An agricultural system includes a towing frame to which a planting row unit is attached. The planting row unit is movable in a forward direction on a field having soil of varying hardness conditions, including a soft soil and a hard soil. The planting row unit includes a planting bin positioned rearwardly of the towing frame for carrying at least one of a fertilizer and seeds to be deposited into the soil. The planting row unit further includes a linkage assembly for coupling the planting bin to the towing frame, and an opener device forward of the towing frame. The opener device prepares the soil and includes an opener blade and a soil-hardness sensor. The opener blade maintains the same soil-penetration depth Z in the soft soil and the hard soil based on soil-hardness changes detected by the soil-hardness sensor.
