A disc opener unit for an agricultural implement has a down pressure adjustment device that automatically adjusts the amount of down pressure applied on a furrowing disc based on strain measurements taken by a strain gauge or load cell. The strain gauge, which may be mounted to an arm that is used to set the position of a depth setting gauge wheel, provides feedback to a processor that in turn controls the amount of hydraulic fluid in a hydraulic cylinder to adjust the down force applied on the disc. The amount of down pressure is therefore adjusted in substantially real-time in response to changes in field conditions, which improves furrow depth consistency and reduces wear on the gauge wheel and its components.