Equipment Floats Over Fields

January 28, 2010 07:17 AM

Downtime is not something Bruce Bishop tolerates. "I work very hard to keep my machinery as simple as possible so there are fewer things to slow me down,” he says.

The McComb, Ohio, farmer's quest for minimal breakdowns and reduced weight inspired him to build two fully mounted 24-row, 30" machines—a corn planter and fertilizer applicator—that float over the field, with nary a lift-assist wheel or carrying wheel for support.

The machines won first prize in the planter and chemical handling categories of Farm Journal's "I Built the Best Contest.” The victories mark Bishop's seventh and eighth category wins.

"Tires are one more thing to maintain, and if you have to replace one it slows you down,” Bishop says. "They make a machine heavier, and they leave tracks.” Eliminating the weight of wheels improves fuel efficiency, he adds, and a lighter machine may let you get back into fields sooner following a rain. 

Bishop's corn planter weighs only 11,900 lb. "Compaction-wise, it's as if you're driving the tractor across the field with nothing behind it,” he says.

Mounting the planter units (which make up half the weight of the planter) as close as possible to the tractor eliminated the need for lift-assist or carrying wheels. To facilitate close mounting, Bishop placed the two bars of the planter's double frame 4' apart instead of the usual 1'. "That let me mount the planter units on the front bar,” he says.

Putting the toolbars 4' apart reduced stress on the second bar. So Bishop was able to use lighter ¼"-wall 4"x4" steel tubing, rather than 3⁄8"-wall 7"x7" tubing, for the second toolbar. He used ¼"-wall 7"x7" tubing, rather than 3⁄8"-wall, for the outer 25' on each wing of the front toolbar.
No wheels.
With the weight of the units close to the tractor and lighter steel in the toolbars, "the planter units can hold up the wings of the planter,” Bishop says. "So the only wheel traffic comes from the 24" tracks on my 765 Cat tractor—one set of tracks every 60'.

"Building the frame from aluminum, rather than steel, would have saved 3,000 lb.,” Bishop notes. "But it would have made construction much more complicated, and the planter would not have lasted as long.”    

In the absence of carrying wheels, a device designed by Bishop maintains constant toolbar height. It consists of a small-gauge wheel which activates a sensor that electronically raises and lowers the three-point hitch.

Bishop eliminated many feet of hose—and more weight—by using the main toolbar for a vacuum line. He plumbed 2" air-piloted valves into the toolbar. The valves shut off vacuum pressure to the seed meters. They are controlled by air switches in the cab, which let Bishop shut off three rows at a time. The system cost $1,500, much less than individual row clutches. 

The planter is equipped with a John Deere CCS air delivery system, John Deere Pro-Series XP row units with Precision Planting eSet vacuum disks in the meters and a Precision Planting 20/20 SeedSense population monitor. The seed tank holds 70 bu. of seed.

Fewer chains to maintain.
A Rawson hydraulic drive controls planting rate.

"Using only one drive motor requires only one set of drive chains for the entire planter, which reduces maintenance,” Bishop explains.

Using only one drive motor requires Bishop to disconnect the driveshaft when he folds the planter. He made a connector from hydraulic hose, with a rod inside that prevents it from twisting.

Bishop subsoils in the fall and then plants corn into a stale seedbed. He equipped the planter with Martin row cleaners but saw no need for no-till coulters. Because the wings are light, he can apply active hydraulic down pressure to push them down when no-tilling; in effect, transferring weight from the seed tank to the toolbar.

Because Bishop's corn is grown in rotation with soybeans or wheat, and because extended-diapause rootworms haven't invaded yet, he had no need for insecticide boxes.

Bishop did not add starter fertilizer attachments because on-farm tests showed starter doesn't pay in his soils. "I considered putting a 400-gal. pop-up fertilizer tank on the front of the tractor,” he says. "But with current fertilizer prices, pop-up doesn't pay in our soils, either.”

On the road.
For travel, the planter folds to a width of 15'. The wings rotate upward and then forward, using four hydraulic cylinders and hinge points. "Those are the only hydraulic cylinders on the entire planter,” Bishop points out. Minimizing the number of cylinders leaves the outside 20' of each wing free of hydraulic lines.

 When folded, no part of the planter is higher than the tractor cab. The only parts wider than the tractor are 6½' above the ground—higher than any vehicles Bishop will meet on the road. The planter stores on a stand, leaving room to park machinery underneath.

The light weight lets Bishop plant an acre of corn using only 0.18 gal. of diesel. He thinks the light weight and his tracked planting tractor helped him get corn planted on schedule despite rainy weather this past spring.
The total cost of the planter, Bishop figures, was about half that of a new 24-row planter. He spent a month building the frame and another month assembling the rest of the planter.

Light-stepping applicator. The principles of weight conservation, compaction and low maintenance equally apply to Bishop's nitrogen applicator, which mounts on a tracked 235-hp Challenger MT755 tractor. The applicator weighs 7,800 lb. when empty and 18,000 lb. when loaded.

The applicator carries a 400-gal. tank on the front of the tractor and a 1,000-gal. tank on the rear that is plumbed with 3" lines. There's also a 7-gal. freshwater tank for cleanup.

As with the planter, Bishop used a toolbar of ¼"-wall steel. The bar carries Clymer coulter injection system units. "The units come with depth spools, which I use as gauge wheels for the toolbar,” Bishop says.
The 24-row, 30" applicator folds the same way as Bishop's planter—upward and then forward, using the same arrangement of four hydraulic cylinders and four hinge points.

A Raven controller varies the rate, which Bishop backs off a bit on sand hills and lower-yielding areas next to woods. The controller lets him shut off four rows at a time to minimize overlap on point rows. The applicator's controller and 2" pump also work for a 120', three-point mounted sprayer that mounts on the same tractor. 
Running his mounted corn planter, soybean planter, sprayer and sidedress applicator in the same tracks sets up a controlled-traffic pattern that varies only when Bishop plants wheat.

Because the tramway gets compacted, Bishop applies no nitrogen behind the tractor track. Instead, he moves the adjacent injectors 5" closer to those rows and applies 50% more fertilizer through each one. He runs the sidedress applicator at 10 mph.

Just as with planting, Bishop credits his light-stepping applicator with helping him sidedress in timely fashion this past spring. "The corn was growing several inches a day and it was time to sidedress, but it was raining once a week,” he remembers. "I was able to get into fields when they were a little wetter than I could have with a conventional applicator.”

Bishop sidedresses because applying nitrogen when the corn needs it lets him use lower rates. He applies 10 gal. of 28% nitrogen solution (30 units of nitrogen) in a weed and feed herbicide treatment before planting, then adjusts his sidedress rate based on crop condition.

The closest thing to a downside with Bishop's mounted machines is that they put a lot of weight on the tractor when he lifts them to turn at the end of a field. "But I can turn in half the distance I used to need with a pull-type planter, so I only run over half as much ground,” he says.

"And I turn the planter, sprayer and applicator in exactly the same tracks, so I don't create any additional compaction when I sidedress fertilizer.” 


You can e-mail Darrell Smith at  


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