• Korean Journal of Soil Science and Fertilizer
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• v.50 no.5
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• pp.391-400
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• 2017

Italian ryegrass (IRG) is one of the fastest growing grasses available to farmers. It offers rapid establishment and starts growing early in the following spring and has fast regrowth after defoliation. So, IRG can be utilized as the dominant/single species of grass used in a farming system, or to play a role as a large producing pasture and sacrificial paddock. The objective of this study was to develop the use of unmanned aerial vehicle (UAV) for the evaluation of feed value of IRG. For this study, UAV imagery was taken on the Nonsan regions two times during the IRG growing season. We analyzed the relationships between $NDVI_{UAV}$ and feed value parameters such as fresh matter yield, dry matter yield, acid detergent fiber (ADF), neutral detergent fiber (NDF), total digestible nutrient (TDN) and crude protein at the season of harvest. Correlation analysis between $NDVI_{UAV}$ and feed value parameters of IRG revealed that $NDVI_{UAV}$ correlated well with crude protein (r = 0.745), and fresh matter yield (r = 0.655). According to the relationship, the variation of $NDVI_{UAV}$ was significant to interpret feed value parameters of IRG. Eight different regression models such as Linear, Logarithmic, Inverse, Quadratic, Cubic, Power, S, and Exponential model were used to estimate IRG feed value parameters. The S and exponential model provided more accurate results to predict fresh matter yield and crude protein than other models based on coefficient of determination, p- and F-value. The spatial distribution map of feed values in IRG plot was in strong agreement with the field measurements in terms of geographical variation and relative numerical values when $NDVI_{UAV}$ was applied to regression equation. These lead to the result that the characteristics of variations in feed value of IRG according to $NDVI_{UAV}$ were well reflected in the model.

• Journal of The Korean Society of Grassland and Forage Science
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• v.40 no.4
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• pp.265-273
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• 2020

We aimed to predict the Italian ryegrass (IRG) productivity change of introduced and domestic varieties based on climate factors and identify suitable areas for IRG cultivation using the RCP 8.5 scenario. The minimum mean air temperature in January showed the highest correlation with productivity. The ratio of possible and low productivity areas was high in Gangwondo, and the ratio of suitable and best suitable areas was relatively high in the central and southern regions in the past 30 years. The change in the IRG cultivation area was found to be 26.9% in the best suitable area between 1981-2010 but increased significantly to 88.9% between 2090s. In the IRG suitability comparison classes between domestic and introduced cultivars, the ratio of suitable and best suitable areas was relatively high in the domestic varieties during the past 30 years. However, there is almost no difference between the IRG domestic and introduced varieties in the IRG suitability classes after the 2050s. These results can predict changes in the IRG suitability classes between domestic and introduced cultivars according to the climate change scenario, but there are limitations in accurately predicting the productivity of IRG because the results may vary depending on other environmental factors.

• Journal of The Korean Society of Grassland and Forage Science
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• v.30 no.2
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• pp.115-120
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• 2010

This study was carried out to determine the forage production and quality of Italian ryegrass (IRG) and forage barley sown in early spring in Suwon, 2009. The five treatments used in this experiment were IRG Kowinearly (early maturity), IRG Kowinmaster (medium maturity), Yuyeon barley, Kowinearly + Yuyeon mixture, and Kowinmaster + Yuyeon mixture. The lodging was observed in IRG, but no lodging was found IRG + barley mixtures. The heading date of Kowinearly and Kowinmaster were 16 May and 22 May, respectively, and that of barley was 13 May. The dry matter (DM) percentage at harvest was 22.2~27.6%. The forage quality among treatments were similar, but the crude protein (CP) content of IRG was higher than that of barley, and in vitro DM digestibility was a little low in Kowinmaster. The yields of DM, CP and digestible DM were high in Kowinearly + Yuyeon barley mixtures as a 13,816 kg, 1,384 kg and 10,387 kg per ha, respectively (p<0.05). In conclusion, the mixture cultivation of IRG and forage barley was very effective, because of preventing of IRG lodging, increasing of forage yield, and stable production of forages. The optimum harvest date for silage manufacture of IRG and barley sown in early spring was recommended early June instead of May.

• Journal of The Korean Society of Grassland and Forage Science
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• v.39 no.4
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• pp.207-215
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• 2019

This study was conducted to establish spring sowing techniques in preparation for the impacts of climate change on sowing time and wintering rates of winter forage crops such as barley, oat and IRG. Oat showed the highest yield in 2017 which had relatively dry climate condition. And when sowing in late Febrnary 2017 yielding 9,408kg/ha were obtained, yielding 4,011kg/ha more than IRG's sown in the same period. In 2018 which had relatively wet climate condition, four barley species decreased in the production from the previous year. Oat also had decreased by 70% from 9,408kg/ha to 2,851kg/ha. On the other hand, IRG maintained the production in the mid-5,000kg/ha range. It was also found that IRG had the least variability due to external influences regardless of seeding period for 2 years. Mixed sowing with IRG and oat in 50:50 ratio was the highest dry matter, 6,584kg/ha, and IRG was 18.5% and Oat was 2.3 times higher than single planting.

• Korean Journal of Soil Science and Fertilizer
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• v.45 no.3
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• pp.385-392
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• 2012

This study was conducted to find out the optimum cropping system for the stable production of forage crops in the newly reclaimed land located at Gwanghwal and Gyehwa region of Saemangum reclaimed tide land from October, 2009 to October, 2011. Whole crop barley (WCB), Rye, Italyan-ryegrass (IRG) as winter crops and Corn, Sorghum${\times}$sudangrass hybrid (SSH) as summer crops were cultivated. Soil chemical properties, nutrient uptake, feed value, growth and yield were examinated. The testing soil was showed saline alkali soil where the contents of organic matter, available phosphate and exchangeable calcium were very low, while exchangeable sodium and magnesium were higher. Changes of soil salinity during the growing season of forage crops were less than 0.2%, and the growth of forage crops was not affected by salt injury. Standing rates of winter crops were higher in the order of Rye, WCB, and IRG, while the dry matter yield of winter crops was higher in the order of IRG, Rye and WCB. The highest crude protein (CP) content was recorded in IRG, and total digestive nutrients (TDN) contents were increased in the order of WCB, IRG, and Rye. The TDN content was higher in corn, whereas other feed value was higher in SSH. The content of mineral nutrients on stem, leaf and grain in IRG, Corn were high. After experiment pH was lowed, contents of exchangeable magnesium, sodium and organic matter were decreased while contents of total nitrogen, available phosphate and exchangeable potassium, calcium were increased. Winer crops and summer crops after continually cultivating in cropping system, fresh matter yield increased, compared to WCB-Corn (74,740 kg $ha^{-1}$), IRG-SSH 10%, IRG-Corn 7%, Rye-SSH 6%, Rye-Corn and WCB-SSH 3%. Dry matter yield increased, compared to WCB-Corn (20,280 kg $ha^{-1}$), IRG-SSH 7%, Rye-SSH 6%, IRG-Corn/Rye-Corn/WCB-SSH 3%. The TDN yield increased, compared to WCB-Corn (13,830 kg $ha^{-1}$), IRG-SSH 2%, WCB-SSH and IRG-Corn 1%. Therefore, we suggest that the crop combination of IRG-SSH and WCB-SSH would be preferred for silage stable production.

• Journal of Korea Multimedia Society
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• v.5 no.1
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• pp.120-127
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• 2002

The common problems found in the data mining methods current in use have following problems. First: It is ineffective in searching for frequent items due to changing of minimal support values. Second: It is not adaptable to occurring of unuseful relation rules. Third: It is very difficult to re-use preceding results while adding new transactions. In this paper, we introduce a new method named as SPM-IRG(Selective Patters Mining using item Relation Graph), that is designed to solve above listed problems. SPM-IRG method creates a frequent items using minimal support values obtained by investigating direct or indirect relation of all items in transaction. Moreover, the new method can minimize inefficiency of existing method by constructing frequent items using only the items that we are interested.

• Journal of The Korean Society of Grassland and Forage Science
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• v.34 no.1
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• pp.9-14
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• 2014

This experiment was carried out to order to determine the forage production and soil characteristics in mixtures of Italian ryegrass (IRG) and annual legumes at the riverbed. The IRG and hairy vetch mixture had the highest in fresh, dry matter (DM) as well as total digestible nutrients (TDN) yields among the forage mixtures. Further IRG and hairy vetch mixture had the highest in DM content. The crude protein (CP) content of IRG and hairy vetch mixture was the highest, Whereas non-fiber carbohydrate (NFC) and TDN contents were lower compared to other mixtures. The total nitrogen (TN) of IRG and hairy vetch mixture was the highest due to high nitrogen fixation in the riverbed soil. The IRG and rape mixture was the highest in organic matter (OM) of soil. Moreover, the available $P_2O_5$ of soil in IRG and crimson clover mixtures was higher compared to other mixtures. Further, the IRG and hairy vetch mixture was the highest in cation exchange capacity (CEC) content. Therefore IRG and hairy vetch mixture is more suitable in forage mixtures due to high forage production and protein as well as high soil CEC content at the riverbed.

• Journal of The Korean Society of Grassland and Forage Science
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• v.33 no.4
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• pp.275-280
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• 2013

We examined the use of basic forage data and indicators of forage productivity in different regions of Korea. The productivity of winter forage crops was evaluated from mid to late May 2012 by directly collecting information from farmhouses. A survey of winter forage crop productivity was conducted with 66 farmers in 16 regions; including, Italian ryegrass (IRG) from 22 farmers in 11 regions, whole crop barley from 21 farmers in eight regions, rye from 11 farmers in five regions, and IRG mixed with whole crop barley from 12 farmers in six regions. The results indicated that the Konju region exhibited higher yields of dry matter (DM) forage (15,128 kg/ha) and that the Dangjin region (reclaimed land) showed the lowest (3,885 kg/ha). The average yield of DM forage was 9,418 kg/ha. Yields of whole crop barley and IRG mixed with whole crop barley were comparatively higher than those of rye and IRG. We conclude that overall forage productivity was influenced by farmer's cultivation ability rather than the forage cultivation environment.

• Korean Journal of Agricultural Science
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• v.47 no.4
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• pp.941-949
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• 2020

This study evaluated the nutritional value of Italian ryegrass (IRG) as a forage source for Hanwoo. The nutritional value of IRG was assessed and compared to that of rice straw, oat hay, and timothy hay using two different methods: 1) in vitro ruminal fermentation 2) in vivo total tract digestibility. In vitro DM digestibility was lower in rice straw compared to the other three forage sources after both 24 and 48 h of incubation (p < 0.01). Among the four forage sources, IRG had a higher NH3-N concentration after both 24 and 48 h of incubation (p < 0.01). In the in vivo digestibility trials, four different substrates were used: 1) 80% concentrate with 20% rice straw, 2) 80% concentrate with 20% oat hay, 3) 80% concentrate with 20% IRG, and 4) 80% concentrate with 20% timothy hay. The dry matter, crude protein, non-fiber carbohydrate, and detergent fiber digestibility were the greatest in the C80-IRG20 among the four forage groups. In summary, IRG had a similar level of energy efficiency compared to oat hay and timothy hay. Furthermore, the result of the chemical composition analysis showing a higher ammonia concentration in the in vitro fermentation experiment and the high protein digestibility in the in vivo experiment indicate that IRG is a good source of protein compared to oat hay and timothy hay.

• Journal of The Korean Society of Grassland and Forage Science
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• v.43 no.2
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• pp.103-108
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• 2023

Due to the recent impact of global warming, heavy rainfall and droughts have been occurring regardless of the season, affecting the growth of Italian ryegrass (IRG), a winter forage crop. Particularly, delayed sowing due to frequent heavy rainfall or autumn droughts leads to poor growth and reduced winter survival rates. Therefore, techniques to improve yield through additional sowing in spring have been implemented. In this study, the growth of IRG sown in Spring and Autumn was compared and analyzed using vegetation indices during the months of April and May. Spectral data was collected using an Unmanned Aerial Vehicle (UAV) equipped with a hyperspectral sensor, and the following vegetation indices were utilized: Normalized Difference Vegetation Index; NDVI, Normalized Difference Red Edge Index; NDRE (I), Chlorophyll Index, Red Green Ratio Index; RGRI, Enhanced Vegetation Index; EVI and Carotenoid Reflectance Index 1; CRI1. Indices related to chlorophyll concentration exhibited similar trends. RGRI of IRG sown in autumn increased during the experimental period, while IRG sown in spring showed a decreasing trend. The results of RGRI in IRG indicated differences in optical characteristics by sowing seasons compared to the other vegetation indices. Our findings showed that the timing of sowing influences the optical growth characteristics of crops by the results of various vegetation indices presented in this study. Further research, including the development of optimal vegetation indices related to IRG growth, is necessary in the future.