What’s Your Seed Monitor Saying?
Planter seed monitors have come a long way from the old Dickey-John “flashers” that flickered a small light bulb every time a seed passed a photo-electric “eye” when falling through the seed tube. If a light bulb went dark, the planter’s operator knew that row had stopped planting.
The latest generation of seed monitors informs operators of singulation, skips, doubles, seed spacing, ride quality, downforce and other variables. Understanding what all those numbers on the screen mean is critical to optimizing planter performance.
Singulation. The simple definition of 100% singulation is, “One seed dropped at every spot you want a seed to drop,” explains Bryce Baker, integrated marketing manager with Precision Planting. Skips and multiples reduce singulation. If a planter plants 3% skips and 2% multiples, the result is 95% singulation.
“Singulation depends on the type of seed meter and how well it’s adjusted,” Baker says. “If [Precision Planting] vSets singulate below 98% to 99%, something is wrong. Mechanical finger pickup meters, depending on seed size, vary from 94% to 99%. Properly adjusted vacuum meters can run at 98% to 99% singulation.”
Seed Spacing. Seed spacing tracks how seeds are spaced in the furrow. Seeds perfectly singulated by the seed meter can be misspaced in the furrow due to ricocheting inside the seed tube or other delivery issues.
Seed monitor manufacturers calculate seed spacing on the go a couple different ways. John Deere seed monitors display Coefficient of Variation. The lower the value, the more accurate the seed spacing, but John Deere recommends keeping it below 0.17.
Precision Planting seed monitors calculate a Seed Release Index, which Baker recommends maintaining between 10 and 15 on 20/20 monitors.
Ride Quality. “People confuse ride quality with downforce,” Baker says. “Ride quality is how much the row unit is moving up and down through the field. Downforce is how much weight the gauge wheels are pressing against the soil. You can smooth ride quality by increasing downforce, but that can create excess compaction that inhibits seedling root development. The better ways to improve ride quality are to slow down the planter, rework the seedbed so it’s smoother or make sure the row cleaners are getting all the clods and rootballs out of the path of the row unit.”
Downforce. Downforce is the total of the inherent weight of a planter row unit combined with additional weight to provide adequate penetration of the disk openers and the desired firming and formation of seed furrows.
In soft soils, the weight of the planter unit alone might be sufficient. In hard soils, it might take several hundred pounds of additional weight for disk openers to penetrate.
With spring-adjusted downforce systems, operators preselect a spring-load to match average soil conditions in a field. Operator-adjustable pneumatic downforce systems allow increases or decreases in downforce, often from the cab. Automatic downforce systems sense and vary the amount of downforce added to the basic weight of the row unit on the go to match changing soil conditions via small hydraulic or pneumatic cylinders on row units.
“Active downforce is like cruise control on a car,” explains Brian Boelens, product specialist, John Deere Seeding Group. “The downforce system increases or decreases pressure to maintain a predetermined downforce under the gauge wheels.”
