Ⅰ. INTRODUCTION
Alfalfa (Medicago sativa L.) is a perennial forage legume distinguished by its deep taproot system, purple flowers, and spiraled pods (Mielmann, 2013). Recognized as one of the oldest cultivated forage crops, its origin is thought to lie in Asia Minor, the Caucasus, or Central Asia (Wang and Şakiroğlu, 2021). Alfalfa is highly valued for its wide adaptability and tolerance to abiotic stresses such as drought, salinity, and heat (Shi et al., 2017;Sălceanu et al., 2023). Compared with grasses, it has faster fiber digestibility, high crude protein, and abundant vitamins, thereby enhancing livestock productivity and overall health (Undersander, 2021). With these nutritional and agronomic advantages, alfalfa is cultivated across more than 30 million hectares worldwide, particularly in North America, Europe, and Asia (Wang and Zhang, 2023). Despite its global importance, alfalfa growth is strongly influenced by soil physical and chemical properties (Orloff, 2007). In particular, excess soil moisture often results in root diseases that reduce yield and stand persistence (Malvick and Grau, 2016). In Korea, limited availability of deep soils (NGII, 2020) and the predominance of paddy and reclaimed lands for forage cultivation exacerbate these environmental stresses, constraining alfalfa production. Consequently, domestic alfalfa supply relies predominantly on imports, accounting for a substantial proportion of total forage imports. This dependence results in considerable foreign currency expenditure (MAFRA, 2024). Such reliance on imports leaves Korea vulnerable to market volatility and supply instability linked to climate change or geopolitical risks. Efforts to introduce alfalfa into Korea began decades ago, and multiple trials have sought to establish reliable cultivation techniques (Kim et al., 2023). Nevertheless, most approaches have been confined to experimental trials, and commercial-scale cultivation of alfalfa has not been established in Korea. For successful expansion of alfalfa cultivation, developing new cultivars specifically adapted to domestic conditions is critical. Similar initiatives have been undertaken elsewhere: Japan developed locally adapted varieties due to the poor performance of foreign cultivars in its warm, humid climate (Inami, 1988); the United States expanded alfalfa in the early 20th century through breeding programs targeting the northern Great Plains (Boe et al., 2020); and in China, where alfalfa is believed to have originated, breeding programs have focused on producing varieties suited to diverse environments and production needs (Shi et al., 2017). In line with these global breeding efforts, the National Institute of Animal Science (NIAS), Rural Development Administration, has been actively collecting diverse germplasm resources and conducting crossbreeding programs to develop cultivars adapted to Korean agro-climatic conditions. These efforts led to the release of ‘Alfaking’ (Lee et al., 2024), which showed strong adaptability and productivity. However, breeding guidelines worldwide emphasize that sustainable alfalfa production requires not only cultivars with appropriate fall dormancy, winter hardiness, and disease resistance, but also diversification of varieties to buffer against environmental variability and pest outbreaks (Rice et al., 2019). Against this backdrop, a new alfalfa variety named ‘Alfaone’ has been developed and submitted for registration to the Korea Seed and Variety Service (KSVS). This study aimed to characterize its agronomic traits, dry matter yield, and forage quality under diverse Korean environments, thereby evaluating its potential contribution to stabilizing domestic alfalfa production and reducing dependence on imports.
Ⅱ. MATERIALS AND METHODS
This study was carried out from 2015 to 2023 at the Forage Production Systems Division, National Institute of Animal Science (NIAS), Rural Development Administration (RDA), with the objective of developing a new alfalfa (Medicago sativa L.) variety possessing superior adaptability to Korean climatic conditions.
1. Selection of lines and development of breeding crosses
Since 2015, alfalfa germplasm maintained by the National Institute of Animal Science (NIAS), together with a wide range of domestic and international varieties, has been screened in the breeding greenhouse for fundamental growth characteristics. In 2016, an artificial cross was performed using Xun Lu as the female parent and RadarⅡ Brand as the male parent, the resulting F1 generation was established. From the F3 generation onward, pedigree breeding was employed to select promising lines. In the 2021 yield trial, one line showing excellent seedling vigor and high productivity was designated as ‘MsCB01’. After completing two years of regional adaptability trials (2022–2023), this line was confirmed to possess outstanding agronomic performance and was officially released as ‘Alfaone’ by the New Variety Selection Committee in July 2023 (Fig. 1).
2. Characterization of agronomic traits in ‘Alfaone’
In 2021, yield trials for the alfalfa breeding line later released as ‘Alfaone’ were carried out at the experimental field at the Forage Production Systems Division, National Institute of Animal Science (NIAS). The agronomic characteristics of this line were assessed following the standard evaluation procedures for alfalfa varieties established by the Korea Seed and Variety Service (KSVS).
3. Regional adaptability trials
Regional adaptability tests for the alfalfa breeding line later released as ‘Alfaone’ were carried out from 2022 to 2023 at four experimental sites: Cheonan, Pyeongchang, Jeongeup, and Jinju, under a collaborative variety development program of the Rural Development Administration (RDA). The candidate line was evaluated in comparison with the standard check variety ‘Vernal’ to determine its adaptability, agronomic traits, and forage productivity. Sowing was conducted on September 28, 2021, in Cheonan; September 14 in Pyeongchang; September 23 in Jeongeup; and October 8 in Jinju. The seeding rate was 20 kg/ha, and 2 × 3 m2 plots were established by drill seeding with 20 cm row spacing; each cultivar was replicated three times. Fertilizer management followed the general recommendations for alfalfa cultivation described by Song et al. (2021). A basal application of fertilizer (N–P₂O₅–K₂O = 80–200 –70 kg/ha) was made at sowing. Maintenance fertilization during the growing season consisted of P₂O₅–K₂O = 150–200 kg/ha, with K₂O applied in split doses of 50 kg/ha in early spring and after each harvest, and P₂O₅ applied entirely at 150 kg/ha in early spring.
4. Forage nutritive value analysis
The forage quality of the alfalfa breeding line later released as ‘Alfaone’ was determined according to the analytical procedures described by Park et al. (2012). Crude protein (CP) concentration was measured using the Kjeldahl procedure with a Kjeltec™ 2400 Autosampler System, following the AOAC (1990) guidelines. The contents of acid detergent fiber (ADF) and neutral detergent fiber (NDF) were quantified using an Ankom Fiber Analyzer (Ankom Technology, 2005a;2005b) with all solutions prepared following according to the method of Goering and Van Soest (1970). The total digestible nutrient (TDN) was analyzed and calculated using the method of Menke and Huss (1980). In vitro dry matter digestibility (IVDMD) was assessed by applying the modified protocol of Moore (1970), which is based on the original procedure of Tilley and Terry (1963).
5. Statistical analysis
All statistical analyses were performed using SAS software (version 9.1.3, SAS Institute Inc., Cary, NC, USA). Mean differences between the test variety and the control (‘Vernal’) were evaluated with Student’s t-test, and statistical significance was considered at the p<0.05 level.
Ⅲ. RESULTS AND DISCUSSION
1. Agronomic characteristics of the new alfalfa variety ‘Alfaone’
The principal morphological and agronomic traits of the new alfalfa variety ‘Alfaone’ are summarized in Table 1. The variety shows an upright growth form with elongated oval leaves of green color, and the flowers are dark purple in appearance. ‘Alfaone’ demonstrated excellent regrowth following winter dormancy, with strong tolerance to diseases. Lodging resistance was also favorable, indicating low vulnerability to lodging stress. The flowering time of ‘Alfaone’ occurred around May 11, which was nearly identical to that of the standard cultivar ‘Vernal’. At the early flowering stage, plant length of ‘Alfaone’ was 93.0 cm, which is 1.3 cm longer than ‘Vernal’, and its plant height (51.5 cm) was also greater. The mean plant height measured from the second to fourth harvests averaged 48.9 cm, which was taller than that of ‘Vernal’ across successive cuts (Table 1).
2. Dry matter yield of the new alfalfa variety ‘Alfaone’
Regional yield trials were carried out over two years (2022– 2023) at four sites—Cheonan, Pyeongchang, Jeongeup, and Jinju —to evaluate the adaptability and productivity of ‘Alfaone’. The mean dry matter yield across all locations was 20,811 kg/ha, which was about 3% greater than that of the reference variety ‘Vernal’ (20,236 kg/ha). When compared across regions, the yield advantage of ‘Alfaone’ was particularly pronounced in Pyeongchang, where the cultivar demonstrated superior productivity. This result suggests that ‘Alfaone’ possesses strong cold tolerance and can be considered highly adaptable to harsh winter conditions (Table 2).
These findings indicate that the new cultivar ‘Alfaone’ combines stable forage quality with higher yield potential and long-term persistence under Korean growing environments. In addition, ‘Alfaone’ exhibited superior regrowth ability after cutting, further supporting its persistence and adaptability. The improved adaptability and sustained productivity of ‘Alfaone’ make it a valuable alternative to imported cultivars such as ‘Vernal’ (Fig. 2).
3. Forage nutritive value of new alfalfa variety 'Alfaone'
The forage nutritive properties of the newly developed alfalfa variety ‘Alfaone’ were assessed relative to the reference cultivar ‘Vernal’ (Table 3). ‘Alfaone’ demonstrated a forage quality profile similar to that of ‘Vernal’, which indicates that its yield gains were not offset by declines in nutritive value. Specifically, ‘Alfaone’ showed crude protein, fiber fraction, and digestibility metrics aligning with those reported for toptier alfalfa cultivars. Consistent with findings by Wan et al. (2022), where fertilizer application raised both yield and crude protein while reducing ADF/NDF in alfalfa in China, ‘Alfaone’ exhibits similar trends without sacrificing productivity. The reduced‐lignin varieties described by Gerhardt et al. (2025) also support the potential to improve forage digestibility with minimal yield trade-offs. Moreover, high-energy alfalfa lines selected for elevated non-fiber carbohydrate in roots or stems, as in Claessens et al. (2025), show enhanced nutritive value similar to that of ‘Alfaone’. Additional studies, such as remote sensing and field sampling by Yu et al. (2024), have shown that environmental and phenotypic variables can reliably predict quality traits (CP, ADF, NDF) in multi-region trials. These works reinforce that ‘Alfaone’ achieving both stable forage nutritive quality and elevated yield makes it a strong candidate for breeding programs seeking to overcome the common trade-off between yield and quality.
Ⅳ. CONCLUSIONS
This research, carried out from 2015 to 2023 by the Forage Production Systems Division of the National Institute of Animal Science (NIAS), Rural Development Administration (RDA), focused on developing a new alfalfa cultivar with improved adaptability to Korean growing conditions and stable productivity. The resulting variety, ‘Alfaone’, displays an erect growth type with green foliage and produces purple flowers, with a flowering time in mid-May, comparable to the standard cultivar ‘Vernal’. At the early flowering stage, plants of ‘Alfaone’ reached a height of about 91 cm. In regional adaptability trials conducted for two consecutive years at four representative sites, the average dry matter yield of ‘Alfaone’ was 20.8 tons/ha, approximately 3% higher than that of ‘Vernal’. Yield advantages were particularly evident in colder regions, indicating enhanced winter hardiness. Regarding forage nutritive value, ‘Alfaone’ showed crude protein, fiber fractions, and digestibility levels comparable to those of ‘Vernal’, confirming that its yield gains were achieved without compromising forage quality. With its strong adaptability to diverse Korean environments and consistent performance, ‘Alfaone’ represents a promising cultivar for nationwide forage production and pasture establishment.
