Improvement of Work Efficiency in Soil Crushing using Tractors Equipped with Automatic Steering Devices in Large Crop Field

The working time of a large tractor equipped with an automatic steering function during disc-harrow work was measured and compared with the case of manual steering （estimated value） in large crop field, Hokkaido.In automatic steering tractors, because the duplicate work space can be narrowed in disc harrow work, tillage width by disc harrow increased and the number of tractors running for field tillage reduced compared to manual steering.When turning on a headland, the automatic steering system used precise travel guidance to reduce the time required to turn.From these system performance, automatic steering reduced the working time per field in harrow work, and the cultivated area per unit time was increased by 1.1 to 1.3 times compared to manual steering.