Effect of Ridge Height on Growth Characteristics and Yield of 6 Year Old Panax ginseng in Cultivation of Paddy Soil

Abstract

Background : Ginseng is mainly grown as a break crop in paddy fields after rice has been cultured for approximately 4 - 5 years, because it reduces the negative effects of continuous rice cropping. However, physiological disorders, such as leaf discoloration, occur in ginseng grown in paddy fields with poor drainage and excessive levels of inorganic components. Methods and Results : This study investigated the effect of ridge height on the growth characteristics and yield of 6 year old Panax ginseng. Ridge height was varied by making 20, 30, and 40 ㎝ high ridges in a pooly drained paddy field. Soil moisture content decreased, while electrical conductivity (EC) as the ridge height increased. The NO₃, K, Ca, Mg, and Na levels also rose as ridge height increased, but organic matter and P₂O₄ levels did not. The leaf discoloration ratio rose as the ridge height increased, and root yield reached a peak when the ridge height was 30 ㎝. Conclusion : A ridge height of 30 ㎝ in poorly drained paddy field improved ginseng growth by reducing leaf discoloration and increasing root survival, owing to more suitable soil moisture and EC levels.