• Journal of The Korean Society of Grassland and Forage Science
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• 제12권4호
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• pp.201-210
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• 1992

This study was designed to investigate the content of inorganic nitrogen($NH_4$, $NO_3$) and its change in the 7 different sites; the permanent meadows of alfalfa, orchardgrass, and reed canarygrass, the fields of rye. corn, rice and a mountain region. the results from this study were summarized as follows; 1. The contents of ammonium and nitrate in meadows were 15.89-16.46 and 1.32-1.86ppm, respectively, showing the lower level than in other sites and no significant diffirences among three meadows. 2. In the rice field, the average content of ammonium(7.19ppm) was the highest among all sites, but the content of nitrate(1 l.l7ppm) was the lowest. In addition, almost all of nitrate were spreaded around the surface. 3. In the mountain region, the content of $NH_4$(5.79ppm) was slightly high, but the content of nitrate ( 15.18ppm) was very low. 4. In the rye field. the average content of $NO_3$ was 35.46ppm and show the highest (92.63ppm) at the deep part of soil in the specific season, but it decreased with increasing temperature. 5. In the corn field, which kept bare after harvesting the corn silage, the content of $NO_3$ was high, regardless of seasons and depths, and increased up to maximum of 103ppm. 6. The ground water concentrations of $NO_3$ were not more than 50ppm in the pasture. In the vegetable house, they were less than 30 ppm during the winter and spring and were 80-100ppm during the summer and fall. 7. The concentrations of $NO_3$ in Han river water were lower during the winter and spring(20-30ppm) and higher dxring the summer and fall (50-90ppm).

• Journal of The Korean Society of Grassland and Forage Science
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• 제15권3호
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• pp.192-197
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• 1995

This experiment was conducted to evaluate the grazing performance of dairy cattle for winter rye, sorghum-sudangrass hybrid and oat including of rape in Hwa seong-gun, Kyeonggido, from 1993 to 1994. Each crops were utilized from the stage of 8-leaves to late blooming for sorghum-sudangrass, and from final leaves to soft dough for winter rye and oat plant. Under three different cropping system of winter rye-sorghum x sudangrass, spring oat-sorghum X sudangrass-autumn oat, and silage corn-autumn oat, a succeshl hehage production was available for grazing performance from April 26 to December 15, continuously. Annual dry matter yields for grazing allowance were 26.1 tontha in average of all cropping system. Autumn oat rnixtured with rape showed the highest herbage utilization with 91.6% grazing intensity and the lowest in sorghum-sudangrass with a value of 60.6- 69.1 %. Labor investment for herbage production were 805 hour in the cutting management and 339 hour per hectar in the grazing utilization.

• KOREAN JOURNAL OF CROP SCIENCE
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• 제68권4호
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• pp.392-401
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• 2023

Corn (Zea mays L.) is one of the world's most important crops, along with wheat and rice, with a global corn production expected to reach 1,154.5 million tons in 2023. Considering this grain production, The generation of corn cob is expected to reach approximately 207.8 million tons in 2023. However, as an agricultural by-product, corn cobs are often considered waste and remain underutilized. Phytosterols, which are abundant in vegetable oils such as corn oil, provide a number of health benefits, including liver health, cholesterol reduction, and protection against chronic diseases such as diabetes. In this study, we investigated the potential of Kwangpyeongok ears, which are commonly used as grain and silage corn in Korea. We also examined the variation in phytosterol content with the maturity of corn ears to identify the optimal time for utilization. At the beginning of physiological maturity, corn cobs had 113.3 mg/100g DW of total phytosterols, which was highest phytosterol abundance during the growth stage. Corn kernels also had the highest phytosterol content at the beginning of physiological maturity. While previous studies on corn bioactive compounds have mainly focused on the kernels, the results of this study highlight that cobs are an excellent source of these compounds. Furthermore, phytosterol levels were influenced by genetic factors and developmental stages, suggesting the to increase the use of cobs as a source of bioactive compounds.

• Asian-Australasian Journal of Animal Sciences
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• 제28권10호
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• pp.1454-1464
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• 2015

Four methods were adopted, including the mobile nylon bag (MNB) method, modified three-step in vitro (MTS) method, original three-step in vitro (OTS) method, and acid detergent insoluble nitrogen (ADIN) estimating method, to evaluate the intestinal digestibility of rumen undegradable protein (DRUP) of 10 types of concentrates and 7 types of roughages. After correlation analysis to determine the DRUP values using the MNB, MTS, OTS, and ADIN methods, the study aimed to find out appropriate methods to replace the MNB method due to its disadvantages such as high price, long time period, and use of a duodenal T-fistula. Three dairy cows with a permanent ruminal fistula and duodenal T-fistula were used in a single-factor experimental design. The results showed that the determined DRUP values using the MNB method for soybean meal, cottonseed meal, rapeseed meal, sunflower meal, corn germ meal, corn, rice bran, barley, wheat bran, corn fiber feed, Alfalfa (Zhao dong), Alfalfa (Long mu 801), Alfalfa (Long mu 803), grass (North), Grass (Inner Mongolia), corn silage and corn straw were 98.13%, 87.37%, 88.47%, 82.60%, 75.40%, 93.23%, 69.27%, 91.27%, 72.37%, 79.03%, 66.72%, 68.64%, 73.57%, 50.47%, 51.52%, 54.05%, and 43.84%, respectively. The coefficient of determination ($R^2=0.964$) of the results between the MTS method and the MNB method was higher than that ($R^2=0.942$) between the OTS method and the MNB method. The coefficient of determination of the DRUP values of the concentrates among the in vitro method (including the MTS and OTS methods) and the MNB method was higher than that of the roughage. There was a weak correlation between the determined DRUP values in concentrates obtained from the ADIN method and those from the MNB method, and there was a significant correlation (p<0.01) between the determined DRUP values of the roughage obtained from the MNB method and those obtained from ADIN method. The DRUP values were significantly correlated with the nutritional ingredients of the feeds. The regression equation was DRUP =100.5566+0.4169CP - 0.4344SP - 0.7102NDF - 0.7950EE ($R^2=0.8668$, p<0.01; CP, crude protein; SP, soluble protein; NDF, neutral detergent fiber; EE, ether extract). It was concluded that both the MTS method and the OTS may suitable to replace the MNB method for determining the DRUP values and the former method was more effective. Only the ADIN method could be used to predict the values of the roughages but conventional nutritional ingredients were available for all of the samples' DRUP.

• Journal of The Korean Society of Grassland and Forage Science
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• 제6권1호
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• pp.14-18
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• 1986

This experiment was conducted to study yield and nutritive value of Korean local corn and imported corn varieties. The results were as follows: Plant and stem height of Suweon 19 were 290.0 and 258.5cm respectively, and were higher than those of the other varieties, and those of Royal dent 100 were hither than the other imported corn variety. Grain yields of Suweon 19 and Royal dent 100 were 1,898 and 1,828kg per 10a respectively. Fresh matter yield of Snow dent 1 was similar with Suweon 19 and those were 6.536 and 6,513kg per 10a, respectively. Dry matter yields of Suweon 19, Snow dent 1 and Royal dent 100 were over 2,000kg per 10a. TDN content was the highest with 70.3% in Snow dent 1, and showed similar level with over 65% in all the varieties. TDN yield was the highest in Suweon 19(1,651.5 kg/10a) and showed in order of Royal dent 100 (1,538.5kg/10a) and Snow dent 1(1,522.9 kg/10a).

• Journal of The Korean Society of Grassland and Forage Science
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• 제22권1호
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• pp.37-44
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• 2002

This study was conducted to investigate the effects of the application rate of cattle slury and urea N on productivity of corn and environmental pollution in com cultivation soil. The experiment was conformed in lysimeter which was constructed with 0.33m diameter and 1m height. This study was arranged in split plot design. Main plots were the application rate of mineral fertilizer, as urea, such as 0, 100 and 200kgN/ha and subplots were the application rate of cattle slurry, such as 0, 200 and 400kgN/ha. The results obtained were summarized as follows. 1. Dry matter yields of corn increased as the application rate of cattle slurry and urea increased. 2. Total nitrogen content of whole corn was increased as the application rate of cattle slurry and urea increased 3. The average nitrate content in leaching water by application rate of the slurry and urea N was 7.78$\mu\textrm{g}$/$m\ell$(ranged from 6.27 to 9.02$\mu\textrm{g}$/$m\ell$). Nitrate content was hardly influenced by application rates of the slurry and urea. However, nitrate content rises in proportion to a rise in precipitation.

• Journal of The Korean Society of Grassland and Forage Science
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• 제32권1호
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• pp.15-28
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• 2012

This study was carried out to know adaptability and growth characteristics, yield, chemical compositions and nutrition yield of corn hybrids for silage at paddy field. The field experiments were conducted at Sangju province for one year (2009). The experimental design was arranged in a randomized block design with three replication. The treatments consisted of eleven corn hybrids. The planting date was on 1 May and harvested at 24 August. Stem diameter, stem hardness and number of ear were higher in P32P75 than other varieties. Ear height, dead leaf and green degree were highest in $NC^+$7117, but number of root system and Brix ($B^{\circ}$) were higher in P3394 than other varieties. Crude protein and crude fat (EE) were highest in P32K61 and P31P41, respectively (P<0.01). NDF and ADF were highest in KPO and KIO, respectively, but no significant differences were found among the varieties. Total mineral contents were the highest in Kwangpyongok (9,775 mg/kg), and P3394 (6,651 mg/kg) was the lowest as compared to other varieties (P<0.01). Crude protein yield, crude fat yield and mineral yield were highest in P3156, P31P41 and KPO, respectively (P<0.01). Total composition amino acid and total fatty acid were the highest in P32K61 and KIO, respectively (P<0.01). Yields of crude protein, fatty acid, composition amino acid and TDN were the highest in P3156 (P<0.01). But yields of crude protein and mineral were the highest in P31P41 and KPO, respectively (P<0.01). Total digestible nutrient (TDN) was higher in order of P3156 > $NC^+$7117 > P31N27 > KPO > P32K61 > P32T83 > P32P75 > P31P41 > P3394 > P32W86 > KIO. Based on the above results, corn hybrid varieties could be recommended in P3156, NC+7117 and P31N27 for growth characteristics, quantitative production and nutrition yield.

• Journal of The Korean Society of Grassland and Forage Science
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• 제34권4호
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• pp.288-295
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• 2014

This study was conducted to evaluate the effect of mixing time for TMR (total mixed rations) mixed with corn silage on particle size, peNDF (physically effective neutral detergent fiber), laceration, and ruminal in situ dry matter degradation. The study also aimed to evaluate the effect of consumption of the TMR on the milk yield and milk components of mid-lactational dairy cows. TMRs were mixed for 30 minutes (T1) and 50 minutes (T2) using the same material. All samples were then analyzed with a Penn State Particle Size Separator (PSPS). The particle size of T1 was significantly lower in the bottom pan (8 mm>) than that of T2 (p<0.01). $peNDF_{&gt;8.0}$ was significantly higher in T1 (17.18%) than in T2 (13.85%) (p<0.01). For ruminal in situ dry matter degradation of particle retention (>19 mm), no significant difference was found after 72 hours incubation, although T1 degradation was significantly higher after 24 hours incubation (p<0.01). Milk yield was no different between the groups of cows, whereas the milk fat from T1 fed cows was significantly higher (p<0.01). The results show that feeding TMR mixed for 30 minutes to dairy cows may improve the physical value of forage without negative effects on the milk yield and milk components.

• Korean Journal of Soil Science and Fertilizer
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• 제22권3호
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• pp.197-204
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• 1989

To evaluate the effect of soil improvement on the chemical properties and corn silage yield, this experiment was carried out in the newly-reclaimed sloped land. Corn (Suwon 19) was cultivated under the six different treatments including integrated improvement plot at Songjeong loam, 20 percent slope, from 1985 to 1987 and various soil chemical properties and silage yield were investigated. pH of topsoil was above 5.0 except for control and phosphate plot, but lime and integrated improvement plots were above 5.0 in subsoil. The contents of organic matter of topsoil were above 2.0% except control and subsoiling plot. Except control, the range of cation exchange capacity was 7.4-7.8 me/100g in topsoil, 7.0-7.7 me/100g in subsoil. Soil bacteria density of root zone was the highest in integrated improvement than the other treatments, and it was higher at the harvesting stage than the heading stage. Mean density of microorganism was $61.3{\times}10^5$ in bacteria, $21.5{\times}10^4$ in fungi and actinomycetes was B/F ratio was 28.5 and B/A ratio was 2.9. Vertical root distribution of total and 10cm depth below was more in the integrated improvement and subsoi ling plot than the other plots. Total nitrogen (T-N) content was higher in integrated improvement plot, and phosphate content of leaves was higher in compost and integrated improvement plot, but stem and grain were not different. Potassium content of the plant was higher in integra ted improvement plot. Correlation between dry matter yield and T-N was more significant than the other elements. And the contents of phosphate, calcium and magnesium were significant at 5%, but potassium was not.

• Journal of The Korean Society of Grassland and Forage Science
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• 제30권3호
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• pp.237-246
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• 2010

This study was conducted to evaluate growth characteristics and yield of silage corn hybrids by different planting dates at paddy and upland field. Days to silking by different planting dates at paddy field were 81 days at planting on April 22, 70 days on May 20 and 62 days on June 10, respectively, and they were getting shorter as planting date delayed. There was no significant difference in days to silking between paddy and upland field. Plant height in paddy field was no significant difference between at planting on April 22 and on May 20, and it was shortened sharply at planting on June 10. There was no significant difference in plant height between paddy and upland field. There was no significant difference in lodging by different planting dates in paddy field. There was significant difference in lodging between paddy and upland field (P<0.05). There was no significant difference in stay-green by different planting dates in paddy field, and no significant difference between paddy and upland field. Ear ratios to total dry matter in paddy field were 43% at planting on April 22, 41% on May 20 and 28% on June 10, respectively, and it was lower as planting date delayed. There was no significant difference in ear ratios to total dry matter between paddy and upland field. Fresh yields in paddy field were lower with 14% at planting on May 20 and 32% on June 10 compared to on April 22 as planting date delayed. There was no significant difference in fresh yield between paddy and upland field. Dry matter yields in paddy field were higher with 9% at planting on May 20 and lower with 24% on June 10 compared to at planting on April 22 as planting date delayed. Dry matter yield in paddy field was lower with 9% compared to 1,931 kg/10a at planting on April 22. TDN (Total digestible nutrients) yields in paddy field were higher with 5% at planting on May 20 and lower with 28% on June 10 compared to at planting on April 22 as planting date delayed. TDN yield in paddy field was lower with 11% compared to 1,340kg/10a at planting on April 22.