Estimation of Optimum N Fertilizer and Sowing Rate for Italian Ryegrass Seed Production in the Saemangeum Reclaimed Land

Abstract

Italian ryegrass (Lolium multiflorum Lam.) was cultivated in a field experiment, on sandy loam soil of the Saemangeum reclaimed land, under different sowing rates and N fertilizer levels to estimate the optimum N fertilizer requirement and the most suitable sowing rate for seed production. The experiment was conducted in a split-plot design with four replications. The main-plots were four sowing rates of 10, 20, 30, and 40 kg ha -1 and sub-plots were five N fertilizer application rates of 0, 45, 90, 135, and 180 kg ha -1 . Harvest index decreased with increasing sowing and N fertilizer rate. The highest N use efficiency was obtained at 10 kg ha -1 sowing rate and 45 -90 kg ha -1 N fertilizer application rates. Maximum seed yield of Italian ryegrass based on the regression curve of N fertilizer application level was 102 kg ha -1 and was decreased with further N application. Economically, optimum rates of N application ranged from 70 to 101 kg ha -1 depending on the sowing rate. Results from this experiment, could therefore inform producers of the best combination of sowing and N fertilizer rates needed to increase profitability of Italian ryegrass seed production alongside preventing N loss. However, further research will be necessary to elucidate on increasing seed quality and stability of cultivation under various environmental conditions.

Spatial Variations in Salinity and Sodicity of Reclaimed Tideland Paddy Soils in Coastal Areas of Southwestern Korea

“…Though RTLs are responsible 22% of national rice production in South Korea, there are increasing social pressures on the use of RTLs for upland crops such as forage (Bae et al, 2021;Yun et al, 2021) and other cereal crops (Lee et al, 2021a(Lee et al, , 2021bOh et al, 2022) due to reduced rice consumption. Therefore, it is necessary to investigate the salinity status of RTLs for assessment of the suitability of RTLs for the cultivation of upland crops (Jeong et al, 2020).…”

Agricultural Water Salinity of Reclaimed Tidelands in Southwestern Coastal Areas of South Korea

“…따라서, 습해 우려가 없고, 재배기간 동안 주기적인 관개로 일시적 제염이 용이한 벼 (Oryza sativa L.)를 주로 재배하고 있다 (Park et al, 2022). 하지만, 최근 쌀 소비량 감소 등에 의해 간척지 밭 작물 재배 필요 성이 증가하고 있어, 간척지 토양에서 사료작물 (Jang et al, 2020;Bae et al, 2021;Yun et al, 2021), 서류 (Lee et al, 2021a), 곡류 (Lee et al, 2021b;Oh et al, 2022) 등 다양한 작물 재배를 위해 토양 염농도 관리 기술 개발에 대한 연구 가 진행되고 있다 (Jeong et al, 2020;Seo et al, 2022).…”

Soil Physico-Chemical Properties and Groundwater Levels at the “Agricultural Life Science Sites” in Saemangeum Reclaimed Land

“…하지만, 최근에는 낮 은 쌀 소비량으로 인해 논에서의 타작물 재배에 대한 관심이 급증함에 따라, 간척지에서도 벼 외에 밭작물을 재배하기 위한 전략을 수립하여 추진하고 있다 (MAFRA, 2020). 이러한 전략에 맞춰 새만금간척지는 내부 토지 29,100 ha와 담수호 11,800 ha가 계획되었으며 (Shin, 2011;Ryu et al, 2020), 30%인 8,570 ha가 현재 밭작물 재배를 목적으로 개 발되고 있다 (Bae et al, 2021).…”