Preliminary results from a three-year research project in North Dakota show row spacings in many soybean fields are too wide to reach their maximum yield potential.
A team of agronomists and extension agents at North Dakota State University are surveying growers to generate baseline data on soybean management practices in the state. Their goal is to identify factors that are preventing soybean growers from reaching maximum yields, as NDSU extension agronomist Hans Kandel explains in this Soybean School episode.
“I was surprised to see how many farmers are still growing in a 30-inch row spacing. It was a large percentage,” he notes.
“When you go to the 30-inch row spacing, that is way too wide for North Dakota, Manitoba and northwest Minnesota. We are not using all the sunlight and translating it into yield,” says Kandel.
Comparing 14, 15, 22 and 30 inch planter spacings, as well as 6-8 inch spacing with an airseeder, the 15-inch spacing appears optimal, he says.
While they’re also collecting variety data, they haven’t been able to identify a trend in the variety/row spacing relationship.
— Kelvin Heppner (@RealAg_Kelvin) December 8, 2016
As for seeding rates, their 2015 data showed a rate of 165 thousand seeds per acre yielding the highest average. However, the difference between targeted seeding rate and final plant stand is surprising to many growers, says Kandel.
“Often farmers do not realize that there is quite a bit of difference between the number of seeds you plant and the number that make it into a plant,” he says, noting there’s usually a 10-15 percent difference between seeding rate and plant stand early in the season. “The difference between plants established at the beginning and there at the end of the season can be another 9-10 percent.”
The benchmarking project started last year, with producers submitting their 2015 soybean production data, with some 2014 information if growers were able to provide it. They’re currently collecting 2016 data and plan to continue the study through the 2017 growing season. The survey team is visiting fields to conduct actual field observations to verify the data.
Kandel discussed the preliminary soybean benchmarking results, comparing planting date, row spacing, seeding rate, variety selection and other factors, at the Prairie Grains Conference in Grand Forks, ND earlier this month: