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

This research was conducted to investigate the optimum level of nitrogen incorporated during formulation of root media as pre-plant fertilizer on the growth of plug seedlings of ‘Bool-am No.3’ Chinese cabbage. A root medium was formulated by blending peatmoss:coir dust:perlite at a ratio of 3.5:3.5:3.0 (v/v/v). The nitrogen was incorporated in the seven treatments at a rate of 0, 100, 250, 500, 750, 1,000, and 1,500 mg·L^-1 during the root medium formulation. The concentrations of other essential nutrients except nitrogen were controlled to equal in all treatments. Then, the root medium was packed into 72-cell plug trays and seeds were sown. The growth measurements as well as tissue and soil solution analysis for nutrients were conducted 2 and 4 weeks after seed sowing. As seedlings grew, the pH in the extracted solution of all treatments tended to decrease. The decreases in the treatments of high N concentrations were more severe than those with low N, but the differences among treatments were not statistically significant. The differences of EC in extracted solution of root media among treatments were sizable until week 3, but the differences began to lessen and the EC decreased in all treatments after week 4. Growth of the aerial parts of plug seedlings at 2 weeks after sowing were highest in the 100 mg·L^-1 and lowest in the 1,500 mg·L^-1 treatments, but those at 4 weeks after sowing were highest in the 500 mg·L^-1 and lowest in the 0 mg·L^-1 treatments among all treatments tested. The tissue N content was highest and lowest in the treatments of 250 and 1,000 mg·L^-1, respectively, when tissues were harvested at 4 weeks after sowing and analysed based on the dry weight of above-ground tissue. The contents of micronutrients were the highest in the 1,000 and 1,500 mg·L^-1 treatments among all treatments. The results shown above indicate that the 250 mg·L^-1 of pre-plant N and elevation of post-plant N concentration to above 100 mg·L^-1 are suitable for raising plug seedlings of Chinese cabbage using inert media.