University of Arkansas, Fayetteville Division of Agriculture


Soybeans must be harvested during a limited time period using expensive combines and associated equipment. Maximizing combine field efficiency, the ratio of the actual harvesting capacity to theoretical harvesting capacity, is an important objective of machinery managers. Spatial and temporal yield data from a 2012 CaseIH 8120 Axial-Flow combine equipped with a 9 meter MacDon D-65 Draper header and the Case-IH Advanced Farming System (AFS) yield monitoring system were used to examine field efficiency when harvesting soybean in three Arkansas Delta irrigated soybean fields during the 2015 season. Time efficiencies (TE) in the three fields ranged from 72.9% to 85.8% (mean = 80.9%, standard deviation (SD) = 9.6%); width efficiencies (WE) ranged from 96.7% to 98.8% (mean = 97.6%, SD = 1.6%); and overall field efficiencies (FE) ranged from 70.4% to 84.8% (mean = 79.0%, SD = 9.7%). Contrary to expectations, neither row length nor unadjusted yield was significantly correlated (P < 0.05) with time efficiency, width efficiency, or field efficiency. Time efficiency explained 90.5% (sr2 = 0.905) of the unique variance in field efficiency, while WE explained only 1.6% (sr2 = 0.016) of the variance in FE when controlling for the effects of TE. Results indicated that the use of geo-referenced field and performance data can be helpful in evaluating combine performance and efficiency.