Taek-Keun Oh

Taek-Keun Oh
Chungnam National University | CNU

Professor

About

96
Publications
7,494
Reads
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436
Citations
Citations since 2016
68 Research Items
396 Citations
2016201720182019202020212022020406080100
2016201720182019202020212022020406080100
2016201720182019202020212022020406080100
2016201720182019202020212022020406080100
Introduction
Biochar, Climate change, Soil amendment, Biomass

Publications

Publications (96)
Article
It has been demonstrated that biochar has a great potential to reduce volatilisations of ammonia (NH3) from fertilised agricultural soils. While there have been several laboratory studies to demonstrate the effects of biochar on gaseous NH3 emissions, there is hardly any data on the influence of biochar amendments on NH3 volatilisations from the so...
Article
Full-text available
It has been demonstrated that biochar has a great potential to reduce volatilisations of ammonia (NH3) from fertilised agricultural soils. While there have been several laboratory studies to demonstrate the effects of biochar on gaseous NH3 emissions, there is hardly any data on the influence of biochar amendments on NH3 volatilisations from the so...
Article
Full-text available
Soil carbon is an important factor in the process of mitigating climate change and solving greenhouse gas problems. However, the previous technology for soil carbon content analysis required a lot of labor, time, and expensive equipment (i.e. an elemental analyzer). In this study, the disadvantages of previous analysis method were secured by using...
Article
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A quick, accurate and cost-effective method for estimating total soil carbon is necessary for monitoring its levels due to its environmentally and agronomically irreplaceable importance. There are several impediments to both laboratory analysis and spectroscopic sensor technology because the former is both expensive and time-consuming whereas the i...
Article
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The use of nitrogen fertilizers to enhance crop growth tends to increase every year. In addition, as eco-friendly agriculture is emphasized, organic fertilizers are preferred over inorganic fertilizers. However, since most of organic fertilizers in South Korea use imported ingredients, an alternative ingredients is needed. Biochar is an eco-friendl...
Article
Biochar's capacity to abate NH3 emissions from fertilised agricultural soils may be enhanced through both modifications and formulation of slow-release biochar-based N fertilisers but there is a dearth of data in this area. Sulphuric acid (H2SO4), hydrogen peroxide (H2O2) and potassium hydroxide (KOH) were used to modify biochars which were denoted...
Article
Full-text available
NH3 emitted into the atmosphere undergoes intricate chemical reactions to form fine particulate matter PM2.5. Nitrogen fertilizers are one of the major sources of gaseous ammonia. Recently, research into using biochar to lessen NH3 emissions from agricultural land has taken center stage and several studies have been executed in that regard. However...
Article
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Eggs are likely to be used in agriculture because they can provide enough nutrients for crop growth. Statistics show that a large number of eggs are lost due to breakage before reaching the final consumer. The purpose of this study was to make a natural liquid fertilizer as a substitute for chemical fertilizers using broken eggs as a resource and t...
Article
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The purpose of this study is to suggest an improvement plan for the National Technical Qualification Practical Evaluation focusing on National Competency Standards. First, in order to strengthen practical techniques such as field abilities and expertise, practical evaluation methods were applied to the National Competency Standards, referring to a...
Article
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Nitrogen (N) is the most important element during the process of plant growth, and the quality of crops varies depending on the amount of nitrogen present. Most of the nitrogen is used for plant growth, but approximately 10-20% of Nitrogen is carried away by the wind in the form of NH 3. This volatilized NH 3 reacts with various oxides in the atmos...
Article
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There is a need for a technology that can quickly and accurately analyze soil carbon contents. Existing soil carbon analysis methods are cumbersome in terms of professional manpower requirements, time, and cost. It is against this background that the present study leverages the soil physical properties of color and water content levels to develop a...
Article
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The purpose of this study was to suggest an improvement plan ultimately to develop practical evaluation methods for national technical qualifications in the field of seeds and horticulture based on the National Competency Standards. Through this, national technical qualifications can be strengthened in terms of professionalism in the seeds and hort...
Article
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The purpose of this study is to suggest an improvement plan for the practical evaluation method used to determine the national technical qualification in field of flower design to improve its development. First, an advisory committee was formed, after which comparisons, an analyses and matching were conducted of the currently used national technica...
Article
Full-text available
Nitrogen plays an important role in plant growth as an essential nutrient. When crops are grown on biochar applied soil, their growth be positive affected. Biochar has been announced as a soil amendment to improve nitrogen (N) use efficiency. The present study aimed to investigate the combined effect of nitrogen fertilizer and biochar amendment on...
Article
Food waste generated at the consumer level constitutes a gigantic portion of the total amount of food wasted/lost and valorisation is touted as the most sustainable way of managing the generated waste. While food waste valorisation encompasses several methods, composting is the cheapest technique that can produce stabilised carbon-rich soil amendme...
Article
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BACKGROUND: Biochar has ability to reduce N loss, increase crop yield, and sequestrate carbon in the soil However, there is still limited study concerning the interactive effects of various biochars on NH3 loss and plant growth. This study, therefore, was conducted to investigate the NH4+ adsorption characteristics of biochar derived from rice and...
Article
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Nitrogen applied to soil is highly prone to leaching and volatilization leading to gaseous emissions of nitrous oxide (N 2 O) and ammonia (NH 3) which are of great environmental concern. Usage of biochar to reduce the discharge of nitrogen to the environment has attracted much interest in the recent past. Biochar is produced by pyrolyzing various b...
Article
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There is a paucity of data regarding the effect of nutrient-enriched biochar amendments on nutrient dynamics in both soil and crops. This is important because unlike pristine biochar, nutrient-enriched biochar is applied to the soil in minute quantities as large amounts may led to over application of the nutrients loaded in it. The current study ex...
Article
Agricultural operations and processes generate copious quantities of particulate matter (PM) both directly and indirectly through emissions of PM precursor gases with dire consequences for human health, environment and climate. PM emissions from agricultural activities are projected to continually rise in the light of soaring food demand driven by...
Article
The need for organic soil amendments is increasing in the Republic of Korea against the backdrop of increased soil acidification and nutrient losses. The pyrolysis of biomass produces biochar which not only increases soil productivity but also provides environmental benefits through carbon sequestration. The portion of the brewer's spent grain (BSG...
Article
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Ultrafine dust causes asthma and respiratory and cardiovascular diseases when inhaled. Ammonia (NH 3) plays a big role in ultrafine dust formation in the atmosphere by reacting with nitrogen oxides (NO x) and sulfur oxides (SO x) emitted from various sources. The agricultural sector is the single largest contributor of NH 3, with the vast majority...
Article
Food waste causes various economic losses and environmental pollution problems such as soil pollution and groundwater pollution. Food waste has been used as a resource in various forms and has been used mostly for feed and composting. This study compared microalgal nutrient medium (BG-11) with food waste compost to determine the possibility of usin...
Article
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The amount of food waste generated in Republic of Korea has been increasing alongside an increasing population and booming economy as such, research on effective treatment and recycling is required. Food waste recycling is complicated by its inferior characteristics such as high levels of water and concern that its continuous application to farmlan...
Article
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Land-use change matrix data is important for calculating the LULUCF (land use, land use change and forestry) sector of the national greenhouse gas inventory. In this study, land cover changes in 2004 and 2019 were compared using the Wall-to-Wall technique with a land cover map of Sejong City from the Ministry of Environment. Sejong City was classif...
Article
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Assessment of soil carbon stock is essential for climate change mitigation and soil fertility. The digital soil mapping (DSM) is well known as a general technique to estimate the soil carbon stocks and upgrade previous soil maps. The aim of this study is to calculate the soil carbon stock in the top soil layer (0 to 30 cm) in Jeolla Province of Sou...
Article
Sawdust is the main bulking agent used to compost food waste in Korea but it is not an economically desirable choice because its availability entirely depends on imports. Since food waste composting provides agricultural, environmental and economic benefits, it is vital that we search for suitable replacements to sawdust from the locally available...
Article
Formulating biochar-based nitrogen fertilisers from charred livestock manure and urea, the two largest emitters of ammonia (NH 3) may help to abate particulate matter emitted from agricultural operations. However, animal manure biochar inadequately retains carbon, thus impairing its primary role of carbon sequestration. Co-pyrolysis of animal manur...
Article
Co-pyrolysis of animal manure biomass with bone meal (BM) and soaking of the resultant biochar in urea containing solutions may offer a sustainable and cheap way of formulating slow-release nitrogen (N) and phosphorus (P) fertilis-ers. This method can lead to optimisation of the carbon sequestration capacity of the biochar, abatement of environment...
Article
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The high intrinsic water content and salinity of food waste prevent a smooth composting process and consequently cause social, economic and environmental problems. In this study, we investigated the distribution of the water content and salinity in food wastes to obtain useful primary data to ensure adequate and quality recycling. A total of 300 fo...
Article
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This experiment was conducted to study the effect of organic fertilizer on the growth of Peucedanum japonicum Thunberg and the change of soil chemical characteristics. The organic matter contents of coffee sludge and dried food waste powder were 44.26 and 51.18%, respectively. These values exceed the organic matter content of organic fertilizers re...
Article
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Straw incorporation is strongly recommended in rice paddy to improve soil quality and mitigate atmospheric carbon dioxide (CO2), via increasing soil organic carbon (SOC) stock. However, straw application significantly increased methane (CH4) emission during rice cultivation, and then its incorporation area was not expanded effectively. To find the...
Article
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In a pilot study, we observed cadmium (Cd) immobilization with citric acid (CA) and suggested that mandarin by-products (MB), which contain CA at ca. 1.65%, can be used as soil amendments that reduce Cd bioavailability. In the present study, we (1) elucidated mechanisms of Cd immobilization by CA and (2) evaluated the use of MB as a soil amendment...
Article
Highly carbonised biochar with desirable characteristics such as high porosity, surface area, mechanical strength, and others is attainable at higher highest treatment temperatures (HTTs). Conversely, however, at these higher temperatures, the availability of most plant nutrients reduces. It is therefore vital to nutritionally enrich such biochar f...
Article
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Despite the widespread use of food waste compost as a soil organic amendment, there is limited information on how it affects the composition of the microbial community as well as its relationship on soil environmental factors. This study investigated the effects of food waste compost on soil microbial-community composition by using FAME analysis. I...
Article
We analyzed the contents of 38 primary metabolites and 9 minerals in the leaves and roots of bell pepper (Capsicum annuum L. var. angulosum) to study metabolic responses to deficiency in nitrogen, phosphorus, potassium, calcium, or magnesium. Induced deficiencies of individual cations reduced the abundance of the other cations in both leaves and ro...
Article
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The application of allelopathy in sustainable agriculture was suggested as an environmentally friendly tool to manage weed infestation. This study aims to determine the phenolic compounds in the sorghum shoot extracts by liquid:liquid extraction using various solvents (ethanol, ethanol–chloroform, ethanol–hexane, ethanol–ethyl acetate, and ethanol–...
Article
The amount of vegetable waste (VW) has increased, and demand for good quality of organic soil amendment is high. For these reasons, successive composting technique was tried to examine the possibility of increasing nitrogen contents in the compost. Collected VW was initially composted after mixing with either sawdust (SD) or cocopeat (CP) at differ...
Article
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This study aims to determine the contents of phenolic compounds from sorghum shoot extracts by fractional extraction in different solvents (ethanol, ethanol-chloroform, ethanol-hexane, ethanol-ethyl acetate, and ethanol-methylene chloride) and to assess their weed control efficacy. Results showed that the highest total amount of phenolic compounds...
Article
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„Manga‟, a near-famine situation which hits the northern region of Bangladesh every year, has forced poor people either to borrow money from usurers at an excessively high interest rate or to sell their labor in advance at an unusually low rate to keep their families from starvation. Many people sell their meager produce of aman crops well before h...
Article
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Biochar is the carbon solid produced through the pyrolysis of biomass from organic sources such as agricultural waste, animal manure, and sludge under limited or anaerobic conditions. It is known to function as a soil amendment, affecting water and nutrient retention, soil acidification, and active growth of soil microorganisms. This experiment was...
Article
The amounts of streamlow in the downstream are influenced from the operation of agricultural reservoirs upstream. To simulate daily streamflow by considering the operation of irrigation reservoirs upstream located in the standard basins, a system was constructed to simulate the amount of streamflow in order from upstream to downstream standard basi...
Experiment Findings
Full-text available
Facing the adverse effects of climate change is one of the biggest challenges for the country of Bangladesh. As a low lying downstream riparian country (70 percent of land area is 5 m or less above sea level), Bangladesh is one of the country's most vulnerable to extreme climate events and the impact of climate change, from both flooding and sea wa...
Article
Facing the adverse effects of climate change is one of the biggest challenges for the country of Bangladesh. As a low lying downstream riparian country (70 percent of land area is 5 m or less above sea level), Bangladesh is one of the country’s most vulnerable to extreme climate events and the impact of climate change, from both flooding and sea wa...
Article
Full-text available
To compare water quantity and quality on the Korean and Japanese rivers, two watersheds with similar watershed area were selected. The one from Korea is called the Yongdam dam watershed in the Geum river basin with watershed area of 930 km², the other from Japan is called the Nakama watershed in the Onga river basin with watershed area of 925 km²....
Article
Two watersheds with similar area were selected to compare water qualities between Korea and Japan. The one from Korea is called the Yongdam dam watershed in the Geum river basin, and the other from Japan is called the Nakama watershed in the Onga river basin. The 2 water quality stations from Korea and 2 stations from Japan within each watershed we...
Article
A survey of weed occurrence was conducted to identify noxious weed species in pear orchards to obtain basic information for effective weed control. The survey was conducted in pear orchards situated in Chungnam province of Korea from April to June 2015, for spring, and from September to October 2015, for autumn. A total of 19 survey sites were rand...
Article
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Sawdust is mainly used as a bulking agent with food waste for composting because of the advantages of absorbing water, providing porosity and adjusting C/N ratio. The objective of this study was to compare the composting properties in relation to the temperature, moisture content, nutrients and the compost maturation index (maturity) with the vario...
Article
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This study was conducted to clarify the morphological characteristics related to the qualitative characters of aerial vegetative tissues in a large collection of ginseng germplasms. A total of 380 germplasm lines collected from different regional sites of Korea were morphologically characterized in detail. We also characterized additional 18 lines...
Article
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Food waste in Korea occupied approximately 26% of the total municipal waste in the year 2013; therefore, the food waste recycling business has been expanded as an alternative to disposal. This study was conducted to assess the competitiveness of Korean technology, research, and development in leading companies by analyzing food waste treatment and...
Article
This study was conducted to investigate the growth response of rice and annual paddy weeds under elevated temperatures. In the context of climate change, temperature is one of the most important climatic factors influencing the growth of crops as well as weeds. Rice and three major annual paddy weeds (Monochoria vaginalis, Echinochloa crus-galli, a...
Article
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As one of the most important mineral nutrient elements, potassium (K) plays crucial roles in many fundamental processes, including enzyme activation, membrane transport, anion neutralization and osmo-regulation, and determines the yield and quality of crop production. In order to better understand and elucidate plant tissue-specific primary metabol...
Article
Food waste (FW) has been recognized as a critical problem in Korea and many research was conducted to efficiently utilize or treat FW. Main purpose of this research was to evaluate a feasibility for producing fermented organic fertilizer with vegetable waste (VW). Three different organic materials (saw dust, coco peat, and waste mushroom media) wer...
Article
Full-text available
Food waste has recognized one of useful sources for potentially agricultural application to supply organic matter and nutrients in arable soil. However, there was little information on application of food waste compost related to the maturity and NaCl content in arable soil. This study evaluated the effect of food waste compost application on yield...