PROBLEM TO BE SOLVED: To provide a work vehicle capable of performing a work by adjusting a headland width from a levee edge to a proper width, regardless of height of steering technique of an operator, when performing a work, while reciprocating in a field by a traveling machine body.SOLUTION: An implement lowering start area is set based on a position at a turning start time of a traveling machine body 2 to be performed on a field end, and the position of the traveling machine body 2 is calculated based on a steering operation by a steering part, on a travel distance by a front wheel 5 and a travel part 6, and on a curvature radius r of the traveling machine body 2 calculated by execution existence of front-wheel speed increase control or automatic brake control of the travel part 6, and lowering of the implement is started, when reaching the implement lowering start area in the state where turning of the traveling machine body 2 is finished.SELECTED DRAWING: Figure 19【課題】圃場を走行機体で往復しながら作業を行う際に、オペレータの操縦技術の高さによらず、畦際からの枕地幅を適切な幅に揃えて作業を行うことができる作業車輌を提供する。【解決手段】圃場端で行われる走行機体2の旋回開始時の位置を基準に作業機下降開始領域を設定し、操向部による操向操作、前輪5及び走行部6による走行距離及び前輪増速制御又は走行部6の自動制動制御の実行有無により算出される走行機体2の曲率半径rに基づいて走行機体2の位置を算出し、走行機体2が旋回を完了した状態で作業機下降開始領域に達すると、作業機の下降を開始する。【選択図】図19
