A material decelerating device is connected in series with a distribution tube in proximity to a material outlet in an agricultural air distribution system for decelerating conveying air which placing material into a furrow in the ground. The material decelerating includes an inlet tube connected to the distribution tube to receive material and conveying air therefrom. The inlet tube is connected at an intermediate location on a center tube of the device which exhausts the air upwardly to an exhaust opening and deposits the material downwardly through an outlet opening. A cap adjustably spans the exhaust opening to vary the amount of air exhausted. The inlet tube is inclined downwardly in alignment with a helical recessed channel within the center tube to guide material to the outlet.
