난지형 목초를 활용한 연중 조사료 생산 및 방목체계 구축 연구

Abstract

In Korea, cool season grasses produce ample forage in the spring and fall, but high temperatures and short-term drought stress often limit growth during the summer months. Warm season grasses can fill this gap with relatively high quality forage when properly managed. In the subtropical zone of the Korea, it is possible to use both cool season grasses and warm season grasses to extend the grazing season. A series of experiments was conducted to evaluate (1) the effects of sowing methods and growth stages on growth characteristics, forage productivity and feed value of warm season grass, (2) effects of seed mixture and seeding frequency on botanical composition, forage productivity and liveweight gain in horse grazing pasture, and (3) effects of seeding rates of Italian ryegrass interseeded into bermudagrass sod on the forage productivity and botanical composition of Italian ryegrass and bermudagrass. The results can be summarized as following. This study evaluated the effects of sowing methods and growth stages on growth characteristics, forage productivity and feed value of warm season grass. The southern type grasses announced for the test were the Bermudagrass cultivars (Giant, Cheyenne, Mohawk, Panchero Frio, Common and Tifton 85) and the Bahiagrass cultivars (TifQuik, Tifton 9, Argentine), and one Teff grass cultivars (Tiffany) and the changes in the productivity and nutrient content were surveyed in Jeju area (450m altitude). The different cultivars were sowed by broadcasting or drill seeding method, and Tifton 85 was transplanted from sprigs. The fresh and dry matter yield showed varying significant differences for different cultivars (p<0.05). The fresh yields of Tifton 85, TifQuik and Tifton 9 were excellent, compared to the other cultivars, and for the dry matter yield, Tifton 85 and Tifton 9 were excellent when compared to the other cultivars. Crude protein content showed significant differences among different cultivars (p<0.05). Cheyenne, Mohawk, Panchero Frio, and Common showed differences in the crude protein content by sowing method and harvest time (p<0.05). The different cultivars showed differences in the crude fiber content (p<0.05), and Tifton 9 registered significantly high content and Mohawk and Tifton 85 showed significant crude fiber content by harvest time (p<0.05). According to these results, the southern type grass cultivars showed big differences in the regenerative capacity against damage from frost, productivity, and nutrient content, so they need to be chosen according to the purposes, and to increase their usage, their evaluation needs to be conducted at various altitudes. This study was carried out to determine the effects of seed mixture and seeding frequency on botanical composition, forage productivity and liveweight gain in horse gazing pasture. Experimental plot was located at 450 m altitude within Jeju racehorse breeding farm, Korea Racing Authority in Jeju from 2016 to 2017. Total six experimental pastures (T1: Newly established with orchardgrass (OG) + perennial ryegrass (PRG), T2: Old pasture overseeded with OG+PRG T3: Tall fescue monoculture, T4: Bermudagrass monoculture, T5: Bahiagrass monoculture) were established in autumn, 2015 for cool season grass pasture and established in spring, 2016 for warm season grass. In grass composition of pasture, the T3 (tall fescue monculture, 79 %) was highest in cool season grass based mixture pasture and warm season grass based pasture (T4, T5, 85~87 %) maintained higher than cool season grass based pasture (T1, T2, T3). Average annual dry matter (DM) yield was the highest at T3 (13,235 kg/ha), then with T5 and T4, average annual DM yield was 12,237 kg/ha and 11,412 kg/ha, respectively. In grazing effects, Content of crude protein (CP) and total digestibility nutrients (TDN) was the highest at T1 ( CP 12.02, TDN 00) in cool season grass based mixture and warm season grass based pasture showed high in ADF (acid detergent fiber) and NDF (neutral detergent fiber) content. Daily DM intake was highest at T1 (11 kg/head), then with T4 (10.3 kg/head) and T5 (9.9 kg/head). Average daily gain for growing horses was highest at Tl (0.59 kg/day) in cool season grass mixture pasture, but T4 (0.57 kg/day) and T5 (0.55 kg/day) in warm season grass pasture were not significant. This study was carried out to determine the effects of seeding rates of Italian ryegrass interseeded into bermudagrass sod on the forage productivity and botanical composition of Italian ryegrass and bermudagrass. Experimental plot was located at 450 and 350 m altitude within Jeju racehorse breeding farm, Korea Racing Authority in Jeju from 2012 to 2014. Seeding rate treatments of Italian ryegrass into bermudagrass sod were arranged in a randomized complete block design replicated three times. Italian ryegrass was drilled in row 18cm apart after clipping the bermudagrass at a cutting height of 2~3 cm. Seeding rate was 20, 30 and 40 kg/ha on planting 15 October. In botanical composition, Italian ryegrass was dominant in pasture growing season during early spring through late spring season and bermudagrass was dominant during early summer through early fall. The dry matter yield of Italian ryegrass was higher in 40 kg/ha seeding amount, the dry matter yields of 30 kg/ha and 40 kg/ha seeding amount were not different. The Italian ryegrass overseeding into bermudagrass sod affect the dry matter yield in the summer harvests of bermudagrass, and the dry matter yield of bermudagrass showed the highest in 30 kg/ha seeding amount. Total annual dry matter yield of overseeding Italian ryegrass into bermudagrass sod showed the highest in 30 kg/ha Italian ryegrass seeding amount (30,559 kg/ha). In conclusion, overseeding warm season perennial grasses with cool season annual forages in the southern Korea has many benefits.