• 한국농공학회논문집
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• 제48권6호
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• pp.31-41
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• 2006

The analysis used in this work was cost-benefit analysis method. All future costs and returns of a given mushroom house were discounted to the time of initial investment (present) by means of 3.5% discount rate. Then the cost of ownership was compared to the return from the system. This analysis method has been developed and coded into a balance sheet for use on a EXCEL program. Using this programmed analysis,a large number of the case studies were examined using different combinations of economic conditions. These results will be very useful to individuals considering investment in a mushroom house, or any similar production system. By the way of the sensitivity analysis for each important parameter, the change of the marginal cost-benefit period could be finally determined. These parameters were typically construction cost of mushroom house, cost of cooling system, required cooling and heating energy amounts, unit price of mushroom media bottle, growing number of media bottles, production weight per unit bottle, sale price of mushroom, and annual number of growing period, etc.

• ALGAE
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• 제35권1호
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• pp.91-106
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• 2020

Incorporating renewable fuel into practice, especially from algae, is a promising approach in reducing fossil fuel dependency. Algae are an exceptional feedstock since they produce abundant biomass and oils in short timeframes. Algae also produce high-valued lipid products suitable for human nutrition and supplement. Achieving goals of producing algae fuels and high-valued lipids at competitive prices involves further improvement of technology, especially better control over cultivation. Manipulating microalgae cultivation conditions to prevent contamination is essential in addition to promoting optimal growth and lipid yields. Contamination of algal cultures is a major impediment to algae cultivation that can however be mitigated by choosing extremophile microalgae. This work describes the isolation of alkali-tolerant / alkaliphilic microalgae native to South Florida with ideal characteristics for cultivation. For that purpose, water samples from Lake Okeechobee were inoculated into Zarrouk's medium (pH 9-12) and incubated for 35 days. Selection resulted in isolation of three strains that were screened for biomass and lipid accumulation. Two alkali-tolerant algae Chloroidium sp. 154-1 and Chlorella sp. 154-2 were poor lipid accumulators. One of the isolates, the diatom Fistulifera sp. 154-3, was identified as a lipid accumulating, alkaliphilic organism capable of producing 0.233 g L^-1 d^-1 dry biomass and a lipid content of 20-30% dry weight. Lipid analysis indicated the most abundant fatty acid within Fistulifera sp. was palmitoleic acid (52%), or omega-7, followed by palmitic acid (17%), and then eicosapentanoic acid (15%). 18S rRNA phylogenetic analysis formed a well-supported clade with Fistulifera species.

• 한국환경농학회지
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• 제40권2호
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• pp.92-98
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• 2021

BACKGROUND: Unintentional residual pesticide in soil derived from preceding crops and the transfer to succeeding crops was considered a critical barrier for positive list system (PLS). Thus, an uncertain risk is predicted for ethoprophos applied at cultivation of preceding crop (Korean cabbage) to succeeding crop (spinach). METHODS AND RESULTS: Ethoprophos was treated on soil following the recommended dose and 5 times dose according to the safe use guidelines for Korean cabbage after seeding. On the 4 days after harvesting of preceding crop, spinach was sowed. The initial residual amounts of ethoprophos on soil (7.081-19.493 mg/kg) were decreased to 3.832-7.218 mg/kg until the harvest of Korean cabbage, and then finally decreased to 0.011-0.079 mg/kg after spinach cultivation. The uptake rates of ethoprophos from soil by Korean cabbage were 0.01-0.03% and distributed to root (0.150-0.903 mg/kg) and shoot (0.021-0.151 mg/kg), respectively. The residual amounts of uptake and translocation from preceding crop cultivated soil to spinach edible part were found to be below LOQ. CONCLUSION: The plant back internal (PBI) for ethoprophos is not recommended during sequential cultivation of leafy vegetables, since the residual amounts of ethoprophos in spinach were less than MRL (0.02 mg/kg).

• 한국산학기술학회논문지
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• 제22권1호
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• pp.313-320
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• 2021

본 연구는 경남 밀양 깻잎 농업의 수급 및 가격 모형을 개발하고 정책 실험을 통해 밀양 깻잎 생산 농가의 총 소득을 극대화하는 적정 생산 규모를 전망한다. 분석 자료는 밀양 깻잎 농업의 총 소득과 관련된 22개년 시계열 자료(1996~2017년)가 이용되었다. 분석 방법은 수요 함수와 평균 비용 함수 추정을 통하여 적정 생산량과 가격을 산출하고 이를 통해 적정 소득을 도출하였다. 또한, 시나리오 분석을 통하여 2030년까지 예상되는 밀양 깻잎 최적 생산량과 이에 해당하는 판매 가격, 총 수입, 총 비용, 총 소득을 전망하였다. 밀양 깻잎 생산 농가 전체를 대상으로 총 소득을 극대화하기 위해서는 2017년에 7천 톤 규모인 밀양 깻잎 생산량을 2030년까지 10~12.5천 톤으로 증가시킬 필요가 있다. 이 경우 밀양 깻잎 농업에 귀속되는 총 소득은 133~213억 원 수준으로 전망된다. 앞으로 밀양 깻잎 생산자 단체는 본 연구에서 제시한 적정 생산 규모를 유지하여 농가에게 귀속하는 총 소득을 증대시키도록 노력해야 할 것이다.

• 한국농림기상학회지
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• 제17권4호
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• pp.399-410
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• 2015

본 연구에서는 호두나무에 대하여 단기임산물 재배적 지도를 바탕으로 기후변화를 고려한 전국의 재배가능지역을 MaxEnt 모델을 이용하여 추출하였다. RCP 4.5 및 8.5 시나리오와 HadGEM2-AO모델을 이용하여 2050년대와 2070년대의 기후변화에 따른 재배지역 변화를 예측하였다. 분석결과, 미래의 재배적지면적을 현재 수치와 비교하였을 때, RCP 4.5에서는 충청남도, 전라북도, 전라남도에 이르는 우리나라 서쪽 지역이 주로 감소할 것으로 나타났으며, RCP 8.5에서는 경상북도, 경상남도 일부 지역을 중심으로 감소할 것으로 나타났다. 하지만, 평균고도가 600m 이상으로 높은 지역인 강원도는 2070년대 RCP 4.5에서 18.3%, RCP 8.5에서 56.6%가 증가할 것으로 나타나 기후변화의 영향 정도에 따라 전국적으로 재배가능지역의 차이가 있는 것으로 나타났다. 현재 호두 생산량이 가장 많은 지역을 분석한 결과 공주시, 김천시, 영동군은 2070년대에는 RCP 8.5에서 재배지역의 감소가 클 것으로 예상되었으며, 공주시는 RCP 4.5에서 감소폭이 더 큰 것으로 나타났다. 무주군과 천안시는 현재의 재배가능지역이 모든 시나리오에서 유지될 것으로 나타났다. 본 연구의 결과는 미래 기후변화에 따른 영향이 불가피한 상황에서 예상되는 피해를 최소화하고 경쟁력 있는 임산물 생산을 위한 기후변화 영향평가 자료로 활용될 것으로 판단된다.

• 한국산학기술학회논문지
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• 제19권8호
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• pp.392-402
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• 2018

제주지역에서 대부분 생산되는 감귤류는 재배방식에 따라 노지에서 재배되는 온주감귤, 시설하우스에서 재배되는 온주감귤, 노지이지만 비가림 시설을 해서 재배되는 온주감귤 그리고 노지 온주감귤 보다 재배 시기가 늦고 품종도 다른 한라봉, 천혜향, 진지향 등 만감류로 구분된다. 만감류는 온주감귤 보다 맛 등 품질이 좋아 소비량이 꾸준히 증대되어 '90년 이후 최근까지 재배면적과 생산량이 지속해서 늘어나고 있고, 비가림 감귤 재배도 정부의 정책적 지원과 더불어 당도개선 등 품질향상 효과가 있어 지속해서 늘어나고 있다. 그러나 이에 반해 2010년 이후 노지 감귤의 재배면적은 지속해서 감소하고 있다. 이 연구는 감귤류 중 생산비중이 높지만 지속해서 재배면적이 줄고 있는 노지 감귤을 연구의 대상으로 삼고, 특히 수급 안정에 핵심적인 역할을 할 수 있을 것으로 파악되는 저장부문의 수급안정 기여 가능성을 탐색하는데 초점을 두고 있다. 노지감귤 중장기 수급모형 추정 및 전망을 위해 노지감귤 개별 품목에 대한 부분균형모형을 구축하고 품목별 모형내 개별방정식은 계량경제학 방법을 이용하여 추정하였다. 생산량 저장 시나리오 분석 결과, 재배면적은 2027년 기준 감귤 생산량을 5% 저장했을 때 14.49ha, 10%인 경우 14.97ha, 15%인 경우 15.50ha에 이를 것으로 분석된다. 이 연구는 현재 산지에서 저장에 초점을 두고 있지 않은 상황에서 저장가능성에 대한 종합적인 기술적 및 경제적인 검토를 하고 있다는 데 선행연구들과 차별성이 있다.

• 한국산림과학회지
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• 제107권3호
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• pp.316-323
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• 2018

본 연구는 고사리, 곰취, 산마늘 등 주요 산채류에 대한 재배공정을 조사하여 소득분석을 실시함으로써 향후 임산물에 대한 손실보상 기준 및 임업경영진단 등에 필요한 기초자료를 제공하기 위하여 실시하였다. 조사결과 품목별 재배형태는 크게 노지재배와 산지재배로 구분되었다. 품목별 단위면적당($3.3m^2$) 연간 평균소득은 고사리 노지재배는 6.5천원, 고사리 산지재배는 3.2천원, 곰취 노지재배는 20.4천원, 산마늘 노지재배는 20.9천원, 산마늘 산지재배는 7.3천원 등으로 나타났다. 특히, 최근 소비자 수요가 크게 증가하고 있는 산마늘과 곰취의 노지재배 단위면적당($3.3m^2$) 연간 평균소득은 고사리에 비해서 매우 높은 것으로 분석되었다. 이러한 원인은 고사리 재배 시 경영비(토지임차료, 고용노동비)의 투입비중이 타 품목에 비해 매우 높기 때문이다. 연간 평균소득이 높은 곰취와 산마늘의 경우 종묘 및 종근 구입 등 초기 투자비용이 경영비의 평균 40% 이상을 차지하고 있어 향후 농산촌지역의 소득원 및 재배 활성화를 위해서는 이에 대한 정부의 적절한 지원이 필요할 것으로 판단된다.

• The Plant Pathology Journal
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• 제36권4호
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• pp.305-313
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• 2020

Host shifting and host expansion of fungal plant pathogens increases the rate of emergence of new pathogens and the incidence of disease in various crops, which threaten global food security. Magnaporthe species cause serious disease in rice, namely rice blast disease, as well as in many alternative hosts, including wheat, barley, and millet. A severe outbreak of wheat blast due to Magnaporthe oryzae occurred recently in Bangladesh, after the fungus was introduced from South America, causing great loss of yield. This outbreak of wheat blast is of growing concern, because it might spread to adjacent wheat-producing areas. Therefore, it is important to understand the host range and population structure of M. oryzae and related species for determining the evolutionary relationships among Magnaporthe species and for managing blast disease in the field. Here, we collected isolates of M. oryzae and related species from various Poaceae species, including crops and weeds surrounding rice fields, in Korea and determined their phylogenetic relationships and host species specificity. Internal transcribed spacer-mediated phylogenetic analysis revealed that M. oryzae and related species are classified into four groups primarily including isolates from rice, crabgrass, millet and tall fescue. Based on pathogenicity assays, M. oryzae and related species can infect different Poaceae hosts and move among hosts, suggesting the potential for host shifting and host expansion in nature. These results provide important information on the diversification of M. oryzae and related species with a broad range of Poaceae as hosts in crop fields.

• 한국작물학회:학술대회논문집
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• 한국작물학회 2017년도 9th Asian Crop Science Association conference
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• pp.352-352
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• 2017

Recently, the South Korean government encourages the cultivation of upland crops in the paddy field to maintain an adequate level of rice production and then to balance the demand and supply of rice. This is mainly because the rice consumption per capita per year has continued to decline from 135 kg in 1979 to 61.9 kg in 2016, although the rice production was relatively stable. As a result, the rice overproduction became a big social problem. As a part of that, various upland crops such as soybean, maize, minor cereals and forage crops are planted in the paddy field 10 years ago. The cultivation of these crops may settle the problem of short supply and mass import of the crops to some extent. However, a systematic remote observation of upland crops in the paddy field is very scarce. This study investigated the cultivation status of upland crops and any changes of crop harvesting in the paddy field by using an unmanned aerial vehicle (UAV). Also, we analyzed the kind of upland crops and cultivation area in the paddy field by utilizing time series observation images. A fixed wing UAV is used for the investigation. This is because it is easy to use the flight operation and to control flight management software, and it can automatically cope with various emergency states such as a strong wind and battery discharge. The material of UAV is expanded polypropylene, which has an advantage of less equipment damage and risk during takeoff and landing. We acquired observed images in Buljeong-myeon, Goesan-gun, Chungcheongbuk-do, South Korea by using fixed wing UAV in 2015 and 2016. The total investigated area reaches 6,045 ha, and among them the agricultural area was 1,377 ha. For the next step, we created an orthoimage from all images taken using Pix 4D mapper program. According to the results of image analyses in 2015, the paddy field covered total 577 ha (75.9%) with crop plant. The cultivation area of beans, ginseng, maize, tobacco and peach was 256 ha (36.6%), 63 ha (9.2%), 37 ha (5.4%), 31 ha (4.5%) and 27 ha (3.8), respectively. And in 2016, the total covered area was 586 ha (77.1%), and it was comprised of 253 ha (35.5%), 88 ha (12.3%), 29 ha (4.1%), 22 ha (3.1%) and 32 ha (4.5%) in the same order. In this study, we focused on identifying the paddy field which was converted to the cultivation of upland crops by using UAV. And, it has been indicated that the cultivation area of rice decreased from 141 ha in 2015 to 127 ha in 2016, although that of ginseng increased by 25 ha. As a result, it is expected that a lot of paddy field could be replaced by high-income crops such as ginseng and fruit tree (peach) instead of relative low-income rice. More specific and widespread research on the remote sensing in the paddy field needs to be done.

• 한국식생활문화학회지
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• 제27권1호
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• pp.66-74
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• 2012

It is well known that sunflower (SF) sprout has more beneficial effects than SF seed due to increased levels of phytochemical components such as vitamins, total phenolics, and isoflavones during germination. This study investigated the physicochemical properties and antioxidative activities of SF seed during both germination and cultivation. In a proximate analysis, the water content of SF groat was 9.17% and then increased to 15.32% on the 11th day after seeding. On a dry weight basis, crude fat content decreased while the contents of carbohydrates, crude protein, and crude ash increased. As cultivation proceeded, the contents of minerals were in decreasing order of K, Mg, Ca, Na, Zn, Fe, Mn, and Cu, in which SF sprout cultivated for 9 or 11 days contained the highest mineral contents. Though vitamin C was not detected on SF groat, the content of vitamin C continuously increased up to the 5th day of cultivation and then decreased gradually. Vitamin E content in SF groat was higher than that in SF sprout. It was also found that the vitamin E content in SF sprout was the highest on the 5th day of cultivation. Daidzin was not detected in SF groat, but its concentration reached a maximum on the 5th day of cultivation in SF sprouts. Furthermore, higher amounts of daidzein were observed on the 3rd, 5th, and 9th days of cultivation. The highest total isoflavone content was observed on either the 3rd or 5th day of cultivation. The highest content of total phenolics was observed on the 5th of cultivation. When DPPH radical and peroxyl radical scavenging activities of SF sprout were measured in order to measure antioxidant efficacy, it was found that 5 day-cultivated SF sprout had the highest scavenging activities. In conclusion, SF sprout cultivated for 9 or 11 days was found to be a good source of minerals. Furthermore, the fifth-day after seeding was the optimal time for the production of SF sprout with effective natural antioxidant activity and high amounts of functional components such as vitamins, total phenolics, and isoflavones.