• Journal of The Korean Society of Grassland and Forage Science
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• v.19 no.2
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• pp.147-154
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• 1999

A field experiment with 200, 400 and 600kg-N/ha/year application levels was carried out to study the nitrate nitrogen accumulation of sorghum sudangrass hybrids(Xtragraze II and Civa 1990) at Iksan College Farm in 1995. The nitrate nitrogen content of Xtragraze II and Civa 1990 was increased by the application of nitrogen and decreased as the plant matured, then the nitrate nitrogen content was below the toxic level of ruminant at the level of 200kg-N application during the whole growing period. The nitrate nitrogen content of Xtragraze II and Civa 1990 exceeded the safe level of ruminant at the level of 400kg-N application, and that in Xtragraze II decreased at the low level in the later stage of growth, but that in Civa 1990 was almost kept constantly at the same level. The nitrate nitrogen accumulation of Civa 1990 had a greater tendency than that of Xtragraze II. A sum exceeding 200kg-N does not necessarily result in increase the amount of nitrate nitrogen in sorghum sudangrass hybrids. It is suggested that 400kg-N application may results in toxic level of nitrate nitrogen, and special attention must be given in feeding them.

• Journal of The Korean Society of Grassland and Forage Science
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• v.36 no.3
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• pp.215-222
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• 2016

Nitrogen (N) fertilizer management is one of the important aspects of economic production of sorghums in sustainable agriculture. The aim of the study was to evaluate the effects of different N application rates and its split N application methods on productivity, growth characteristics, N accumulation, N use efficiency (NUE), and feed value of Sorghum ${\times}$ Sudangrass hybrids. Treatments consisted of five N application rates (0, 150, 200, 250, and $300kg\;ha^{-1}$) and two split N application methods (40% in basal N, 30% at the growing stage, and 30% after the first harvest vs. 50% in basal N and 50% after the first harvest). Plant height, leaf width, and stem diameter were increased ($p{\leq}0.05$) with increasing N fertility rates at each harvest. Chlorophyll content (expressed as SPAD values) was the highest at a rate of $300\;kg\;N\;ha^{-1)$ (first harvest, 46.32; second harvest, 33.09). It was the lowest at zero N (first harvest, 21.56; second harvest, 18.5). Total N, N uptake, and NUE were increased with higher N rates. Split N application had little effect on total N, amount of N uptake, or NUE. Total dry matter yields were the highest ($21,715\;kg\;ha^{-1}$) at a rate of $300\;kg\;N\;ha^{-1}$. It was the lowest ($10,054\;kg\;ha^{-1}$) at zero N. Our results suggest that more than $300\;kg\;N\;ha^{-1}$ can improve dry matter yield to be above 116% compared to zero N, thus enhancing the agronomic characters of sorghums. However, no significant effect had been found for split N application. Further work is needed to determine the optimal N levels and the effect of split N application rates.

• Journal of Bio-Environment Control
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• v.21 no.2
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• pp.108-113
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• 2012

This study was conducted to evaluate soil nutrient concentrations and fertilizer recovery of sorghum- sudangrass hybrid (Sorghum bicolor (L.) Moench) as affected by organic nutrient sources. The treatments included livestock compost, alfalfa hay, oilcake, and chemical fertilizer. Nutrient applications were made at the rates equivalent to approximately 210 kg N per hectare. The oilcake and alfalfa materials had the lowest C : N ratio, but the livestock compost had the highest C:N ratio such as 33.7 : 1. The livestock compost resulted in the highest input to ground surface, which increased nutrient concentrations in soil. The oilcake and alfalfa materials with low C : N ratios increased N-mineralization rate in soil compared to livestock. The N uptake efficiency in plants treated by alfalfa or oilcake was approximately 60% of those treated with chemical fertilizer; but those with livestock compost had N uptake efficiency lower than 20%. The $P_2O_5$ uptake efficiency was the highest in the plants treated with the alfalfa hay, but the lowest in those with livestock compost. Recommendation of organic material selection should consider C:N ratio of the raw materials based on the individual crop requirement.

• Journal of The Korean Society of Grassland and Forage Science
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• v.27 no.4
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• pp.275-280
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• 2007

This experiment was conducted to investigate the selection of regional double cropping system for production of organic forage in middle part of Korea. The species of forage crop used in this experiment were corn, $sorghum\;{\times}\;sudangrass$ hybrid and japanese millet for summer crops and rye and Italian ryegrass for winter crops. $Sorghum\;{\times}\;sudangrass$ hybrid showed higher DM (dry matter) and TDN (total digestible nutrient) yield than that of corn. Dry matter yield of corn decreased to 56% that of control because of weed. In winter crops, DM and TDN yield of rye is higher than that of Italian ryegrass. Rye was more adequate to produce organic forage in middle part of Korea. We could not find out the difference of nutrient value between each treatments. It means that the amount of nutrient is affected by DM productivity of each crop. The result of this study indicated that $sorghum{\times}sudangrass$ hybrid (summer crop) and rye (winter crop) cropping system could be recommended as producing high yield of organic forage in middle part of Korea.

• Journal of The Korean Society of Grassland and Forage Science
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• v.6 no.1
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• pp.65-70
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• 1986

This experiment was carried out to identify the main pathogens infected with Piper sudangrass and to evaluate the qualitative and quantitative damage of the plants infected with leaf blight (Helminthosporium turcicum PASS) under different levels of nitrogen fertilizer (20, 30 and 40 kg/10a). The experiment was design as a randomized block design with 4 replications at experimental field of Livestock Experiment Station in Suweon, 1984. The results obtained are summarized as follows: 1. The main fungi isolated from sudangrass were identified as Helminthoporium turcicum and Collectotricum graminicolum, but 1 species fungus was not identified. 2. Leaf blight was first found on June 20 and appeared extremely in the regrowth plants from July to September. The rate of attack was associated with increasing of nitrogen fertilization (P<0.01). 3. Fresh and dry matter yields were as much as 47 and 38 percentage lower in leaf blight infected plants (disease severity: V) than those of no visible infection. 4. Concentrations of crude fat and crude protein were decreased in the plants infected with Helminthosporium leaf blight, but lignin content was increased. Dry matter and organic matter digestibility of the plants were negative correlated with the infection of leaf blight(P<0.01).

• Journal of The Korean Society of Grassland and Forage Science
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• v.3 no.2
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• pp.58-66
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• 1983

This experiment was carried out to investigate the effects of the nitrogen rates and cutting heights on the appearance dry weight and death of new bud (branch and tiller) of sorghum-sudangrass hybrid (Sorghum bicolor (L.) Moench). The cultivar used in the present study was Pioneer 988. The experiment was arranged as a split plot design and undertaken in the Experimental Livestock Farm of Agriculture Coll., Seoul Nat'l Univ. in Suweon, 1981 and 1982. The results obtained are summarized as follows: 1. The appearance and death of branch and tiller were not influenced with high nitrogen fertilization. 2. The frequency of the branching was decreased as the low stubble height, and the rate of the tillering was decreased in the high stubble height. 3. The yield of forage mostly depended on the tiller regardless of cutting height, and minor portion of the yield was resulted from the branch. 4. The low cutting height resulted in the increased number of dead bud (p<0.05).

• Journal of the Korea Organic Resources Recycling Association
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• v.25 no.4
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• pp.23-29
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• 2017

This experiment was carried out to compare the productivity and feed value between standard cultivation and organic mixed expeller cake fertilizer cultivation to develop organic cultivation technology except from standard cultivation using chemical fertilizers in the field of forage production. This study was conducted in the rice field of Livestock Research Institute Jacheon-myeon, Gangin-gun Jellanam-do. Organic mixed expeller cake fertilizer consists of 4.0% nitrogen, 65% castor, 30% seeds and 5% fish meal. Sorghum-Sudangrass Hybrids(SX17) was sowed 40kg per hectare on May 25. Test group formation was consisted of a standard group and test treatment. The standard group(Con.) was fertilized chemical fertilizer according to the N-P-K kg/ha, 200-150-150 (basal 100kg, uptake 100kg). Test treatment was carried out organic fertilizer 100%(T1), organic fertilizer 150%(T2) and organic fertilizer 200%(T3) according to the nitrogen content of standard group(Con.). Plant height of harvest time depending on the treatment was that Con was 317cm, T1 was 252cm, T2 was 269cm and T3 was 293cm. Dry matter yield was that Con was 11,386kg/ha, T1 was 6,015kg/ha, T2 was 6,799kg/ha, T3 was 7,627kg/ha. In the test treatment, plant height and dry matter yield increased with increasing fertilizer. Crude protein was the height in Con(7.0%) and Crude protein of test treatment was T1(5.7%), T2(6.3%), and T3(5.1%). As a result of this study, T2 was recommended.

• Journal of The Korean Society of Grassland and Forage Science
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• v.41 no.1
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• pp.1-9
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• 2021

In the winter forage study, Italian ryegrass(IRG) and barley were selected. In 2018, the dry matter yield of IRG was 16,915kg per ha under the Agrivoltaic System; this was a little more than 16,750kg per ha of outdoors. On the contrary, the dry matter yield of barley was slightly less under the Agrivoltaic System than that of outdoors. In 2019, the dry matter yield under the Agrivoltaic System was 12,062kg per ha for IRG and 12,195kg per ha for the barley; this was 5.4% and 11.5% less than that of outdoors, respectively. In the summer forage study, corn and sorghum×sudangrass were selected. In 2019, the dry matter yield of corn under the Agrivoltaic System was 13,133kg per ha which was 17% less than that of outdoors. The dry matter yield of sorghum×sudangrass was 12,450kg per ha, which was 82.5% of that of outdoors. In 2020, the dry matter yield of corn under the Agrivoltaic System was 8,033kg per ha which was 7.9% less than that of outdoors. The dry matter yield of sorghum×sudangrass was 5,651kg per ha, which was 11.4% less than that of outdoors.

• Journal of The Korean Society of Grassland and Forage Science
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• v.41 no.1
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• pp.41-46
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• 2021

Sorghum×sudangrass hybrid (Sorghum bicolor (L.) Moench, SSH) is one of the most important summer forage crop and it is widely used for silage in Korea. Agriculture is highly dependent on the climate condition and experiencing significant loss of productivity due to climate change. This study was conducted to investigate the correlation analysis between productivity of forage SSH and climatic factors in Central Northern region of South Korea for 3 years (2017 to 2019). Plant height and dry matter yield of SSH were significantly higher in Gyeonggi-do than Ganwon-do. The productivity of SSH is more closely related with temperature than other climatic factors. Maximum temperature and Growing degree days in May and June showed a positive correlation. However, correlation between production of SSH and precipitation was not clear in this study, but rainy days showed a negative correlation (0.42). In conclusion, temperature is most important climatic factor to the maintenance of plant yield.

• Journal of The Korean Society of Grassland and Forage Science
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• v.40 no.4
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• pp.259-264
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• 2020

The aim of this study was to investigate the feasibility of discrimination 12 different cultivar of sorghum × sudangrass hybrid (Sorghum genus) seed through near infrared spectroscopy (NIRS). The amount of samples for develop to the best discriminant equation was 360. Whole samples were applied different three spectra range (visible, NIR and full range) within 680-2500 nm wavelength and the spectrastar 2500 Near near infrared was used to measure spectra. The calibration equation for discriminant analysis was developed partial least square (PLS) regression and discrimination equation (DE) analysis. The PLS discriminant analysis model for three spectra range developed with mathematic pretreatment 1,8,8,1 successfully discriminated 12 different sorghum genus. External validation indicated that all samples were discriminated correctly. The whole discriminant accuracy shown 82 ~ 100 % in NIR full range spectra. The results demonstrated the usefulness of NIRS combined with chemometrics as a rapid method for discrimination of sorghum × sudangrass hybrid cultivar through seed.