Abstract:The outer grooved wheel fertilizer apparatus commonly used in rape direct seeding machine, has problems of inadequate fertilizer stability and low consistency coefficient of each row. Therefore, a quad-screw double-row fertilizer discharging device was designed. The movement of fertilizer particles in the device was analyzed. The range of the screw pitch and the speed of screw rotation were studied. The discharging device was best performed when the number of discharging screw was four and the screw pitch was 24mm, which was analyzed by EDEM simulations. The bench tests studied the discharging affection for the speed of screw rotation and adaptability with different fertilizers. The results showed that the discharging rate was increased while the speed of screw rotation was added from 20r/min to 60r/min;the discharging rate of single-row was raised from 461.19g/min to 1328.57g/min as well. The coefficient of variation (CV) of discharging rate was dropped with the increment of the screw rotation speed. When the screw rotation speed was over 30r/min, the CV of discharging rate was less than 6.5%. The CV of the total discharge rate and the CV between two single-row were both less than 2.2%. Also the results showed that the quad-screw double-row fertilizer discharging device was compatible with different types of fertilizers commonly used for rapeseed direct-seeding in Hubei Province. The CV of three kinds of fertilizers were all in keeping with the fertilization standards, and the CV of the total discharge rate and the CV between two single-row was less than 3.3%. Field test results showed that when the actual discharging amount was set as 28.87kg, the error of the discharging device between the actual discharging amount and the theoretical amount was 2.33%, the CV of discharging was 6.73%, and the CV between two single-row were both 1.98%. The results showed that the quad-screw double-row fertilizer discharging device met the demand of fertilization for rapeseed direct-seeding. The research result may provide a reference for the structural improvement of fertilizer discharging device for rapeseed direct-seeding.