• 한국수자원학회:학술대회논문집
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• 한국수자원학회 2023년도 학술발표회
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• pp.394-394
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• 2023

The world's sustainable growth is being severely hampered by the inefficient use of water resources. Despite the widely acknowledged importance of trade in global and regional water and food security, societal reliance on local production as well as international trade remains inadequately assessed. Therefore, using South Korea as a case study, this study fills in this research gap by applying the virtual water concept, the logarithmic mean divisia index (LMDI) method, and the Tapio decoupling model. The virtual water concept was used to estimate South Korea's net virtual water trade for major grain crops from 1992 to 2017. Then, the LMDI method was utilized to assess the driving factors causing changes in net virtual water trade. Lastly, the Tapio decoupling model was used to investigate the decoupling relationships between economic growth and the driving factors of net virtual water trade. Results showed that South Korea remains a net importer of virtual water flows with respect to grain crops, with an average import of 16,559.24 million m³ over the study period. In addition, the change in net virtual water trade could be attributed to water intensity effect, product structure effect, economic effect, and population effect. However, water intensity and economic effects were the major decisive factors for decrease and increase in net virtual water trade respectively, while the population and product structure effects had minor positive influences on the net virtual water trade. Furthermore, water intensity and economic growth showed a strong decoupling in most periods, while the decoupling state between product structure and economic growth was observed as expansive negative decoupling. Likewise, population size and economic growth showed a weak decoupling in most periods. The results reveal South Korea's status as it concerns the virtual water trade of grain crops, thus providing valuable insights into the sustainability of trade activities for the management of local water resources.

• 한국작물학회지
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• 제56권2호
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• pp.134-139
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• 2011

본 연구에서는 잡곡 재배 시 가장 문제가 되는 잡초관리방법을 개선하고 피복작물과 잡곡의 작부체계를 개선 및 효율을 비교하기 위하여 피복작물인 헤어리베치와 호밀이 잡곡생육과 수량에 미치는 영향을 알아보았다. 1. 헤어리베치구에서 수수의 초장과 엽록소 함량, 엽록소 형광, 종실수량은 무처리구 보다 각각 46.4%, 88.7%, 7.9% 높았으며 수량 또한 105.1% 많았다. 조의 경우도 무처리구 보다 각각 45.6%, 50.9%, 37.8%로 초장, 엽록소 함량, 엽록소형광이 높았으며 종실수량도 134.9% 높은 결과를 보였다. 호밀처리구에서 수수의 초장과 엽록소 함량, 엽록소형광은 무처리구 보다 각각 7.1%, 10.8%, 10.8% 높았으나 수량은 25.8% 감소하였다. 조는 무처리구 보다 각각 28.9%, 17.2%, 1.3% 감소하였으며 수량 또한 119.1% 감소하였다. 헤어라베치구에서 잡곡에 대한 녹비 효과가 좋았다. 2. 잡곡 출수 전 헤어리베치와 호밀의 잡초 발생량은 무처리에 비해 감소하였고 건물중은 헤어리베지와 무처리 차이가 없었으나 호밀은 31.6% 감소하여 호밀에서 잡곡 출수 전 잡초억제 효과가 인정되었다. 그러나 출수 후에는 혜어리베치의 장초발생량은 159%, 건물중은 55.2% 증가하였으며 호밀에서는 각각 55.2%, 10.9%로 증가하였다. 따라서 출수 후 헤어리베치와 호밀의 잡초 억제효과는 미약하였다. 3. 발생한 주요 잡초종은 총 16종으로 일년생잡초 12종으로 가장 많은 비중을 차지하였다. 특히 8월~9월의 우점 잡초종으로는 헤어리베치는 바랭이와 돌피였으며, 호밀 처리 시 강아지풀, 바랭이, 돌피 등이 우점하였다.

• 식물병연구
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• 제25권3호
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• pp.114-123
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• 2019

Quantum Dot LED (QD LED) 조명은 소형의 크기, 좁은 대역파장, 긴 수명, 전자 시스템을 통한 제어가 용이하여 현재 시설재배에 이용되는 형광등, 할로겐램프, HID, HSP 램프의 단점을 보완할 수 있는 작물생육에 이상적인 광원으로서 잠재력을 가지고 있다. QD LED 조명을 이용하여 식물 병원성 미생물의 방제가 가능하다면 작물재배에 사용되는 인력 및 비용을 절감하고 화학적 방제제를 사용하지 않은 안전성 높은 생산물을 얻을 수 있다는 장점이 있다. 본 연구에서는 식물공장 및 온실에서 많이 재배되고 있는 상추에 큰 피해를 입히는 주요 식물 병원성 곰팡이에 대한 QD LED 조명의 영향과 생장억제효과를 확인하기 위해 시행하였다. 상추에 주로 발생하여 작물에 피해를 입히는 Rhizoctonia solani, Phytophthora drechsleri, Sclerotinia sclerotiorum, Sclerotinia minor, Botrytis cinerea, Fusarium oxysporum, Pectobacterium carotovorum, Xanthomonas campestris균을대상으로 QD LED 조명에 의한 균사생장억제 효과를 조사하였으며 처리한 6종류의 조명 중 BLUE (450 nm) 조명은 Sclerotinia sclerotiorum는 50 cm 거리에서 16.7%의 억제율을 보였으며 30 cm 거리에서 94.1%의 균사생장억제율을 보였다. S. minor는 50 cm 거리에서 80.4%, B. cinerea는 50 cm 거리에서 36.3%의 균사생장이 억제되었으며 30 cm 거리에서 S. minor와 B. cinerea는 100%의 균사생장억제율을 보였다. 15 cm 거리에서는 3종의 병원균 모두 100%의 억제율을 보였다. QD RED (M1), QD RED (M2)조명은 30 cm와 15 cm 거리에서 Sclerotinia minor와 Botrytis cinerea의 균사생장을 100% 억제했으며 Sclerotinia sclerotiorum의 경우 30 cm 거리에서 QD RED (M1)과 QD RED (M2)조명에 대해 각각 75.2%, 100%의 억제율을 보였으나 15 cm 거리에서는 각각 5.8%, 36.3%의 억제율을 보였다. 상추에 병원균을 접종하여 LED 광원 하에 생장을 확인한 결과 QD RED (M2)광원에서 S. sclerotiorum의 감염을 59.9% 억제하였고 S. minor는 BLUE (450 nm), QD RED (M1), QD RED (M2) 광원에서 59.9%의 억제율을 보였다. B. cinerea의 경우 BLUE (450 nm) 광원에서 84%의 높은 억제율을 보였다.

• 한국토양비료학회지
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• 제8권3호
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• pp.113-119
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• 1975

Volcanic Ash Soils are widely distributed in Jeju island, and constitute the important upland soils which are either presently being cultivated or are suitable for reclaiming. The characteristics of Volcanic Ash Soils according to data made available by previous studies in Jeju and the outside of the country are as following: The most conspicuous mineralogical property is the presence of amorphous mineral colloids. The colloids have large and highly reactive surface to which the common physical and chemical properties are related. Soils are low in bulk density and higher both in porosity and permeability. Accumulation of humus in the upper part of soil is found in great quantity. Cation exchange capacity is high mainly due to high humus content, but the absorbing intensity of ammonium and potassium is weaker than that of crystalline clays. The phosphate absorption coefficient is extremely high and deficiency of minor element may occur both crops and animals. Soils are densely populated with actinomycetes and anaerobic bacteria. Nitrification and activity of urease are distinctly stronger than that of non-Volcanic Ash Soils.

• 산업공학
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• 제16권2호
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• pp.248-257
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• 2003

In a heated rolling process of a steel mill where steel plates are pressed to a sheet coil by spreading and expanding, an irregularly-shaped head portion as well as a tail portion of the sheet coil need to be cropped. Any crop which is not clearly cut and separated from the sheet coil may cause critical damages to the facilities of the following processes. As the cropping process is performed very fast, human eyes are not proper for continuous monitoring of the cropping process. To solve this problem, we have developed a machine-vision based crop-drop detection system. The system also measures lengths of major and minor axes for the crops and thereby determines the proper crop size to minimize steel sheet losses.

• 식물병연구
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• 제27권3호
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• pp.107-114
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• 2021

During a disease survey on weeds and minor cultivated crops in Korea, a brown leaf spot disease was observed on Sonchus asper. Leaf lesions were round or irregular in shape, and grayish brown to brown with a purple margin. In severe infection, lesions enlarged and coalesced, resulting in blighting of the leaves. The isolates from these leaf lesions were identified as Alternaira sonchi based on morphological characteristics and phylogenetic analyses of Internal transcribed spacer region, Alternaria allergen a1, glyceraldehyde 3-phosphate dehydrogenase, RNA polymerase II, and translation elongation factor genes. This study provides a comprehensive description of the morphological characteristics and phylogenetical traits of A. sonchi causing brown leaf spot on S. asper in Korea.

• Mycobiology
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• 제49권2호
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• pp.188-195
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• 2021

The genus Pseudoperonospora, an obligate biotrophic group of Oomycota, causes the most destructive foliar downy mildew disease on many economically important crops and wild plants. A previously unreported disease by Pseudoperonospora was found on oriental pickling melon (Cucumis melo var. conomon) in Korea, which is a minor crop cultivated in the temperate climate zone of East Asia, including China, Korea, and Japan. Based on molecular phylogenetic and morphological analyses, the causal agent was identified as Pseudoperonospora cubensis, and its pathogenicity has been proven. Importantly, two phylogenetic clades of P. cubensis, harboring probably two distinct species, were detected within the same plots, suggesting simultaneous coexistence of the two clades. This is the first report of P. cubensis causing downy mildew on oriental pickling melon in Korea, and the confirmation of presence of two phylogenetic clades of this pathogen in Korea. Given the high incidence of P. cubensis and high susceptibility of oriental pickling melon to this disease, phytosanitary measures, including rapid diagnosis and effective control management, are urgently required.

• Mycobiology
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• 제50권5호
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• pp.382-388
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• 2022

White mold (or Sclerotinia stem rot), caused by Sclerotinia species, is a major air, soil, or seed-transmitted disease affecting numerous crops and wild plants. Microscopic or culture-based methods currently available for their detection and identification are time-consuming, laborious, and often erroneous. Therefore, we developed a multiplex quantitative PCR (qPCR) assay for the discrimination, detection, and quantification of DNA collected from each of the three economically relevant Sclerotinia species, namely, S. sclerotiorum, S. minor, and S. nivalis. TaqMan primer/probe combinations specific for each Sclerotinia species were designed based on the gene sequences encoding aspartyl protease. High specificity and sensitivity of each probe were confirmed for sclerotium and soil samples, as well as pure cultures, using simplex and multiplex qPCRs. This multiplex assay could be helpful in detecting and quantifying specific species of Sclerotinia, and therefore, may be valuable for disease diagnosis, forecasting, and management.

• 한국농공학회논문집
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• 제60권5호
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• pp.69-80
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• 2018

This study investigated climate change influences over crop water requirement (CWR) and irrigation water requirement (IWR) of the wheat-rice cropping system of Upper Chenab Canal (UCC) command in Punjab Province, Pakistan. PRECIS simulated delta-change climate projections under the A1B scenario were used to project future climate during two-time slices: 2030s (2021-2050) and 2060s (2051-2080) against baseline climatology (1980-2010). CROPWAT model was used to simulate future CWRs and IWRs of the crops. Projections suggested that future climate of the study area would be much hotter than the baseline period with minor rainfall increments. The probable temperature rise increased CWRs and IWRs for both the crops. Wheat CWR was more sensitive to climate-induced temperature variations than rice. However, projected winter/wheat seasonal rainfall increments were satisfactorily higher to compensate for the elevated wheat CWRs; but predicted increments in summer/rice seasonal rainfalls were not enough to complement change rate of the rice CWRs. Thus, predicted wheat IWRs displayed a marginal and rice IWRs displayed a substantial rise. This suggested that future wheat production might withstand the climatic influences by end of the 2030s, but would not sustain the 2060s climatic conditions; whereas, the rice might not be able to bear the future climate-change impacts even by end of the 2030s. In conclusion, the temperature during the winter season and rainfall during the summer season were important climate variables controlling water requirements and crop production in the study area.

• 한국환경농학회지
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• 제40권4호
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• pp.345-352
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• 2021

BACKGROUND: Salinity is one of the major limiting factors in agriculture that affect the growth and productivity of crops. It is economically difficult to artificially purify the soil affected by salt. Therefore, the use of plant growth-promoting bacteria (PGPB) in an effort to reduce stress caused by salt is emerging as a cost-effective and environment-friendly method. In this study, the purpose was to isolate the salt-tolerant bacteria from the rhizosphere soil and identify their ability to promote plant growth under salt stress condition. METHODS AND RESULTS: The isolates KST-1, KST-2, AST-3, and AST-4 that showed plant growth-promoting activity for barley in salt conditions were close to Bacillus cereus (KST-1, KST-2, and AST-4) and Bacillus thuringiensis (AST-3) and showed high salt tolerance up to 7% of additional NaCl to the media. When inoculated to barley, the strains had only minor effect on the length of the barley. However, the concentrations of chlorophyll in the barley leaves were found to be higher from the bacteria-inoculated pots than those from the uninoculated control. In particular, the chlorophyll concentration in Bacillus cereus AST-4 experiment was 5.45 times higher than that of the uninoculated control under the same experimental condition. CONCLUSION(S): The isolated salt-tolerant bacteria were found to influence on chlorophyll concentration of the barley. As represented by the strain AST-4, microbes may suggest a cost-effective and environmentally benign method to alleviate salt stress of crops cultivated in salt-accumulated soils such as reclaimed lands.