• Journal of Mushroom
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• v.10 no.1
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• pp.21-28
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• 2012

Studies were made to optimize the media composition and cultural condition for mycelial growth of Agrocybe cylindracea. Sawdust spawn of media composition for optimal growth was found to be pine sawdust combination of 30% wheat bran and poplar sawdust combination of 20% corn bran were the best of the optimal combination. The optimal concentration of white sugar was 1.0~1.5%. The nitrogen sources was found to be yeast extract and soybean powder. Also, optimal concentration were $0.7g/{\ell}$ and $0.1g/{\ell}$, respectively. The mineral sources of optimal medium compositions were $MgSO_4{\cdot}7H_2O\;0.3g/{\ell}$, $KH_2PO_4\;0.5g/{\ell}$ and $K_2HPO\;1.2g/{\ell}$. Optimal amount of inoculum for cultivation of A. cylindracea were $20{\sim}25g/850m{\ell}$ and $25m{\ell}/850m{\ell}$ in the sawdust spawn and liquid spawn, respectively.

• Korean Journal of Soil Science and Fertilizer
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• v.40 no.1
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• pp.98-107
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• 2007

Most of plastic film house plots in Korea have salinity problems caused by salt accumulations associated with continuous cropping including the heavy applications of chemical fertilizers, and high evapotranspiration. The objective of this study was to investigate soil properties and watermelon (Citrullus lanatus Thunb.) productivity in plastic film houses as influenced by the short-term crop rotation in the continuous watermelon-cultivated soils. The short-term rotational crops selected were corn, Chinese cabbage, radish, young radish, lettuce, spinach, and onion. Soil pH increased in most plots where a short-term crop was added to the crop rotation, except where radish was added. The content of soil organic matter significantly decreased in the lettuce-cultivated plot. The available phosphorus content in the soils increased with the cultivations of spinach and onion. Exchangeable Ca and Mg tended to increase in most of plots where a short-term rotational crop was grown, whereas the exchangeable K was clearly reduced by more than 50% in the same plots. Cultivation of rotational crops during the post-harvest season significantly decreased the electrical conductivity (EC) and the concentrations of soluble anions, such as chloride ($Cl^-$), nitrate ($NO_3{^-}$), and sulfate ($SO{_4}^{2-}$) in the soils. In particular, the EC decrease was related with the decrease in soil $K^+$ to $Ca^{2+}$ and $Mg^{2+}$ ratio. In all plots cultivated with the shot-term rotational crops, the ratios of bacteria to fungi (B/F) increased. However, the improvement in soil properties after adding a rotational crop did not result in a clear improvement in watermelon quantity or quality as measured by fruit weight and sugar content. Therefore, the addition of short-term rotational crops to a continuous watermelon cropping system would be beneficial to improve target soil properties in plastic film house plots studied.

• Korean journal of applied entomology
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• v.60 no.4
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• pp.431-448
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• 2021

We decided the efficient application timings of organo-synthetic insecticides for controlling the first generation larvae of O. furnacalis through investigations of insect stage-specific densities, damage aspects in maize, and effects of insecticides. A waxy maize cultivar, Ilmichal, was cultivated from April 20 (sowing) to July 26 (harvest, dough stage of maize) in Suwon, 2016. The maximum and 50% cumulative catch dates of the overwintering generation adults in the sex pheromone trapping were May 29 and May 31, respectively. Most of the first generation larvae finished their occurrence till the early reproductive stage of maize. The first generation larvae fed on leaves inside the whorl leaves before tassel and stem development of maize, sequentially moved to tassel and stem, and then moved finally to stem and ear parts. In the results of insecticide applications at different dates, the 9-11 leaf stage (June 10~17) and the 6-7 leaf stage (June 3) of maize were the most efficient application timings for direct spray of Etofenprox EC to maize, and for application of Carbofuran granules onto soil surface, respectively, which resulted in suppression of tunnelling damages. The timings for the two insecticides were 12-19 days and 5 days after the adult maximum catch date, respectively. Those timings after the 50% cumulative adult catch date were advanced 2 days.

• Journal of Practical Agriculture & Fisheries Research
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• v.21 no.1
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• pp.81-87
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• 2019

The investigation of mycelial growth for artificial cultivation in T. albuminosus determined that within PDA, YM, MEA medium, both KNCAF 9001 and 9002 strains showed the highest mycelial growth in MEA media with 89, 81 mm, respectively, followed by YM, PDA in respected order. Furthermore, optimal mycelial growth of 89 and 77 mm in 9001 and 9002, respectively, at 25 ℃. Mycelial growth rapidly decreased at 30 ℃, but it was confirmed that it survived at 40 ℃. At pH 6, mycelial growth was fast with growth of 89 and 88 mm for both 9001 and 9002, respectively. In the case of 9001, the addition of with cotton seed hull(80%) and rice bran (20%) each other resulted in maximum productivity of 99 mm/10 days. The result differed in order of corn cob(97 mm), oak sawdust(96 mm) and poplar sawdust(93 mm). Ultimately, the result confirmed that addition of rice bran in comparison to bran resulted in higher yield. Even with identical medium component, 9002 showed the same tendency as 9001 but its growth was relatively slower than 9001. The effect of mycelial growth on the moisture content of the medium was best at 101. 94 mm/10 days when the moisture content of 9001 and 9002 was 65%. Mycelial growth rate tended to be slower when the moisture content was higher or lower than 65%.

• Proceedings of the Korean Society of Crop Science Conference
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• 2022.10a
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• pp.52-52
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• 2022

Recently, PE (polyethylene) film has been used increasingly in com cultivation. However, PE films often cause soil and environment contamination. In order to reduce this problem, many researches have been carrying out studies on biodegradable films (BF) that are easily decomposed by soil microorganisms. Therefore, this study was conducted to determine which BF is optimal for growth and yield of com crops while also having the highest rates of film decomposition. BFs Farmsbio (Farm Hannong), Heulgro Film (Sejin Bio), Vonto Film (Eco-Hansung) as well as a selected PE film were used in this study. For the control, we used crops grown without any kind of mulching. Experimental fields were fertilized according to conventional cultivation methods, tilled, and then covered by either BF or PE. After 1 week, com (cv. MIBECK2ho) at the 3-leaf stage (16 days after seeding) was transplanted. Plant height was measured at 18 and 32 days after transplanting and heading stages. Yield components and yield were also measured at harvest. In addition, pH, EC, and decomposition and light transmittance levels of films were investigated during the experimental period. Daily average temperature, relative humidity and organic matter in soils were also measured during the experimental period. There was no significant difference in plant height, heading date, and silking between crops with BFs and PE, but the crops grown with BFs and PE films reached higher growth parameters in a shorter amount of time than the crops in the non-mulching control. Additionally, there were no significant differences in yield components such as length of ears, ear width, ear weight, and yield in crops that were grown using films or crops in the control plot. Light transmittance and decomposition levels of films generally increased with time after transplanting, and was highest in the Heulgro film than other BFs. Soil pH and organic matter in crops using BFs and PE films were significantly higher than in the control plot at 99 and 113 days after transplanting. In general, the EC contents in the control plot was lower than in crops using BFs and PE films. The average daily moisture in soil was higher when BFs and PE films were used than in the control plot. However, the daily average soil temperature was higher in crops using BFs and PE films than in the control plots at the beginning of the experimental period, but there was no consistent difference in soil temperature towards the later part of the experimental period. Therefore, the BFs used in this study were shown to be helpful without causing negative impacts on the growth and yield of com.

• Korean Journal of Agricultural Science
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• v.45 no.3
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• pp.355-363
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• 2018

This study was conducted to investigate suitable rice cultivars for various rice based cropping systems in a paddy field in the Yeongnam plain area. Thirteen rice cultivars (5 early, 3 medium and 5 mid-late maturing cultivars) and three transplanting dates (June 5, June 25 and July 5) were evaluated in this study. The mid-late and early maturing cultivars for the July 5 and June 25 transplanting headed before August 30 which is the safe heading date in the Yeongnam plain area, ranging from Aug. 26 - 28 and Aug. 18 - 23, respectively. The safe harvest time of rice for double and triple cropping systems should be before the middle of October for the cultivation of the succeeding winter crops. The rice yield was the highest for the June 5 transplanting regardless of the rice cultivars, and it gradually decreased as the transplanting date was delayed from June 5 to July 5 due to a decrease in the spikelet numbers per panicle number and in the ripened grain rate. In contrast, the other yield parameters that include the panicle number per $m^2$, the 1,000-brown rice weight, and the ripened grain ratio were not significantly affected. The result indicates that based on the milled rice, heading time and harvest time, a medium maturing cultivar (Haiami and Samdeog) would be applicable to a winter barley/wheat, garlic/onion-summer rice double cropping, while a mid-late cultivar (Saeilmi, Saenuri and Hyunpoom) would be suitable for a spring potato/waxy corn-summer rice double cropping in the Yeongnam plain area. On the other hand, an early maturing cultivar (Unkwang, Jokwang and Haedamssal) would be preferable for a triple cropping because of the short growth period of rice.

• Journal of Animal Science and Technology
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• v.53 no.3
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• pp.261-268
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• 2011

The increasing demand of the crops (soybean and corn) for biofuel production has increased the focus of the animal nutritionists to look for alternative feeds, which are economic and environmental friendly. To identify microalgae as suitable candidate as an alternative feed, growth response of Chlorella vulgaris was studied under varying concentrations of carbon dioxide (0.07, 1.4, 3.0 and 5.0%) and photon densities (39.19, 72.97, 105.41, 116.22, 135.14, $175.68\;{\mu}mol/m^2/s$) by employing a photo-bioreactor. Swine wastewater was also investigated as nutritional source to economize the biomass production. Results showed that the higher biomass production was found to be at 3.0% $CO_2$ compared to other $CO_2$ concentrations. However, no difference in biomass production was found at $105.41\;{\mu}mol/m^2/s$ and above photon densities with 12 h of photoperiodicity. It was observed that C. vulgaris could easily grow in 200 times diluted swine wastewater and growth was found to be similar with that of artificial medium. Provided the conducive conditions for optimal growth, it has also the potentiality of depleting ammonia nitrogen ($NH_4$-N) and orthophosphate ($PO_4^{3-}$-P) completely from the wastewater after 3~4 days of cultivation. Thus, growing C. vulgaris would not only solve the problem of animal feed, but also help in biological $CO_2$ mitigation and wastewater treatment.

• Journal of The Korean Society of Grassland and Forage Science
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• v.27 no.1
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• pp.67-76
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• 2007

The conclusion of free Trade Agreement between South Korea and USA can become a serious threat to the Korean agriculture. On the strategic scheme the foodstuffs is the basis for protection of the state sovereignty. The Amur oblast of Russian Federation is region, which can supply South Korea cheap and good qualitative feeds. It means South Korea should create agricultural cooperation with the Amur oblast of Russian Federation with the purpose to begin organic agriculture in this area and it will help South Korea to counteract a quantitative attack on Korea from the side of american agricultural production. In the Amur oblast there are following fodder crops; Alfalfa, Smooth brome grass (gromus adonis L.), Siberian couch grass, Sudan pass, Colza rape (Brassica napus) and Amaranth (Avfranthus). In the same area also exist oatmeal, wheat, corn and barley, which is possible to use for feeds. All these above written cultures are cultivated organically, therefore it is possible to use them as organic forages in South Korea. It is very important to know system of crop rotation in the Amur oblast. There is a scheme of crop rotation, which is connected with increase and preservation of fertility of soil, maintenance of growth of productivity of agricultural cultures and reception of high-quality production. It is necessary to begin organic agriculture in a southern part of Amur oblast, where, in 2001 year, 97% of all sowing areas was concentrated. The acidity degree of soil in this part is not high ($ph5.1{\sim}5.5$), therefore does not require liming.

• Toxicological Research
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• v.19 no.1
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• pp.1-12
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• 2003

New breeding method by genetic engineering is expected as a key technology to solve food shortage due to the growing world population in the year 2000s. Many genetically modified organisms (GMOs) were already developed and the commercial cultivation had started. The first GMO, Flavr Savr tomato, which rotted at a much slower pace than ordinary ones, was developed in US in 1994. Since then, over than 70 different agricultural products including corn, cotton, soybean, papaya, potato, and squash made with genetically modified plants are reportedly on sale worldwide. Supporters favor the GMOs because they have greater yields, longer shelf lives and stronger resistance to disease and insects. On the other hand, opponents say that the supporters ignore a potential danger that they may damage the environment as well as human beings. To assure the safe development and use of GMOs as food and other biotech products, the possible risks on biological environment and human health should be throughly examined and regulated by developer and government. Because the biosafety problem is a global, environmental, and trade issue, a new international treaty is under development. The Cartagena Protocol on Biosafety was adopted at the 1 st Extraordinary Conference of Parties of the Convention on Biological Diversity which was held at Mont-real, Canada, Jan. 29th, 2000. The adoption of the Protocol is seen as a breakthrough in that it is based on the" Precautionary Principle" despite scientific uncertainties surrounding potential risks that GMOs may inflict on human health and the environment and that it has laid the ground for introduction of specific steps to handle international trading of GMOs. In this paper, the authors would like to introduce the current status and perspective of environmental and human risk assessment of GMOs.t of GMOs.

• Journal of Mushroom
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• v.12 no.2
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• pp.117-121
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• 2014

The experiments were conducted to provide information on the chemical concentrations and cultural characteristics in the periods of hyphal incubation, primordial formation, and fruiting bodies yield of winter mushroom, Flammulina velutipes at the mixture ratio of the raw materials. Substrates were analyzed for pH, total carbon (T-C), total nitrogen (T-N), and C/N ratio. In case of Flammulina velutipes, yield of fruiting bodies were 190.5 g/850 ml in the substrates, [Corn-cob + Rice bran + Soybean curd residue (75:20:5)], which was increased 20.4% more than the control, [Douglas fir sawdust + Rice bran (75:25)]. But the periods of hyphal incubation took 28 days, which was 7 days longer than the control. Also, in the substrates [Douglas fir sawdust + Rice bran + Soybean curd residue (75:20:5)], the yields was 172.7 g/850 ml and the periods of hyphal incubation was 21 days.