• 한국환경농학회지
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• 제27권4호
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• pp.314-320
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• 2008

During the summer season, more than half of the annual precipitation in Korea occurs during the summer season due to the geographical location in the Asian monsoon belt. So, this causes severe soil erosion from croplands, which is directly linked to the deterioration of crop/land productivity and surface water quality. Therefore, much attention has been given to develop accurate estimation tools of soil erosion. The aim of this study is to assess the performance of using the empirical Universal Soil Loss Equation (USLE) and the physical-based model of the Water Erosion Prediction Project (WEPP) to quantify eroded amount of soil from agricultural fields. Input data files, including climate, soil, slope, and cropping management, were modified to fit into Korean conditions. Chuncheon (forest) and Jeonju (level-plain) were selected as two Korean cities with different topographic characteristics for model analysis. The results of this current study indicated that better soil erosion prediction can be achieved using the WEPP model since it has better power to illustrate a higher degree of spatial variability than USLE in topography, precipitation, soils, and crop management practices. These present findings are expected to contribute to the development of the environmental assessment program as well as the conservation of the agricultural environment in Korea.

• Proceedings of the National Institute of Ecology of the Republic of Korea
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• 제3권1호
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• pp.7-12
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• 2022

Farming practices that balance environmental friendliness with biodiversity are increasingly valuable. Wild plants on farmlands compete for nutrients with crops and create a crucial microhabitat and resources for animals such as natural enemies. Investigating farmlands and their surrounding plants with limited human and material resources has become an essential aspect of evaluating the agricultural ecosystem services. This study investigated plants in six agricultural long-term ecological research sites in Taiwan from 2017 to 2020 to determine the ideal season for investigation. Cluster analysis was performed to group habitats with similar plant composition, and the species-area curves of the clusters in each season were created. The results indicated that the agricultural ecosystem could be divided into farmlands, banks, orchards, and tea gardens. The habitats were divided into farmland, bank, Chia-Yi orchard, Gu-Keng orchard, and tea garden clusters. Ground plant cover can be investigated all year with at least 18 quadrats. However, if human and material resources are limited, 10 quadrats should be the minimum for farmlands in autumn and for the other microhabitats in spring. The minimum number of quadrats is 10 for banks, 17 for orchards, and 9 for tea gardens.

• 농업과학연구
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• 제50권4호
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• pp.883-902
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• 2023

Water is critical to the health and productivity of fruit trees. Efficient monitoring of water stress is essential for optimizing irrigation practices and ensuring sustainable fruit production. Short-range sensing can be reliable, rapid, inexpensive, and used for applications based on well-developed and validated algorithms. This paper reviews the recent advancement in fruit tree water stress detection via short-range sensing, which can be used for irrigation scheduling in orchards. Thermal imagery, near-infrared, and shortwave infrared methods are widely used for crop water stress detection. This review also presents research demonstrating the efficacy of short-range sensing in detecting water stress indicators in different fruit tree species. These indicators include changes in leaf temperature, stomatal conductance, chlorophyll content, and canopy reflectance. Short-range sensing enables precision irrigation strategies by utilizing real-time data to customize water applications for individual fruit trees or specific orchard areas. This approach leads to benefits, such as water conservation, optimized resource utilization, and improved fruit quality and yield. Short-range sensing shows great promise for potentially changing water stress monitoring in fruit trees. It could become a useful tool for effective fruit tree water stress management through continued research and development.

• 한국농공학회지
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• 제31권2호
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• pp.92-103
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• 1989

This study was performed in order to produce the basic data for devising irrigation project and desalinization countermeasure through analyzing salt movement and desalinzation effects. The Desalinization experiments with water management practices were carried out, using the soil samples collected in New Manguem tideland. The changes of electrical conductivity, exchangeable sodium percentage, pH and hydraulic conductivity during the desalinization experiments, and the correlations between various factors influencing desalinization, were analyzed by the statistical method. The results obtained from this study were summarized as follows: 1. The sample soils used in this study were salin-sotlic soils with the high electrical conductivity and the high exchangeable sodium percentage, and the soil texture was silt loam. 2. A large amount of the soluble salts was removed in the begining of desalinization experiments. The initial electrical conductivity and the initial exchangeable sodium percentage decreased considerably in the beginning, and were gradually slow in the rate of decrease 3. The value of pH showed a tendency to increase during the desalinization and were little by little slow in the rate of increase, and could be estimated by the regression equation. 4. The initial hydraulic conductivity were raised greatly with gypsum treatment and the penmeability was maintained adequately, The hydraulic conductivity and the leaching time elapsed during the desalinization could be estimated by the regression equation. 5. The water requirement for desalinization with various water management practices could be estimated for a given electrical conductivity, exchangeable sodium percentage, and pH reading respectively.

• 농촌지도와개발
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• 제9권2호
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• pp.147-160
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• 2002

Although the philosophy of sustainable community development does not give the cure-all solutions for the major problems faced in the communities, it is theoretically and practically recognized as a newly emerging paradigm toward community development theoretically and practically. However, more specific tasks and issues of sustainable community development remain unchallenged and descriptive statements. The main objective of this study was to find out the extensive community development practices through the review of current works in the area of sustainable community development indicator, local agenda 21 and the relative issues. The recommendations of this study were the following; 1) The sustainable community development indicators available in the community level should be selected. Also, how to integrate the objective condition and subjective perception in community development practices, and how to weigh the indicator item should be solved in order to compare and measure the implementation of community development works. 2) In relation to local agenda 21, how to secure the implementation mechanism is more important than the developing the local agenda 21. 3) The policies aimed to raise the resident's awareness, formation of community field, create community social capitals, and define strategies to the selective community development programs should be considered to make the philosophy of sustainable community development active in the field level.

• 한국물환경학회지
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• 제30권2호
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• pp.159-165
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• 2014

Vegetative Filter Strip (VFS) is one of effective Best Management Practices (BMPs) to prevent sediment-laden water problem, is installed at the edge of source area such agricultural area so that sediment occurred in source area is trapped by VFS before it flow into stream or river. Appropriate scale of it needs to be simulated before it is installed, considering various field conditions. In this study, a model using VFSMOD-w model and Genetic Algorithm to determine effective VFS length was developed, it is available to calibrate input parameter related to source area sediment yield through thousands of VFSMOD-w simulations. Useful DBs, moreover, are stored in the model so that very specific input parameters can be used with reasonable values. Compared simulated values to observed data values for calibration, R2 and Nash-Stucliffe model efficiency coefficient were 0.74 and 0.65 in flow comparison, and 0.89 and 0.79 in sediment comparison. The model determined 1.0 m of Filter Length, 0.18 of Filter Slope, and 0.2 cm of Filter Media Spacing to reduce 80% of sediment by VFS. The model has not only Auto-Calibration module also DBs for specific input parameters, thus, the model is expected to be used for effective VFS scale.

• 한국농공학회지
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• 제36권1호
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• pp.73-82
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• 1994

This paper presents the experimental results of runoff and soil losses from sloping runoff plots under three cropping practices. Twenty-nine runoff plots having slopes of 10, 20, and 30 percent in gradient, and lengths of 10, 20 and 30 meter, respectively, were cultivated with soybean, alfalfa, and fallow conditions during 1989~1990 seasons. Crop stages were grouped based on crop canopy conditions and the cropping management factors of the Univer- sal Soil Loss Equation were derived as ratios of the soil losses to fallow conditions. The results from this study are summarized as follows : 1. Annual rainfall erosivity factor at Ichun station varied from 127 to 1336, averaging 472 and 200 in 1989. The month variations reach the peak in July, being 19& 2. Canopy cover percent for soybean that was taken by a photographic method increased sharply during 30 to 80 days after seeding and the results were used to identify periods for the six crop stages. 3. Annual average runoff rates from soybean and alfalfa plots were 35 and 16 percent of those from fallow ones, respectively. The runoff rates decreased as the crops grew. 4. Soil losses from soybean and alfalfa plots were 14 and 16 percent of those from fallow plots. And the crop coefficients were proposed for different crop stages.

• 한국농공학회논문집
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• 제59권6호
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• pp.73-80
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• 2017

The objective of this study is to investigate whether the daily rainfall depth derived from daily data represents the event rainfall depth derived from hourly data. For analysis, the 85th, 90th, and 95th percentile daily rainfall depths were first computed using daily rainfall data (1986~2015) collected at 63 weather stations. In addition, the storm event was separated by the interevent time definition (IETD) of 6, 12, 18, and 24 hr using hourly rainfall data. Based on the separated storm events, the 85th, 90th, and 95th percentile event rainfall depths were calculated and compared with the using hourly rainfall data with the 85th, 90th, and 95th percentile daily rainfall depths. The event rainfall depths computed using the IETD were greater than the daily rainfall depths. The difference between the event rainfall depth and the daily rainfall depth affects the design and size of the facility for controlling the stormwater. Therefore, the designer and policy decision-maker in designing the stormwater best management practices need to take into account the difference generated by the difference of the used rainfall data and the selected IETD.

• 농촌계획
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• 제25권4호
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• pp.151-159
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• 2019

The aim of this paper is to identify the characteristics of social economy in social farming practices, and to explore three core factors of experiment, openness and locality, which have a significant impact on the working-mechanism of social innovation. Though a few social farming practice appear nowadays in Korea, it can be witnessed social economic factors such as cooperation between networks and solidarity actors, pursuing social values in social farming. On the basis of the conceptual framework on the social economy characteristics, this study examines case analysis in order to find the possibilities as a social innovation of the social farming. Three farms perform multiple functions of care, labour integration, training in farming area, and sometimes make collaboration work with artists and local residents. Social farming can be social innovation practices in the view of the interaction of experiments, openness and locality within the context of an innovation process, networking, enhancing social capital.

• 한국작물학회지
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• 제27권4호
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• pp.452-461
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• 1982

Average yield of wheat and barley cultivars has been increased 3 percent every year by varietal improvement. The major characteristic changes of those improved cultivars were the early maturing and lodging resistance using dwarf genes, 70-90cm of culm length appearances, under the heavy fertilizer application. Looking back the cultural practices of wheat and barley for the last 20 years, the introduction of early maturing and lodging resistance cultivars around 1970 brought the changes of seeding rate from 65kg to 130- 200kg per hector and the tillering increased by heavy fertilizer. The utilization of livestock and man power for preparation of seedbed were gradually disappeared by increasing agricultural mechanization. The narrow-spaced seeding $(40cm {\times} l8cm)$ and drill seeding $(20cm {\times} 5cm)$ in upland, broadcasting or drilling on high ridge $(120cm {\times} 90cm)$ with the power-toller and whole area broadcasting in paddy field were improved as the main cultural method. The use of agricultural machineries reduced the labour consumption of 940 man hours to 180 man hours per hector from seeding to harvest.