• Asian-Australasian Journal of Animal Sciences
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• v.18 no.7
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• pp.1029-1035
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• 2005

A 3${\times}$4 factorial field experiment with a complete randomised split-plot design with four replicates was conducted from June 2002 to March 2003 at the experimental farm of the Nong Lam University, Ho Chi Minh City, Vietnam, to determine effects of different harvesting heights (10, 30 and 50 cm above the ground) and cutting intervals (45, 60, 90 and 285 days) on yield of foliage and tubers, and chemical composition of the foliage. Cassava of the variety KM 94 grown in plots of 5 m${\times}$10 m at a planting distance of 30 cm${\times}$50 cm was hand-harvested according to respective treatments, starting 105 days after planting. Foliage from the control treatment (285 days) and all tubers were only harvested at the final harvest 285 days after planting. Dry matter and crude protein foliage yields increased in all treatments compared to the control. Mean foliage dry matter (DM) and crude protein (CP) yields were 4.57, 3.53, 2.49, and 0.64 tonnes DM $ha^{-1}$ and 939, 684, 495 and 123 kg CP $ha^{-1}$ with 45, 60, 90 and 285 day cutting intervals, respectively. At harvesting heights of 10, 30 and 50 cm the DM yields were 4.27, 3.67 and 2.65 tonnes $ha^{-1}$ and the CP yields were 810, 745 and 564 kg $ha^{-1}$, respectively. The leaf DM proportion was high, ranging from 47 to 65%. The proportion of leaf and petiole increased and the stem decreased with increasing harvesting heights and decreasing cutting intervals. Crude protein content in cassava foliage ranged from 17.7 to 22.6% and was affected by harvesting height and cutting interval. The ADF and NDF contents of foliage varied between 22.6 and 30.2%, and 34.2 and 41.2% of DM, respectively. The fresh tuber yield in the control treatment was 34.5 tonnes $ha^{-1}$. Cutting interval and harvesting height had significant negative effects on tuber yield. The most extreme effect was for the frequent foliage harvesting at 10 cm harvesting height, which reduced the tuber yield by 72%, while the 90 day cutting intervals and 50 cm harvesting height only reduced the yield by 7%. The mean fresh tuber yield decreased by 56, 45 and 27% in total when the foliage was harvested at 45, 60 and 90 day cutting intervals, respectively. It is concluded that the clear effects on quantity and quality of foliage and the effect on tuber yield allow alternative foliage harvesting principles depending on the need of fodder for animals, value of tubers and harvesting cost. An initial foliage harvest 105 days after planting and later harvests with 90 days intervals at 50 cm harvesting height increased the foliage DM and CP yield threefold, but showed only marginal negative effect on tuber yield.

• Journal of The Korean Society of Grassland and Forage Science
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• v.34 no.3
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• pp.179-186
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• 2014

The objective of this study was to determine the best performing switchgrass (Panicumvirgatum L.) cultivar with three different seeding dates as a bioenergy source in Republic of Korea. Split-plot in time with three replications was performed and three switchgrass cultivars, Carthage (CT), Cave-in-Rock (CIR), and Forestburg (FB) were used in this experiment from 2009 to 2012. Plots were seeded on April 23, May 4, and May 13, 2009 and were harvested once in November each year. No fertilizer was applied to the field for the first year; however, in second and third years (June 2010 and May 2011, respectively), N, $P_2O_5$ and K2O fertilizers were applied in 67,45 and 90 kg $ha^{-1}$, respectively. Soil pH (5.9) and climate condition including temperature ($10.4{\sim}17.5^{\circ}C$) and precipitation (89.4~109.8 mm $month^{-1}$) were suitable for switchgrass cultivation. Total dry matter yields were higher in CT and CIR compared to FB and were 16.9, 15.9, and 4.5 ton $ha^{-1}$, for CT, CIR, and FB, respectively (p<0.0001). The samples were analyzed for dry matter (DM), crude protein (CP), neutral detergent fiber (NDF), acid detergent fiber (ADF), crude fiber (CF), ether extract (EE), and ash. No significant differences in energy content (p = 0.96) and chemical composition among cultivars (p>0.05) were found. Seeding dates did not affect DM yield (ton $ha^{-1}$), chemical composition and energy content significantly (p>0.05). Significant difference was observed for heights among CT, CIR, and FB (177.59, 169.98, and 94.89 cm, respectively, p = 0.0002). In conclusion, based on soil characteristics and climate condition in Korea compared to other countries, switchgrass can be cultivated successfully. Considering dry matter yield and energy content of these three cultivars of switchgrass CT and CIR adapted better to climate in Middle Eastern of Republic of Korea than Forestburg for bioenergy purpose.

• Journal of The Korean Society of Grassland and Forage Science
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• v.14 no.3
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• pp.247-256
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• 1994

This experiment was carried out to determine harvesting date and cultivar effects on growth characteristics, forage yield and quality of spring sown oats(Avena surivu L.) at the forage experimental field, College of Agricultural and Life Sciences, Swul National University, Suwwn from March 22 to June 20, 1993. The experiment was arranged in a split plot design with three replications. The main plots consisted of the harvesting dates such as early(24 May), mid(8 June) and late(20 June). The subplots consisted of different maturities of oat cultivm such as Speed oat, Cayuse, Foothill, Sv841034 and Magnum.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.56 no.2
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• pp.159-166
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• 2011

This experiment was carried out to evaluate the effects of top dressing of nitrogen and harvest time on the growth, feed value and anthocyanin content for developing functional feed of colored barley. A colored barley cultivar, Boanchalbori, was tested in this experiment. Top dressing was applied at seven separate growth stages, regeneration time (RT), and intervals of 20, 30, 40, 50, 60, and 70 days after RT, and harvested at different time from 20 days after heading (DAH) to 40 DAH with 10 days interval in split plot design with three replications. Plant height was increasing with earlier top dressing, but not affected by harvest time. Percent dry matter was increasing with earlier top dressing and later harvests. Protein content was increased with later top dressing and harvests, but percent NDF, ADF and TDN was not significant. Total anthocyanin content was increased with earlier top dressing, included increasing C3G (cyanidin-3-glucoside) and delphinidin. The C3G and delphinidin were detected from 25 DAH and P3G (pelargonidin-3-g1ucoside), cyanidin and perlagonidin from 30 DAH. Their contents were increased significantly as harvest was delayed. This experiment provides some interesting results with respects to optimum top dressing and harvest time for the functional feed production of the colored barley.

• Journal of The Korean Society of Grassland and Forage Science
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• v.24 no.4
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• pp.309-316
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• 2004

This experiment was carried out to assess the growth and development of five rye(Secale cereale L.) cultivars based on the Feekes scale in relation to sowing date at the Experimental Livestock Farm, Seoul National University(SNU), Suwon from 30 September 2001 to 4 May 2002. The experiment was conducted in split plot design with three replications. The main plots consisted of two sowing date such as early(30 September) and late(15 October). The subplots consisted of rye cultivars of five different maturity groups such as 'Kodiak', 'Koolgrazer', 'Danko', 'Homil22' and 'Olhomil'. The plant height of early sowing rye cultivars was higher than that of late one. Among the rye cultivars tested, plant heights of early maturing cultivars were higher than those of the other cultivars. The tiller number at early sowing(48.0) was higher than that of late(24.3), however, late maturing cultivars were higher than those of the other cultivars among the rye cultivars tested. Growth and development in the early sowing were generally three days earlier than those of late sowing cultivars. Growth and development in 'Olhomil' rye cultivars was earlier than 'Danko' rye cultivars when sown in early, but 'Olhomil' and 'Koolgrazer' rye cultivars showed an early maturity than 'Danko' rye when sown in late. Therefore, the developmental stages of winter rye cultivars could be categorised the following maturity; 'Olhomil' and 'Koolgrazer' are early in maturity, 'Homil22' is medium, and 'Kodiak' and 'Danko' are late in maturity.

• Journal of The Korean Society of Grassland and Forage Science
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• v.22 no.3
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• pp.221-226
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• 2002

The effects of drill widths and nitrogen application levels on the growth characteristics and seed productivity of Italian ryegrasss(Lolium multiflorum Lam.) were evaluated. The experimental design was a split-plot arrangement with three replications. The main-plots were three drill widths of 15, 30 and 45cm, and subplots were three nitrogen application rates of 50, 75 and 100 kg/㏊ in early spring. Among the growth characteristics, lodging tolerance appeared to be highest in the treatment including 45cm of drill width and 50kg/㏊ of nitrogen application compared to other treatments. The numbers of stem per one square meter tended to be increased more in drill width of 15cm than in that of 30 or 45cm, but other growth characteristics were similar among treatments. In seed yield components, the numbers of spike per one square meter were getting increased according as drill width was narrower, but spike length and 1,000 seed weight were longer and heavier. respectively. The rate of ripened pains was highest in treatment including 30cm of drill width and 50kg/㏊ of nitrogen application. Maximum seed yield was also obtained in same treatment.

• Journal of The Korean Society of Grassland and Forage Science
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• v.22 no.1
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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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• v.27 no.2
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• pp.79-84
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• 2007

This study was carried out to investigate the effects of growing period and cultivars on physiological characteristics and photosynthetic rates of kenaf in Cheorwon, Korea, The possibility of their utilization as forage plant was also discussed. A split plot design composing 3 growing periods (53, 84 and 115 days after sowing) and 3 cultivars (Dowling, Everglade-41 and Tainung-2) was applied for this experiment. Leaf photosynthetic rate was highest 28.6 $CO_2{\mu}mol\;m^{-2}s^{-1}$ in Everglade-41 at the beginning of August when solar irradiation was most intense. In the final biomass of kenaf, Dowing wa the highest among cultivars, with 534.6g/F.W./plant and 109.6g/D.W./plant, respectively. In addition, Dowling was the best in stem thickness among cultivars evaluated. Our results exhibited that all cultivars planted in Cheorwon exhibited decreased yield production compared to a previous report experimented in Jaeju. It may result that cultivation in Jaeju utilized wider planting space and longer cultivating time. In the basis of our data, it is suggest that extending cultivation time and using wider planting space should increase yield in Cheorwon with potential utilization of kanef as a forage crop.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.33 no.4
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• pp.329-335
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• 1988

[n order to find out the effects of nitrogen fertilizer and planting density on the leaf characteristics of high yielding cultivars of rice, Dongjin (Japonica type) and Samkang (Tongil type) were .grown under two nitrogen levels (150 and 250 kg N/ha) and three planting densities (30 ${\times}$ 15 cm, 30 ${\times}$ 12 cm, 30 ${\times}$ 9 cm. Leaf blade, sheath and dry weight of individual leaf. the number of green leaves after flowering were measured. Samkang was characterized as longer and wider leaf blade and sheath than Dongjin, less sensitive to nitrogen fertilizer and planting density, and higher proportions of green leaves after flowering. These morphological characteristics of Samkang caused an increase of grain yield by 30 per cent.

• Journal of The Korean Society of Grassland and Forage Science
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• v.25 no.3
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• pp.143-150
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• 2005

These experiment was conducted to determine the effect of nitrogen fertilizer levels and mixture small grains on productivity and quality of spring forage rape at south region of Korea(Mokpo). The experiment was arranged in a split plot design with three replications. The main plots consisted of three different levels of nitrogen fertilizer(100, 150 and 200 kg/ha). The sub plots consisted of five kinds of mixed small grain species(Rye, Oat, Barley, Italian ryegrass, and Rape monoculture). The results obtained are summarized as follow. Dry matter(DM) content of Rye + Rape and Ba.ley + Rape mixtures were increased by $2\~3\%$ compared to Rape monoculture. The high level of nitrogen application increased the fresh matter yield, and yield of Rye + Rape and Rape monoculture were higher than that of others. Dry matter yield of Rye + Rape mixture and Rape monoculture with 200kg/ha of nitrogen application were higher by 9,449 and 9,227 kg/ha, respectively. The crude protein(CP) content of rape was high as $18.6\%$ while average CP content was $16\%$. The average total digestible nutrient(TDN) content showed high as $70\%$. It is suggested the Rye + Rape mixture or Rape monoculture would recommendable for spring usage of rape at south region of Korea.