Korean Journal of Soil Science and Fertilizer ISSN:0367-6315(Print) 2288-2162(Online) 한국토양비료학회 학회지

Excessive nitrogen fertilization influences crop yields and quality as well as environmental pollution. In this study, yields, nitrogen use efficiency and free sugar contents of burdock (Arctium lappa L.) were evaluated at different levels of nitrogen fertilization. Nitrogen fertilizer was applied at 5 levels (0, 50, 100, 150, 200%) based on the conventional fertilization (N = 230 kg ha^-1), and phosphate and potassium fertilizer were treated by conventional P and K fertilization (P₂O₅ - K₂O = 140 - 210 kg ha^-1) in all plots. The root yields of burdock were the highest in N 100~150% treatment plots. Nitrogen use efficiency and nitrogen recovery decreased from over N 150% treatment. Nitrogen uptake of root was greater than that of shoot in N 50~200% treatments. Fructose contents in root were inversely proportional to the level of nitrogen fertilization. As considering nitrogen recovery and root quality, economical burdock yield was obtained in N 230 kg ha^-1.

The cumulative runoff amounts of soil/water (a,d), nitrogen (b,f), and phosphorus (c,g) by rainfall. Vertical bars indicate standard deviations of the means.