This study was conducted to evaluate the effects of productivity-limiting factors associated with boron(B), molybdenum(Mo), rhizobium, and lime on dry matter yield(DMY) and nutritive value of alfalfa. The experiment was carried out in a greenhouse at the National Institute of Animal Science, Cheonan, Republic of Korea, from April 2022 to August 2024. Alfalfa cultivar ‘SW5615’ was sown at a rate of 20 kg ha⁻¹. The experiment was arranged in a randomized complete block design with three replications. The treatments consisted of a control, in which all productivity-related factors were supplied, and four limitation treatments: B limitation, Mo limitation, Rhizobium limitation, and Lime limitation. Alfalfa was harvested five times at the early flowering stage, approximately 10% bloom. DMY and forage nutritive value, including crude protein(CP), neutral detergent fiber(NDF), acid detergent fiber(ADF), total digestible nutrients(TDN), and relative feed value(RFV), were analyzed. Productivity-limiting factors significantly affected DMY (p<0.05). Compared with the control, relative DMY was 97.8% under B limitation, 82.2% under Mo limitation, 63.1% under Rhizobium limitation, and 64.6% under Lime limitation. Among nutritive value parameters, only CP concentration differed significantly among treatments(p<0.05), whereas NDF, ADF, TDN, and RFV were not significantly affected(p>0.05). The highest CP concentration was observed under Lime limitation, which was likely associated with reduced biomass accumulation or delayed maturity rather than improved forage productivity. These results indicate that Rhizobium and Lime limitations were the major factors reducing alfalfa DMY, followed by Mo limitation, while B limitation had little effect under the present experimental conditions.

This study estimated whole crop maize (WCM; Zea mays L.) yield damage under abnormal climate conditions using a machine-learning approach based on Representative Concentration Pathway (RCP) 8.5 and visualized the results as spatial maps. A total of 3,232 WCM observations were compiled, and climate data were obtained from the Korea Meteorological Administration (KMA) Open Data Portal. The machine learning model used DeepCrossing. Dry matter yield (DMY) was predicted using the DeepCrossing model and climate data from the Automated Synoptic Observing System (ASOS; 95 stations). The calculation of damage was the difference between the DMYnormal and DMYabnormal. The normal climate was set as the 40-year of climate data according to the year of WCM data (1978-2017). The level of abnormal climate by temperature and precipitation was set as RCP 8.5 standard. The predicted DMYnormal ranged from 13,845-19,347 kg/ha. The damage from WCM varied by region and the severity of abnormal climate, including abnormal temperature and precipitation. Under abnormal temperature conditions, damage in 2050 and 2100 ranged from –243 to –133 and –1,797 to –245 kg/ha, respectively. Under abnormal precipitation conditions, damage in 2050 and 2100 ranged from –2,998 to 1,447 and –11,308 to 29 kg/ha, respectively. Overall, DMY of WCM tended to increase with higher mean monthly temperature. The damage calculated through the RCP 8.5 standard was presented as a spatial distribution using QGIS. Although this study used an RCP scenario based on greenhouse gas concentrations, further research is needed to apply an integrated Shared Socioeconomic Pathway (SSP) that accounts for socioeconomic factors.

This study was carried out to evaluate the seeding date and performance of early maturing rye cultivars for the Dry matter yield (DMY) and nutritive value during 2016 and 2017 in Yeongseo region of Gangwondo, South Korea. The experimental field was designed as a split-plot arrangement. The treatments were two planting dates on September 25 and October 02 as the main plots, and two cultivars of forage rye including Gogu and Koolgrazer as sub-plots. The cultivars were harvested on April 26 at the heading stage of both years. In this experiment, the sowing dates and cultivars of the forage rye did not effect on DMY. The DMY had no significant differences among the cultivars of forage rye and seeding date of both years. Similarly, no significant difference was observed in the DMY of Gogu and Koolgrazer in both seeding date and years. The CP, NDF, ADF, and RFV had no significant differences among the cultivars of forage rye and seeding date of both years. Considering the DMY and nutritive value of the current experiment, seeding of forage rye cultivars Gogu and Koolgrazer on September 25 and October 2 could be used as an recommended seeding date at northern area. In addition, based on the climate characteristics of the region, both cultivars had relatively similar forage yield and quality that makes them to be recommended for cultivation in the region. This study is meaningful in that DMY was first presented in Yeongseo region where there is no cultivation data for forage rye.