Soybean germplasm possesses a lot of untapped yield potential, says Farm Journal Field Agronomist Ken Ferrie. But there’s no cookbook recipe that is guaranteed to bring it out.
That’s because so much of soybean yield is based on environmental conditions. The high soybean yields experienced by many farmers in 2010 may have resulted from unusually good growing conditions.
Ferrie provides the following tips to help capture high soybean yields. In the Late Spring issue of Farm Journal, you’ll find these tips plus 10 more to help you navigate the 2011 soybean growing season. You’ll find the issue in your mailbox the first week of May.
Don’t waste seed
“It’s hard to increase soybean yield by pushing population to the extent that you can with corn,” Ferrie says. From 1992 through 2007, Ferrie compared seeding rates of 120,000, 160,000 and 240,000 viable seeds in row widths of 7½", 10", 15", 20", 30" and twin rows.
“From those results, 120,000 would stand with or beat most populations in 10" and 15" rows,” he says. “In 20" and 30" rows, the results were less consistent, but the worst population usually was 200,000 or higher.”
First-ever Soybean College offered due to farmer request! Held Aug. 1 to 2 in Coldwater, Mich., this event is led by Farm Journal associate Field Agronomist Missy Bauer to help you take soybean yields higher. Learn more.
In 2008, a notoriously late spring when soybeans were not planted until the last day of June, things were different. “The 200,000 rate still wasn’t the best, but for the first time, 120,000 fell short in all row spacings,” Ferrie says. “In 2008, the 120,000 population got hurt worse in 20" and 30" spacings than in narrower rows.
“That was because of the June 30 planting date. The indeterminate soybean varieties went into the reproductive stages too quickly, and we got short plants. The lesson is that if you are planting late, you have to kick up the population. After all, you don’t double-crop soybeans at 120,000 plants per acre.”
Plant beans like corn
Plant soybeans 1" to 1½" deep. Try to plant at the correct time—when soil temperatures are above 55°F in the Corn Belt or by the calendar if you farm in the South. “If you stick beans into cold, wet soil, you probably will be replanting,” Ferrie says.
Set your planter to do a good job of singulating because you’ll likely get a more uniform pod load, which is important to yield.
If you do have to plant in tough conditions and get a less than ideal stand, don’t give up on the crop—soybeans have a remarkable ability to compensate. “Because soybeans set their yield later in their development, a tough start for beans doesn’t carry the yield penalty that it does for corn,” Ferrie points out.
Planter box fungicides
Know the type and amount of disease pressure you face in each field. “If a field has a history of water molds, such as Phytophthora and Pythium, treat the seed with a fungicide,” Ferrie says.
If a field hasn’t grown soybeans for a few years, inoculate the seed with rhizobium bacteria. Ferrie’s studies have shown that inoculating does not always increase yield. In some situations where water runs across a field, the soil may get reinoculated automatically. But if an inoculant is needed, the payoff can be great. “An inoculant is too cheap to leave out,” Ferrie says.
Stay ahead of pests
Because pest management is such a critical part of high soybean yield, designate a pest boss on your staff or hire a consultant to scout fields.
You or your pest boss must know the critical stages in soybean and pest development and the economic thresholds for treatment. Stay on top of diseases and manage them with fungicide application, rotation and varieties.
Editor’s Note: Look for the Late Spring issue of Farm Journal, where you’ll find Ferrie’s 15 tips to help you navigate the 2011 soybean growing season. The issue will be in your mailbox the first week of May.