Submitted to: Agricultural & Environmental Letters
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 8/17/2020
Publication Date: 9/8/2020
Citation: Kharel, T.P., Owens, P.R., Ashworth, A.J. 2020. Tractor path overlap is influenced by field shape and terrain attributes. Agricultural & Environmental Letters. 5:e20027. https://doi.org/10.1002/ael2.20027.
Interpretive Summary: By following the predefined field path and using Global Navigation Satellite Systems (GNSS), Tractor guidance (TG) system reduce overlap and gap during field operation and improve the spatial coverage efficiency. Small farm fields with diverse terrain attributes might affect spatial coverage efficiency. Field study was conducted in small farm fields (Dale Bumpers Small Farms Research Center, Booneville, AR) to explore relationship between TG system and overlap associated with field shape, size and terrain attributes. Six field for fertilizer application and four fields for chemical spray application were evaluated in 2018 with and without TG system. Overall (without separating TG-On and TG-Off), overlap increased with complex field irregularities (higher shape index), shorter pass lengths (requiring more turns), increasing within field slope and terrain roughness index. Independent of slope, overlap area decreased from 41 m**2 to 17 m**2 per 50 x 50 m grid cell by using TG system (TG-On). These results are important to consider for future design of machinery, sensors and components that goes with TG system to automate field operation.
Technical Abstract: Tractor overlaps and gaps during field operations reduces production efficiencies. Field studies on tractor overlaps and its relationship with field and terrain attributes are limited. The objective of this study is to explore the relationship between field shape index, terrain attributes and tractor guidance (TG) system on tractor path overlap during field operations. Six fields with varying shapes and sizes were used for fertilizer and herbicide application with and without TG system. Overlap polygon and terrain attributes were overlaid and sampled for each 50 x 50m grid cell. Results showed overlap increased with increasing field irregularities, shorter pass lengths, and higher slope and higher roughness index value. Averaged across slope class, overlap area decreased from 41 m**2 to 17 m**2 per grid cell by using TG system. These results are important to consider for future design of machinery, sensors and components that goes with TG system to automate field operation.