on 17 January 2021). Ginseng grown for 6 years or more is considered to be medicine; otherwise, it can only be used as food. Ginseng mainly grows in the northern regions in China. The annual change is reflected in the physical form of reed head, which is easy to identify. The difference between medicine and food also provides different economic values to ginseng in different growth years. Thus, the ginseng market induced a phenomenon of disguising young ginseng as old ones by changing its appearance. Therefore, the identification method based on the appearance characteristics, such as reed, root, body, and fibril, is no longer reliable [3,4]. The microscopic identification method is based on examining calcium oxalate cluster crystal contents in reed heads [5]. Mass spectrometry identifies ginseng growth years by the analysis of saponins and other components, and all three types of ginensoides were successfully detected and visualized in images, which proved the advantages of matrix-assisted laser desorption/ionization time-of-flight mass spectrometry imaging (MALDI-TOF-MSI) over traditional methods for the analysis of herbs. However, the differentiation of ginensoides isomers was not available in the analysis of ginseng by MALDI-TOF-MSI [6,7]. Liquid chromatography [8, 9, 10, 11] and other methods have high identification accuracy in terms of the year, but all of them need to cause damage to ginseng samples. Laser-induced identification methods induce little damage to samples and have good accuracy and high identification speeds [12,13], but they still require complex processes such as purification, drying, grinding, and high-pressure pressing. The above methods are not applicable to non-professionals and do not have value for on-site identification and promotion. [PERSON] et al. measured ginseng leaves in the farmland and judged the growth years only by using direct spectral observation information, with a recognition accuracy of 94.8%. Although there is no direct measurement of dried ginseng roots (medicinal part), the direction of ginseng growth years identified by spectral information was pointed out [14].  
Using only spectral information, it has the advantage of nondestructive, fast, and simple identification in reflective spectral bands [15, 16, 17, 18, 19, 20]. [PERSON] et al. used the near-infrared (NIR) reflectance spectra to classify ginseng successfully [15]. [PERSON] et al. proposed a fusion model based on data fusion and decision fusion from hyperspectral images to detect the foreign materials on the surfaces of broiler breast fillets, and the detection accuracy is up to 95% [16]. [PERSON] et al. predicted egg freshness by using transmission visible near infrared spectroscopy, and it showed good prediction abilities [18]. [PERSON] et al. detected Jaggery adulterants in honey using near-infrared spectroscopy techniques with Chemometrics, and the calibration error was only 0.00751 [19]. The previous research studies used specific spectral ranges such as visible and near-infrared (VNIR), short wave infrared (SWIR), and terahertz. However, the importance of different spectral ranges was not compared and analyzed.  
At 400-2500 nm wavelengths, the electromagnetic wave only reflects light signal; it provides no thermal radiation information and has no penetrability toward opaque targets. Therefore, hyperspectral reflectance basically reflects only the surface layer information of ginseng, which can be used to carry out year identification research. In order to test and construct spectral recognition methods of ginseng growth years, the hyperspectral images of 400-2500 nm were obtained by using garden ginseng (artificially planted) samples with growth years of 1-7 years. The model of ginseng growth years identification was trained by machine learning methods, and the feature bands were extracted by providing the importance of every wavelength band.