom ground of the Big Sioux River," McKee noted.

McKee readily admitted growing conditions in 2014 were ideal for soybeans. "We had rains every week of at least one-half to three-quarters of an inch. The low ground escaped the early frost that hit the high ground and gave us almost a month of additional growing season," he said.

McKee practices conventional tillage; he aims to chisel most fields in the fall to break up any hardpan and get air and moisture down into the soil profile. For soybeans the following spring, he makes a pass with a disk or field cultivator, depending on corn residue, and incorporates his preemergent herbicide.


When it comes to nutrients, McKee applied what his fertilizer dealer recommended for the acreage: 200 pounds per acre of 11-52-60. "It's a straight rate, not variable-rate applied," McKee said.

"We also had lots of rain last year and perfect growing conditions," he added. However, his attention to the crop during the growing season has repeatedly helped him head off yield-robbing problems before they get established.

"I scout the fields heavily looking for aphids or weed outbreaks. A bug infestation that gets ahead of you can easily steal 2 to 4 bushels per acre," he said.

With each scouting, McKee makes two passes over the field and uses a magnifying glass to get a close-up look at any pests, such as aphids. Waterhemp is the main weed problem on the farm.


High seed populations take advantage of McKee's stoked-up fertility. In 2014, he seeded beans in 15-inch rows at 240,000 seeds per acre. This year, he seeded his yield contest acres at 280,000 seeds per acre. Those seed loads require steady rains, though.

It was a mid- to late-Group II soybean variety (Pioneer 92Y70) treated with a custom blend of seed treatments that included fungicide, insecticide, nematicide and a mix of biological that reached the 103.7-bushel mark. The Group III soybeans in his contest plot yielded 94.4 bushels per acre. "On our farm, we average close to 60 bushels per acre for soybeans. The county average is in the 50-bushel range," he said.

Seedbed preparation and row cleaners combine to help consistently place seed at 1.5 to 2 inches deep. Since he doesn't have a 15-inch planter, he plants 120,000 plants per acre (ppa) and makes another pass to split the rows to achieve 240,000 ppa. On his non-contest soybean acres, he will plant in 30-inch rows at 180,000 seeds per acre.

"Participating in yield contests is a good way to try new things and to challenge what you can do to improve your operation," he said. "Every year is different, but I learn something every year, too."

The following are some of McKee's tips for success:

1. Know your planter, and keep an eye on it. McKee aims to achieve 95%-plus seeding rate accuracy.

2. Listen to your elders. Consider their input while you're making variety selection and other cropping decisions. "My father has been involved with this farm since birth, and he knows the fields and their tendencies," McKee noted.

3. Location, location, location. McKee said the 12-acre field where he strives for yield contest success is special ground that is close to the home place where he can keep an eye on it. It's the best ground he farms, he said.

4. Build up fertility and keep it there. "If it doesn't get used one year, it can be used the next," he said.

Editor's Note: The United Soybean Board has set the ambitious goal of reaching a 60-bushel-per-acre national average by 2025. Many U.S. soybean growers have already surpassed that milestone and set their sights on reaching 100-bushel yields. In this seven-part series, DTN/The Progressive Farmer looks at some of these top producers and their practices. This is the seventh and final story in the series.