• Korean Journal of Environmental Agriculture
• /
• v.19 no.4
• /
• pp.339-344
• /
• 2000

Utilization of animal excreta in aquaculture can have potentials of high fish production and low maintenance costs for fish farming and it can reduce water pollution caused by animal waste disposal. Integration of wastewater treatment pond system with aquaculture has been utilized in many countries. Ecologically balanced pond ecosystem is formed through the stabilization of wastes, the growth of aquatic plants, and the cultivation of fish. The most appropriate fish for rearing in these ponds are those which can feed directly on phytoplankton, especially algae. Carp were introduced into a tertiary pond - water depth of 2.2 m, water surface area of $130\;m^2$, volume of $148\;m^3$ - of a pond system treating milk cow excreta. The carp production was $125g{\cdot}m^{-2}year^{-1}$ which falls into upper range of $18\;-\;137g{\cdot}m^{-2}year^{-1}$ of treated sewage-fed carp farming of other countries. Average $BOD_5$ and T-N of the pond was 19.8 and $21.0\;mg{\cdot}L^{-1}$ respectively, and the ecological environment of it was suitable for growth of carp. Several carp of 100g were introduced in August into a secondary pond of the treatment system, whose average $BOD_5$ and T-N was 27.9 and $30.8\;mg{\cdot}L^{-1}$ respectively. They were died within one week, which may be attributed to the depletion of dissolved oxygen at dawn. Effluents from primary treatment can be used in fish pond with dilution and those from secondary treatment can be directly funnelled into it. Waste stabilization pond treating animal excreta can be utilized for fish rearing when its water quality maintains secondary treatment level.

• Korean Journal of Organic Agriculture
• /
• v.21 no.4
• /
• pp.753-767
• /
• 2013

Soil contamination has continuously increased worldwide, thus the remediation for the contaminated soils has risen steadily. However, the consideration of ecological safety for the remediated soils and their agricultural uses has been very limited. Therefore, this study was to investigate the influences of selected environmentally-friendly agricultural materials, organic by-product fertilizer (OF), charcoal (CC), and biochar (BC), as soil conditioners for improving poor chemical properties of fuel-oil removed soil by land farming technique. Two different remediated soils, remediated soil A (RSA) and remediated soil B (RSB), were selected. Soil texture of both RSA and RSB was sandy loam. The chemical properties of RSA and RSB were as follows: soil pHs of 8.5 and 8.7, soil organic matter contents of 7.4 and 5.5g $kg^{-1}$, total nitrogen contents of 0.26 and 0.10g $kg^{-1}$, available phosphorus concentrations of 7.2 and 4.4mg $kg^{-1}$, and exchangeable calcium concentrations of 14.8 and $11.7cmol_c$ $kg^{-1}$, respectively. Results of the properties were not reached for the optimal values for cultivating crops that were recommended by National Academy of Agricultural Science at Rural Development Administration in Korea. However, after applying OF, CC, and BC, the chemical properties of soils were selectively improved, which were that soil organic matter content and available phosphorus concentration increased, whereas the soil pH were not changed. In particular, the chemical properties were positively changed more with the application of 5.0% biochar. Thus, continuous management of the remediated soils with applying the eco-friendly agricultural materials can improve the quality of reme-diated soils.

• Korean Journal of Remote Sensing
• /
• v.30 no.6
• /
• pp.797-807
• /
• 2014

The Sea Surface Temperature (SST) is one of the most important oceanic environmental factors in determining the change of marine environments and ecological activities. Satellite thermal infrared images can be effective for understanding the global trend of sea surface temperature due to large scale. However, their low spatial resolution caused some limitations in some areas where complicated and refined coastal shapes due to many islands are present as in the Korean Peninsula. The coastal ocean is also very important because human activities interact with the environmental change of coastal area and most aqua farming is distributed in the coastal ocean. Thus, low-cost airborne thermal infrared remote sensing with high resolution capability is considered for verifying its possibility to extract SST and to monitor the changes of coastal environment. In this study, an airborne thermal infrared system was implemented using a low-cost and ground-based thermal infrared camera (FLIR), and more than 8 airborne acquisitions were carried out in the western coast of the Korean Peninsula during the periods between May 23, 2012 and December 7, 2013. The acquired thermal infrared images were radiometrically calibrated using an atmospheric radiative transfer model with a support from a temperature-humidity sensor, and geometrically calibrated using GPS and IMU sensors. In particular, the airborne sea surface temperature acquired in June 25, 2013 was compared and verified with satellite SST as well as ship-borne thermal infrared and in-situ SST data. As a result, the airborne thermal infrared sensor extracted SST with an accuracy of $1^{\circ}C$.

• Korean Journal of Soil Science and Fertilizer
• /
• v.42 no.spc
• /
• pp.20-28
• /
• 2009

The sustainability of conventional agriculture which is characterized by input dependent and ecologically simplified food production system is vague. Chemicals and present practices used in agriculture are not only costly but also have widespread implications on human and animal health, food quality and safety and environmental quality. Thus there is a need for alternative farming practices to sustain food production for the escalating population and conserve environment for future generations. The present research scenario in the area of plant microbe interactions for maintaining sustainable agriculture suggests that the level of internal regulation in agro-ecosystems is largely dependent on the level of plant and microbial diversity present in the soil. In agro-ecosystems, biodiversity performs a variety of ecological services beyond the production of food, including recycling of nutrients, regulation of microclimate and local hydrological processes, suppression of undesirable organisms and detoxification of noxious chemicals. Controlling the soil microflora to enhance the predominance of beneficial and effective microorganisms can help improve and maintain soil chemical and physical properties. The role of beneficial soil microorganisms in sustainable productivity has been well construed. Some plant bacteria referred to as plant growth-promoting rhizobacteria (PGPR) can contribute to improve plant growth, nutrient uptake and microbial diversity when inoculated to plants. Term PGPR was initially used to describe strains of naturally occurring non-symbiotic soil bacteria have the ability to colonize plant roots and stimulate plant growth PGPR activity has been reported in strains belonging to several other genera, such as Azotobacter, Azospirillum, Arthrobacter Bacillus, Burkhokderia, Methylobacterium, and Pseudomonas etc. PGPR stimulate plant growth directly either by synthesizing hormones such as indole acetic acid or by promoting nutrition, for example, by phosphate solubilization or more generally by accelerating mineralization processes. They can also stimulate growth indirectly, acting as biocontrol agents by protecting the plant against soil borne fungal pathogens or deleterious bacteria. Present review focuses on some recent developments to evolve strategies for better biotechnological exploitation of PGPR's.

• Journal of Environmental Impact Assessment
• /
• v.15 no.1
• /
• pp.1-12
• /
• 2006

Changes in the soil physical property and the topographic condition derived from agricultural activities like as farming activities, land clearance and cutting down resulted in environmental and economic problems including the outflow of nutrient from farms and the water pollution. Several theories on the soil conservation have been developed and reviewed to protect soil erosion in the regions having a high risk of erosion. This study was done using the USLE model developed by Wischmeier and Smith (1978), and model for the slope length and steepness made by Desmet and Govers (1996), and Nearing (1997) to evaluate the potential of the soil erodibility. Therefore, several results were obtained as follows. First, factors affecting the soil erosion based on the USLE could be extracted to examine the erosion potential in farms. Soil erodibility (K), slope length (L), and slope steepness (S) were used as main factors in the USLE in consideration of the soil, not by the land use or land cover. Second, the soil erodibility increased in paddy soils where it is low in soil content, and the very fine sandy loam exists. Analysis of the slope length showed that the value of a flat ground was 1, and the maximum value was 9.17 appearing on the steep mountain. Soil erodibility showed positive relationship to a slope. Third, the potential soil erodibility index (PSEI) showed that it is high in the PSEI of the areas of steep upland and orchard on the slope of mountainous region around Dokjigol mountain, Dunji mountain, and Deummit mountain. And the PSEI in the same land cover was different depending on the slope rather than on the physical properties in soil. Forth, the analysis of land suitability in soil erosion explained that study area had 3,672.35ha showing the suitable land, 390.88ha for the proper land, and 216.54ha for the unsuitable land. For unsuitable land, 8.71ha and 6.29ha were shown in fallow uplands and single cropping uplands, respectively.

• Korean Journal of Ecology and Environment
• /
• v.39 no.4 s.118
• /
• pp.508-515
• /
• 2006

This study was conducted from July to December 2004, in order to find measures to improve the water quality and the function of pond ecosystems which are often negatively affected by phytoplankton and suspended particle matters. Most of the time, the management of ponds in Korea does not consider the ecological concepts such as self-purification and nutrient recycling. Instead, conventional methods depend on other factors such as fish farming and the function of fountains and waterfalls. Sustainability of pond ecosystems must be studied with the highest emphasis given to water quality. Water discharges of inflow and outflow as well as balance adjustment for different factors must be thoroughly studied. There is a great need for studies on sustainability because it can be realized through the horizontal or vertical balances of an ecosystem. Our current research offers useful information to the academia and public on maintaining sustainability in terms of structure and function of the pond.

• Animal cells and systems
• /
• v.12 no.4
• /
• pp.269-277
• /
• 2008

Siberian flying squirrel, an endangered species in South Korea, is distributed through major mountain regions of South Korea. The number of Siberian flying squirrel(Pteromys volans) in South Korea has decreased and their habitats are fragmented and isolated because of anthropogenic activities. So far no molecular genetic data has, however, been available for their conservation and management. To obtain better information concerning genetic diversity and phylogenetic relationships of the Siberian flying squirrel in South Korea, we examined 14 individuals from South Korea, 7 individuals from Russia, and 5 individuals from northeastern China along with previously published 29 haplotypes for 1,140 bp of the mtDNA cytochrome b gene. The 14 new individuals from South Korea had 7 haplotypes which were not observed in the regions of Russia and Hokkaido. The level of genetic diversity(0.616%) in the South Korean population was lower than that in eastern Russia(0.950%). The geographical distribution of mtDNA haplotypes and reduced median network confirmed that there are three major lineages of Siberian flying squirrel, occupying; Far Eastern, northern Eurasia, and the island of Hokkaido. The South Korean population only slightly distinct from the Eurasia, and eastern Russian population, and is part of the lineage Far Eastern. Based on these, we suggest that the South Korean population could be considered to belong to one partial ESU(Far Eastern) of three partial ESUs but a different management unit. However, the conservation priorities should be reconfirmed by nuclear genetic marker and ecological data.

• Journal of the Economic Geographical Society of Korea
• /
• v.19 no.2
• /
• pp.399-416
• /
• 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 Wetlands Research
• /
• v.20 no.1
• /
• pp.20-26
• /
• 2018

The purpose of this study is to construct a GIS / DB by grasping a small but ecologically valuable village wetland distribution, and to propose conservation management and wise use plan. The study area is Seocheon-gun, a typical farming village. Firstly, based on the digital topographical map (1:5,000), the Arc-GIS tool was used to identify the provisional(draft) village wetlands. In addition, for the management of village wetlands, wetlands with an area of more or less than $625m^2$ each were derived and according to ecological regions study area was classified into urban areas, inland areas and coastal areas. And finally, according to the wetland identifying indicators, the village wetlands were identified as the final village wetlands through indoor and field trips. The results of the study show that there are 570 village wetlands in Seocheon - gun province, which are 74 in urban areas, 220 in inland areas, and 276 in coastal areas. The case study for village wetland identification was conducted in one out of two urban areas (Seocheon - eup), two of four coastal areas (Biin - myeon and Seo - myeon), and three of seven inland areas (Masan - myeon, Hansan - myeon, and Sicho - myeon). The distribution of village wetlands was found mainly to be a village wetland with an area of less than $625m^2$. In addition, compared with inland areas, the discrimination rate of village wetlands in coastal areas and urban areas was relatively low, indicating that inland areas were still less disturbed, and land use in urban areas and coastal areas is changing rapidly. Especially, land with less awareness such as village wetlands is relatively easily damaged, and management strategy is urgent.

• Journal of Marine Life Science
• /
• v.5 no.2
• /
• pp.64-71
• /
• 2020

Gloiopeltis tenax is one of the most economically useful species in China and Japan that has been applied to glue and food since ancient times. The material used in the experiment was a large quantity of basal crusts obtained from the culture of tetraspores that were released from the mature tetrasporophytes collected at Gyeokpori, Byeonsan-myeon, Buan-gun, Jeollabuk-do in Korea. The basal crusts were cut into quadrisect under a dissecting microscope so as to monitor the process of regeneration and growth. The cut crusts were cultured under varying conditions, where the photoperiod was 16:8 h L:D; the temperature range was 10, 15, 20, and 25℃; the irradiance range was 30 and 85 µmol photons m^-2s^-1. The quadrisect basal crusts grew to an oval shape, then formed a vertical axis of cylindrical shape. The maximum growth of basal crusts was 9.61±3.59 mm² under the condition of 15℃ temperature and 85 µmol photons m^-2s^-1 irradiance, after 12-weeks culture. The mean relative growth rate after 12-weeks culture showed the maximum rate of 5.15±0.80 %day^-1 at 15℃ and the minimum growth rate was 3.15±0.94 %day^-1 at 10℃, with a statistically significant difference (p < 0.05). In conclusion, it has shown the possibility that growth of basal crusts of G. tenax is one of the good farming method of potential alga.