Handling several hundred seed bags in a day made John Greenough, Lake Crystal, MN, feel more like a dockworker than a farmer. “Bags were a real pain,” he says. “By the end of the day, I'd be exhausted.”

Not anymore. Greenough built a pneumatic seed delivery system in 1998 that took the drudgery out of filling planter boxes. Freedom from bag-fill chores provided more energy to work longer hours and to make management decisions, such as marketing grain, while operating a planter in the field.

“It's a lot less fatiguing this way,” he says. “I stay much more alert, fresh and focused.”

Besides helping to relieve physical and mental fatigue, the switch to pneumatic delivery more than doubled Greenough's planter-box loading speed. “This really helped to kill downtime,” he says. “I can fill a 16-row planter in about six minutes now, when bags would have taken between 15 and 20 minutes and required another person, typically a teenager, to help.”

Planter-box fill time now totals a little more than an hour per day for soybeans, says Greenough. In comparison, bag-filling once consumed more than three hours per day, he says. “This gives me two more hours to plant soybeans — or 60 more acres per day.”

Those two extra hours boost the planter's efficiency about 13%, calculates Bill Lazarus, a University of Minnesota Extension economist. “The increased efficiency reduces planting-time costs by about 25¢/acre,” he says. “Fewer labor requirements might add another 76¢/acre in savings — if it eliminates the need for an extra worker to help with the bags.”

Yet, the greatest cost savings that might result from a speedier fill time could simply be in avoiding possible planting delays and potentially reduced yields, adds Lazarus. “It's hard to pin down the economics of bulk seed delivery systems,” he says. “What is an extra two hours of planting time worth in a day? The opportunity cost of that might be a lot higher than the wage rates.”

Bulk seed delivery systems are becoming increasingly more common as growers try to farm more acres and stay timely in the process, says Mark Hanna, Iowa State University Extension ag engineer. “Sometimes the limiting factor in planter efficiency comes down to how fast you can fill,” he says.

For farmers who don't have the time or expertise to build their own bulk-delivery system, many commercial options are available, says Hanna. “The most common setup would be an auger or a pneumatic device that fits onto the bottom of a gravity-flow wagon. However, pneumatic handling tends to be gentler on seed, and it's also self-cleaning, which is a plus for maintaining identity preservation when changing varieties.”

Vern Hofman, North Dakota State University Extension ag engineer, agrees. “Some pneumatic conveyors can damage seed, so you have to look at them closely,” he says. “In general, pneumatic conveyors handle soybeans more gently than augers, but brush augers and plastic augers can handle soybeans safely, too. Typically, pneumatic conveyors have more speed, though.”

In Greenough's eyes, the main drawback to an auger system is the need to move the wagon two or three times in order to load a 16-row planter. He agrees that an air system results in less damage to soybean seed and is quicker than an auger.

“I've had this (pneumatic system) for six years now,” he says, “and I've had no problems with seed damage.”

To build this bulk-fill system, Greenough modified a Christianson SeedVac bulk seed conveyor that was originally intended for use with a gravity box. “I coupled the blower and airlock within 10 in. of each other,” he says. “Along with the engine, I've combined them all into one little unit on wheels.”

The modified SeedVac rolls along a track that is secured to a 12,000-lb. tandem trailer, which Greenough hauls behind his pickup. Home-fabricated steel frames on the trailer support three Probox bulk-seed boxes. The SeedVac rolls underneath the seed boxes, where it can be used to unload one of three different seed varieties.

“If I had more than the three boxes on the trailer, it would be too heavy to pull with my pickup,” he explains. “The tandem trailer has brakes on it, so I can tow it safely down the road.”

A potential alternative was to string together six to eight Proboxes on a semi-trailer. However, that arrangement would have necessitated easy road access to fields or field areas where the planter could meet with a semi parked alongside the road.

“Most of my fields and roads don't mate up well,” he says, “so that wasn't an option for me.”

Seed spills while unloading were another potential problem that this system avoids. “A local manufacturing company made a little hopper on top of the airlock to mate with the bottom of the Proboxes,” explains Greenough. “This helps to prevent spillage when emptying.”

To build a similar bulk-seed delivery system today would likely cost about $9,100, estimates Greenough. That cost would include about $4,700 for the SeedVac, $2,800 for the tandem trailer and $1,600 for a manufacturer to fabricate the steel stands and other miscellaneous items. For example, a longer hose was added to the SeedVac so that it could easily extend across the whole length of a 16-row planter.

The cost to build this system was about $5,000 six years ago, says Greenough, partly because he already had a trailer, and he fabricated his own steel frames for about $700. The SeedVac cost about $800 less then than it does now, he adds.

Future modifications to the system are unlikely, says Greenough. “Even if I decide to upgrade to a planter with a central seed unit, this would still work,” he says. “Then I could avoid climbing up those steep steps to unload bags.”

Although Greenough buys almost all his corn and soybean seed in bulk now, he still purchases about 20 bags of each to finish planting. “You need to do some planning when purchasing seed,” he says. “I usually have some bags left over at the end of the season that I can return, but once they're opened, you can't return the bulk boxes.”

Opening a bulk seed box in order to plant only a portion of the seed would be an unwelcome outcome, says Greenough. “I wouldn't want to crack open a 50-unit Probox at $160 per-bag equivalent and find out after planting that I'd used only 16 units,” he says. “No one wants to get stuck with a lot of expensive seed that they don't plant.”