• Korean Journal of Soil Science and Fertilizer
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• v.37 no.4
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• pp.288-291
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• 2004

The development of land classification and soil productivity rating systems (SPR) are examined for their application to valuation of agricultural land in South Dakota, USA. For current and impending environmental and agricultural land issues, there is virtually no hard data available. Therefore, the study works with government and private sector clients to identify needs, and develop and apply a variety of techniques to mine data and carry out appropriate assessment methods. The application of SPR data to land valuation work conducted by real estate appraisers, tax assessors, and economists are discussed along with an assessment of its benefits and limitations. However, the actual value of the agricultural land can be determined by fulfilling the agricultural's vision of protecting and improving the environment by agricultural activities besides the safe food production. Therefore, it is increasingly important that we understand the impacts of farming and forestry on land, water and air.

• Spatial Information Research
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• v.17 no.4
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• pp.431-443
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• 2009

Recently, turbidity problem is one of the hot issues in dam and reservoir management works. Main reason to bring about high density turbid water is sediment yield by rainfall intensity energy. Because existing researches didn't consider diverse types of crops, it was difficult to calculate more accurate soil erosion and sediment yield. This study was evaluated the reduction efficiency of soil erosion and sediment yield using ginseng layer extracted from IKONOS satellite image, and the area and the ratio of ginseng area represented $0.290km^2$ and 0.94%. The reduction efficiency of soil erosion considering ginseng area represented low value in 0.9% using GIS-based RUSLE model, because the area of ginseng was small compared to areas of other agricultural lands. To reflect future land use change, this study was calculated the reduction efficiency of soil erosion and sediment yield by considering many scenarios as kinds of crops of paddy, dry field, orchard, and other agricultural areas convert to the ginseng district. As result of analysis of them according to scenarios, scenario (1) in which dry field was converted to ginseng area and scenario (2) in which fully agricultural lands were converted to ginseng area showed high reduction efficiency as 31.3% and 34.8% respectively, compared to existing research which didn't consider ginseng area. Methodology suggested in this study will be very efficient tools to help reservoir management related to high density turbid water.

• Proceedings of the Korean Society for Agricultural Machinery Conference
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• 2000.11c
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• pp.684-689
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• 2000

In harvesting rice and barley using combine, the inclination of the body caused by the irregular surface condition of the field and the soil sinking from the unbalanced weight during the grain collection used to make harvesting operation difficult and even impossible. To overcome such a problem, automatic leveling control system for a combine has been developed and tested. The system was composed of the sensor for measuring left and right inclination of the combine chassis and the hydraulic control system. The adaptability of the control system was investigated by analyzing system response in time domain. And the limit angle of the leveling control was set up to be +/- 7$^{\circ}$. The proposed control and hydraulic power system was implemented to the prototype combine. The prototype combine was designed and built as a separable structure with chassis and track. This paper shows results of the leveling performance tested in the laboratory and the grain field.

• Journal of the Korean Association of Geographic Information Studies
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• v.14 no.1
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• pp.94-106
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• 2011

The muddy water occurrence possibility of reservoir were analyzed by considering GIS based soil erosion model, sediment delivery ratio and effective reservoir capacity. For the purpose, the weakness factors for the establishment of countermeasures of basin were analyzed by evaluating input factors of RUSLE model based on spatial data such as DEM, soil map, landcover map and so on. The potential of soil erosion was estimated considering highland upland. The sediment yields of Chungju-Dam and Soyanggang-Dam showed the highest result in sediment yield using sediment delivery ratio with considering basin area. The sediment concentration of Imha-Dam and Chungju-Dam showed the highest value as 0.791 $kg/m^3/yr$ and 0.526 $kg/m^3/yr$ respectively in sediment concentration with considering effective reservoir capacity. Especially, sediment yield of Imha-Dam was about 2.36 times lower than Soyanggang-Dam, but the sediment concentration was 1.90 times higher preferably, because the effective reservoir capacity of Imha-Dam was about 4.48 times lower. This study calculated sediment concentration using the 10 years mean rainfall event and could consider the aspects of soil, terrain, landcover, cultivation condition and effective reservoir capacity of each basin effectively through the results. Therefore, these quantitative sediment concentration data could be used to estimate the potential of high density turbid water for reservoir and applied with effective tools for the management of reservoir.

• Journal of Environmental Science International
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• v.28 no.12
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• pp.1061-1069
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• 2019

Common reed (Phragmites australis) is widespread in reclaimed land and wetland habitats. Every year, the common reed produces extensive colonies by means of underground rhizomes and ground-surface stolons. From an agricultural point of view, the common reed's large biomass is a good material for supplying organic matter. However, it has not yet been studied in terms of seedling production, transplanting conditions, and decomposition characteristics in reclaimed land. Seeds were harvested from the native common reed in Saemangeum, South Korea, the previous year and stored on an open field. The seeds were sowed in the greenhouse at the beginning of April. Common reed decomposition was studied from June to September, with the use of coarse mesh (5 mm) stem litterbags, on three samping dates and with five replicate packs per sample. These packs were dug in five soil condition (low-salinity topsoil, subsoil, high-salinity topsoil, subsoil, paddy topsoil) to 0.2 m and 0.4 m depth. The highest germination rate of common reed seeds was observed in non-salt solution, but the exhibited germination rate was 70% at 9.38 dS m^-1. The plant height of young reed decreased steadily with increasing salinity, but leaf number did not decrease by 9.38 dS m^-1. The survival rate of the two-year-old reed was 83.3%, which was 35% higher than that of the one-year reed. The transplant success rate was 0% in the no vinyl mulching in the soil, but the first year and second year seedlings survived rates were 63% and 83.3%, respectively, in vinyl mulching. Common reed decomposition rates were faster low salinity than high salinity. All nutrient contents were found to fluctuate significantly with time by soil conditions. We also need to study the growth rate of reed transplanting seedlings by soil moisture contents and the comparison of degradation in common reed tissues.

• Journal of the Korean Association of Geographic Information Studies
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• v.13 no.1
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• pp.1-15
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• 2010

This study analyzed the change of flowout and suspend solid in Andong and Imha basin according to the climate change to develop evaluation index about turbid water occurrence possibility and to support the countermeasures for turbid water management using GIS-based Soil and Water Assessment Tools (SWAT). MIROC3.2 hires model values of A1B climate change scenario that were supplied by Intergovernmental Panel on Climate Change (IPCC) were applied to future climage change data. Precipitation and temperature were corrected by applying the output value of 20th Century Climate Coupled Model (20C3M) based on past climate data during 1977 and 2006 and downscaled with Change Factor (CF) method. And future climate change scenarios were classified as three periods (2020s, 2050s, 2080s) and the change of flowout and suspended solid according to the climate change were estimated by coupling modeled value with SWAT model. Flowout and suspended solid of Andong and Imha basin in 2020s, 2050s, and 2080s were simulated as increasing compared with standard year (2006). Also, as the result of seasonal change, flowout and suspended solid of Andong and Imha basin in spring, autumn, and winter showed as increasing compared with standard year. And them of Andong and Imha basin in summer were analyzed as decreasing compared with standard year.

• The Korean Journal of Soil Zoology
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• v.5 no.2
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• pp.101-112
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• 2000

Spiders usually have poor vision but not the jumping spiders. Their eight eyes are located on its distinctive box-shaped head and relatively well developed. The Spiders were fixated with 3% glutaraldehyde and thin section was performed with ultra-microtome. The specimens were observed with light microscopy, transmission and scanning electron microscopy. Eye area of jumping spider is competed of three rows. The first eye row comprise four eyes. Among them, two anterior median eyes are the largest and two anterior lateral eyes are relatively small. The former are main-eyes and have excellent vision. The second row, which has the two smallest eyes, is located about midway between the first and third rows. The third row is about half-way back on the thorax and eyed of which are middle size. To investigate ultrastructure of salticid spiders'eye, Menemerus fulvus was chosen. All of Menemerus fuvus's eyes are composed of cornea, lens, vitreous body and retina in histologically. Cornea layer, linked to exocuticle of exoskeleton. is regular layer structure without any cell tripe. Lenses are biconvex type. Retinas comprise well developed microvilli-shape rhabdomeres, unpigmented supporting cells, and pigmented cell. Retinas of anterior median eyes are surrounded by circular cylinder-shaped vitreous body, photoreceptor, i.e. rhabdomeres, of it is irregularly arranged compared to the other eyes.

• Korean Journal of Environmental Agriculture
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• v.37 no.2
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• pp.73-78
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• 2018

BACKGROUND: Soil salinity of reclaimed tidal land in Korea is highly important factor. High salinity is harmful to crop productivity. Jerusalem artichoke (Helianthus tuberosus L.) is known to be salt-tolerant and has high adaptability to diverse pedo-climatic conditions. The objective of this study was to assess the changes of soil properties and crop productivity according to salt concentration in the reclaimed tidal lands. METHODS AND RESULTS: Experimental sites were selected at Saemangeum ($35^{\circ}46^{\prime}N$, $126^{\circ}37^{\prime}E$) reclaimed tidal land, and their dominant soil series were Munpo (coarse loamy, mixed, non-acid, mesic, typic Fluvaquents). H. tuberosus L were collected from 12 locations across Korea. Tubers were planted at $75{\times}25cm$ with EC 2 to $7dS\;m^{-1}$. Soil samples were periodically collected from both 0~20 cm and 20~40 cm depths of each site. Soil salinity and soil moisture contents were varied depending on weather conditions. Soil electrical conductivity varied from 1.0 to $5.9dS\;m^{-1}$, and soil moisture contents varied from 9.2 to 28.7%. The white-colored tubers of H. tuberosus L. collected from 'Yeongwol-gun' exhibited the highest height (207 cm), followed by the white-colored tubers of H. tuberosus L. collected from 'Iksan-si'(202 cm). The white-colored tubers of H. tuberosus L. collected from 'GyeongJu-si' showed the highest yield (549 kg/10a). The purple-colored tubers of H. tuberosus L. collected from 'Yeongwol-gun' showed the highest yield (615 kg/10a). CONCLUSION: Our results indicate that the plant height and tuber yield did not appear to be correlated. Considering yield and inulin content, the GyeongJu-si seemed to be suitable as the white-colored tubers of H. tuberosus L. and the Yeongwol-gun seemed to be suitable as the purple-colored tubers of H. tuberosus L. in the reclaimed tidal lands. However, it is necessary to consider the relationship between the inulin content and the yield.

• Journal of Biosystems Engineering
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• v.43 no.2
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• pp.103-109
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• 2018

Purpose: This study has been conducted to develop a potato yield monitoring system, consisting of a segmentation algorithm to detect potatoes scattered on a soil surface and a counting system to count the number of potatoes and convert the data from two-dimensional images to masses. Methods: First, a segmentation algorithm was developed using top-hat filtering and processing a series of images, and its performance was evaluated in a stationary condition. Second, a counting system was developed to count the number of potatoes in a moving condition and calculate the mass of each using a mass estimation equation, where the volume of a potato was obtained from its two-dimensional image, and the potato density and a correction factor were obtained experimentally. Experiments were conducted to segment potatoes on a soil surface for different potato sizes. The counting system was tested 10 times for 20 randomly selected potatoes in a simulated field condition. Furthermore, the estimated total mass of the potatoes was compared with their actual mass. Results: For a $640{\times}480$ image size, it took 0.04 s for the segmentation algorithm to process one frame. The root mean squared deviation (RMSD) and average percentage error for the measured mass of potatoes using this counting system were 12.65 g and 7.13%, respectively, when the camera was stationary. The system performance while moving was the best in L1 (0.313 m/s), where the RMSD and percentage error were 6.92 g and 7.79%, respectively. For 20 newly prepared potatoes and 10 replication measurements, the counting system exhibited a percentage error in the mass estimation ranging from 10.17-13.24%. Conclusions: At a travel speed of 0.313 m/s, the average percentage error and standard deviation of the mass measurement using the counting system were 12.03% and 1.04%, respectively.

• Journal of the Korea Society of Computer and Information
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• v.29 no.4
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• pp.55-62
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• 2024

In this paper, we propose a thin-film hydroponic plant cultivator using HMI display and IoT technology. Existing plant cultivators were difficult to manage due to soil-based cultivation, and it was difficult to optimize environmental conditions due to the open cultivation environment. In addition, there are problems with plant cultivation as immediate control is difficult and growth of plants is delayed. To solve this problem, a cultivation environment was established by connecting the MCU and sensors, and the environment information could be checked and quickly controlled by linking with the HMI display. Additionally, a case was applied to minimize changes in environmental information. Implementation of a thin-film hydroponic cultivation system made soil management easier, improved functionality through operation and control, and made it easy to understand environmental information through the display. The effectiveness of rapid growth was confirmed through crop cultivation experiments in existing growers and hydroponic growers. Future research directions will include optimizing growth information by transmitting and storing cultivation environment information and linking and comparing growth information using vision cameras. It is expected that this will enable efficient and stable plant cultivation.