Experimental research on rice seeds based on high-voltage electric field treatment

Mechanical forces can induce internal microcracks and latent damage, significantly compromising grain quality during rice seeds harvest, and conventional mechanical sorting fail to detect such defects. As a dielectric material, seeds exhibit polarisation under non-uniform electric fields, and closely correlated to their dielectric properties. The purpose of this study was to investigate the effects of high-voltage electric field treatment on the germination potential and seedling growth of rice seeds, and to clarify the underlying dielectric mechanisms. A simplified seed model and equivalent circuit were developed. By analysing the dielectric polarisation process and calculating the field strength inside and outside the seeds, the macroscopic electromagnetic motion laws of the dielectric in seeds were determined. Orthogonal experiments on electric field seed treatment were conducted. Range analysis identified the primary and secondary factors affecting germination potential and average seed height, while variance analysis determined the optimal treatment combination and tested the model’s significance. Results indicated that the complex impedance of the seed equivalent circuit depends on the circular frequency (ω) of the applied electric field, the film capacitance (C) and film resistance (R) of the seed. The relative dielectric constant ε and the macroscopic polarisation rate χ are equivalent in describing the dielectric constant of seeds. The external electric field has a more significant effect on seeds with higher vitality. The optimal parameters for higher germination potential and average seed height are an alternating current electric field with an intensity of 520 kV ∙ m-1 for 150 seconds under experiments. Stronger field strength and longer treatment time result in higher average seed height, benefiting long-term seed vitality. This is because a lower dielectric constant in seeds is advantageous. Therefore, seeds treated by high-voltage electric fields can significantly enhance seed vitality and increase yield, promoting the development of efficient, precise, non-destructive, and automated selection and grading technologies