A working element is mounted on an agricultural machine having a deformable connecting structure including upper arms and lower arms. The connecting structure includes a system for adjusting the down-pressure having a movable mechanism and a reference member. The mechanism includes a lever and a resilient member that are articulated about a first axis. The mechanism allows an engaged state in which it is held against the reference member in a working position, subjecting the working element to a down-pressure, and an adjusting state in which it is movable about a lower axis with respect to the reference member. The mechanism includes a second axis about which the lever is pivotable in an intermediate state.