An agricultural machine (10) provided with cultivation devices (12), which are mounted on a vertically adjustable support arm (231) or support frame of a chassis (24), said devices (12), via the support arm (231), thereof being arranged to at least assume a working depth (19) at which said devices (12) process the ground at a preselected working depth, the agricultural machine (10) being provided with a force regulation device comprising a lateral force sensor (17, 31, 32) connected to a control system (15), which in turn is connected to a hydraulic system (16), which is connected to at least one lifting device (25), for instance a hydraulic cylinder, which is arranged to regulate the working depth of the cultivation device (12) depending on a control signal from the lateral force sensor (17, 31, 32), and a method and a force regulation device for such a one.
