• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.10
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• pp.39-45
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• 2016

This study analyses the macroeconomic effects of the direct payment system (DPS) for environment-friendly agriculture in Korea. We utilized the applied general equilibrium model (AGE model) for the general agricultural sector as well as the environmentally-friendly agricultural sector. We considered several scenarios based on various direct payment amounts to measure and analyze economic impacts. Scenario 1 considers the current direct payment system. Scenario 2 examines an additional 5% increase from the direct payment amount in scenario 1. Scenario 3 reviews an increase of 10% in direct payment amount while Scenario 4 considers an additional increase of 15% compared with Scenario 1. Lastly, scenario 5 examines a 20% increase in direct payment amounts compared with scenario 1. In addition, the baseline considers conditions prior to the introduction of the direct payment system. The simulation analysis results show that capital formation, production volume, and labor productivity increased in the environment-friendly agricultural sector. In contrast, employment in the environment-friendly agricultural sector decreased. The price of environment-friendly agricultural products following the introduction of the DPS remain consistent with the price of environment-friendly agricultural product before introducing the DPS. This results from price elasticity of supply and demand are inelastic, and there is no change in the income of consumers during the analysis period. However, additional research is necessary for improvement of the model using complementary statistical data for the environmental-friendly agriculture sector.

• Journal of the Korean Association of Geographic Information Studies
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• v.5 no.1
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• pp.27-37
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• 2002

The classification accuracy of land cover has been considered as one of the major issues to estimate pollution loads generated from diffuse landuse patterns in a watershed. This research aimed to assess the effects of the acquisition methods and sampling size of training reference data on the classification accuracy of land cover using an imagery acquired by optical sensor(OPS) on JERS-1. Two kinds of data acquisition methods were considered to prepare training data. The first was to assign a certain land cover type to a specific pixel based on the researchers subjective discriminating capacity about current land use and the second was attributed to an aerial photograph incorporated with digital maps with GIS. Three different sizes of samples, 0.3%, 0.5%, and 1.0% of all pixels, were applied to examine the consistency of the classified land cover with the training data of corresponding pixels. Maximum likelihood scheme was applied to classify the land use patterns of JERS-1 imagery. Classification run applying an aerial photograph achieved 18 % higher consistency with the training data than the run applying the researchers subjective discriminating capacity. Regarding the sample size, it was proposed that the size of training area should be selected at least over 1% of all of the pixels in the study area in order to obtain the accuracy with 95% for JERS-1 satellite imagery on a typical small-to-medium-size urbanized area.

• Korean Journal of Environment and Ecology
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• v.33 no.5
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• pp.596-604
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• 2019

This study conducted a sediment culture experiment to investigate the effects of sediment oxygen demand (SOD) and environmental factors on sediment and water quality. We installed a leaching tank in the laboratory, cultured it for 20 days, and analyzed the relationship between P and Fe in the sediment. As a result, the dissolved oxygen of the water layer decreased with time, while the oxidation-reduction potential of the sediment progressed in the negative direction to form an anaerobic reducing environment. The SOD was measured to be 0.05 mg/g at the initial stage of cultivation and increased to 0.09 mg/g on the 20th day, indicating the tendency of increasing consumption of oxygen by the sediment. The change is likely to have caused by oxygen consumption from biological-SOD, which is the decomposition of organic matter accumulated on the sediment surface due to the increase of chl-a, and chemical-SOD consumed when the metal-reducing product produced by the reduction reaction is reoxidized. The correlation between SOD and causality for sediment-extracted sediments was positive for Ex-P and Org-P and negative for Fe-P. The analysis of the microbial community in the sediment on the 20th day showed that anaerobic iron-reducing bacteria (FeRB) were the dominant species. Therefore, when the phosphate bonded to the iron oxide is separated by the reduction reaction, the phosphate is eluted into the water to increase the primary productivity. The reduced substance is reoxidized and contributes to the oxygen consumption of the sediment. The results of this study would be useful as the reference information to improve oxygen resin.

• Korean Journal of Plant Resources
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• v.20 no.5
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• pp.471-474
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• 2007

This study was conducted to provide basic data for productivity of Saururus chinensis Baill. depending on rhizome size. The kinds of the treatment were 4 including below 5mm of rhizome size. Major results were summarized as follows. Sprouting was earlier in above 9mm of rhizome size and the number of last sprouting was increased $84{\sim}109%$ compared with 8.0 $individual/m^2$ of 6mm of rhizome size. Growth of stem showed a good tendency in 6mm of rhizome size with the longer stem length and the thicker stem but the number of tiller was more rhizome was more thicker. Though the number of commercial leaf was more above 9mm of rhizome size leaf length, leaf width and the number of noncommercial leaf did not showed difference by rhizome size. Dry weight of commercial foliar in 9mm of rhizome size over was increased $35{\sim}37%$ compared with 6mm of rhizome size. Therefore, rhizomes size above 9mm showed most effective for increasing sprout and wight of stem and leaves of Saururus chinensis.

• Korean Journal of Soil Science and Fertilizer
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• v.34 no.1
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• pp.42-54
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• 2001

The use of nitrogen fertilizer in intensive agricultural production is of major concern due to its role on agricultural productivity and water quality. Crop production inputs on farm are usually applied at a uniform rate across an entire field. However, actual input requirements often vary within fields. The field variations in yield potential, soil moisture, soil N status, and the efficiency of fertilizer use, uniform application of crop production inputs does not allow optimum efficiency or profitability. This occurs because uniform application often results in areas of over- and under-application which may affect water quality and crop yield. This study used biophysical and economic models to assess the economic feasibility and water quality benefits of site specific nitrogen management for 10 soil types and 35 sample fields in Goodwater Creek watershed located near Centralia, Missouri. Results showed that the economic feasibility and water quality benefits of variable rate application were sensitive to the distribution of soil types within a field. Variable rate(VR) application was not uniformly more profitable than uniform rate(UR) application for the four agricultural systems evaluated and the water quality benefits were insubstantial relative to uniform application of N.

• Korean Journal of Soil Science and Fertilizer
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• v.32 no.4
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• pp.405-411
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• 1999

Growth responses and yields of cucumber, the populations of soil microorganisms, and the control value of nematodes were examined with six different treatments of chemical fertilizer, compost, microbial fertilizer(MF), and the combined applications of NPK + MF and compost. Cucumber, Eunseong Bakdadaki cultivar, was cultivated in the greenhouse. Higher plant height was appeared with treatments of the combined application of NPK + compost and NPK + MF compared to other treatments, especially at the early growth until 20th day after transplanting. Also, higher number of opened flowers showed with the combined treatments of NPK + compost and NPK + MF than those with others. The control value of nematodes at 60th day after transplanting with treatments of MF and NPK + MF was about 39.0% and 61.6%, respectively. The density of soil microorganisms was higher in order of actinomycetes, bacteria, and fungus. Their densities were not clearly different with treatments. Fruit yields of cucumber with treatments of NPK, compost, microbial fertilizer, and additions of compost and microbial fertilizer to NPk were higher, about 40 to 60%, than that with the control. The highest fruit yield was with NPK + MF and next highest fruit yield was with NPK + compost. It is assumed that the combined application of chemical fertilizers, compost, and microbial fertilizers would be increased the plant productivity.

• Korean Journal of Soil Science and Fertilizer
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• v.31 no.1
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• pp.39-45
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• 1998

As a basic research for developing a sludge application technique in forestry, this study was conducted to investigage a reasonable amount and period of sludge to be applied onto forest nursery of Acer palmatum Thunb. The paper mill sludge was used for the study, and ammonium nitrate was treated to some of them to reduce the C/N ratio lower than 40. The maximum amount of applied sludge was 7ton/ha/year, and they were spread on spring and on late summer. The sludge application did not stimulate early growth of the trees during a year. Since there was no significant changes in soil chemical properties, the amount of applied sludge was thought to be too little to result in a significant role for tree growth. However, the soil water showed significant increase of Cu when the activated sludges were applied during late summer. Thus, the time of application need to be determined cautiously with considering the risk of ground water contamination. In conclusion, if we set a goal from the view point of long-term concept such as forest productivity rather than to get a short-term product, the uncomposted sludge in small amount during growing season might be considered to be applied on forest nursery.

• Korean Journal of Labor Studies
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• v.24 no.3
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• pp.35-71
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• 2018

The purpose of this study is to examine which job-related factors are associated with presenteeism, which is defined as attending work while ill. Although presenteeism is a relatively new concept in academic research, it should be regarded as an important social issue in that presenteeism threatens employees' job prospects and quality of life as well as it causes loss of work productivity. I analyzed a cross-sectional survey of 24,571 wage workers over 15 from the fourth wave of the Korean Working Conditions Survey in 2014. Five logistic regression models were analyzed on experience of presenteeism, and work hours and private life, occupational environment, job insecurity, rewards and welfare were assessed as key predictors of presenteeism. I found that 1) work hours with bad fit with private life, 2) high level of work time-pressure, and low job satisfaction 3) job insecurity, and 4) low benefits are associated with experience of presenteeism. The findings are fairly consistent with the theory of job-person mismatch, which explains that workers tend to preserve their personal resources by going to work while ill (presenteeism) when job demands or work conditions do not match with their level of personal expectation and, thus, workers are afraid of loss of personal resources. Presenteeism influences worker's long-term health and quality of life negatively as well as causes serious social costs. Therefore, we need organizational efforts to prevent the negative effects of presenteeism on society as well as workers.

• Journal of Wetlands Research
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• v.21 no.1
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• pp.43-56
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• 2019

Irrigated and flooded rice paddy contributes to the greenhouse gas emissions (GHG) that affect climate. This in turn affects the supply and reliability of the water needed for rice production. This dynamic makes current rice production methods foreseeably less sustainable over time while having other undesirable effects. Intermittent irrigation by a means of the system of rice intensification (SRI) and alternate wetting and drying (AWD) methods was reviewed to reduce global warming potential (GWP) from 29% to 90% depending on site-specific characteristics from flooded rice paddy and analyzed to be a promising option for enhancing the productivity of water as well, an increasingly constraining resource. Additional benefits associated with the SRI/AWD can be less arsenic in the grain and less degradation of water quality in the run-off from rice paddies. Adoption and expansion of intermittent irrigation of SRI/AWD may require costly public and private investments in irrigation infrastructure that can precisely make irrigation control, and the involvement and upgrading of water management agencies and farmer organizations to enhance management capabilities. Private and public collaboration as a means of earning carbon credit under the clean-development mechanism (CDM) with SRI/AWD for industries to meet as a part of their GHG emission quota as well as a social contribution and publicity program could contribute to adopt intermittent irrigation and rural investment and development. Also, inclusion of SRI and AWD in programs designed under CDM and/or in official development assistance (ODA) projects could contribute to climate-change mitigation and help to achieve UN sustainable development goals (SDGs).

• Journal of Mushroom
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• v.17 no.3
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• pp.132-135
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• 2019

This study aimed to develop a new method of Lentinula edodes cultivation to reduce labor and waste disposal. To identify the optimum container for L. edodes cultivation, box, bottle, and bag containers were assessed for their effects on the cultural characteristics and mushroom yield. Among the three approaches, box-cultivation with 7 kg of substrate had the shortest browning period (42 days) and resulted in the highest mushroom yield (1,253 g). Contrastingly, bottle-cultivation was unsuitable for cultivation due to low production of the fruiting bodies and poor quality. Further studies on the box-cultivation approach will be required for commercial applications of L. edodes.