Objective  In order to solve the problems that the fertilization mode of banana orchard in South China does not meet the agronomic requirements, the fertilization efficiency and the automation level of fertilization machinery are low, a precision fertilization device with automatic target for banana stalk was designed.

Method  According to the fertilization process and agronomic requirement of banana orchard, the control principle of the device and the installation location of key components were determined, and the time lag model related to fertilization was established. Through the innovative design of the fluted fertilizer distributer, the mathematical models of single cycle and periodic fertilization amount were established, and the motion characteristics of fertilizer were verified by EDEM simulation. In order to meet the fertilizer requirements of banana at different growth stages, the response surface methodology was used to optimize the parameters of fertilizer discharging mechanism. The variation coefficient of fertilization amount, variation coefficient of fertilization length and offset distance from the center of banana stalk were used as the evaluation indexes. Field test was performed using the combination of optimization parameters to further verify the performance of the precision fertilization device.

Result  The optimal parameters were determined as follows: The rotational speed of fertilizer-distributer shaft was 85 r/min, and the initial length of inner core of fluted roller was 6 mm. The field test showed that the variation coefficients of fertilization amount and fertilization length were both below 4%, and the highest average offset distance from the center of banana stalk was 7.4 cm, meeting the agronomic requirements.

Conclusion  The working performance of the device can meet the requirements of banana fertilization. This study can provide references for the design of the precision fertilization device for banana orchard.