An agricultural system comprising: an agricultural baler, comprising a rotary input shaft connected by way of a baler driveline to a rotatable flywheel, the driveline including one or more clutches (49, 54) for controllably transferring rotary drive between the input shaft and the flywheel; and a control unit that is configured to, as part of a start-up procedure of the agricultural baler when power is initially transferred from an agricultural work vehicle to the input shaft: receive input-power-data indicative of a drive power available at the rotary input shaft; and determine a clutch-control-signal for controlling an amount of torque transferred from the input shaft to the flywheel via the one or more clutches, on the basis of the input-power-data, wherein the one or more clutches (49, 54) are friction clutches and the clutch-control-signal is applicable to set a clutch-pressure applied to engage friction surfaces of the one or more clutches (49, 54), and wherein: the input-power-data comprises measured-input-power-data that represents measurements of one or more operating parameters of the agricultural system or the agricultural work vehicle, and characterised in that the control unit is configured to: determine an error-factor that is an indicator that one or more of the measurements has dropped below an expected value, and determine the clutch-control-signal for decreasing a rate at which torque is transferred to the flywheel via the one or more clutches based on the error-factor. an agricultural baler, comprising a rotary input shaft connected by way of a baler driveline to a rotatable flywheel, the driveline including one or more clutches (49, 54) for controllably transferring rotary drive between the input shaft and the flywheel; and a control unit that is configured to, as part of a start-up procedure of the agricultural baler when power is initially transferred from an agricultural work vehicle to the input shaft: receive input-power-data indicative of a drive power available at the rotary input shaft; and determine a clutch-control-signal for controlling an amount of torque transferred from the input shaft to the flywheel via the one or more clutches, on the basis of the input-power-data, receive input-power-data indicative of a drive power available at the rotary input shaft; and determine a clutch-control-signal for controlling an amount of torque transferred from the input shaft to the flywheel via the one or more clutches, on the basis of the input-power-data, wherein the one or more clutches (49, 54) are friction clutches and the clutch-control-signal is applicable to set a clutch-pressure applied to engage friction surfaces of the one or more clutches (49, 54), and wherein: the input-power-data comprises measured-input-power-data that represents measurements of one or more operating parameters of the agricultural system or the agricultural work vehicle, and characterised in that the control unit is configured to: determine an error-factor that is an indicator that one or more of the measurements has dropped below an expected value, and determine the clutch-control-signal for decreasing a rate at which torque is transferred to the flywheel via the one or more clutches based on the error-factor. determine an error-factor that is an indicator that one or more of the measurements has dropped below an expected value, and determine the clutch-control-signal for decreasing a rate at which torque is transferred to the flywheel via the one or more clutches based on the error-factor.