This study aimed to improve and refine climate exposure indicators developed in a previous study by incorporating and analyzing two years of Italian ryegrass field trial data from the Jinju and Jangheung regions. The objective was to evaluate the relationships between productivity and climatic factors. The field trial results demonstrated that plant height, fresh yield, and dry matter yield of Italian ryegrass was significantly higher in 2018–2019 than in 2017–2018. Precipitation and temperature during the winter and spring seasons of 2018–2019 were also greater than those recorded in 2017–2018. Correlation analyses revealed significant positive associations between productivity and precipitation in Oct, Dec, Feb, and Mar. Productivity was also positively correlated with mean temperature and mean minimum temperature in Oct, Dec, Jan, Feb, Mar, and Apr, as well as with growing degree days in Oct, Dec, Jan, Feb, and Mar. The climate exposure indicators derived in this study are expected to serve as valuable tools for predicting Italian ryegrass productivity and assessing vulnerability to climate impacts. Nevertheless, considering the complex interactions between climatic factors and field conditions, further refinement through additional experiments and analyses remains necessary.
Molecular markers have been widely applied in population genetics, diagnostic taxonomy, and genetic mapping, and they can also be used for classifying varieties of Italian ryegrass during field selection. In this study, genome-wide sequence information was generated for 10 Italian ryegrass cultivars (40 samples), including ‘Kowinearly’ (KW), using next-generation sequencing (NGS). Single nucleotide polymorphism (SNP) analysis revealed that only three SNP loci were sufficient to distinguish KW from the other cultivars. Furthermore, 21 alternative barcode sets, each consisting of three SNPs, were identified. These SNP barcode sets provide a reliable criterion for cultivar discrimination in Italian ryegrass and can contribute to the protection of domestic varieties and the advancement of the forage industry in Korea. More broadly, the development of distinguishing markers across Italian ryegrass cultivars will enhance genetic resource identification and support the breeding of high-quality new varieties.
This study reports the development of a new alfalfa (Medicago sativa L.) variety, ‘Alfaone’, at the Forage Production Systems Division, National Institute of Animal Science, Rural Development Administration, Korea, from 2015 to 2023. The variety originated from an artificial cross between Xun Lu (maternal parent) and RadarⅡ Brand (paternal parent), followed by pedigree selection and performance testing. The elite line ‘MsCB01’ was subsequently released as ‘Alfaone’. Regional adaptability trials were conducted for two years (2022–2023) across four representative sites in Korea (Cheonan, Pyeongchang, Jeongeup, and Jinju) to evaluate agronomic traits, forage yield, and quality. Evaluated characteristics included plant height, regrowth ability, winter survival, and lodging resistance. The average dry matter yield of ‘Alfaone’ was 20,811 kg/ha, approximately by about 3% higher than that of the standard cultivar ‘Vernal’ (20,236 kg/ha). Yield superiority was particularly evident in Pyeongchang, suggesting excellent cold tolerance and winter hardiness. Assessment of forage nutritive traits indicated that ‘Alfaone’ was comparable to ‘Vernal’, demonstrating that its yield advantage did not come at the expense of quality. Overall, ‘Alfaone’ is a promising cultivar that combines high productivity with strong adaptability to unfavorable environments, particularly cold-prone regions. Its release is expected to promote the expansion of alfalfa cultivation, enhance forage self-sufficiency, and reduce dependence on imported hay in Korea.
This study evaluated the growth characteristics, forage productivity, and feed value of three Italian ryegrass (Lolium multiflorum Lam.) cultivars ‘Earlybird’, ‘Green call’, and ‘Greenfarm2ho’ over two consecutive growing seasons. Growth traits such as cold tolerance, lodging resistance, disease resistance, and insect resistance were assessed, along with plant height. Forage yield was measured as both fresh and dry matter yields, and feed value was analyzed in terms of CP, NDF, ADF, DMI, DDM, RFV and CA content. Among the tested cultivars, ‘Earlybird’ demonstrated superior performance in several key traits. It showed the greatest lodging resistance and plant height, along with the highest fresh and dry matter yields, although differences in yield were not statistically significant. In terms of feed quality, ‘Earlybird’ had the highest CP (10.8%), lowest NDF (54.7%), and highest RFV (109), indicating excellent palatability and digestibility. ‘Greenfarm2ho’ showed intermediate values across all parameters, suggesting balanced productivity and quality. In contrast, ‘Green call’ showed relatively lower lodging resistance and feed value. Overall, ‘Earlybird’ was identified as a promising cultivar for forage production in temperate climates, combining stable yield performance with high nutritional value. These findings offer valuable guidance for cultivar selection in livestock forage systems aiming to improve both productivity and feed efficiency.
The global e-waste problem is becoming increasingly serious. China, as one of the largest producers and consumers of electronic products, still has a low formal recycling rate. Consumers, as the owners of waste electronics, are the key to successful reverse logistics. However, many choose to store or dispose of e-waste at home rather than use official recycling channels. While many previous studies focus on factors that encourage recycling, fewer examine what stops people from taking part. This study applies Valence Theory to identify the factors that increase consumers’ psychological resistance to recycling small e-waste in China’s first-tier cities. It also examines how these factors influence social value and resistance behavior. The research model includes perceived price unfairness, perceived inconvenience, perceived benefits, and information publicity, with social value as a mediator. Data were collected through an online survey of 303 residents in Beijing, Shanghai, Guangzhou, and Shenzhen. Structural equation modeling (SEM) was used for analysis. The results show that perceived inconvenience and perceived benefits significantly influence social value. Perceived price unfairness, perceived inconvenience, and social value significantly affect consumer resistance. These findings expand the application of Valence Theory in e-waste research and address gaps in the Theory of Planned Behavior by considering both perceived risks and benefits. Practically, this study suggests that manufacturers, recyclers, and policymakers should improve recycling facilities, make the process more convenient, ensure fair and transparent pricing, and create targeted measures to reduce consumer resistance and encourage participation in formal recycling systems.
The development of high specific surface area and mesoporous activated carbons is required to improve the electrochemical performance of EDLC. In this study, kenaf-derived activated carbons (PK-AC) were prepared for high-power-density EDLC via phosphoric acid stabilization and steam activation. The pyrolysis behavior of kenaf with respect to the phosphoric acid stabilization conditions were examined via TGA and DTG. The textural properties of PK-AC were studied with N2/ 77 K adsorption–desorption isotherms. In addition, the crystalline structure of PK-AC was observed via X-ray diffraction. The specific surface area and mesopore volume ratio of PK-AC were determined to be 1570–2400 m2/ g and 7.7–44.5%, respectively. In addition, PK-AC was observed to have a high specific surface area and mesopore volume ratio than commercial coconut-derived activated carbon (YP-50F). The specific capacitance of PK-AC was increased from 77.0–99.5 F/g (at 0.1 A/g) to 49.3–88.9 F/g (at 10.0 A/g) with activation time increased. In particular, K-P-15-H-9–10 observed an approximately 35% improvement in specific capacitance at a higher current density of 10.0 A/g compared to YP-50F. As a result, the phosphoric acid stabilization method was confirmed to be an efficient process for the preparation of high specific surface area and mesoporous biomass-derived activated carbons, and the kenaf-derived activated carbons prepared by this process have great potential for application as electrode active materials in high-power EDLC.
In this study, nitrogen and fluorine co-doped carbon nanocages (NF-CNCs) were synthesized as anode materials for potassium- ion batteries (KIBs), and their structural evolution with heat treatment and electrochemical behavior with different functional groups was investigated. NF-CNCs were prepared by physically mixing coal tar pitch (CTP) with a SiO2 template, followed by heat treatment and subsequent fluorination with NF3 gas. A systematic investigation of the structural properties revealed that graphitization increased with increasing heat treatment temperature as the carbon structure transitioned from amorphous at 500 and 1000 °C to graphite-like at 1500 °C. Furthermore, nitrogen and fluorine functional group analysis revealed significant changes, particularly in terms of covalent and semi-ionic C‒F bonds. Among the samples, NF-CNC 1000 displayed excellent electrochemical performance, with a specific capacity of 395.1 mAh g− 1 and a capacity retention rate of 94% during 1000 cycles at 50 mA g− 1. The exceptional performance of NF-CNC 1000 is attributed to its high porosity, amorphous carbon structure, and semi-ionic C‒F bonds, which facilitate the efficient adsorption and intercalation of potassium ions. These findings provide valuable insights into the design of advanced anode materials for next-generation KIBs.
This study was conducted from 2022 to 2024 at the Grassland and Forage Crops Division, National Institute of Animal Science (RDA), in Cheonan, Korea, to develop a medium-maturing variety of Italian ryegrass (Lolium multiflorum Lam.). The newly developed tetraploid cultivar, named ‘Spider’, is characterized by its green leaves, semi-erect growth habit in late autumn, and erect growth habit in mid-spring. With a heading date of May 16, ‘Spider’ is classified as a medium-maturing variety. Compared to the control cultivar ‘Kowinmaster’, ‘Spider’ has a 1.0 mm wider leaf blade, a 1.6 cm longer leaf blade, and is 5 cm taller in plant height. Its dry matter yield (10,169 kg/ha) is significantly higher than that of ‘Kowinmaster’ (p<0.05). The crude protein content of ‘Spider’ is 10.4%, which is 0.2% higher than that of the control. Additionally, ‘Spider’ has a neutral detergent fiber (NDF) content of 49.5% and an acid detergent fiber (ADF) content of 26.6%, showing a 2.2% lower NDF and a 0.2% higher ADF compared to ‘Kowinearly’.
The commercial feed additive, native rumen microbes (RC), derived from a diverse microbial community isolated from the rumen of Hanwoo steers is being explored to enhance rumen fermentation and improve ruminant feed utilization. This study evaluated the impact of native rumen microbes supplementation on methane emissions, microbial diversity, and fermentation efficiency on in vitro assessment. Treatments were as follows: CON (basal diet, without RC); T1 (basal diet + 0.1% RC); T2 (basal diet + 0.2% RC). Rumen fermentation parameters, total gas, and methane production were assessed at 12, 24, and 48 h of incubations. The in vitro gas production was carried out using the Ankom RF Gas Production System. Supplementation of RC significantly reduced the total gas production at 12, 24, and 48 hours of incubation (p < 0.05). Volatile fatty acid concentrations were increased, while acetate and propionate were decreased (p < 0.05) at 48 h by the supplementation of RC. Notably, the 0.1% inclusion level of RC significantly reduced methane production by 28.30% and 21.21% at 12 and 24 hours. Furthermore, microbial diversity analysis revealed significant shifts (p < 0.05) in bacterial composition between the control and treatment groups, while supplementation also promoted the growth of bacterial populations, such as Succiniclasticum. These findings suggest that native rumen microbes supplementation, particularly at 0.1% inclusion level, can enhance rumen microbial composition while significantly reducing methane production in vitro.
This study investigated the flowering response of three Korean native Aster species, namely A. hayatae, A. spathulifolius, and A. koraiensis, to varying photoperiods. Three-month-old plants propagated from cuttings were grown under four different photoperiods: 9, 12, 14, and 16 h. Aster hayatae flowered under all conditions, with flowering rates of 92%, 85%, 65%, and 27% under 9-, 12-, 14-, and 16-h photoperiods, respectively. Flowering in A. hayatae was promoted by shorter photoperiods, classifying it as a facultative short-day plant. Aster spathulifolius flowered only under 9- and 12-h photoperiods, with no significant difference between these treatments, suggesting that the species is an obligate short-day plant. However, given the low A. spathulifolius flowering rates of 27% and 13% under 9- and 12-h photoperiods, respectively, further research is required. Aster koraiensis did not flower under any photoperiod, possibly due to vernalization requirements or juvenility. These findings offer valuable insights into the photoperiodic flowering responses of these three Korean native Aster species, enhancing our understanding of their ecological traits and potential horticultural applications.