Abstract:Layered fertilization technology has broad prospect for its less time requirement, labor saving and high utilization efficiency. A layered fertilization device which consists of adjustable instrument, one fixed fertilization mouths and two adjustable fertilization mouths was designed. The adjustable instrument consists of removable working piece, groove ear and guiding groove. Based on the discrete element method (EDEM), simulation tests were conducted to investigate the trend of fertilizer distribution ratio for different lift angles α and working length of fertilizationpiece L. The simulation model of fertilizer and layered fertilizing device was built. The results showed that larger lift angle led more fertilizer particle flowing into the up two fertilization mouths. And increasing the working length of fertilizationpiece is helpful for obtaining more fertilizer by making more particles colliding with the tube. In order to determine the suitable working parameters of layered fertilization device, four kinds of fertilizers commonly used for maize, were selected for laboratory tests. According to relatively references, the desirable fertilizing ratio was determined as 1〖DK〗∶6〖DK〗∶3. Test results showed that these kinds of fertilizers were influenced by the lift angle of device, working length of fertilizationpiece samely, which was consistent with simulation results. When the lift angle was at 30°~40°, fertilizing proportion amplification of up mouth was 10% and middle mouth was 3%, which proved that the increase of lift angle was in favor of improving up layer fertilizing ratio. Simultaneously, working parameters of layered fertilization device were determined as α of 36° and L of 13~16mm. To explore the working performance of this device, field experiments were conducted at speed of 1.36~7.58km/h. Three types fertilizing devices, adjustable and nonadjustable layered device, common layered device, were used and soil crosssection area after fertilizing were obtained to compare the distribution of fertilizer. Results showed that the adjustable layered fertilization device could layer fertilize into three layers and middle layer gained the most, second was bottom layer, which met the corn requirement for fertilizer.