A heat pump system using wasted heat from thermal effluent to supply the heating energy can reduce energy consumption and emissions of greenhouse gases by greenhouse facilities nearby. The Jeju National University consortium constructed a heat pump system using the thermal effluent from the Jeju thermal power plant of KOMIPO to provide with cool or hot water to greenhouse facilities located 2.5km from the power station. In this paper, the system configuration of the heat pump system was summarized, and the results of operations for demonstration of a heating performance carried out during the winter season in 2018 were investigated. Therefore, if the heating control by supplying thermal effluent to the facility greenhouse, it can contribute to reducing the energy cost and improving quality.
Background : Root diseases caused by Cylindrocarpon destructans and Fusarium solani decrease the yield and quality of ginseng. Cylindrocarpon root rot is a major disease caused by replanting failure in ginseng garden. Methods and Results : Solarization was done in the infested soil of the greenhouse for summer season (from July 24 to Autumn 31, 2014) after putting green manure (Sudan grass) and calcium cyanamide (CC) into the soil. Mycelium and conidia of C. destructans died at 4 0℃ after 15 hours, and 45℃ after 5 h, but it did not die at 35℃ after 15 h. Those of C. destructans died after keeping it for 2 hours daily at 40℃ for 9 days, and 45℃ for 8 days, but did not die at 38℃ for 9 days. Maximum soil temperature was 55.4℃ in 5 cm depth, 48.7℃ in 10 cm, 44.7℃ in 15 cm, 42.5℃ in 20 cm, and 31.9℃ in 30 cm by putting green manure into the soil and solarization. Reduction of sudan grass increased electrical conductivity (EC), organic matter, P2O5, K, and Mg, while decreased pH, NO3-N, and Na. Addition of calcium cyanamide and urea gave a negative effect on the growth of ginseng because EC and NO3-N were increased excessively than the optimal range. Solarization using green manure mixed with CC was the most effective in decreasing soil-borne pathogens of 2-year-old ginseng. But the root disease that occurred between single treatment of sudan grass and the treatment mixed with calcium cyanamide showed not a significant different. Addition of calcium cyanamide showed the decrease of root weight because leaves were dead early by a excessive increase of EC and NO3-N. Conclusion: Soil disinfection using green manure and solarization in greenhouse was effective in inhibiting root rot, however, it did not completely kill the soil-borne pathogens.
Background: Root diseases caused by Cylindrocarpon destructans and Fusarium solani decrease the yield and quality of ginseng. Cylindrocarpon root rot is a major disease caused by replant failure in ginseng fields. Methods and Results: Solarization of infested greenhouse soil was carried out during the summer season after applying green manure (Sudan grass) and Calcium Cyanamide (CC) on the soil. Mycelium and conidia of C. destructans died at 40℃ after 15 h, but they did not die at 35℃ after 15 h. They also died after keeping the soil at 40℃ for 2 h daily for 9 days, and at 45℃ for 8 days, but they did not die at 38℃ for 9 days. Maximum soil temperature was 55.4℃ at 5 ㎝ depth, 48.7℃ at 10 ㎝, 44.7℃ at 15 ㎝, 42.5℃ at 20 ㎝, and 31.9℃ at 30 ㎝ by incorporating green manure into the soil and using solarization. Solarization using green manure mixed with CC was the most effective in decreasing soil-borne pathogens of 2-year-old ginseng. However, the addition of CC decreased the root weight due to the increase in EC and NO3-N. Conclusions: Soil disinfection using green manure and solarization in a greenhouse environment was effective in inhibiting root rot, however, it did not completely kill the soil-borne pathogens.