This study was carried out to study the effect of supplementary nitrogen fertilization application time according to regrowth date on growth date on growth characteristics, feed value, and productivity of Italian ryegrass (Lolium multiflorum Lam.; IRG) from 2019 to 2021 in Cheonan region. In order to determine the regrowth time, IRG was cut from experimental plots 3cm above soil level and the time when 1cm grew was judged as the regrowth time. The regrowth dates were February 15th and February 12th in 2020 and 2021 respectively. The experimental design was a randomized block design with three replications. The treatments were no fertilizer, immediately after the regrowth period, after 10 days of the regrowth period, and after 25 days of the regrowth period. Dry matter yield of IRG was significantly influenced by the supplementary N-fertilization application time. Dry matter yield was reduced for the delayed application time. The dry matter yield of immediately after the regrowth period was approximately 34.8 % higher than that no fertilizer application. In delaying the supplementary N-fertilization application time resulted in increased crude protein content. However, no significant statistical difference was neutral detergent fiber and acid detergent fiber(p>0.05). After wintering, productivity of IRG reduced for the delayed application time. Therefore, it is essential to application N-fertilizer immediately after the regrowth period for high productivity of IRG.

ABSTRACT
Ⅰ. 서론
Ⅱ. 재료 및 방법
    1. 시험설계
    2. 통계처리
Ⅲ. 결과 및 고찰
    1. IRG 재배지의 토양 및 기후 특성
    2. 추비 시기에 따른 IRG의 생산성
Ⅳ. 요약
Ⅵ. REFERENCES

• 이배훈(국립축산과학원) | Bae Hun Lee (National Institute of Animal Science, RDA)
• 박형수(국립축산과학원) | Hyung Soo Park (National Institute of Animal Science, RDA)
• 오미래(국립축산과학원) | Mirae Oh (National Institute of Animal Science, RDA)
• 정종성(국립축산과학원) | Jeong Sung Jung (National Institute of Animal Science, RDA) Corresponding author