• Proceedings of the Korean Society of Grassland Science Conference
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• 2001.06a
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• pp.103.1-103
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• 2001

• Journal of The Korean Society of Grassland and Forage Science
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• v.38 no.3
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• pp.170-174
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• 2018

Environmental stresses caused by climate change, such as high temperature, drought and salinity severely impact plant growth and productivity. Among these factors, high temperature stress will become more severe during summer. In this study, we examined physiological and molecular responses of maize plants to high temperature stress during summer. Highest level of $H_2O_2$ was observed in maize leaves collected July 26 compared with June 25 and July 12. Results indicated that high temperature stress triggers production of reactive oxygen species (ROS) in maize leaves. In addition, photosynthetic efficiency (Fv/Fm) sharply decreased in leaves with increasing air temperatures during the day in the field. RT-PCR analysis of maize plants exposed to high temperatures of during the day in field revealed increased accumulation of mitochondrial and chloroplastic small heat shock protein (HSP) transcripts. Results demonstrate that Fv/Fm values and organelle-localized small HSP gene could be used as physiological and molecular indicators of plants impacted by environmental stresses.

• Journal of The Korean Society of Grassland and Forage Science
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• v.14 no.4
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• pp.264-270
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• 1994

This experiment was undertaken to determine the effect of pasture ages on the total production and seasonal yield trends, botanical composition and forage quality of pasture mixtures. This experiment was conducted at the Livestock Experiment Station, RDA, Suweon. The results obtained were as follows : 1. Total dry matterDM) yield of pasture mixtures was the highest in the first year, and thereafter no significant reduction in the 2nd through the 4th year, but decreased by 30% in the 5th year. 2. The 34.4% of total DM yield was produced at the first cut, and decreased from then on. Total DM yield of pasture mixtures varied by year and climatic facton. In 1992, Total DM and TDN yields of pasture mixtures were 13.4 and 8.5 IvlT/ha, respectively. 3. The content of crude protein(CP), in virro DM digestibility(IVDMD) and TDN of pasture mixtures were 12-14, 70-80, and 62-65%, respectively. The highest forage quality was obtained at the 4th cutting. 4. The botanical compositions of legumes and weeds were increased as the year of establishment advanced, and highly increased at the 3rd cut after summer growth. 5. Based on the results of this study it appears that economic forage production could be expended to the 4th year with proper management, and the special renovation techniques may be needed for maintenance of pasture yield from the 5th year.

• Asian-Australasian Journal of Animal Sciences
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• v.28 no.5
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• pp.703-715
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• 2015

One of the challenges to increase milk production in a large pasture-based herd with an automatic milking system (AMS) is to grow forages within a 1- km radius, as increases in walking distance increases milking interval and reduces yield. The main objective of this study was to explore sustainable forage option technologies that can supply high amount of grazeable forages for AMS herds using the Agricultural Production Systems Simulator (APSIM) model. Three different basic simulation scenarios (with irrigation) were carried out using forage crops (namely maize, soybean and sorghum) for the spring-summer period. Subsequent crops in the three scenarios were forage rape over-sown with ryegrass. Each individual simulation was run using actual climatic records for the period from 1900 to 2010. Simulated highest forage yields in maize, soybean and sorghum- (each followed by forage rape-ryegrass) based rotations were 28.2, 22.9, and 19.3 t dry matter/ha, respectively. The simulations suggested that the irrigation requirement could increase by up to 18%, 16%, and 17% respectively in those rotations in El-Nino years compared to neutral years. On the other hand, irrigation requirement could increase by up to 25%, 23%, and 32% in maize, soybean and sorghum based rotations in El-Nino years compared to La-Nina years. However, irrigation requirement could decrease by up to 8%, 7%, and 13% in maize, soybean and sorghum based rotations in La-Nina years compared to neutral years. The major implication of this study is that APSIM models have potentials in devising preferred forage options to maximise grazeable forage yield which may create the opportunity to grow more forage in small areas around the AMS which in turn will minimise walking distance and milking interval and thus increase milk production. Our analyses also suggest that simulation analysis may provide decision support during climatic uncertainty.

• Journal of The Korean Society of Grassland and Forage Science
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• v.41 no.2
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• pp.71-76
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• 2021

In order to establish optimal double cropping system for getting the maximum annual productivity, we investigated annual fresh and dry yields of winter forage crops (WFC), Italian ryegrass (IRG) 'Kowinearly', triticale 'Joseong' and summer forage crop (SFC), 'Jonong' and 'Jowoo' as whole crop silage rice in the paddy field of Yeongseo of Gangwon Province. The double cropping of each crops was applied with 2 standard cultivation method of WFC and SFC from 2018 to 2020. For the WFC, the average percentage of dry matter (29.6%) of IRG 'Kowinearly' was lower than that (35.5%) of triticale 'Joseong'. The average fresh matter yield of IR G 'Kowinearly' was 2,662kg/10a that there was no significant difference from the 2,836kg/10a of triticale 'Joseong'. The average dry matter yield (996kg/10a) of triticale 'Joseong' was more than that (696kg/10a) of IRG 'Kowinearly'. For the summer forage crops, the average percentage of dry matter of whole crop silage rice, 'Jonong' was 34.5% that there was no significant difference from the 35.0% of 'Jowoo'. The average fresh matter yield (5,367kg/10a) of 'Jowoo' was more than that (3,966kg/10a) of 'Jonong'. And the average dry matter yield (1,936kg/10a) of 'Jowoo' was more than that (1,433kg/10a) of 'Jonong'. The total maximum dry matter yield was 2,982kg/10a with the combination of the WFC triticale, 'Joseong' and the SFC whole crop silage rice, 'Jowoo'. In conclusion, the combination of crops that can obtain the maximum yield of high quality forage for double cropping is sowing the WFC triticale, 'Joseong' in mid-October, harvesting 'Joseong' around the end of May and then SFC whole crop silage rice, 'Jowoo', to be transplanted in early June.

• Journal of The Korean Society of Grassland and Forage Science
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• v.41 no.3
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• pp.198-204
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• 2021

Intercropping cereals with legumes is known to improve forage production and crude protein yield. Sorghum × sudangrass hybrids (SSH) have excellent dry matter content and high cultivation temperatures. In this study, we investigated the growth characteristics, forage productivity, and feed value of intercropping SSH with different legumes in rice paddy fields. We used five treatments in this study SSH monocropping and four intercropping treatments of SSH with, lablab, cowpea, sesbania, and two cultivars of soybean (Chookdu 1 and 2). SSH plant height was not significantly different between the monocropping and intercropping treatments. However, the plant heights of lablab, cowpea, and sesbania were significantly higher than those of the two soybean cultivars. The total dry matter yield (kg/ha) was significantly higher in SSH monocropping than in intercropping; among the intercropping treatments, the one with SSH and Chookdu 2 yielded the highest total dry matter yield. The SSH feed value was significantly different between the monocropping and intercropping treatments, although there were no differences between the intercropping treatments. Among the intercropped legumes, lablab showed the highest neutral detergent fiber and acid detergent fiber contents, and cowpea had the highest crude protein content. These results reveal that intercropping SSH with legumes in paddy fields could be a promising cultivation technique to maintain stable forage productivity.

• Journal of Animal Science and Technology
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• v.65 no.4
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• pp.792-803
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• 2023

This study aimed to assess the impact of weather events on the sorghum-sudangrass hybrid (Sorghum bicolor L.) cultivar production trend in the central inland region of Korea during the monsoon season, using time series analysis. The sorghum-sudangrass production data collected between 1988 and 2013 were compiled along with the production year's weather data. The growing degree days (GDD), accumulated rainfall, and sunshine duration were used to assess their impacts on forage production (kg/ha) trend. Conversely, GDD and accumulated rainfall had positive and negative effects on the trend of forage production, respectively. Meanwhile, weather events such as heavy rainfall and typhoon were also collected based on weather warnings as weather events in the Korean monsoon season. The impact of weather events did not affect forage production, even with the increasing frequency and intensity of heavy rainfall. Therefore, the trend of forage production for the sorghum-sudangrass hybrid was forecasted to slightly increase until 2045. The predicted forage production in 2045 will be 14,926 ± 6,657 kg/ha. It is likely that the damage by heavy rainfall and typhoons can be reduced through more frequent harvest against short-term single damage and a deeper extension of the root system against soil erosion and lodging. Therefore, in an environment that is rapidly changing due to climate change and extreme/abnormal weather, the cultivation of the sorghum-sudangrass hybrid would be advantageous in securing stable and robust forage production. Through this study, we propose the cultivation of sorghum-sudangrass hybrid as one of the alternative summer forage options to achieve stable forage production during the dynamically changing monsoon, in spite of rather lower nutrient value than that of maize (Zea mays L.).

• KOREAN JOURNAL OF CROP SCIENCE
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• v.66 no.2
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• pp.155-170
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• 2021

Oats (Avena sativa L.) represent a good forage crop for cultivation in regions with short growing periods and/or cool weather, such as the mountainous areas of southern Korea. In this study, using the Korean elite summer oat varieties 'High speed' and 'Dark horse', we aimed to determine the optimal time to plant and harvest forage oats seeded in spring and summer in a mountainous area. Seeds were planted three times from late February and early August at 9- or 10-days intervals, respectively, and plants were harvested three times from late May to October at 10-day intervals. The experiment was carried out in an upland field (Jangsu-gun Jeonbuk) in 2015 and 2016. We investigated the changes in forage yield (FY) and quality [crude protein (CP) and total digestible nutrient (TDN) contents] based on the time of planting and harvest. Neither the forage quality nor yield of either spring and summer oats was significantly influenced by the time of planting. The CP of spring oats harvested three times at 10-day intervals from late May was 12.0%, 8.2%, and 6.5%, thereby indicating a reduction with a delay in the time of harvest. In summer oats, CP ranged from 8.4% to 8.7%, although unlike CP in spring oats, was not significantly influenced by the time of harvest. For both forage types, harvest time had no significant effect on TDN. The FY of spring oats harvested in late May and early and mid-June was 10.2, 18.7, and 19.5 ton ha^-1, respectively, with that of oats harvested on the latter two dates being significantly increased by 83% and 91%, respectively, compared with that in late May. Similarly, the FY of spring oats harvested in late October and early and mid-November was 7.1, 12.5, and 12.1 ton ha^-1, respectively, with that of oats harvested on the latter two dates being significantly increased by 75% and 71%, respectively, compared with that in late October. Taking into consideration forage yield and quality (not less than 8% CP), it would be profitable to plant spring oats in the mountainous areas of southern Korea until March 15 and harvest around June 10, whereas summer oats could be beneficially planted until August 25 and harvested from early November.

• Journal of The Korean Society of Grassland and Forage Science
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• v.11 no.4
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• pp.203-208
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• 1991

This experiment was carried out to compare the effects of summer temperature and nitrogen application on carbohydrates and fiber contents in orchardrass stubble grown in the cool summer year, 1980 and in the hot summer year, 1984. For this study, the contents of carbohydrates, neutral detergent fiber (NDF), acid detergent fiber(ADF) and hemicellulose in orchardgrass stubble were investigated. 1. Total water soluble carbohydrates(TSC) in orchardrass stubble were accumulated during the period of cool season and were declined when the weather was hot and dry. The reserve level of those were decreased when a new leaf emerged after the start of plant growth and then were increased as the plant was in full flourish. 2. The reserve of carbohydrate content in orchardgrass stubble was about twice times higher in cool summer year than that in hot summer year, and the reserve rate of carbohydrates showed to be fast in cool summer year. When the nitrogen fertilizer applied, the content of TSC in orchardgrass stubble more lowered but not significantly different(p<0.05). 3. The contents of NDF, ADF and hemicellulose in orchardgrass stubble in cool summer year were not significantly different from those in hot summer year. These contents showed also no significant difference among different levels of nitrogen applications. 4. The relationship of carbohydrate, NDF, ADF and hemicelluose contents according to the levels of nitrogen applications were negatively correlated in cool summer year. But there was no consistency in hot summer year.

• Proceedings of the Korean Society of Grassland Science Conference
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• 2005.06a
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• pp.160-161
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• 2005