Evaluating how operator experience level affects efficieny gains for precision agricultural tools

Authors: Kharel, Tulsi; Ashworth, Amanda; Owens, Phillip

Submitted to: Agricultural & Environmental Letters
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 7/5/2022
Publication Date: 8/15/2022
Citation: Kharel, T.P., Ashworth, A.J., Owens, P.R. 2022. Evaluating how operator experience level affects efficieny gains for precision agricultural tools. Agricultural & Environmental Letters. https://doi.org/10.1002/ael2.20085.
DOI: https://doi.org/10.1002/ael2.20085

Interpretive Summary: Tractor guidance (TG) system help to navigate during field operation and improve environmental gains by reducing overlap and gaps. Environmental gains usually compared with non-TG system although experience level of operator can impact significantly on these calculations. Studies evaluating how tractor operator experience for non-guidance comparisons impact gains are nonexistent. Scientists from USDA-ARS,Crop Production Systems Research Unit, Stoneville, MS; Poultry Production and Product Safety Research Unit, Fayetteville, AR; and Dale Bumpers Small Farms Research Center, Booneville, AR evaluated spatial relationships of overlaps and gaps with 3 operator experience level (0-1; 2-3; 6+ years) without TG system during fertilizer and herbicide applications. These overlap and gap by 3 operators were then compared with the overlap and gap while operating tractor with TG system for the same field operation. Six pasture field from Dale Bumpers Small Farms Research Center, Booneville, AR were used for this study during 2018 and 2019. Results showed that operators with 6+ years of experience reduced overlap 7.7% and 20.6% compared to drivers with 2-3 and 0-1 years of experience, respectively. New operators (0-1and 2-3 years experience) had consistently higher overlap across all slope (<0.5, 0.5-1, 1-2, 2-5, 5-9, and 9-15%) and roughness classes (<0.1, 0.1-0.2, 0.2-0.3, 0.3-0.5, 0.5-0.7, 0.7-1 and > 1). These results illustrate operator experience level is critical to estimate TG efficiency gains and consistent drivers experience levels are needed when evaluating economic and environmental gains from TG. This information help scientists and policy makers to adjust environmental gains estimation from precision agriculture tools.

Technical Abstract: Tractor guidance (TG) improve environmental gains relative to non-precision technologies; however, studies evaluating how tractor operator experience for non-guidance comparisons impact gains are nonexistent. This study explores spatial relationships of overlaps and gaps with operator experience level (0-1; 2-3; 6+ years) during fertilizer and herbicide applications based on terrain attributes. Tractor paths recorded by global navigation satellite systems were used to create overlap polygons. Results illustrate operator experience level is critical for better efficiency gains estimation (for non-TG comparisons). Operators with 6+ years of experience reduced overlap 7.7% and 20.6% compared to operators with 2-3 and 0-1 years of experience, respectively. New operators had consistently higher overlap across all slope (<0.5, 0.5-1, 1-2, 2-5, 5-9, and 9-15%) and roughness classes (<0.1, 0.1-0.2, 0.2-0.3, 0.3-0.5, 0.5-0.7, 0.7-1 and > 1). A low interpersonal reliability value of 0.02-0.03 indicates operator experience is crucial to estimate TG efficiency gains and consistent drivers experience levels are needed when evaluating economic and environmental gains from TG.