THE RESEARCH PLAYBOOK
At Veterans Park , a Toro Workman 200 Spray System ( 18-foot boom ) with Ninja GPS Spray Control , a Smart7 GNSS receiver , and Polaris autosteer was used ( Figure 1 ). At Southwood Athletic Park , a John Deere ProGator with an Above Par Tech sprayer ( 20-foot boom ), a GPS 7500 GNSS receiver , and SteadySteer autosteer was employed ( Figure 2 ). Both sprayers featured correctional services , individual nozzle control , automatic rate control , on-screen guidance and adjustable spray parameters .
One experienced operator with nearly 20 years of sports field spraying experience , including three years with GNSS and autosteer , was assigned to each location . Four inexperienced college students — new to both spraying and the technology — were assigned to specific locations and field types , ensuring their inexperience remained consistent . Each student received a 30-minute training session on sprayer controls before their first application .
Field boundaries were georeferenced once using the sprayers ’ GNSS receivers to establish consistent target areas for all fields , aiding in GNSS and GNSS + autosteer treatments . The average target areas were 74,899 ft ² for Veterans Park ’ s softball fields and 37,631 ft ² for Southwood Athletic Park ’ s baseball fields , with soccer fields averaging 88,244 ft ² and 33,644 ft ² at Veterans and Southwood , respectively . Water was used for treatments at 65 gallons per acre , and designated level areas were marked for filling and draining the sprayers . Sprayers were filled to 150 gallons for Veterans and 80 gallons for Southwood , based on field size .
At Veterans Park , the dual-nozzle sprayer used FastCap 422FC11004 and 422FC11006 nozzles , while Southwood
Figure 2 . An inexperienced operator making an application using the GNSS sprayer at Southwood Athletic Park
Athletic Park used a single-nozzle sprayer with COMBO- JET SR110-08 nozzles . The accuracy of the water volume in the tank was confirmed by measuring in five-gallon increments and validating the flow meters against the computer outputs before the initial treatments .
Treatment applications occurred from December 2022 to May 2023 at Veterans Park and from June to July 2023 at Southwood Athletic Park , depending on field availability and weather . To prevent tire tracks from being used as a guide , sufficient time was allowed between applications for the tracks to disappear . Sprayers operated at 2.5 mph , controlled by a speed regulator .
For manual treatments , monitors were covered , and foam markers guided operators , who manually controlled the booms . GNSS treatments used foam markers and onscreen maps , while GNSS + autosteer treatments added autosteer . Both GNSS treatments featured individual nozzle control , with a 100 % overlap setting . After each treatment , remaining water was drained via valve and hand pump . Spray data were stored in the sprayers ’ computers and later exported for analysis .
DATA PROCESSING AND ANALYSIS The study measured target area misses , overlaps and overspray . Data downloaded from the sprayer computers included field boundaries , sprayer paths and coverage . The percentage of target area missed and overlapped was calculated by comparing the spray coverage to the field boundaries , excluding non-target areas . Missed areas were identified where no spray was applied , and overlaps where sections were sprayed more than once . These percentages were then calculated as a proportion of the total target area . Overspray was calculated by subtracting the amount of water left in the tank after spraying from the initial volume . The percentage of overspray was determined by dividing the actual volume applied by the intended volume for the target area , then multiplying by 100 . Any values over 100 % indicated overspray .
The percent total volume saved between treatments was determined by subtracting the lower percentage from the higher one , dividing the absolute value of this difference by the higher percentage , and then multiplying by 100 to convert it into a percentage . For example , if treatment A used 105 % of the intended volume ( i . e ., 5 % overspray ) and treatment B used 110 % of the intended volume ( i . e ., 10 % overspray ), then the total volume savings by using treatment A is 4.6 %, calculated as ((| 105-110 |)/ 110 )* 100 = 4.6 %. sportsfieldmanagementonline . com November 2024 | SportsField Management
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