Horticultural Science and Technology ISSN:1226-8763(Print) 2465-8588(Online) 원예과학기술지

Objective of this study was to investigate the altered physical properties of root media by the successive cultivation with nutrient solution in multiple years and supplement effects of perlite on growth of Panax ginseng. After collecting one year, two years, and three years used media, the degrees of difference in physical properties were investigated by comparing to fresh medium [new and composed of 70% peat moss and 30% perlite (v/v)]. The 1 and 3 years used media were supplemented by the perlites with the grade of 3-5 mm and 1-3 mm in diameter and supplement rates were varied. Then, physical properties were measured again to determine the degree of improvement and to decide optimum supplemental rates. Compared to the new medium, the increased number of years in successive cultivation of Ginseng seedlings resulted in the lowered proportion of large particles and the get higher proportion of small particles. The increase in the rates of small particles resulted in the rise of container capacity (CC) and the decrease of air-filled porosity (AFP) compared to fresh medium. The treatments of 1+4:9 (one year used medium supplemented with 4 g of 3-5 mm and 9 g of 1-3 mm perlites), 3+2:7 (three years used medium supplemented with 2 g of 3-5 mm and 7 g of 1-3 mm) and 3+4:9 (three years used media supplemented with 4 g of 3-5 mm and 9 g of 1-3 mm perlites per 100 g of used medium) showed similar particle size distribution, CC and AFP to fresh medium. In the ginseng cultivation experiment, there were no significant differences between new medium and the 1+4:9 medium in the growth of above-ground tissue. The ginseng growth in root medium used for 3 years showed significant lower growth than those in new medium, but the growths in the 3+4:9 treatment showed significant improvement compared to those in the 3 years used medium. The root growth in terms of root fresh and dry weights in the treatment of three years used were also significantly lighter than those of other treatments. However, growth of Panax ginseng was significantly improved in the treatment of 3+4:9 (corrected medium of 3 years used).