Air bags to control downforce on planter units were a tremendous step forward in technology. At least that's how Pete Illingworth looks at it. Illingworth installed air bags on the John Deere planter he uses a couple of years ago. He's a mechanic and also does planting at the Purdue University Throckmorton Ag Center near Romney.
"The single springs that came with the John Deere planter would break more often than I liked," he says. There is no question that the mechanical coiled springs represented old technology, used for some time to control and put more down force on planter units.
The John Deere system with springs typically has four settings. Basically they are notches with a metal handle. You set the notch on each row unit where you think it should be.
Many experts still advise clients running planters with springs, at least of the John Deere variety, to set them in the third notch. Then check behind the planter to see if you are getting the depth you want, without too much pressure on the seed trench. Too much pressure exerted by the springs can result in sidewall compaction and make it difficult for young roots to get out of the planting trench and begin growing.
Time will tell if air bags were the technology of the future, or a bridge between springs and hydraulic technology for controlling down force.
Precision Planting has introduced a hydraulic unit that allows each row to be controlled for down force independently of the other rows. It costs more than the air system. It also requires a tractor with enough hydraulic power to handle it in the field, and still supply adequate hydraulic capacity to other functions, which may include the air system on vacuum planters.
Time will tell which technology is most economical and yet most practical.