• KOREAN JOURNAL OF CROP SCIENCE
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• v.54 no.3
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• pp.327-331
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• 2009

Korean government has promoted the policy of chemical fertilizer reduction by 40% reduction from 2003 to 2013. Hairy vetch (Vicia villosa Roth) fixes nitrogen from the atmosphere and rye (Secale cerale L.) accumulates soil nitrogen to reduce potential nitrogen loss. The objective of this research was to identify optimum seeding rates of hairy vetch-rye mixtures in the central regions of Korea. The experiment of mixture rate was carried out for maximum production in 2006 and 2007. The best seeding rate mixture for maximum biomass production was 6.75 kg hairy vetch and 5 kg rye per 10a. Pure hairy vetch and rye were used as control. The nitrogen production of mixture treatments were higher than pure rye. The hairy vetch and rye mixture can scavenge potentially leachable nitrogen, while maintaining soil fertility by adding fixed nitrogen to the cropping system.

• Horticultural Science & Technology
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• v.30 no.3
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• pp.329-333
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• 2012

A new Asiatic hybrid lily 'Redsky' cultivar was selected from a cross between 'Vivaldi' cultivar with pale pink color flower as mother plant and 'Prato' with orange colored flower in 2000 year. The selected bulb line was propagated and cultivated for line nomenclature as 'Gonong-F-na-10'. The survey of the growth and flower characteristics of 'Gonong-F-na-10' were conducted from 2005 to 2007 on summer cropping system under structure in Highland Agriculture Research Center, NICS, RDA. After all 'Gonong-F-na-10' was named as 'Redsky'. The flowers of the 'Redsky' cultivar had not soft hair and fragrance, and had orange red (O-R N30D) colored petals with dark brown spots in center of flower. The stem color was dark pink and brown caused by anthocyanin pigment, the stigma and pollen colors were brown. Flowering direction was upward. The flowering date was July 7 so early flowering. The plant height was 97.2 cm so long, number of flowers was 4.9 ea, and length of flower bud was 9.3 cm. The bulb weight was about 34.8 g and its bulb size was about 14.8 cm in circumference. 'Redsky' cultivar was registered as a new variety with No. 3119 in Korea Seed and Variety Service on June of 2010.

• Korean Journal Plant Pathology
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• v.3 no.3
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• pp.217-222
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• 1987

Pathogenicity of nine Rhizoctonia solani isolates of different anastomosis groups (AG) on seed and hypocotyls of red pepper, cucumber, Chinese cabbage and radish varied considerably from nonvirulent to highly virulent. Rhizoctonia solani AG 1 was highly virulent on the above four plant species. AG 2 type 1 was highly virulent on radish and Chinese cabbage, moderately virulent on red pepper, and AG 2 type 2 was avirulent or weakly virulent except red pepper. R. solani AG 5 was moderately virulent on hosts tested. In general, virulence of the R. solani isolates to a given host varied among anastomosis groups, but not within anastomosis groups. Anastomosis groups lacked host specificity. The pathogenicity was stronger in steam-sterilized soil than in non-sterilized field soil, if the inoculated plants were closely related with orginal host from which the pathogen was isolated. On the other hand, pathogen was more virulent in non-sterilized field soil than in steam-sterilized soil, if the inoculated ones were not closely related. Generally, contrary to other soil-brone plant pathogenic fungi, Rhizoctonia isolates tended to be more virulent in non-sterilized field soil than in the same soil which had been steamed. A potential danger of building up propagules of R. solani in southern horticultural area are discussed in terms of cropping system.

• Research in Plant Disease
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• v.19 no.2
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• pp.84-89
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• 2013

The incidence factors of Rice stripe virus (RSV) were analyzed by studying the population density and the viruliferous insect rate (VIR) of small brown planthopper (SBPH), the incidence of stripe disease, alternate host, and susceptible cultivar in Chungnam Province. The population of overwintering SBPH had been decreasing, but the VIR of overwintering SBPH had not been differing for three years, 2008 to 2010. No RSV was detected in the natural host plants, such as short awn, annual bluegrass, and barley. In 2009, relatively large population of SBPH with the VIR of 5.4% migrated from China. However, there was no evidence relating of migration large amount of SBPH from China in 2008 and 2010. Also the infection rate of RSV in rice was less than 1% in these periods. The cultivation area of the susceptible varieties had steadily decreased from 41% to 19% from 2007 to 2009. Therefore, the reduction factors of rice stripe disease in Chungnam Province with higher influx of inoculum could be with an appropriate forecasting and chemical control, cultivation of resistant varieties, changes in the cropping system, and the low winter-spring temperature.

• Korean Journal of Organic Agriculture
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• v.23 no.4
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• pp.813-827
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• 2015

This study was conducted to evaluate the effect of organic inputs on soil properties in a newly reclaimed organic soils. The soil of the experiment site was very low in soil fertility and the physico-chemical properties were poor. Several organic input treatments with different source of nutrient were placed, including compost in combination with green manures for organic agricultural practices, chemical fertilizers for conventional agricultural practices, and control without fertilizer. The experiment was conducted with continuous cropping system during 3 years. The chemical properties concentration in compost+green manure treatment was increased continually compare to control and chemical fertilizer treatment, and closed to the recommended rate of fertilizer. The organic matter value for compost+green manure treatment was increased from 0.86~0.96% to 2.00~2.29% by continuous nutrient supply of compost and green manure. However, further investigation on increasing of organic matter value for 3 years is necessary to monitor carefully during the long-term because it will help to clarify the all mechanisms of organic matter on organic input application way. The available phosphate value for compost+green manure treatment was generally increased from 21.9~27.1 mg/kg to 182.0~394.1 mg/kg. In case of exchange cation, the concentration for compost+green manure treatment was increased during 2 years within the range to the recommended rate of fertilizer, however, it is expected to cause a rather over supply for 3 years.

• Korean Journal of Soil Science and Fertilizer
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• v.25 no.2
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• pp.133-137
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• 1992

The rate and pattern of soil nitrogen mineralization were investigated under conditions of a paddy-upland switching cultivation system. Experimental results obtained are as follows 1. Amounts of soil nitrogen mineralized were different in the order of potato-cabbage>soybean>continuous paddy plot for the first year, but potato-cabbage>continuous paddy>soybean plot for the second year, respectively. 2. In the third year cropping under upland condition a higher amount of soil nitrogen was found mineralized at the plot of continuous upland cultivation than at the alternate paddy-upland switching plot in the case of potato-cabbage, on the contrary, however, the higher amount was found at the alternate paddy-upland switching plot in the case of soybean cultivation. 3. The amounts of total soil nitrogen and carbon were lower in paddy-upland switching plots than in continuous paddy plots. This trend is significant in soybean plots. 4. A positive correlationship was found between phosphate buffer solution method for available nitrogen and submerged soil method for $NH_4-N$, both being utilized for the estimation of soil fertility.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.10
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• pp.209-214
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• 2017

The purpose of this study is to identify the factors that led greenhouse grape farms to delay their heating periods after the coming into force of the Korea-Chile Free Trade Agreement (FTA). Panel data on the cropping (system) changes from 2004 through 2016 were used for the analysis. According to the panel logistic model, the estimated coefficient of the cultivation area was 0.0002, which was statistically significant at the 10% significance level, the estimated coefficient of grape imports was 1.4258, which was statistically significant at the 1% significance level, and the estimated coefficient of the regional dummy was 0.808, which was statistically significant at the 5% significance level. The results indicated that the use of wider cultivation areas, increase in grape imports, and colder climate(in the mid-northern part of Korea) increased the likelihood of delayed heating. The Korean government is offering direct payment programs and business closure support to the greenhouse grape farmers. While these actions can relieve the damage caused by the increase in grape imports, they will not provide the ultimate solution. Various support measures are needed, such as renewing the varieties to meet the changing demand of grape consumers, providing agricultural materials to reduce the heating expenses, and modernizing greenhouse facilities to improve the energy efficiency and reduce the costs.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.59 no.3
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• pp.307-311
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• 2014

This study was conducted to evaluate effect of plants number per hill (PNH) on growth and yield of sorghum in drained paddy field for 2 years. Crop growth and development and yield in the field was examined to know the efficiency of proposed cropping system. At seeding after 40 days, leaf number and stem diameter were highest at 1 PNH plot, on the other hands, plant height was at 5 PNH plot the $1^{st}$ and $2^{nd}$, respectively. The harvest stage, 5 PNH plot was highest culm length of 183, 188 cm the $1^{st}$ and $2^{nd}$, however, culm diameter was lowest. Culm length of sorghum was highest by 183, 188 cm at 5 PNH plot also, culm diameter was thickest by 19.18, 20.13 mm at 1 PNH, respectively. Yield components of ear length, seed number per ear and 1000-seed weight were highest at 1 PNH the $1^{st}$ and $2^{nd}$, respectively. As yield of sorghum was highest at 2 PNH plot $344kg{\cdot}10a^{-1}$, $382kg{\cdot}10a^{-1}$ yearly, respectively that it were in order of 1 PNH plot > 3 PNH plot > 4 PNH plot > 5 PNH plot.

• Korean Journal of Organic Agriculture
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• v.17 no.3
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• pp.381-391
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• 2009

Crop production can be secured by the cycle of green manure crops as an alternative of the chemical fertilizer. Recently, rapeseed (Brassica napus L.) has been cultivated in the south part of Korea for the production of biodiesel. In this research, we focused on recycling rapeseed residue, which is produced after harvesting the rapeseed for biodiesel, as a potential source of nitrogen to the succeeding crop. Pot experiment was conducted to evaluate the effects of winter rapeseed as green manure on mineralization and uptake of nitrogen to the succeeding corn (Zea mays L.). Result showed that total nitrogen and C/N ratio of rapeseed at the harvesting stage was 0.54% and 63, respectively. The incorporation of rapeseed without decomposition period slightly inhibited nitrogen uptake to the succeeding corn compared to those with 30 days decomposition period. The pH and EC values of soils increased by increasing the period of decomposition of rapeseed from 5.2 to 6.4 and from 0.05 dS/m to 0.21 dS/m, respectively. Significant amounts of $NH_4^+$ and $NO_3^-$ are released by incorporation of rapeseed. The succeeding corn took up 86% and 88% of inorganic nitrogen released from the rapeseed with and without decomposition period, respectively. The overall results suggested that the utilization of rapeseed residue as green manure can be an alternative source of nitrogen in corn-rapeseed double cropping system.

• Korean Journal of Weed Science
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• v.30 no.3
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• pp.243-251
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• 2010

The study was conducted to evaluate the weed suppressing effects of two winter cover crops, Chinese milk vetch (CMV) and rye, in minor cereal fields in 2009. The suppressing activities of cover crops were due to the allelopathy of cover crops during weed emerging periods and competitive activity during vegetative growth of weeds. Weed suppression by cover crops were changed from 26.5 g $m^{-2}$, 0.1 g $m^{-2}$ and 0.2 g $m^{-2}$ in control, rye field and CMV field, respectively, on June 22 to 428.6 g $m^{-2}$, 1 g $m^{-2}$ and 403.9 g $m^{-2}$ in control, rye field and CMV field, respectively, on July 22. The weed dry weights were further changed to 656.3 g $m^{-2}$, 607.8 g $m^{-2}$ and 511.8 g $m^{-2}$ in control, rye field and CMV field, respectively, on August 22. The suppressing effect of cover crops also observed in minor cereals. Plant height and dry weight of sorghum was reduced to 68.7% and 33.6% of handweeding, respectively, on August 5. The reduction was recovered to 82.7% and 55.6% of control, respectively, on August 26. In addition, heading date of minor cereals was delayed by 7 days with rye.