• Korean Journal of Environmental Agriculture
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• v.27 no.3
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• pp.267-273
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• 2008

Energy efficiency and nutrient balance are good methods for environmental assessment of the environmentally-friendly agriculture. The objectives of this study were 1) to estimate the energy efficiency and nutrient balance of the organic rice farming, and 2) to suggest a solution to improvement the energy efficiency and nutrient balance. The set of estimation was performed at the organic rice farming area (8.9 ha) in Wanju-gun during the paddy cultivation period from 2006 to 2007. The organic farming complex consists of four weeding methods using 1) duck, 2) apple snail, 3) duck and apple snail and 4) hands and machinery. Results from this estimation should that the organic rice farming area was less efficient than conventional rice farming. The efficiency of organic farming area in 2006 was higher than in 2007. For the calculation of the nutrient balance, the N, P and K contents of input materials (cattle manure, milk vetch, mixed oilcake, rice bran, rice straw and barley straw) and output (farm products) were analysed. Annual environmental loads of N, $P_2O_5$ and $K_2O$ were estimated at 4.4 kg/10a, 13.8 kg/10a and 14.5 kg/10a, respectively. Cattle manure had the largest portion among the inputs items and nutrient concentration of cattle manure was high. Thus energy efficiency and nutrient balance depend on cattle manure input. Therefore it is necessary to control the manure input to improve the efficiency of organic rice farming.

• Korean Journal of Environmental Biology
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• v.38 no.3
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• pp.486-495
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• 2020

We surveyed disease outbreak status that has recently become a problem in organic tomatoes and cucurbit in plastic greenhouse that were grown without spraying pesticides during the plastic greenhouse growing season of 2015 to 2019. It was found that the incidence of leaf mold, tomato spotted wilt virus, and tomato chlorosis virus disease was severe in tomato, and disease incidence of powdery mildew and zucchini yellow mosaic virus were severe in Cucurbit. The disease outbreak was found to be faster and more severe in crops grown in pesticide-free cultivation plastic greenhouses than in plastic greenhouses that are cultivated in general using pesticides. In particular, the occurrence of viral diseases mediated by thrips and aphids was found to be severely damaged. Therefore, in order to produce good organic products, it is important to effectively control pests, and in order to minimize the damage caused by disease, sanitation and physical blocking, and comprehensively utilize organic materials or microorganisms to prevent them.

• Korean Journal of Soil Science and Fertilizer
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• v.49 no.6
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• pp.655-661
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• 2016

Relationships between saturated conductivity (Ks) and separate contents were evaluated from 44 soil series of arable lands: 18 for paddy fields and 26 for upland crop fields. Saturated hydraulic conductivities of A, B, and C horizons were determined with tension infiltrometer and Guelph permeameter in situ. Sand, silt, clay, and organic matter content of each horizon were analyzed. Based on correlation analysis, sand separate had a positive relationship with Ks for both paddy (r=0.27, p=0.017) and upland fields (r=0.24. p=0.030). Clay content had a negative relationship with Ks for paddy soils (r=-0.32, p=0.005) while significant correlation between them was not found for upland crop fields (r=-0.20, p=0.07). Organic matter content showed a positive relationship with Ks only for upland crop fields (r=0.33, p=0.002). Due to low correlation coefficients between separate contents and Ks, performance of pedotransfer functions was not enough to estimate Ks. It implies that hydraulic properties of arable lands were affected by other factors rather than particle characteristics. Platy structure and plow pan were suggested to limit Ks of paddy fields. Soil compaction and diversity of parent materials were proposed to influence Ks of upland crop fields. It suggests that genetic processes and artificial managements should be included in pedotransfer functions to estimate hydraulic properties appropriately.

• Journal of the Korea Organic Resources Recycling Association
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• v.16 no.4
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• pp.50-56
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• 2008

Aqueous thermal liquefaction of rice, barley, wheat, and rapeseed straws was investigated to compare the amount of heavy oil with catalysts such as $K_2CO_3$, NaOH and KOH in the reaction temperature at $320^{\circ}C$ for 10 minutes. The reaction was carried out in a 5,000ml liquefaction system with dispenser and external electrical furnace. Raw materials (160g), 2,000ml of distilled water and 10% (wt/wt) of catalyst to plant residue were fed into the reactor. It was observed that the maximum heavy oil yield was about 29% from the feeding stock, barley straw, with addition of KOH. The caloric values of crude oil from different crop residues were ranged from 55% to 66% relative to the raw materials depend on crop residue. It was appeared that its maximum calorific value from wheat straw was approximately 6190 kcal/kg.

• Proceedings of the Korean Society of Organic Agriculture Conference
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• 2009.12a
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• pp.313-313
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• 2009

지속 가능한 농업과 안전한 농산물의 생산을 유지시키면서 환경부담 물질 투입량을 절감시킬 수 있는 농법을 개발하기 위해서 유기농자재 사용실태 및 효과를 조사했다. 전북 익산시 웅포면 유기농업 시범마을 현지 농가에서 사용 중인 유기 농자재의 실태를 조사하고 또한 유기농자재의 성분을 분석하였다. 유기농 자재 시용효과를 검증하기 위해서 시범마을 현지 농가포장에서 삼광벼 품종으로 포트 육묘 후 기계이앙을 실시하고 유기농자재를 시용하여 조사하였다. 유기농업 종합기술 시범마을에서 활용중인 유기농자재는 27.5%가 유기농 목록에 공시된 자재를 사용하고 있었다. 시범마을에서 활용중인 유기농자재의 성분 중 수분은 평균 50.1%, 유기물함량은 36.0%, 총 질소함량은 1.71% 이며 염분은 0.56% 이였다. 경종방법과 유기농자재를 이용하여 새로운 유기농 벼 재배 기술을 개발할 목적으로 시험포를 조성한 지역에서 토양의 화학성분을 조사한 결과 pH, 마그네슘, 규산은 망성 단지에서 낮은 경향을 보였고, 유기물, 인산, 규산, 칼륨은 삼기단지에서 높았다. 포트육묘 후 이앙을 실시한 결과 단위면적당 이앙주수별 생육에서 재식밀도가 높을 수록 초장과 경수가 적었다. 산파육묘와 포트육묘 이앙 모두 도복 발생은 없었으며, 포트 육묘 3절의 두께가 양호하였다. 쌀겨 시용에서 잡초발 생량이 적었으며, 포트육묘 이앙에서 병해충이 적었다. 수량은 산파육묘에 비해 포트육묘 방식에서 5~10% 높았는데, 포트 육묘에서 주당 수수, 수당 립수가 많았고, 천립중이 무거웠다.

• Korean Journal of Organic Agriculture
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• v.10 no.2
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• pp.67-83
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• 2002

In the paper, the actual situation of Korean organic agriculture and its development history regards to basic skills of organic farming were reported. And an education for organic farming in the universities with schools of agriculture in European countries was also reported to deliver the information on the course of organic agriculture for Korean Universities facing the problem which have a lower admission competition than previous Year. The examination for organic engineer certificate which was introduced in 2001 and the proposed government research institute, so called "Research Center of Organic Agriculture" were also shortly discussed. In the conclusion, \circled1 the establishment of "research Center of Organic Agriculture" which should by attached RDA for the systematic approach of research for organic agriculture and the test of agricultural materials using for organic farming, \circled2 department of organic agriculture in the Universities with schools of agriculture to offer next generation an opportunity to learn an organic farming parallel to conventional farming, \circled3certification body system by third party, and \circled4 full support by Korean government and scientist society for "Asian Research Network of Organic Agriculture (ARNOA)" headquartered in Korea as international research organization were strongly suggested.

• Korean Journal of Organic Agriculture
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• v.21 no.2
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• pp.233-246
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• 2013

This study was performed to investigate the recognition of Korean farmers for the safety of environment-friendly organic materials (EFOMs). The main purchase line of environment-friendly organic materials was the sustainable agriculture organizations, and decisive basis for the materials purchase was because they thought that agricultural produce cultivated with EFOMs were safe. Currently farmers obtained the most information about EFOMs through farmer's education operated by agricultural technology center. Sixty nine percent of respondents hoped that they would get the information on the website and through official education opened by of the government or relative institutions. Whereas, only a few respondents hoped that they would get the information from the sellers. Therefore we thought that government and related institutions should operate the education program to give the sellers the scientific and accurate information about EFOMs. In addition, farmers are highly recognized the necessity of safety-related information provided by government and related institutions. Most Farmers thought that safety education for farmers using EFOMs was very important. Also, it was confirmed that farmer respondents thought to need to establish the shelf-life and user guideline and to label about toxic category of EFOMs. The Cronbach' alpha coefficient calculated in order to verify the reliability of survey questions was 0.699. That value indicates that responses of the respondents in this study might be reliable.

• Proceedings of the Korean Society for Agricultural Machinery Conference
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• 1996.06c
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• pp.701-710
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• 1996

Composting has gained rapid acceptance as a method of recyling relatively dry organic materials such as leaves and brush and , when alternative disposal costs are high, even moist materials such as grass clippings and dewatered sewage sludges. However, as moisture contents rise above 60% , the need for a dry bulking amendment increase the costs of composting , both by direct purchases of amendment and though increased reactor capacity and materials handling requirements. High moisture materials also present increased risks of anaerobic odor formation through reduced oxygen transport (Miller , 1991) . These costs and operational challengers often constrain the opportunities to compost high moisture materials such as agricultural manures. During the last several decades economies of scale in livestock production have been increasing livestock densities and creating manure management challenges throughout the world. This issue is particularly pressing in Korea, where livestock arms typically manage little or no cropland, and the nutrients and boichemical oxygen demand in manure pose a serious threat to water quality. Composting has recently become popular as a means of recycling manure into products for sale off the farm, but bulking amendments (usually sawdust) are expensive designed to minimize bulking agent requirements by using the energy liberated by decompostion. In this context the composting reactor is used as a biological dryer, allowing the repeated use of bulking amendment with several batches of manure.

• Korean Journal of Agricultural Science
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• v.24 no.1
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• pp.94-107
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• 1997

Producing organic farm products is one of the high-payoff farming practices considering the rapid increase of consumer's purchasing power. The purpose of this study is to identify the optimal organic farming system in relation to farm income. To cope with the above objectives, present farming conditions and profitability of 15 farmers producing organic products including rice and leaf vegetables as lettuse and cabbage were surveyed in Hongsung and Ahsan Gun, Chungnam Province. Based on the surveyed data, maximization of organic farm income were analyzed under the constrained conditions such as limited monthly labour inputs and competitive use of land by Linear Programming Model. The results of this study can be summarized as follows. 1. In the profitability analysis of 15 farmers producing organic products, rice farmers could earn their farm income more than that of conventional farmers by 50%. On the other hand, the controlled lettuce farmers could get more about 100% than that of it. But the controlled cabbage farm could get more about 40% of it. These organic farm products were saled at high prices comparing with the prices of conventional farm products by 170% ~ 230% even though the crop yields produced by organic materials had decreased. 2. According to the labor requirement of the organically produced crops, rice cultivation was needed more labour inputs than the conventional farming method by 130%. On the other hand lettuce and cabbage could saved labour requirement by 40% and 80% of those respectively. Especially for the rice cultivation concern, higher labor requirement was due to the activities as organic fertilization, soil preparation and pest and weed controll, etc. 3. With the surveyed data from farmers who produced farm commodities, L.P. analysis was implemented to find out the optimul farming system and the maximum income. According to the results of L.P. analysis, 58% of total farm income could get more than the conventional farming system In the case of rice cultivation, one ha of paddy was recommendable to save more labour inputs than the controlled leaf vegetables such as lettuse and cabbage. However, in the controlled leaf vegatables, only 73% of total upland equivalent to 0.3 ha should be cultivated under the condition of labor shortage as the restricted 4 workers. And increasing the size of hogs raising should be recommened to achieve self-sufficiency of organic fertilizer. As pointed out the possibility of organic farming, present farmers producing organic farm products could be able to maximize their income by expanding organic farm size with regard to all conditions of our organic industry. Of course, there are many difficulties in the course of developing organic agriculture. So Government should effort to support the development of our organic agriculture considering the various aspects of production, marketing, Quality certification of organic produces.

• The Korean Journal of Pesticide Science
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• v.18 no.4
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• pp.376-382
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• 2014

The soluble loess-sulfur mixture allowed standing to remove insoluble component materials for five weeks after manufacturing. We decreased the pH level of soluble loess-sulfur mixture at pH 1.0 modified with decreasing 25% sodium hydroxide than original content. The pH ranges of soluble loess-sulfur mixture solutions were adjusted to pH 5.0-pH 11.0 (pH 1 unit) with brown rice vinegar (pH 2.8). The pH of original loess-sulfur mixture was about pH 13 and damaged the foliar parts and young leaves of tomato after twice application. These stock solutions can be diluted 500:1 with tap water to make a 0.05% working solution and were sprayed two times with 7 days interval to the leaf and stem of tomato, which were spontaneously infected with E. cichoracearum. Control efficacy of powdery mildew ranged from 85% to 90% at 7 days after first application. After second application, each loess-sulfur mixture solutions adjusted pH level significantly suppressed the powdery mildew disease in tomato. Consequently, loess-sulfur complex adjusted pH level with brown rice vinegar was suggested to be low in acute toxicity at all different pH values and suggested to use an agent for control of tomato powdery mildew in organic farming.