Climatic change affects agricultural, environmental and livestock production. Forage productivity is highly dependent on the weather change. The Pyeongchang region has more difficulty in cultivation of Sorghum-Sudangrass hybrids (SSH) than other warm regions because of the cold weather. This experiment was carried out to analysis the agronomic characteristics, productivity, and nutritive value of three cultivars of Sorghum-Sudangrass hybrids in the Pyeongchang region from 2021 to 2022. Two harvests were taken in each year, and the agronomic characteristics, dry matter yield, and nutrient content of the whole SSH crops were determined. The plant height ranged between 281-291 cm and 165-172 cm in the first and second harvest, respectively. Plant height of Superdan (291±49 cm) was the highest in the first cut and Dairy mens Dream (172±30 cm) was the highest in the second cut time. Stem diameter ranged from 9.5 to 8.8 mm with Superdan having a higher level than the other two cultivars. The Dairy mens Dream variety produced significantly higher dry matter yield (15,695 kg/ha) than those of Superdan (14,584 kg/ha) and Supergreen (14,300 kg/ha) over a two-year experimental period. In terms of nutritional quality, the crude protein content, neutral detergent fiber and acid detergent fiber of SSH cultivars were analysed. There were no significant changes in the content of CP, ADF and NDF ranges among the cultivars. In addition, the Superdan cultivar had slightly higher CP content (10.17%) and was followed by Dairy mens Dream (9.84%) and Supergreen (9.54%) in the second cut time of 2-year average. Dairy mens dream had lower ADF and NDF values than other cultivars; however, no significant differences amongst cultivars in fiber content were observed. Therefore, these three cultivars displayed the potential growth characteristics, DM yield and nutritive values in Pyeongchang region. Hence, the SSH cultivars have a potential to withstand the climatic change and improve SSH productivity in the study area.

In recent decades, biofiltration has been widely accepted for the treatment of contaminated air stream containing low concentration of odorous compounds or volatile organic compounds (VOCs). In this study, conventional biofilters packed with flexible synthetic polyurethane (PU) foam carriers were operated to remove toluene from a contaminated air stream. PU foams containing various amounts of pulverized activated carbon (PAC) were synthesized for the biofilter media and tested for toluene removal. Four biofilter columns were operated for 60 days to remove gaseous toluene from a contaminated air stream. During the biofiltration experiment, inlet toluene concentration was in the range of 0-150 ppm and EBRT (i.e., empty bed residence time) was kept at 26-42 seconds. Pressure drop of the biofilter bed was less than 3 mm H2O/m filter bed. The maximum removal capacity of toluene in the biofilters packed with PU-PAC foam was in the order of column II (PAC = 7.08%) > column III (PAC = 8.97%) > column I (PAC = 4.95%) > column IV (PAC = 13.52%), while the complete removal capacity was in the order of column II > column I > column III > column IV. The better biofiltration performance in column II was attributed to higher porosity providing favorable conditions for microbial growth. The results of biodegradation kinetic analysis showed that PU-PAC foam with 7.08% of PAC content had higher maximum removal rate (Vm = 14.99 g toluene/kg dry material/day) than the other PU-PAC foams. In overall, the performance of biofiltration might be affected by the structure and physicochemical properties of PU foam induced by PAC content.