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In order to solve the fertilizer layered problem caused by the different density of mixed pellet fertilizer in Heilongjiang province, a four-element variable rate fertilization control system was developed based on 2BJM fertilizer machinery. According to the four different speeds of fertilizer feed shafts，the control system could work on either setting value or fertilizer maps condition by electro-hydraulic proportional control technology. It also integrated a submeter-scale differential GNSS device. The system could calculate the target speed of the hydraulic motor in real time according to the target value, and send the speed instruction to the fertilizer controller synchronously. Once the system received motor speed signal, the opening of proportional valve could be adjusted automatically. And then the four-element synchronization variable fertilization (nitrogen, phosphorus, potassium, and micronutrient fertilizer) could be carried out. The results of field experiment showed that the errors of the fertilizer tubes were less than 3.0%, and the variation coefficient was less than 0.05. Compared with the traditional machinery area, though the maize growth indexes of height, weight, aboveground biomass and SPAD did not increase significantly, all of these variable coefficients reduced obviously. The nitrogen and phosphorus fertilization contents reduced from 217kg/hm2, 232kg/hm2 to 150kg/hm2, 200kg/hm2 respectively. The potassium fertilization content increased from 79kg/hm2 to 108kg/hm2. The final yield data was 12200kg/hm2, increasing by 1.81%. All the experiments showed that the four-element variable rate fertilization control system could solve the fertilizer layered problem and satisfy the need in practice.