Effect of Compost and Mixed Oilseed Cake Application Rates on Soil Chemical Properties, Plant Growth, and Yield of Organic Bulb Onions

Jongtae Lee,Sunkyoung Hwang,Byeonggyu Min,Heedae Kim,Juyeon Kim,Kwangpyo Hong,Sangdae Lee,Sangin Shim,George E. Boyhan 한국원예학회 2018 원예과학기술지 Vol.36 No.5

This study was performed to determine the effect of the application rate of beef cattle manure compost (BCMC) and mixed oilseed cake (MOC) on soil nutrients, plant growth, and bulb yield of intermediate-day onions (Allium cepa L.) in two different locations over two consecutive growing seasons. Trials were conducted at two organic onion growers’ fields (one in Sangju county and one in Hamyang county) during the growing seasons of 2012/2013 and 2013/2014. Treatments included BCMC applied at a rate of 0 or 30 t·ha<SUP>-1</SUP> and MOC applied at rates of 0, 3, 6, and 9 t·ha<SUP>-1</SUP>. The average air temperature in 2013/2014 was higher than that in 2012/2013 at both sites. All soil nutrient contents in the experimental fields were higher at harvest in 2013/2014 than in 2012/2013 except for exchangeable calcium. Soil nutrients were higher at harvest in Sangju than in Hamyang except for available phosphorus. Soils incorporated with BCMC had higher electrical conductivity, nitrogen, average phosphorus, and exchangeable potassium contents compared with soil without compost. Onions grown in 2013/2014 at Hamyang with BCMC produced higher yields compared to those grown in 2012/2013 at Sangju without BCMC. However, differences in plant growth between the two experimental sites and among MOC application rates were not affected by soil nutrient content. Onions grown in 2013/2014 at Hamyang with BCMC produced higher yields compared to those in grown in 2012/2013 at Sangju without BCMC. Application of MOC increased bulb yield compared with no MOC; however, there was no significant difference among application rates. Therefore, we recommend applying BCMC at a rate of 30 t·ha<SUP>-1</SUP> every year and restricting MOC fertilizer applications to 3 t·ha<SUP>-1</SUP> based on soil nutrient status to produce optimum organic onion yields.

Evaluation of Composted Pig Manure and Organic Fertilizer for Organic Onion Production in Paddy Soil

Jongtae Lee,Heedae Kim,Sangdae Lee,Chiwoong Ro 한국원예학회 2012 원예과학기술지 Vol.30 No.2

A two year study was conducted on the effects of composted pig manure applications on organically managed intermediate-day onion (Allium cepa L.) with mid-season production. The manure application rates were 0, 4.0, 6.0, and 8.0 ton·ha-¹, and accompanied by organic fertilizer with 240 ㎏·ha-¹ nitrogen for all treatments. There was a positive linear effect on the marketable bulb yield with increasing applications of pig manure. However, pig manure rates of 6.0 or 8.0 ton·ha-¹ did not affect the marketable yields or bulb weights at harvest. There was no significant difference between pig manure application rates and mineral concentration or nutrient uptake in onion bulbs. Soil pH and electric conductivity (EC) were lower at harvest compared to preplant soil, while exchangeable potassium and calcium contents increased at harvest. However, there were no significant effects on soil pH, EC, and organic matter or exchangeable cations caused by different pig manure application rates. Mineralized NO₃-N content was not affected by pig manure application rates except at transplanting and 129 day after transplanting. Based on the results of this study, when organic fertilizer is applied at a rate of 240 ㎏·ha-¹ N, 6.0 ton·ha-¹ composted pig manure should be adequate for producing onions using an organic production system.

Understanding why the public agricultural information services would meet troubles?: based on systems thinking approach

Jongtae Lee,Kyuhyun Park 한국농식품정보과학회 2017 Agribusiness and Information Management Vol.9 No.2

Abstract1)This study aims to understand why public information systems in agricultural fields have shown lower performances than other industrialized fields and industries and how these problems would be fixed and overcame. To accomplish this research purpose, this study would overview the previous studies on developing agricultural information systems in public sectors and would find out meaningful and considerable factors. This study would accept the methodologies of literature review and systems thinking approaches to understand the relationships among the found factors and to suggest the conceptual research model. Agricultural information system should take care to reduce implement and maintenance costs to reduce the negative relationships between costs and expected service value and between expected service value to perceived service value. Also, it should be understood that impersonal response would reduce the eager to use the services, so the government sectors should consider positively to adopt the concept of CRM even though the government sectors traditionally have ignored its necessity. The failure of public information systems/services may be caused not only by lack of the contents but also by the failure of the persistent post management.

IT Investment Portfolio for Mobile Office : Conceptual Framework

Jongtae Lee,Sunggoo Yoo,Junghoon Moon,Hyunggoo Kang,Minghao Huang 한국경영정보학회 2012 한국경영정보학회 학술대회논문집 Vol.2012 No.1

A Follow-up Study on Smart Divide Issues in Korean Rural Area

Jongtae Lee 한국농식품정보과학회 2016 Agribusiness and Information Management Vol.8 No.1

Digital divide commonly means the gap among diverse stakeholders, businesses, physical areas, and individual people in terms of opportunities, accessibilities, and usabilities (Acılar, 2011). Lee and Park (2011) and Barzilai-Nahon (2006) suggested that the digital divide issues should be considered as an important public issue because proper public response may enhance or reduce the information gaps by the digital divide. This study is a follow-up study of the study of Lee and Park. This study’s main aim is to clarify the changes of the digital divide in the rural areas during five years and to find out meaningful factors to reduce the gaps between the rural area and urban area. To achieve the research aim, this study analyzes the public data by ITSTAT and previous studies on the digital divide. Also this study follows the system thinking approach to model the causal relationships among diverse factors on the digital divide. With the results, this study suggests that the factors to measure the digital divide should be re-designed including smartphone penetration and accessibilities. Especially, current digital divide scoring factors should be considered in the way of social welfare.

A Follow-up Study on Smart Divide Issues in Korean Rural Area

Lee, Jongtae Korean Society of Food and Agricultural Informatio 2016 Agribusiness and Information Management Vol.8 No.1

Digital divide commonly means the gap among diverse stakeholders, businesses, physical areas, and individual people in terms of opportunities, accessibilities, and usabilities (Acilar, 2011). Lee and Park (2011) and Barzilai-Nahon (2006) suggested that the digital divide issues should be considered as an important public issue because proper public response may enhance or reduce the information gaps by the digital divide. This study is a follow-up study of the study of Lee and Park. This study's main aim is to clarify the changes of the digital divide in the rural areas during five years and to find out meaningful factors to reduce the gaps between the rural area and urban area. To achieve the research aim, this study analyzes the public data by ITSTAT and previous studies on the digital divide. Also this study follows the system thinking approach to model the causal relationships among diverse factors on the digital divide. With the results, this study suggests that the factors to measure the digital divide should be re-designed including smartphone penetration and accessibilities. Especially, current digital divide scoring factors should be considered in the way of social welfare.

Global Policy Directions To Promote The Future Agri-Food Industry: A Focus on the Voucher Projects for Young Job Seekers and Entrepreneurs

Lee, Jongtae Korean Society of Food and Agricultural Informatio 2020 Agribusiness and Information Management Vol.12 No.1

This is a summary of a comparative study of the national policies to foster the agri-food industry implemented by the leading countries of the industry before and after the COVID-19-induced global economic crisis. By comparing the policies of each country, we discovered that key leading countries of the agri-food industry had given up or suspended one-on-one, face-to-face support programs that they had maintained for years, and have started providing financial assistance to companies or self-employed people in relative industries. Korea should implement such decisive policies for the Korean agri-food industry to tackle this unprecedented economic shrink and maintain the competitiveness of the industry. Considering the scale and speed of the spreading of the pandemic, the new policies should be implemented swiftly and boldly. This study can be used as a base material for developing new policies to minimize damage to the agri-food industry and national economy caused by COVID-19.

Coffee-Driven Green Activation of Cellulose and Its Use for All-Paper Flexible Supercapacitors

Lee, Donggue,Cho, Yoon-Gyo,Song, Hyun-Kon,Chun, Sang-Jin,Park, Sang-Bum,Choi, Don-Ha,Lee, Sun-Young,Yoo, JongTae,Lee, Sang-Young American Chemical Society 2017 ACS APPLIED MATERIALS & INTERFACES Vol.9 No.27

<P>Cellulose, which is one of the most-abundant and-renewable natural resources, has been extensively explored as an alternative substance for electrode materials such as activated carbons. Here, we demonstrate a new class of coffee-mediated green activation of cellulose as a new environmentally benign chemical-activation strategy and its potential use for all-paper flexible supercapacitors. A piece of paper towel is soaked in espresso coffee (acting as a natural activating agent) and then pyrolyzed to yield paper-derived activated carbons (denoted as 'EK-ACs'). Potassium ions (K+), a core ingredient of espresso, play a viable role in facilitating pyrolysis kinetics and also in achieving a well-developed microporous structure in the EK-ACs. As a result, the EK-ACs show significant improvement in specific capacitance (131 F g(-1) at a scan rate of 1.0 mV s(-1)) over control ACs (64 F g(-1)) obtained from the carbonization of a pristine paper towel. All-paper flexible supercapacitors are fabricated by assembling EKACs/carbon nanotube mixture-embedded paper towels (as electrodes), poly(vinyl alcohol)/KOH mixture-impregnated paper towels (as electrolytes), and polydimethylsiloxane-infiltrated paper towels (as packaging substances). The introduction of the EKACs (as an electrode material) and the paper towel (as a deformable and compliant substrate) enables the resulting all-paper supercapacitor to provide reliable and sustainable cell perforinance as well as exceptional mechanical flexibility. Notably, no appreciable loss in the cell capacitance is observed after repeated bending (over 5000 cycles) or multiple folding. The coffee mediated green activation of cellulose and the resultant all-paper flexible supercapacitors open new material and system opportunities for eco-friendly high-performance flexible power sources.</P>

Overcoming the Digital Divide in Rural Areas : Focusing on the Mobile Divide

Jongtae Lee,Myeong-Cheol Park 한국농식품정보과학회 2011 Agribusiness and Information Management Vol.3 No.2

Although the diffusion of mobile services appears to be occurring much more rapidly than the spread of wired services, there are risks of a new type of digital divide: the mobile divide. The mobile divide, which refers to a specific digital divide that involves the unbalanced diffusion of mobile technologies, must be concretely studied. Thus, this study focuses on the mobile divide with respect to disadvantaged populations. Although various studies suggest that the diffusion of mobile devices may reduce the digital divide, somestudies argue against the positive effect of mobile devices in addressing traditional digital devices. Low and O’Connell (2006) insisted that equity of access to mobile technologies should be considered in the contextof the traditional digital divide; they argued that there may be socio-economic barriers to accessing mobile devices and the mobile Internet that are similar to the socio- economic barriers to accessing stationary computers and the stationary use of the Internet. Focusing on the smartphone divide, this study suggests that emphasizing utilization is an appropriate manner in which to bridge the mobile divide rather than focusing on other factors, such as accessibility and capability, thatprevious studies have used to measure the traditional digital divide.

Effects of gamma irradiation and Shewanella putrefaciens on the sorption of uranium by goethite

Lee, Jae-Kwang,Lee, Seung-Yeop,Jeong, Jongtae,Baik, Min-Hoon Springer-Verlag 2016 Journal of radioanalytical and nuclear chemistry Vol.307 No.3

<P>Batch experiments were carried out to investigate the influence of gamma irradiation and an iron-reducing bacterium (Shewanella putrefaciens) on the sorption of uranium by goethite in an anoxic condition. Samples were irradiated using a Co-60 gamma source for 5 days at a dose rate of 2 Gy/h for a total dose of 230 Gy. The ionizing radiation and microbial activity may induce the reductive dissolution of goethite, which subsequently may influence the redox behavior of uranium in a deep geological environment. Moreover, gamma irradiation improves the microbial activity, which resulted in the increase of the sorption of uranium.</P>