Background : There are studies on the planting distance, sowing periods, and over wintering method of Saururus chinesis, but lesson the necessary soil moisture content for rhizome growth. This study examines the effects of soil moisture content on the growth of Saururus chinesis.
Method and Results : The radicles of Saururus chinesis were harvested in the beginning of March and cut into three joints. The planting densities were determined as 40 ㎝ × 10 ㎝, 40 ㎝ × 20 ㎝ and 40 ㎝ × 30 ㎝, and the soil moisture content was adjusted through continuous flooding treatment, wetting (0 ~ -10 kPa), and field moisture capacity (-20 ~ -50 kPa). As a result of investigating the ground growth of Saururus chinesis, the growth through continuous flooding was best with the planting distance of 40 ㎝ × 20 ㎝ that yielded a plant height of 7.4 ㎝, stem diameter of 5.2 ㎜, and leaf number of 5.5. The growth through field capacity (-20 ~ -50 kPa) was poorest at the planting distance of 40 ㎝ ×10 ㎝. The transpiration rate, indicating the breathing of leaves, was highest at 1.4 s ㎝-1 through continuous flooding at 40 ㎝ × 30 ㎝, and decreased to 0.5 s ㎝-1 with the field capacity of (-20 ~ -50 kPa) 40 ㎝ × 20 ㎝. The investigation on the leaves showed that the leaf weight was heaviest at 23.1 g/plant through continuous flooding of 40 ㎝ × 30 ㎝ that also showed a wider leaf area and rich chlorophyll. At continuous flooding of 40 × 10 ㎝, the leaf weight was as light as 9.5 g/plant, showing no consistency among treatments. The investigation on the underground growth showed the best results through continuous flooding with a planting distance of 40 × 10 ㎝ where the root length was 50.7 ㎝, root diameter 6.7 ㎜, and fresh root weight of 45.3 g/plant, which decreased to 24.4 g/plant with field capacity (-20 ~ -50 kPa). The investigation on the polyphenol content as a functional component showed the richest content in the leaf of the plant at 752.5 ㎎/100g through continuous flooding, and lowest at 661.0 ㎎/100g with field capacity. With the field capacity (-20 ~ -50 kPa) it was the highest at 262.0 ㎎/100g.
Conclusion : It was the most advantageous for mass Saururus chinensis radical production with continuous flooding treatment for soil moisture and a planting distance of 40 × 10 ㎝.