Precision agriculture is maturing quickly as a host of electronic systems keep implements on track and running at the proper depth and moving across fields in repeatable passes that vary less than an inch from one another.
Tillage equipment is beginning to see systems aimed at improving the seedbed and mapping problem areas on the go, in a move to smarten up “dumb iron” in a way never before seen. Case IH’s Soil Command system unveiled earlier this year and John Deere’s TruSet on-the-go implement control system, which has been in the field for several years, are examples of where precision agriculture is heading.
In fact, Scott Shearer, professor and chair of Ohio State University’s Department of Food, Agricultural and Biological Engineering, says precision agriculture applications for tillage equipment is on the cusp of rapid expansion and predicts significant advances in its use on ground-engaging equipment in the next several years.
Application technology, however, seems to be where many advancements have settled with continual refinement in swath control and boom-height control — both areas that improve application efficiency, crop-protectant efficacy and environmental stewardship.
“Section Control” of 15 years ago that allowed 3-7 sections of the spray boom to be turned on or off from the cab has evolved into individual nozzle control with instantaneous-operating pulse width modulated nozzles. The new systems significantly improve sprayer accuracy through GPS-guided controllers that are programmed to turn nozzles on or off depending upon sprayer speed or field condition.
By adjusting for relative speed of nozzles over the ground or canopy, extremely accurate turn compensation is available to avoid over application on the inside of turns and under application at the boom’s tips.
Tim Heins, Raven Industries, says one study using Raven’s Hawkeye PWM individual nozzle control system showed savings of 3-acres worth of chemicals on an 80-acre field when PMW nozzle technology was used in place of conventional swath control.
Those savings came from variable rate application linked to overall sprayer speed on straight runs in the field and nozzle speed over the canopy in turns.
Automatic boom height control, too, has been a target of precision agriculture engineers. Today’s systems maintain sprayer boom height over the ground, the actual crop canopy or a computer-generated “virtual canopy” as modern controllers such as those from Topcon Agriculture seek to maintain the proper nozzle height to preserve the most effective spray pattern — day or night.
In Europe, Amazone has introduced a pull-behind sprayer with spring and hydraulic dampening systems to reduce boom whip and bounce, thus eliminating over- and under-application due to unwanted boom movements.
Late last year Amazone introduced its AmaSpot weed-detecting system which uses machine vision to reduce herbicide costs for no-tillers spraying in fallow ground or on bare soil by applying crop-protectants only where individual weeds or areas of high weed activity are sensed. The company says the system is effective, with sub-inch accuracy, day or night, at speeds up to 12 mph.
In Nebraska, precision ag engineer Joe Luck is developing a variable-orifice nozzle controlled by electrically operated linear actuators, which will give growers nozzles capable of spanning four droplet sizes.
“With this technology, we could further modify the sprayer’s flow rate to provide even more precise control of droplet sizes on-the-go,” Luck explains. “We plan to have a working prototype available for wind tunnel and field tests in about 18 months.”
During his own graduate work at Ohio State University, Luck developed a direct-injection system similar to modern EPA-approved 2-stroke outboard motor fuel systems, or those found among the most clean-burning diesel applications, to introduce crop protectants into a mixing chamber with the carrier at 1,000 psi just ahead of the sprayer nozzles.
“We reduced on-and-off lag time with our nozzles by using PWM solenoid valves,” he explains. “This system helped us keep the chemical and the carrier separate — good for cleanout and cross-contamination prevention — and we were able to achieve good product dilution at the same time.”
Other signs of maturation in precision agriculture on application equipment include the integration of in-cab controllers that give operators a visual cue as to on-the-go sprayer operation.
A good example is Ag Leader’s DirectCommand liquid system, which provides at-a-glance tip performance, droplet size monitoring and on-the-go pressure rate measurements.
In addition, the system also generates automated records of chemical applications, applied rates, as-applied maps, weather conditions and more directly from the display.
