A gauge wheel load sensor for an agricultural planter having a row unit that includes a pivotably mounted gauge wheel and a down pressure controller for controlling the down pressure on at least a portion of the row unit. The load sensor includes a mechanical element mounted for movement in response to the downward force applied to the row unit; a fluid-containing device containing a movable element coupled to the mechanical element for changing the fluid pressure in response to the movement of the mechanical element; and a transducer coupled to the fluid-containing device for producing an output signal in response to changes in the fluid pressure. An energy storage device, such as an accumulator, may be coupled to the fluid-containing device for receiving a limited amount of fluid in response to changes in the fluid pressure to damp pressure spikes in the output signal of the transducer.