A baler connectable to a tractor for providing round bales, comprising: - a frame supported on a wheel axle; - a chamber for receiving crops and for housing a formed bale, the chamber having a fixed, predetermined size; - a tailgate connected to the frame and movable between a closed position, for cooperating with the frame to delimit the chamber, and an open position, for discharging the formed bale; - a conveying assembly, which delimits the chamber for imparting a rotating movement to the crops contained in the chamber, and has a first portion provided in the frame and a second portion provided in the tailgate; - a cylinder-piston actuator, which includes a closing chamber and is connected to the frame and to the tailgate to move the tailgate from the open position to the closed position, upon receiving an actuating fluid in the closing chamber; - a binder, configured for binding the formed bale with a fastening element; - a control unit, configured to generate an alert signal; - a pressure sensor for detecting a control signal representative of a pressure inside the closing chamber of the cylinder-piston actuator, wherein the control unit is programmed for generating the alert signal as a function of the control signal, wherein the control unit is programmed for setting a reference pressure value based on a user selection, and for comparing the control signal to the reference pressure value, to generate the alert signal depending on the reference pressure value being exceeded by the control signal wherein the baler comprises a user interface, which can be positioned on the tractor, wherein the control unit is programmed for displaying, at the user interface, graphical data representative of the control signal and/or of the reference pressure value, wherein the alert signal is intended to inform the user that a step of forming the bale is completed or is about to be completed. - a frame supported on a wheel axle; - a chamber for receiving crops and for housing a formed bale, the chamber having a fixed, predetermined size; - a tailgate connected to the frame and movable between a closed position, for cooperating with the frame to delimit the chamber, and an open position, for discharging the formed bale; - a conveying assembly, which delimits the chamber for imparting a rotating movement to the crops contained in the chamber, and has a first portion provided in the frame and a second portion provided in the tailgate; - a cylinder-piston actuator, which includes a closing chamber and is connected to the frame and to the tailgate to move the tailgate from the open position to the closed position, upon receiving an actuating fluid in the closing chamber; - a binder, configured for binding the formed bale with a fastening element; - a control unit, configured to generate an alert signal; - a pressure sensor for detecting a control signal representative of a pressure inside the closing chamber of the cylinder-piston actuator, wherein the control unit is programmed for generating the alert signal as a function of the control signal, wherein the control unit is programmed for setting a reference pressure value based on a user selection, and for comparing the control signal to the reference pressure value, to generate the alert signal depending on the reference pressure value being exceeded by the control signal wherein the baler comprises a user interface, which can be positioned on the tractor, wherein the control unit is programmed for displaying, at the user interface, graphical data representative of the control signal and/or of the reference pressure value, wherein the alert signal is intended to inform the user that a step of forming the bale is completed or is about to be completed.