This experiment was conducted to study on the growth characteristics and seed productivity of Italian ryegrass (Lolium multiflorum Lam., IRG) planted in the Spring in Gangwon Highland according to the seeding distance (20, 30 and 40 cm). The field was located in highland around 600 m above sea level. The experimental design was randomized block design with three replication and the tested IRG variety was ‘Greencall’ developed by National Institute of Animal Science (NIAS). IRG was sown on March 26, 2020, and harvested on July 2. The plant height was the shortest at 80.5 cm in the 40 cm seeding distance plot (P<0.05), and there was no significant difference between the 20 and 30 cm seeding distance. The number of spike per square meter (m2) was significantly higher in the 20 cm seeding distance plot than that of 40 cm (937 vs. 571). The dry matter (DM) content of seed and straw after harvesting was 49.70 and 33.36 % on average, and there was no significant difference between treatments (P>005). However, there was a significant difference in the fresh and DM yield of seeds and straw (P<0.05). DM yield of seeds was significantly higher in 20 cm distance than that of 40 cm, and the yield of straw was the same trend. On the other hand, there was no significant difference in DM yield between 20 cm and 30 cm and also in the feed value of straw after seed harvesting among seeding distance. The average CP, ADF, NDF, and TDN contents were 6.91, 36.76, 61.75 and 59.86%, respectively, and the RFV value was 91. Considering the above results, the production of Italian ryegrass seeds sown in the spring in the highlands of the Gangwon is lower than that of autumn sowing, but it is judged that it needs to be reviewed in case it is unavoidable. In the future, there should be an economic analysis and the development of technology that can increase production.

ABSTRACT
Ⅰ. 서 론
Ⅱ. 재료 및 방법
    1. 이탈리안 라이그라스의 재배
    2. 이탈리안 라이그라스의 수확
    3. 종자특성 평가 및 사료가치 분석
    4. 기상 상황
    5. 통계처리
Ⅲ. 결과 및 고찰
    1. 생육특성
    2. 종자 특성
    3. 종자 및 짚의 생산성
    4. 짚의 사료가치
Ⅳ. 요 약
Ⅵ. REFERENCES

• 정은찬(서울대학교 국제농업기술대학원) | Eun Chan Jeong (Graduate School of International Agricultural Technology, SNU)
• Li Yan Fen(서울대학교 국제농업기술대학원)
• 김학진(서울대학교 그린바이오과학기술연구원) | Hak Jin Kim (Research Institute of Eco-friendly Livestock Science, GBST, SNU)
• 김맹중(서울대학교 그린바이오과학기술연구원) | Meing Joong Kim (Research Institute of Eco-friendly Livestock Science, GBST, SNU)
• 지희정(국립축산과학원 초지사료과) | Hee Chung Ji (Department of Grassland and Forage Science, NIAS, RDA)
• 김종근(서울대학교 국제농업기술대학원/서울대학교 그린바이오과학기술연구원) | Jong Geun Kim (Graduate School of International Agricultural Technology, SNU/Research Institute of Eco-friendly Livestock Science, GBST, SNU) Corresponding author