• Korean Journal of Agricultural and Forest Meteorology
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• v.21 no.4
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• pp.307-316
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• 2019

In the agricultural sector, greenhouse gas emissions vary depending on the interaction of all ecosystem changes such as soil environment, weather environment, crop growth, and anthropogenic farming activities. Agricultural sector greenhouse gas emissions resulting from many of these interactions are highly variable. Uncertainty-based evaluation that defines the interval with confidence level of greenhouse gas emission and absorption is necessary to take account of the variance characteristics of individual emissions, but research on uncertainty evaluation method is insufficient. This study aims to decide on the effect of reducing N₂O emissions from upland soils using an uncertainty-based approach. An uncertainty-based approach confirmed whether there was a difference between confidence intervals in the 5 different fertilizer treatment groups to reduce greenhouse gas emissions. Unlike the statistically significant test with three repetition averages, the uncertainty-based approach method estimated in this study is able to estimate the confidence interval considering the distribution characteristics of the emissions, such as the dispersion characteristics of individual emissions. Therefore, it is considered that the reliability of emissions can be improved by statistically testing the variance characteristics of emissions such as the uncertainty-based approach. It is hoped that the direction of the uncertainty-based approach for the effect of reducing greenhouse gas emissions in agriculture will be helpful in the future development of agricultural greenhouse gas emission reduction technology, adaptation to climate change, and further development of sustainable eco-social system.

• Proceedings of the Korean Society of Environment and Ecology Conference
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• 2003.10a
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• pp.105-126
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• 2003

In Korea most of annual rainfall is concentrated in several episodic heavy rains during the season of summer monsoon and typhoon. Because of uneven rainfall distribution many dams have been constructed in order to secure water supply in dry seasons. The Han River system has the most dams among Korean rivers, and the river is a series of dams now. Reservoirs need different strategy of water quality control from river water. Autochthonous organic matter and phosphorus should be the major target to be controlled in lakes. In this Paper some problems are discussed that makes efforts of water quality improvement ineffective in lakes of Korea, even after the substantial investment to wastewater treatment facilities.1) Phosphorus is the key factor controlling eutrophication of lakes and the reduction ofphosphors should be the major target of water treatment. However, water quality management strategy in Korea is still stream-oriented, and focused on BOD removal from sewage. Phosphorus removal efficiency remains as low as 10-30%, because biological treatment is adopted for both secondary treatment and advanced treatment. The standard for TP concentration of the sewage treatment plant effluent is 6 mgP/l in most of regions, and 2 mg/l in enforced region near metropolitan water intake point. TP in the effluents of sewage treatment plants are usually 1-2 mg/1, and most of plants meet the effluent regulation without a further phosphorus removal process. The generous TP standard for effluents discourages further efforts to improve phosphorus removal efficiency of sewage treatment. Considering that TP standard for the effluent is below 0.1 mg/l in some countries, it should be amended to below 0.1 mg/l in Korea, especially in the watershed of large lakes.2) Urban runoff and combined sewer overflow are not treated, even though their total loading into lakes can be comparable to municipal sewage discharges on dry days. Chemical coagulation and rapid settling might be the solution to urban runoff in regard of intermittent operation on only rainy days.3) Aggregated precipitation in Korea that is concentrated on several episodic heavyrains per year causes a large amount of nonpoint source pollution loading into lakes. It makes the treatment of nonpoint source discharge by methods of other countries of even rain pattern, such as retention pond or artificial wetland, impractical in Korea.4) The application rate of fertilizers in Korea is ten times as high as the average ofOECD countries. The total manure discharge from animal farming is thought to be over the capacity of soil treatment in Korea. Even though large portion of manure is composted for organic fertilizer, a lot of nutrients and organic matter emanates from organic compost. The reduction of application rate and discharge rate of phosphorus from agricultural fields should be encouraged by incentives and regulations.5) There is a lot of vegetable fields with high slopes in the upstream region of the HanRiver. Soil erosion is severe due to high slopes, and fertilizer is discharged in the form of adsorbed phosphorus on clay surface. The reduction of soil erosion in the upland area should be the major preventive policy for eutrophication. Uplands of high slope must be recovered to forest, and eroded gullies should be reformed into grass-buffered natural streams which are wider and resistant to bank erosion.

• Korean Journal of Veterinary Research
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• v.45 no.1
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• pp.85-91
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• 2005

Much of the interest on the chemopreventive properties of herbs and plants has been raised, whereas little is regarding to anti-tumor effect of farming and aquatic products. In the present study, the anti-tumor effect of hot-water extract of a seaweed, BLC (Sargassum fulvellum) and BLC/HEN egg was investigated using MCF-7 cells in vitro and in vivo systems. We found that the BLC extract and BLC/HEN egg inhibited cell proliferation in a dose-dependent manner, which might be mediated through up-regulation of p53. Furthermore, this test compound can directly induce apoptosis in MCF-7 cells, which might be mediated through up-regulation of a pro-apoptotic Bax protein and down-regulation of a anti-apoptotic Bcl-2 protein, not by immune system. Nude mice bearing established breast tumors (with exogenous estradiol) were treated with BLC extract and BLC/HEN egg. Treatment BLC extract and BLC/HEN egg caused a 42% and 71% inhibition of tumor growth, respectively. Both agents caused a significant inhibition of volume and weight growth of estrogen independent human breast tumors established from MCF-7 cells. Our results suggested that BLC extract and BLC/HEN egg have the efficacious effect of human breast cancer not only in vitro but also in vivo.

• Journal of the Economic Geographical Society of Korea
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• v.19 no.2
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• pp.399-416
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• 2016

The main aim of the research attempts to identify value relations appropriated and realized in the coffee frontier of Vietnam by investigating the ways in which it is integrated into coffee global value chains driven by multinational companies, and to provide some implications of the integration of the frontier into sustainable coffee global value chains for creating shared value in Dak Lak, Vietnam. Recently Dak Lak has gone through the transition of value relations from exploitative value chains based upon conventional coffee production into shared value chains relied upon the production of sustainable or certified coffee in Dak Lak. The transition has been expected to result in sustainability in the creation of value by enhancing regional competitive advantages and regional bargaining power in global value chains driven by multinational companies. However, the reality has shown the intensification of hierarchical profits allocation among stakeholders such as farmer, middlemen, and multinational companies in the region. The main reasons for this could be found in two perspectives. Firstly, the formation of exclusive relations among farmers, middlemen, and processors has led to stakeholders to secure market, but resulted in the intensification of hierarchy among them in global value chain, because multinational companies could control indirectly over the farming system through exclusive middlemen. Secondly, social and ecological costs imputed by multinational companies to coffee farmers in the name of creating shared value has deteriorated the economic profits of stakeholders such as farmers and middlemen. As a result, it has led to the configuration of systematically hierarchical and subordinated global value chain in Dak Lak.

• Journal of the Korean Association of Geographic Information Studies
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• v.15 no.3
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• pp.23-35
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• 2012

The optimum location of the prehistoric sites of Ulsan Metropolitan City are investigated by both quantile and natural breaks methods through GIS, and the settlement pattern is studied based on the possibility of presence of the prehistoric sites which are also analyzed with these methods. Such factors including elevation, slope, distance from the nearest water, aspect, geological features, soil drainage classes, subsoil and land use recommended are employed in the analysis. The optimum geographical environment is the place where it includes the water-base in the area that is the southern aspect of the gentle slope land of lowland. The geology is the Quaternary alluvium. The drainage class is fine and the deep soil saturn is the fine loamy soil and the recommendation of land use is the area that is the field. As a result of the forecast of distribution, the prehistoric sites showed the higher possibility of presence in the downstream region where the Taehwa river and Dongcheon river join because the region come close to the watercourse and the drinking water use is easy. And the aspect and elevation is the low area. The alluvium accumulated from the upper stream of the Taehwa river and Dongheon river was made roomily, the area where is suitable for the farming life. Therefore, this region is judged that the possibility of presence of the prehistoric sites is high.

• Korean Journal of Soil Science and Fertilizer
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• v.50 no.5
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• pp.391-400
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• 2017

Italian ryegrass (IRG) is one of the fastest growing grasses available to farmers. It offers rapid establishment and starts growing early in the following spring and has fast regrowth after defoliation. So, IRG can be utilized as the dominant/single species of grass used in a farming system, or to play a role as a large producing pasture and sacrificial paddock. The objective of this study was to develop the use of unmanned aerial vehicle (UAV) for the evaluation of feed value of IRG. For this study, UAV imagery was taken on the Nonsan regions two times during the IRG growing season. We analyzed the relationships between $NDVI_{UAV}$ and feed value parameters such as fresh matter yield, dry matter yield, acid detergent fiber (ADF), neutral detergent fiber (NDF), total digestible nutrient (TDN) and crude protein at the season of harvest. Correlation analysis between $NDVI_{UAV}$ and feed value parameters of IRG revealed that $NDVI_{UAV}$ correlated well with crude protein (r = 0.745), and fresh matter yield (r = 0.655). According to the relationship, the variation of $NDVI_{UAV}$ was significant to interpret feed value parameters of IRG. Eight different regression models such as Linear, Logarithmic, Inverse, Quadratic, Cubic, Power, S, and Exponential model were used to estimate IRG feed value parameters. The S and exponential model provided more accurate results to predict fresh matter yield and crude protein than other models based on coefficient of determination, p- and F-value. The spatial distribution map of feed values in IRG plot was in strong agreement with the field measurements in terms of geographical variation and relative numerical values when $NDVI_{UAV}$ was applied to regression equation. These lead to the result that the characteristics of variations in feed value of IRG according to $NDVI_{UAV}$ were well reflected in the model.

• Korean Journal of Agricultural Science
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• v.22 no.1
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• pp.110-126
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• 1995

Korean economy has been developed successfully in the course of implementing the five year economic development plans since 1962. The gap of incomes and quality of life between rural and urban area has been widened and it made rural farm laborers drain to urban areas. Therefore the prevailing situation of labor shortage and wage hike in rural area has made farm management deteriorate in recent years. Under the internal and international unfavorable economic conditions, marginal farm land of 66.5 thousand ha has been idled as of end of 1993. The total area outside agricultural development zone with bad farming conditions including irrigation and drainage, and land consolidation for mechanization were estimated at 360.4thousand ha equivalent to 17.5% of the total farm land area in Korea. Considering the topographical conditions of marginal lands, the effective use of marginal lands should be studied from the view point of public interest rather than from the view point of individual economic conditions. Considering the present agricultural economic settings, such as price decrease, unfavourable benefits of farm products, labour shrotage, free trade of farm products and poor physical condition of marginal lands, the institutional and realistical measures for the effective utilization of idle and marginal land should be studied as soon as possible. Detail land use pattern should be surveyed in the areas outside agricultural development zone and have to be classified as orchard farms, grass land, fish culture farms, lawn and ornamental tree farm, sight seeing and leisure farms for urban peoples, special crops production farms and common farms to be developed for farm mechanization. According to the surveyed results, the expected utilization patterns of the idle and marginal lands could be considerd as village common use, farm land base development, leisure farm development, mutual complementary utilization between urban and rural areas, G't purchase and management, credit supply and new extension services, improvement of cropping patterns and sight seeing and leisure farm patterns. For the successful and reasonable management of the marginal lands, the actions such as institutional improvement, prohibition of idle marginal land, enforcement of activities of farm management committee members and land banking system of RDC including development and utilization systems should be included.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.11 no.2
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• pp.150-155
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• 2018

In Korea, the mechanization ratio of field farming is about 58.3%. Especially, mechanization ratio of harvest operation is 10% or less. So, it is required to improve the mechanization ratio of harvest operation to analyze the power requirement analysis of agricultural tractor. The purpose of this study is to analyze power requirement of the underground crop harvester attached on agricultural tractor for traction operation. First, a power measurement system was developed and installed in 45 kW agricultural tractor. Second, field experiments were conducted at two driving speed levels (1.41, 2.17 km/h), and axle torque and rotation speed were analyzed. At 1.41km/h driving speed, the average power requirement of driving axle is 3.13 kW, respectively, at 2.17km/h driving speed, the average power requirement of driving axle is each 4.20 kW. In addition, the field tests show that as the driving speed increases by 53%, the power requirement of the underground crop harvester attached on agricultural tractor increases by 34%. Therefore, it indicated that the power requirement of agricultural tractor was affected by the driving speed.

• Journal of Biosystems Engineering
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• v.41 no.4
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• pp.313-318
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• 2016

Purpose: This study measured and analyzed the PTO (power take off) torque of a transplanter according to the planting conditions during field operation. Methods: A torque measurement system was constructed with torque sensors to measure the torque of a PTO shaft, a measurement device to acquire sensor signals, and a power controller to provide power for a laptop computer. The field operation was conducted at four planting distances (26, 35, 43, and 80 cm) and two planting depths using the transplanter on a field with similar soil conditions. One-way ANOVA with planting distance and Duncan's multiple range test at a significance level of 0.05 were used to analyze the PTO torque. The torque ratio was calculated based on the minimum torque using the average PTO torque measured under each planting condition. Results: The average torques on the PTO shaft for planting distances of 26, 35, 43, and 80 cm at a low planting depth were 11.05, 9.07, 7.04, and 3.75 Nm, respectively; the same for planting distances of 26, 35, 43, and 80 cm at a middle planting depth were 12.20, 9.86, 7.94, and 4.32 Nm, respectively. When the planting distance decreased by 43, 35, and 26 cm, the torque ratio at a low planting depth increased by 88, 142, and 195%, respectively. When the planting distance decreased by 43, 35, and 26 cm, the torque ratio at the middle planting depth increased by 84, 128, and 182%, respectively. Conclusions: PTO torque fluctuated by planting distance and depth. Moreover, the PTO torque increased for short planting distances. Therefore, farmers should determine the planting conditions of the transplanter by considering the load and durability of the machine. The results of this study provide useful information pertaining to the optimum PTO design of the transplanter considering the field load.

• Journal of the Korean Geographical Society
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• v.39 no.2
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• pp.229-240
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• 2004

This article aimed to suggest a program for environmental protection and sustainable development in southwest Primorskii Krai of the Russian federation by analysis of Natural conditions, natural resources and current economic activities. Issues relating to protecting unique biodiversity toward economic development are examined. Special attention is given to functional zoning of the Russian part of lower Tumen River drainage. Functional zoning is key to protecting the unique biodiversity found in wet and marshlands of the lower Tumen River. Recommendations for acceptable economic activity are provided. The major components for a Sustainable Development Program in this area are: to define economically effective and ecologically acceptable types of regional activity (aquaculture; deer farming; recreation) and effective forms of territorial organization; to determine the restrictions on regional industrial and economic development; to organize rational regional land use by carrying out functional zoning and by coordinating this activity with all land users, including restructuring existing protected territories into a single system and include it into an international biospheric network.