Biological Systems Engineering


Date of this Version



Published in Applied Engineering in Agriculture Vol. 20(5): 563−572. Copyright 2004 American Society of Agricultural Engineers. Used by permission.


Field efficiency is an important criterion for determining field capacity during field operations and, indirectly, for making important machinery management decisions. Geographic location data gathered with a yield monitor during harvest and a data logger during planting were used to provide time−motion studies of equipment and operator productivity. This study used these spatial and temporal data to quantify field performance of a combine and a planter. Seven Nebraska fields were used to compare results from soybean and corn production systems. Fields that were relatively flat with straight rows were contrasted with contoured fields with slopes of 3% to 5%. Two unique traffic patterns in fields with a center pivot were compared. Four traffic pattern indices were developed and averaged across each field to indicate the steering behavior (or adjustments) made during field operations. Geo−referenced data were used to predict field efficiency for various traffic patterns. Of the four indices compared, the average steering angle (θ) and its standard deviation had the strongest association with field efficiency with Pearson correlation coefficients of −0.654 and −0.664, respectively. The average steering angle for contoured traffic patterns were two to four times in magnitude that of straight− and gently curved−row traffic patterns. The steering angle index gave valuable information about field operating conditions but differences in data recording methods and operational characteristics imposed limitations on statistically appropriate comparison analyses.