The Effect of Boom Leveling on Spray Dispersion

Automatic boom height systems reduce the variability of agricultural sprayer boom height. When a boom is not at its target height, this can lead to uneven spray dispersion from the nozzles. Boom heights and sprayer position were previously measured in time for three commercially-available boom leveling systems for three test runs for at least three speeds over each of a mild, medium and rough terrain course. A computational model was created to use measured spray dispersion from a nozzle, measured boom heights in time, and measured sprayer position in time to calculate a spray coverage map. The model was used to calculate the spray dispersion performance of three automatic boom height control systems: John Deere BoomTrac Pro^TM (System A), Raven AutoBoom XRT® (System B), and Norac UC5^TM Passive Roll^TM (System C) for three runs at one speed (26 km/h, 16 mi/h) on a medium terrain course. Spray dispersion error was calculated for the coverage map relative to the spray dispersion of a level boom for the same run. The model showed that the improved boom leveling performance of System B led to improved spray consistency. System B had significantly more consistent spray dispersion than System A on the R4045 and more consistent (but not significantly) spray dispersion than System C on the RoGator.