This experiment was carried out to evaluate the effect of natural drying methods on moisture content reduction and germination of Italian ryegrass seeds in Saemangeum reclaimed land, Kimje, Korea, from 2024 to 2025. The natural drying treatments included seed spread thicknesses (2.5, 5.0 and 7.5 cm), three seed reversal frequencies (1, 2 and 3 times per day), and two reversal methods (seed-only reversal and complete mixing of seed with a dry mat). A thinner spread thickness significantly accelerated moisture reduction (p<0.001). Although the effects of reversal frequency (p<0.017) and reversal method on moisture reduction were statistically significant, the magnitude of the differences was small, approximately 1~2%. Seeds with an initial moisture content of approximately 31.5% required 1.0, 1.5 and 2.0 days to reach 14% moisture when dried at spread thickness of 2.5, 5.0 and 7.5 cm, respectively. When seeds with an initial moisture content of 31.5% were dried at a thickness of 2.5 cm, the germination rate was 82.0%, which did not differ significantly from the rates observed at 5.0 cm (83.7%) and 7.5 cm (87.2%). These results suggest that, to achieve faster drying and maintain high seed quality, Italian ryegrass should be harvested at 30~35% seed moisture content, dried directly in the cultivation field, and spread at a thickness of 2.5 to 5.0 cm.

This study evaluated the growth characteristics and forage productivity of quackgrass (Agropyron repens) and meadow foxtail (Alopecurus pratensis) as novel forage resources under abnormal climatic conditions in Cheonan, Chungcheongnam-do, South Korea, during the 2024–2025 growing seasons. Both species, sown on 26 September 2024, exhibited good establishment, vigorous pre-winter growth, and strong cold tolerance. Following harvest, quackgrass and meadow foxtail showed superior regrowth compared with orchardgrass and tall fescue. Dry matter yields of quackgrass (QG2), a mixed sward of meadow foxtail (50%) and quackgrass (50%), tall fescue and quackgrass (QG1) were 21.4, 20.4, 19.2 and 19.0 t ha⁻¹, respectively, with no significant differences among treatments. In contrast, the dry matter yield of meadow foxtail alone (18.4 t ha⁻¹) was significantly lower than that of quackgrass (QG2) (p<0.001). Crude protein contents of quackgrass and meadow foxtail (12.3% and 13.4%, respectively) were higher than that of tall fescue (11.9%), whereas total digestible nutrient contents ranged from 61.4% to 61.7%, slightly lower than those of tall fescue. These results suggest that quackgrass and meadow foxtail are promising forage species for mixed pasture systems to enhance adaptability to abnormal climatic conditions.

This experiment aimed to evaluate the growth characteristics and forage productivity of novel forage resources in order to cope with abnormal climatic conditions in Pungse-myeon, Cheonan City, Chungcheongnam-do, South Korea from 2024 to 2025. Italian ryegrass (IRG), Perennial ryegrass (PRG)+IRG mixtures and Meadow foxtail (MF)+IRG mixtures sown on 26 September 2024 grew vigorously before and after winter, and exhibited strong cold resistance, achieving a 100% overwintering rate. At harvest, plant length of IRG, PRG+IRG mixtures and MF+IRG mixtures reached approximately 118 cm. The heading dates of IRG and MF+IRG (2 May) were 8 days earlier than that of tall fescue. The dry matter yield (11.5 ton/ha) of IRG single pasture did not differ significantly from that of MF+IRG and PRG+IRG mixture, but was 29~30% higher than that of MF and PRG single pasture (p<0.001). The crude protein content of IRG and MF+IRG mixture was 7.0%, which was lower than that of MF (9.6%) and tall fescue (9.0%). The total digestible nutrient content of MF+IRG mixture was 63.2%, slightly lower than that of IRG but higher than that of tall fescue. In conclusion, these findings demonstrate that PRG+IRG and MF+IRG mixtures have strong potential as novel forage resources to mitigate cold damage of IRG under abnormal climatic conditions.

This experiment was carried out to study the effect of elapsed time after air flow cutoff on the germination rate of Italian ryegrass seed with different moisture contents during natural drying on reclaimed land, Jangheung and Kimje of Korea from 2023 to 2024, respectively. Seeds with moisture contents of 15.3, 22.3 and 28.0% were placed in vinyl bag (30 × 40 cm) at storage thicknesses of 10, 15, and 20 cm, and air flow was cutoff for 48 h. Seed moisture content, seed temperature (℃) and germination rate were investigated at 12-h intervals. After 48 h of airflow cutoff during natural drying, seed moisture content did not significantly differ among storage thickness treatment (p>0.05). When Italian ryegrass seeds with moisture contents of 27~28% were stored under conditions with air flow cutoff at 15~20cm thickness for 48 h, the seed temperature reached up to 30℃ and the germination rate was excellent at around 70~80%.

This experiment was carried out to evaluate the effect of natural drying methods on the moisture content and germination of Italian ryegrass seed in Jicheon reclaimed land, Jangheung, Korea, from 2023 to 2024. The natural drying methods tested included seed spread thicknesses of 2.5, 5.0 and 7.5 cm; seed reversal frequencies of 1, 2 and 3 times per day; and two reversal methods: seed-only reversal and complete mixing of seed with a dry mat. The thinner seed spread thickness significantly accelerated moisture content reduction(p<0.001). However, the reduction in moisture contents due to the number and method of seed reversal was minimal, approximately 1%. Seeds initially having around 48.9% moisture content required 2, 4 and 5 days to reach a moisture content of 14% when dried at spread thickness of 2.5, 5.0 and 7.5 cm, respectively. Seeds with an initial moisture content of 23-26% required 1 to 2 days to reach 14% moisture content while maintaining approximately 80% germination rate under the tested natural drying methods. When seeds with an initial moisture content of 48.9% were dried at a spread thickness of 2.5 cm, the germination rate was 74.6%, which was significantly lower than the 83.8 and 81.6% germination rates observed for seeds dried at 5.0 and 7.5 cm thickness, respectively(p<0.002). These results suggest that for faster drying and higher-quality Italian ryegrass seed, harvesting at 30% seed moisture content, utilizing the cultivation field as a seed drying place, and applying a seed spread thickness of 2.5 to 5.0 cm are optimal practices.

This study was conducted at the National Institute of Animal Science (NIAS) from 2010 to 2017 to develop a late-maturing variety with high productivity for cultivation in the southern region of South Korea. The new variety of Italian ryegrass, ‘IR901’, was a late-maturing variety, and its heading date was 22 May, 17 days later than that of the control variety ‘Kowinearly’. ‘IR901’ had a flag leaf width of 11.2 mm, flag leaf length of 31.8 cm, and plant length of 103 cm on its heading date. The combined average dry matter yield of ‘IR901’ in all three adaptability evaluation regions (Cheonan, Pyeongchang and Haenam) was 7,747 kg/ha, which was similar to that of the ‘Kowinearly’ variety (7,734 kg/ ha). However, the average dry matter yield over three years in Cheonan and Pyeongchang was 82% and 96%, respectively, compared to that of the control, which was most likely because of the poor cold tolerance of ‘IR901’. By contrast, in Haenam, in the southern region, the average dry matter yield of ‘IR901’ was 19% higher than that of the ‘Kowinearly’ variety. The proportions of crude protein (CP), total digestible nutrients (TDN), acid detergent fiber (ADF), and neutral detergent fiber (NDF) in ‘IR901’ were 8.6%, 59.7%, 36.9%, and 54.8%, respectively; the proportions were 0.2% lower, the same, the same, and 2.5% lower than those in the ‘Kowinearly’ variety. The determined in vitro dry matter digestibility (IVDMD) of ‘IR901’ was 72.2% higher than that of ‘Kowinearly’ (67.2). In general, of the two varieties, the forage quality of ‘IR901’ was marginally superior to that of ‘Kowinearly’.

This experiment was carried out to study the effects of different environmental conditions and cultivation techniques on productivity of grasslands in central and southern area of Korea on 2017 and 2018. Average dry matter yield of grasslands at 10 actual production sites was 7,496 kg/ha. that was ranged from 4,652 to 13,292 kg/ha with least significant difference(LSD) of 1,577kg/ha between grasslands (p<0.05) on 2017. Average dry matter yield of grasslands at 10 actual production sites was 7,914 kg/ha. that was ranged from 3,927 to 12,372 kg/ha with LSD of 1,577kg/ha between grasslands(p<0.05) on 2018. Dry matter(DM) yield of grasslands have positive correlation with soil fertility (p<0.01) but not correlated with rainfall and air temperature among cultivation environments. And also DM yield of grasslands have positive correlation with grassland management techniques(p<0.01). These results suggest that practices of grassland management techniques and improvement of soil fertility are more important than cultivation environments by climate change for increasing the DM yield of grassland in central and southern area of Korea.

This study was conducted to find out the effects of seed mixture using new domestic grass varieties orchardgrass ‘Onnuri’ and tall fescue ‘Greenmaster’ on botanical composition and dry matter productivity from 2015 to 2018 in oversown hilly pasture, the central northern area of Korea. This experiment was consisted of 4 mixed grasses (Treatment 1 : tall fescue oriented mixture with imported varieties; Treatment 2 : orchardgrass oriented mixture with imported varieties; Treatment 3 : orchardgrass oriented mixture with domestic varieties, Treatment 4 : tall fescue oriented mixture with domestic varieties). Evaluation of seasonal changes in botanical composition of pasture showed that orchardgrass was the highest in all treatments, ranging from 46 to 89% and Kentucky bluegrass was the second highest in all treatments. Treatment 3 (7,633 kg ha-1) and Treatment 4 (7,570 kg ha-1), mixed grasses using domestic varieties, were showed the highest dry matter yield than Treatment 1(6,950 kg ha-1) and Treatment 2 (6,934 kg ha-1), which were mixed grasses using introduced varieties. Therefore, these results showed that the orchard grass oriented grasses mixture with domestic varieties was good for grassland vegetation and productivity in oversown hilly pasture, the central northern area of Korea.

This experiment was carried out to study the effects of different environmental conditions and cultivation techniques on productivity of forage corn in central and southern area of Korea on 2017 and 2018. Average dry matter yield of forage corn at 34 cultivation regions was 13,510kg/ha. Forage productivity of forage corn cultivated at actual production sites have positive correlation with cultivation techniques(p<0.01) but not correlated with cultivation environments. Forage productivity of forage corn have positive correlation with seeding techniques(p<0.01) but not correlated with fertilization techniques. These results suggest that practices of cultivation techniques are more important than cultivation environments for increasing the forage productivity of forage corn. Therefore, yield prediction techniques of forage corn in Korea have to be considered the practices of cultivation techniques along with soil and climate conditions.