AUTHOR=Zhao Liang , Zhou Hongping , Xu Linyun , Yuan Weidong , Shi Minghong , Zhang Jian , Xue Zhong 

TITLE=Parameter optimization of the spiral fertiliser discharger for mango orchards based on the discrete element method and genetic algorithm

JOURNAL=Frontiers in Plant Science

VOLUME=Volume 14 - 2023

YEAR=2023

URL=https://www.frontiersin.org/journals/plant-science/articles/10.3389/fpls.2023.1169091

DOI=10.3389/fpls.2023.1169091

ISSN=1664-462X

ABSTRACT=In view of the problems of inaccurate fertilization, unstable fertilization, and low fertiliser utilization with fertilization in mango orchards, this study designed a small spiral fertiliser discharger based on the agronomic fertilization characteristics of mango orchards. The fertilizing performance test and parameter optimization of the spiral fertiliser discharger were conducted by combining the bench test and simulation test. Firstly, the main influencing factors of the fertilizing performance of the spiral fertiliser discharger were analysed by theoretical calculations, and the ranges of values were preliminarily determined.Meanwhile, the discrete element models of the spiral fertiliser discharger and the granular fertiliser were established. Then, by taking the variable coefficient of fertilizing stability as the response value, the method of single-factor test was used to explore the parameters having a significant influence on the variable coefficient of fertilizing stability. The results showed that the diameter of the spiral blade, the pitch, and the rotational speed of the fertilizing shaft have significant influence on the variable coefficient of fertilizing stability. Subsequently, The response surface method (RSM) was employed to simulate the fertilizing performance test. Based on the quadratic regression orthogonal rotation combination test, a second-order regression mathematical model between the variable coefficient of fertilizing stability and the significant parameters was established. The variable coefficient of fertilizing stability was as small as possible. Afterward, the genetic algorithm (GA) was exploited to optimize the regression model, and the optimal parameter combination of the spiral fertiliser discharger was obtained: 98.44 mm for the diameter of the spiral blade, 54.8 mm for the pitch, and 24.43 r/min for the rotational speed of the fertilizing shaft.Finally, the verification test of the fluidity and applicability of different fertilisers was carried out. The results indicated that the mass flow rate of different types of fertilisers and the variable coefficient of fertilizing stability could meet the agronomic fertilization requirements of mango orchards. Also, the reliability of the discrete element simulation test results and the research methods of the spiral fertiliser discharger was verified. The study results provide a reference for developing mango orchard fertilization machinery and related fertilizing performance tests.