• The Korean Journal of Applied Statistics
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• v.27 no.7
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• pp.1187-1196
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• 2014

Italian Ryegrass (IRG), which is known as high yielding and the highest quality winter annual forage crop, is grown in mid-south area in Korea. This study aims to analyze the cause-and-effect relationship between IRG yield and climate variables such as temperature and precipitation by using IRG data and climate data of Korea Weather Bureau. From path analysis of structural equation model under multivariate normality, we found that there was a weather effect on IRG yield that the winter grass IRG yield was directly affected by spring temperature and indirectly affected by spring rainfall. These results showed that IRG can be sown in early spring in the area where it is hard to prepare for winter due to low temperature. This paper can contribute to increase IRG yield by showing the cause-and-effect relationship and this study can be extended to various structural equation models for other crops.

• Journal of The Korean Society of Grassland and Forage Science
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• v.38 no.2
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• pp.84-90
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• 2018

Cultivation of high-quality forage crop by using fallow field during winter is required for national high feed self-sufficiency and establishment of self-supply system of high-quality forage crop. Field experiments for cultivation of high-quality winter forage crop were conducted at the paddy and upland fields in Cheonan and Anseong city with treatments of single Italian ryegrass(IRG) and IRG mixed with forage barley at the paddy field and of single forage barley and forage barley mixed with IRG at the upland field in the Mid-west plain. Several cultivation conditions such as broadcasting IRG seed under standing rice, sowing time, tillage method, drainage condition, mixed sowing with forage barley were compared to know the change of growth, yield and quality of winter forage crop. In particular, over-wintering rate and dry matter yield were decreased significantly in late-sown IRG and moisture-stressed forage barley. Yield and quality of forage crops were increased by sowing after tillage, mixed sowing of IRG with barley at the paddy field with good drainage. High yield as much as dry matter $10MT\;ha^{-1}$ with high feed value could be obtained by early sowing of feed barley mixed with IRG at the upland field. Cultivation conditions such as early sowing, sowing after tillage, drainage management are required for higher dry matter yield, quality and stable cultivation of winter forage crops in the mid-west plain of Korea.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.65 no.2
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• pp.142-150
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• 2020

This experiment was conducted to set ideal harvest time for itallian ryegrass (IRG) seed in reclaimed land. For IRG 'Kowinearly' variety sown in both autumn and spring, the peak growth in reclaimed land occurred in 20-30 days after heading. Plant height of IRG seedings in the spring was 90.4% of the fall-sown's plants. The yield of IRG seeds in reclaimed land was generally lower than that of farm land due to poor growth conditions. After heading, the lodging and shattering increased gradually with time. The highest yield of seed in the fall-sown trial treatment was 238 kg/10a. However, in the spring-sown treatment, the highest yield reached 169 kg/10a, which was 71% that of the fall-sown treatment. To set optimum harvesting time for IRG seed, morphological changes in the plant, moisture content of seed, and germination rate were analyzed according to time series after heading. After heading, IRG stem color had turned pink in 18 days and seed color also changed after 20 days. Following 20-25 days after heading, the seed moisture content decreased to below 55% and germination rate increased to over 90%. Therefore optimum harvesting time for IRG 'Kowinearly' variety in reclaimed land was 20-30 days after heading because germination rate and yields were high and shattering percentage was low.

• Korean Journal of Soil Science and Fertilizer
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• v.49 no.5
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• pp.495-502
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• 2016

Italian Ryegrass (IRG), which is known as high yielding and the highest quality winter annual forage crop, is grown in mid-south area in Korea. The objective of this study was to evaluate the use of unmanned aerial vehicle (UAV) for the monitoring IRG growth. Unmanned aerial vehicle imagery obtained from middle March to late May in Nonsan, Chungcheongnam-do. Unmanned aerial vehicle imagery corrected geometrically and atmospherically to calculate normalized difference vegetation index (NDVI). We analyzed the relationships between $NDVI_{UAV}$ of IRG and biophysical measurements such as plant height, fresh weight, and dry weight over an entire IRG growth period. The similar trend between $NDVI_{UAV}$ and growth parameters was shown. Correlation analysis between $NDVI_{UAV}$ and IRG growth parameters revealed that $NDVI_{UAV}$ was highly correlated with fresh weight (r=0.988), plant height (r=0.925), and dry weight (r=0.853). According to the relationship among growth parameters and $NDVI_{UAV}$, the temporal variation of $NDVI_{UAV}$ was significant to interpret IRG growth. Four different regression models, such as (1) Linear regression function, (2) Linear regression through the origin, (3) Power function, and (4) Logistic function were developed to evaluate the relationship between temporal $NDVI_{UAV}$ and measured IRG growth parameters. The power function provided higher accurate results to predict growth parameters than linear or logistic functions using coefficient of determination. The spatial distribution map of IRG growth was in strong agreement with the field measurements in terms of geographical variation and relative numerical values when $NDVI_{UAV}$ was applied to power function. From these results, $NDVI_{UAV}$ can be used as a new tool for monitoring IRG growth.

• Journal of The Korean Society of Grassland and Forage Science
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• v.31 no.3
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• pp.261-268
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• 2011

This study was carried out to determine the forage production and quality of Italian ryegrass (IRG) and forage barley developed by Korea in Suwon, 2009~'10. The nine treatments were two IRG varieties (Kowinearly with early maturity and Kowinmaster with medium maturity), five barley varieties (Youngyang, Wooho, Yuyeon, Dami and Youho), and two mixtures (Kowinearly + Yuyeon and Kowinmaster + Yuyeon). The heading dates of Kowinearly and Kowinmaster were 14 May and 18 May, respectively. The growth stage of barley investigated at 22 May were late milk in Youngyang and Wooho, early dough in Dami and early to medium dough in Yuyeon and Youho. Plant length of IRG in IRG + barley mixtures was 117~118 cm, which was longer than those of IRG monoculture of 98~101 cm, and no lodging was found in mixtures. The dry matter (DM) percentage at harvest was 20.7~25.4% in all treatments. The botanical composition of IRG in mixtures was 43.1%. The percentage of spike per barley plant was become high according to progressed maturity, as a 35.7%, 44.1%, 54.8% and 57.2% in late milk, dough, yellowish and full ripeness stage, respectively, and the spike percentages of Youngyang and Wooho were tends to high. The crude protein (CP) content of IRG as 9.0~10.0% was higher than that of barley (7.0~8.5%), and the contents of NDF and ADF of barley were lower than those of IRG, and in vitro DM digestibility were 64.4% in Kowinearly, 64.1% in Kowinmaster, 64.5% in mixture, and 60.2% (Youho) to 66.4% (Wooho) in barley. The yields of DM, CP and in vitro digestible DM were high in Kowinmaster+barley mixture as a 11,508 kg, 1,046 kg and 7,422 kg per ha, respectively (p<0.05). However, no significant differences in forage yield were observed among cultivar of IRG, and barley, although Wooho was tends to high in digestibility and forage yield among five barley varieties. In conclusion, the mixture cultivation of IRG Kowinmaster + forage barley was recommended, because of preventing of IRG lodging, higher plant length of IRG, increasing of forage yield, and stable production. Selection of suitable winter forage species and variety for district, climate environment, and utilization type of farm was also important.

• Nuclear industry
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• no.7
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• pp.41-44
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• 1979

$\lceil$방사성폐기물관리에 관한 관계성청검토 group$\rfloor$ (IRG)는 최근 $\lceil$폐기물처리에 있어서는 질서 정연한 착실한 의지결정 program에서 추구되어 야 할 것이다.$\rfloor$라고 하는 최종보고서를 정리, 발표하였다. 이 최종보고서에서는 IRG의견해, 정책검토 권고가 들어있는 IRG에 보내진 comment에 대해서도 그 전부에 대해 반영하도록 시도되었다.

• Journal of The Korean Society of Grassland and Forage Science
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• v.36 no.4
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• pp.271-279
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• 2016

The objective of this study was to determine the effect of the moisture content and pellet mill type on the physical and chemical characteristics of Italian ryegrass (IRG) pellet. Moisture content of raw material significantly (p<0.05) affected IRG pellet formation. Moisture content at 25% was the best condition for IRG pellet formation in terms of shape, power load and temperature changes. The hardness of pellet was decreased when moisture content was increase. However, the hardness of pellet was not affected by pellet mill type. Moisture content at 30% dramatically (p<0.05) decreased the durability compared to moisture content at 25%. Dry matter content of IRG pellet was increased (p<0.05) after pelleting. Total count of microorganism was decreased in pellet due to pressure heat and moisture losses during the pelleting process. These results indicated that the proper moisture content of Italian ryegrass pelleting would be at 25%. In addition, Roll & flat die type would be more suitable than Ring die and Die & flat die type in IRG pelleting. Pelleting works would be beneficial for improving forage quality and long storage.

• Journal of The Korean Society of Grassland and Forage Science
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• v.31 no.1
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• pp.39-46
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• 2011

This study was carried out to determine the forage yield, quality, and regrowth of Italian ryegrass (IRG) and barley sown on 2 March 2009 in Suwon. The five treatments were two IRG cultivars (Kowinearly with early maturity and Kowinmaster with medium maturity), one barley cultivar (Yuyeon), and two mixtures (Kowinearly + Yuyeon and Kowinmaster + Yuyeon). The first harvest date was 26 May, which was at late heading, heading and early dough stage of Kowinearly, Kowinmaster and barley, respectively. Regrowth yield was investigated on 29 June. The heading dates of Kowinearly and Kowinmaster were 16 May and 22 May, respectively, and that of barley was 13 May. The dry matter (DM) percentage were 13.0~18.4% at first harvest, and 22.5~24.8% at regrowth in all treatments. The forage yield of barley and Kowinmaster + Yuyeon mixture at first harvest was higher than that of IRG (p<0.05), but higher regrowth yield was observed in IRG, and then IRG + barley mixtures (p<0.05). The crude protein (CP) content and in vitro DM digestibility (IVDMD) of IRG at first harvest were 16.7~17.1% and 78.3~80.4%, respectively, which were higher than those of barley (CP 12.2% and IVDMD 72.6%) and IRG + barley mixtures. The total yields of DM, CP and digestible DM were high in Kowinmaster + Yuyeon mixture as 11,628 kg, 1,669 kg and 8,457 kg per ha, respectively. In conclusion, spring seeding of IRG + barley mixtures and/or barley were recommended when early harvest. Regrowth of IRG sown in early spring was vigorous. Mixture cultivation of IRG and barley was effective, because of forage yield and stable production, and harvest at June instead of May was desirable for forage productivity of spring sown IRG and barley.

• Proceedings of the Korean Society of Crop Science Conference
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• 2017.06a
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• pp.268-268
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• 2017

Common sowing method of italian ryegrass (IRG) has been using the backpack seed sprayer (BSS) in Korea. It has weak point including a hard work and a little sowing area. This study was conducted to find out the effects of sowing IRG using unmanned helicopter (UH) under the established rice field. We checked the labour saving of sowing IRG and the growth and yield of rice after using IRG as forage crop. Two sowing implements(using by UH and backpack seed sprayer (BSS)) were tested for the ability of sowing IRG. For proper pretreatment of IRG seeds for aerial sowing using with UH, we tested one-day soaking seeds, iron-coated seeds, coated seeds sold in stores and untreated seeds. Aerial sowing of IRG seeds using UH was tested under the speed 10 km/h and flying altitude 3~4m. We tried to confirm the effects on rice growth in a paddy field after IRG had been used as forage in mid May. In 6 hours of seeding per day, UH had a seeding area of 21.8 hectares, three times wider than BSS. UH had a decrease of about 63 percent of sowing-seed cost in comparison with BSS. In the IRG aerial sowing using UH, coating seeds had the wider sowing width of 5~6 meter than 3~4 meter untreated seeds. Residual dry matter of IRG after using forage had 4.5 ton per hectare and 20 percent of top dry matter. The amount of nitrogen remaining in residual IRG in the soil was 12 kg per hectare, and the other nutrients such as calcium and potassium was incorporated into the soil with less than 10 kg/ha. The rice yield after the harvesting IRG was 5 percent higher than that of rice single cropping. Consequently, IRG sowing using UH was effective in reducing sowing time and sowing cost compared with conventional methods and, it is considered that there is a positive effect on the rice cultivation compared to rice single cropping.

• Asian-Australasian Journal of Animal Sciences
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• v.12 no.4
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• pp.531-536
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• 1999

This study was conducted to compare the effects of lactic acid bacteria (LAB) or LAB+cellulases on the cell wall compositions and the in vitro dry matter digestibility (IVDMD) of Rhodesgrass (RG) and Italian ryegrass (IRG) silages. LAB (Lactobacillus cassei) at a concentration of $10{\times}10^5\;cfu.g^{-1}$ fresh forage was added to all ensiling samples (except the untreated control) of RG and IRG. The cellulases used were Acremoniumcellulase (A), Meicelase (M) or a mixture of both (AM). Each cellulase was applied at levels of 0.005, 0.01 and 0.02 % fresh sample. The samples were incubated at 20, 30 and $40^{\circ}C$ for about 2 months of storage. LAB inoculation did not affect cell wall components or IVDMD of both the RG and IRG silages, but LAB+cellulase treatments did. Increasing the amount of cellulase addition resulted in further decreases of cell wall concentrations. This reduction more markedly occurred with cellulases A and AM than it did with cellulase M. Cell wall components losses were higher in the IRG silages than in the RG silages. LAB+cellulase treatments decreased IVDMD of the RG silages, but had no effect on the IRG silages. The different effect of LAB+cellulase treatments on cell wall degradation and IVDMD of the RG and IRG silages suggested that RG contains more structural carbohydrates, which were difficult to degrade with cellulase, than did IRG.