동계 맥류의 만파 재배 시 질소 시비 방법이 생육 및 수량에 미치는 영향 = Effect of nitrogen fertilization strategies on growth and yield of winter wheat and barley under delayed sowing

다국어 초록 (Multilingual Abstract)

Global average temperatures are projected to rise by up to 6.2°C by the late 21st century, intensifying climatic variability and increasing the need for climate-adaptive technologies in agriculture. In particular, frequent high temperatures and rainfall during autumn hinder timely sowing, resulting in more delayed planting in winter cereal production. This study was conducted from 2023 to 2025 at the Field Crop Experimental Site of the National Institute of Crop Science to evaluate the effects of nitrogen split ratios and topdressing levels in wheat and barley under delayed sowing conditions.

Delayed sowing shortened the growing period and reduced early growth, resulting in yield reductions of up to 15% in wheat and 6% in barley. However, appropriate nitrogen (N) management partially mitigated these negative effects. Adjusting the N split application ratio enhanced post-winter regrowth, increased aboveground biomass at heading, and contributed to yield improvement. In contrast, increasing top-dressed N improved yield only in years with high N demand during the reproductive stage, indicating that its effectiveness depended on annual environmental conditions. In 2024, adjusting the N split ratio markedly increased tiller number and biomass, whereas in 2025, responses were limited due to low temperatures during the regrowth period.

Overall, this study demonstrates that optimizing the N split application ratio can improve yield recovery under delayed sowing conditions without increasing total N input. These findings provide fundamental information for developing crop- and environment-specific N management strategies, particularly as climate change is expected to increase the frequency of sowing delays.

목차 (Table of Contents)

• 목차 ⅰ
• List of Table ⅱ
• List of Figures ⅲ
• ABSTRACT ⅴ
• Ⅰ. 서언 1
• Ⅱ. 재료 및 방법 4
• Ⅲ. 결과 9
• Ⅳ. 고찰 32
• Ⅴ. 참고문헌 37