The experiment was conducted to determine the changes in seed productivity of Italian ryegrass (Lolium multiflorum Lam.) according to nitrogen fertilization levels in the southern region of Korea. Italian ryegrass (IRG) variety 'Green Call' was sown in the fall of 2021 in Jinju, Gyeongsangnam-do. The experiment consisted of three nitrogen fertilizer levels (100, 120, and 140 N kg/ha) with three replications using a randomized complete block design. Harvesting was done approximately 30 days after heading on May 18th. There was no difference in heading date among treatments, which occurred on April 18th. The longest IRG was observed in the 140 N kg/ha treatment, but there was no significant difference. No significant differences were observed in lodging, disease resistance, and cold tolerance among treatments, but lodging was severe in all treatments. The length of the spike averaged 44.95 cm, with no difference among treatments, and the number of seeds per spike was highest in the 120 N kg/ha treatment. Seed yield increased with increasing nitrogen fertilizer levels, averaging 3,707 kg/ha (as-fed basis). DM content of seed and straw averaged 76.95% and 62.19%, respectively, with no significant differences among treatments. The remaining straw after harvesting averaged 6,525 kg/ha on a dry matter basis, with the highest value observed in the 140 N kg/ha treatment. Overall, considering the results, the optimal nitrogen fertilizer application rate for seed production of Italian ryegrass in the southern region when sown in autumn was found to be 120 N kg/ha.

Ⅰ. 서론
Ⅱ. 재료 및 방법
    1. 이탈리안 라이그라스 재배
    2. 이탈리안 라이그라스의 수확
    3. 종자특성 평가
    4. 사료가치 분석
    5. 기상 상황
    6. 통계처리
Ⅲ. 결과 및 고찰
    1. 생육특성
    2. 종자 특성
    3. 종자 및 짚의 생산성
Ⅳ. 요약
Ⅴ. 사사
Ⅵ. REFERENCES

• 유영상(서울대학교 국제농업기술대학원) | Young Sang Yu (Graduate School of International Agricultural Technology, SNU, Pyeongchang, 25354, Korea)
• Wang Li Li(서울대학교 그린바이오과학기술연구원)
• Li Yan Fen(서울대학교 국제농업기술대학원)
• Xaysana Panyavong(서울대학교 국제농업기술대학원)
• 이배훈(국립축산과학원 초지사료과) | Bae Hun Lee (Grassland and Forage Division, NIAS, RDA, Cheonan, 31000, Korea)
• 김종근(서울대학교 국제농업기술대학원, 서울대학교 그린바이오과학기술연구원) | Jong Geun Kim (Graduate School of International Agricultural Technology, SNU, Pyeongchang, 25354, Korea, Research Institute of Eco-friendly Livestock Science, GBST, SNU, Pyeongchang, 25354, Korea) Corresponding author