• Journal of the Korean Society of Industry Convergence
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• v.25 no.3
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• pp.349-356
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• 2022

Currently, the agricultural population in Korea indicates a decreasing and aging orientation. As the population of farm labor continues to decline, so farmers are feeling the pressure to be stable crop production. To solve the problem caused by the decreasing of farm labor, it is necessary to change over to "Digital agriculture". Digital agriculture is tools that digitally collect, store, analyze, and share electronic data and/or information in agriculture, and aims to integrate the several digital technologies into crop and livestock management and other processes in agriculture fields. In addition, digital agriculture can offer the opportunity to increase crop production, save costs for farmer. Therefore, in this study, for data-based Digital Agriculture, a greenhouse environment monitoring system for crop growth monitoring based on Node-RED, which even beginners can use easily, was developed, and the implemented system was verified in a hydroponic greenhouse. Several sensors, such as temperature, humidity, atmospheric pressure, CO₂, solar radiation, were used to obtain the environmental data of the greenhouse. And the environmental data were processed and visualized using Node-RED and MariaDB installed in rule.box digital. The environment monitoring system proposed in this study was installed in a hydroponic greenhouse and obtained the environmental data for almost two weeks. As a result, it was confirmed that all environmental data were obtained without data loss from sensors. In addition, the dashboard provides the names of installed sensors, real time environmental data, and changes in the last three days for each environmental data. Therefore, it is considered that farmers will be able to easily monitor the greenhouse environment using the developed system in this study.

• Korean Journal of Soil Science and Fertilizer
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• v.45 no.3
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• pp.353-359
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• 2012

The identification of effective root zone would clarify dynamics of plant available water and soil water balance. Using the relationship between soil properties and electrical resistivity (ER) the purpose of this research is to identify soil zone affected by a plant root activity using electrical resistivity tomography (ERT) technique. Four plastic containers were prepared for two different soil textures (clay and sandy loam) and one container for each texture was selected for planting four corn seedlings (Zea mays L.) and the others were prepared for the blank. For ERT monitoring, we prepared 0.8 m plastic sticks with 17 electrodes installed with 5 cm space. The Ministing (AGI Inc., Texas) instrument for electrical resistivity measurement and semi-auto converter of electrode arrangement were set up for dipole-dipole array. During 2 months of the corns growing, ERT monitoring was made 3 to 4 days after the irrigation practice. Despite of the same amount water supplied into soils, two textures showed very different apparent resistivity values due to different clay content. The apparent electrical resistivity is consistently lower in clay loam comparing to sandy loam soil implying that plant root does not significantly alter the overall trend of resistivity. When plant root system, however, is active both soils with plants showed 2-7 times higher electrical resistivity and higher coefficient variation than soils without plant, implying the effect of root system on the resistivity, in which may caused by. This result suggests plant root activities regulating the soil water dynamics mainly control the variation of electrical resistivity over soil textural difference. Therefore the identification of water uptake zone would highly be correlated to plant root activities, thus ERT will be feasible approach to identify spatial characteristics of a plant root activity.

• Journal of the Korea Organic Resources Recycling Association
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• v.23 no.3
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• pp.85-92
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• 2015

For concerning the climate change issues, the carbon sequestration and importance of soil organic matter are receiving high attention. To evaluate carbon sequestration in soil is important to determine the soil organic carbon (SOC) fractions such as WESOC (Water extractable soil organic carbon), and $CO_2$ emission by soil microbial respiration. However, the analyses for those contents are time-consuming procedure. There were studied the feasibility of MIRS (Mid-Infrared Spectroscopy), which has short analysis time for determining the WESOC and an incubated carbon in this study. Oven-dried soils at $100^{\circ}C$ and $350^{\circ}C$ were scanned with MIRS and compared with the chemically analyzed WESOC and cumulative carbon dioxide generated during 30, 60, 90, and 120 days of incubation periods, respectively. It was observed that an optimized determination coefficient was 0.6937 between WESOC and untreated soil processed by spectrum vector normalization (SNV) and 0.8933 between cumulative $CO_2$ from 30 days incubation and soil dried at $350^{\circ}C$ after subtracting air-dried soil processed by 1st derivatives. Therefore, it was shown that Quantification of soil organic carbon fractions was possibility to be analyzed by using MIRS.

• Journal of Korean Society on Water Environment
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• v.24 no.3
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• pp.291-296
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• 2008

Pollutant unit load developed by Ministry of Environment (MOE) in 1995 has been a tool commonly used for water quality management and environmental policy decision. In spite of the convenience of the method in application, the shortcoming of the method has been criticized especially for nonpoint source pollution from paddy field. In this paper the estimation procedures of pollutant unit load from paddy field in the major river basins (Han, Nakdong, Geum, and Youngsan river) were investigated, and some suggestions of improvement measures of the unit-load estimation were made. The investigation showed that the distributions of rainfall, run-off, and run-off ratio, which are the most important factors affecting discharge amount of pollutants, were not similar among river basins. Such differences seemed to result in a greater unit loads estimation at Han river and at Nakdong river watersheds compared to the others. Therefore, it is not likely to be rationale to compare unit load among the watersheds without consideration of such differences. We conclude that estimation of unit-load through an intensive monitoring of pollutant discharge is crucial for better estimation of unit-load. When such an intensive monitoring is not easy due to labor and expense restriction, we suggest that unit-load should be estimated based on the storm-events which is a representative rainfall-runoff event of the area.

• Research in Plant Disease
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• v.22 no.4
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• pp.297-302
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• 2016

Tomato yellow leaf curl virus (TYLCV) is a viral disease causing severe economic losses on tomato. Practical prevention of the TYLCV disease is to control tabacco whitefly (Bemisia tabaci) or to cultivate TYLCV-resistant tomato cultivars, because no agrochemical products are available to control TYLCV. In this study, TYLCV resistance of the commercial tomato cultivars were evaluated using the DNA markers tightly linked to TYLCV resistance genes Ty-1 and Ty-3 and infection with the TYLCV clones mediated by Agrobacterium. In marker genotyping, resistance alleles were detected from 4 oval type tomato cultivars (Titichal, TY tinny, TY saengsaeng II, TY sense Q). Four cheery type cultiavrs (TY endorphin, TY smartsama, Tiara TY, Olleh TY) and 6 round type cultivars (TY kingdom, TY ace, TY homerun, TY altorang, Dotaerang TY winner, Styx TY). The seedling bioassay indicated that tomato cultivars of the oval type and cherry type showed consistancy in marker genotype and phenotype while slight disease symptom was observed from some round type cultivras (TY ace, TY homerun, Styx TY) with resistance marker genotype. For fruit yields, TY tinny was greater than its control cultivar Titichal in oval types, TY smartsama was greater than its control Smile in cherry type, and TY ace and TY kingdom were greater than their control Dabok. These cutliavrs can be a good choice for high-yielding TYLCV-resistant tomato cultivars.

• Proceedings of the Korean Society of Organic Agriculture Conference
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• 2009.12a
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• pp.288-288
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• 2009

WTO가 진행되고 한미 FTA 협상타결로 농업농촌이 어려움을 격고 있으며 EU, 중국, 인도 등과의 FTA 협상도 검토되고 있다. 또한 소득수준 향상으로 소비자들이 웰빙 건강식품에 대한 관심이 고조되면서 이제는 농산물의 안전성과 기능성, 맛 등이 우수한 고품질 안전농산물 생산이 농업의 핵심과제로 대두되고 있다. 이와 같이 급변하는 농업여건에 대응해 나가기 위해서는 농업정책의 최우선과제인 친환경농업에 적극 동참하여 안전하고 우수한 농산물을 생산해야 할 것이다. 잎들깨의 재배에 있어 주생산 요소의 한 가지는 영양생장을 잘 조절해야 하고 기비보다는 추비에 보다 많은 기술이 요구되고 있다. 이에 본 연구의 목적은 잎들깨 추비시용에 있어 화학비료를 대체 유기질 비료를 이용하여 추비수준별 생육 및 수량성을 구명 하는데 있다. 재배방법은 재식거리는 10 cm${\times}$7cm(137,500주/10a) 로 하였으며 기비는 유기질비료(N-P-K=3.2:4.2:1.1)를 N량 기준으로 5.2kg/10a 을 시용하였다. 추비시용 처리는 10a당 N 0kg, N1.2kg, N1.5kg, N 1.8kg 등 4처리를 두었으며, 추비는 유기질 비료 (N-P-K=4.0-2.0-1.5)를 N 기준으로 생육에 따라 매회 수확 후에 시용 하였으며, 시용 방법에 있어 관수는 1 회 급여시 유기질 비료를 10a당 물 5톤에 희석하여 총 5회를 주었으며 관수방법은 점적호스를 이용하여 저면 관수 하였다. 재배기간 중 10a당 T-N 시용량은 N 0kg 재배는 5.2kg, N 1.2kg 재배는 11.2kg, N 1.5kg재배는 12.7kg, N 1.8kg재배는 14.2kg을 시용하였다. 재배 후 처리별 N 흡수량은 N 1.8kg구 33.1kg, N 1.5kg구 30.0kg, N 1.2kg구 25.7kg, N 0kg구 18.1kg순으로 나타났다. 생육은 초장, 경경, 엽장, 엽폭, 엽중은 추비 시용량이 높을수록 향상되었고, 마디수 발생은 추비 수준 간 변동이 없었다. 병해충 발생정도는 병은 시들음병, 역병, 노균병 순으로 발생하였고, 충은 잎말이나방, 잿빛곰팡이, 진딧물 순으로 발생되었다. 수량성은 N 1.5kg 재배구가 N 1.2kg 대비 115%, N 0kg 대비 169%를 수확하여 타 처리에 비해 비교적 높게 나타났다.

• Journal of Mushroom
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• v.8 no.1
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• pp.11-15
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• 2010

The word spawn is derived from an old French verb, espandre, meaning to spread out or expand. Spawn is also defined as "the mycelium of fungi, especially of mushrooms grown to be eaten, used for propagation". The effects of bag spawn to sawdust substrate on the growth of Pleurotus ostreatus were conducted. The duration of mycelial growth and days of pinhead formation of bag spawn(2.5kg) were 18~19days and 7~8days, whereas bottle spawn ($1,000m{\ell}$) was 18days and 6days, respectively. The yield of mushroom fruitbody was that bag spawn is 100~118g, bottle spawn is 95~115g. In economical analysis, bag spawn is increased to 50%, compared to bottle spawn in relative income.

• Korean Journal of Soil Science and Fertilizer
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• v.38 no.4
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• pp.222-229
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• 2005

A simplified one-dimensional model STELLA was used to predict soil water movement in lllinois corn fields using soil water balance sheets. It offered the potential to increase understanding of soil nitrate and agrochemical leaching process. The model accounted for aU possible annual inputs and outputs of water from a closed ecosystem as represented by corn fields. Water inputs included precipitation, while outputs included runoff, transpiration, evaporation and drainage. To run the model required daily inputs of two climatic data measurements such as daily precipitation and pan evaporation. Vertical water flow through the soil profile was calculated with first order equation including the difference in hydraulic conductivity and matric potential at the various soil types. The output results included daily changes of water content in the soil layers and daily amount of water losses including run-off, percolation, transpiration. This model was verified using Illinois corn field data for the soil water content measured by neutron scattering methods through 1992 to 1994 growing seasons. Approximately 22 to 78% of simulated water contents agreed with the measured values and their standard deviation, depending on soil types, whereas 30 to 70% of simulated water values agreed with the measured values and their standard deviations depending on soil layers.

• Journal of Mushroom
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• v.18 no.2
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• pp.135-140
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• 2020

We examined the chemical properties of mixed media and the yield of Pleurotus pulmonarius using bag culture (1 kg) and also evaluated their relationship. The yield of mushrooms in the first flush appeared to be correlated with total nitrogen content. The highest yield of mushroom in the first flush occurred when the nitrogen content of the media was 1.12 %; however, when the nitrogen content was lower or higher than 1.1 %, the yield decreased. The yield of mushrooms in the second flush was highly correlated with various chemical properties including total nitrogen, total carbon, and C/N ratio; for example, higher nitrogen and carbon content produced a higher yield in the second flush. Therefore, when cultivating bottle culture, the nitrogen content of the media should be approximately 1.1 %, such that most mushrooms are harvested in the first flush. Additionally, when cultivating bag culture for harvesting two or more times, it is advantageous to have higher nitrogen and carbon contents in the media than the amount required for bottle culture media.

• Korean Journal of Environmental Agriculture
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• v.39 no.4
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• pp.297-304
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• 2020

BACKGROUND: Emission of nitrous oxide (N2O) from the soil is expected to depend on the types of nitrogen fertilizer used. Biochar has recently been proposed as a potential mitigation of climate change by reducing the N2O emission. Although laboratory studies reported that biochar applications could reduce N2O emission, the number of field-based studies is still limited. Therefore, a field experiment was conducted to investigate the effect of biochar on N2O emission when different nitrogen fertilizers were applied in corn cultivated field. METHODS AND RESULTS: The field experiment consisted of six treatments: urea fertilizer without biochar (U), ammonium sulfate fertilizer without biochar (A), oil cake fertilizer without biochar (O), urea fertilizer with biochar (U+B), ammonium sulfate fertilizer with biochar (A+B), and oil cake fertilizer with biochar (O+B). Biochar was applied at a rate of 10 t/ha. Greenhouse gas fluxes were measured during growing seasons using static vented chambers. The cumulative N2O emissions were 0.99 kg/ha in the U, 1.23 kg/ha in the A, 3.25 kg/ha in the O, 1.19 kg/ha in the U+B, 0.86 kg/ha in the A+B, and 1.55 kg/ha in the O+B. CONCLUSION: It was found that N2O emission was related to application of both nitrogen fertilizer type and biochar. In particular, the N2O reduction effect was the highest in the corn field incorporated with biochar when oil cake was applied to the soil.