• Korean Journal of Soil Science and Fertilizer
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• v.45 no.1
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• pp.9-15
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• 2012

This study was performed to produce basic data for silty reclaimed tidal lands and to develop techniques of environmentally-friendly utilization in agricultural system. We chose the two sites in Saemangeum reclaimed tidal lands, one (Site I) has been treated with cultivating green manure and conducting the desalinization process through submergence since April, 2007 and the other (Site II) has been under natural condition without artificial treatment. In situ and ex situ physic-chemical properties were determined and comparisons were made for soil profiles examined at these two sites in April 2009. Surface soil of Site I had lower EC and higher field saturated hydraulic conductivity than those of Site II, uncultivated land. Especially, exchangeable sodium content was lowest in Site I Ap1 layer than in other layers. This is probably due to flooding desalination and green manure cultivation. Besides, Ap1 and A2 layers of soil profile in Site I showed brighter soil color and more root observation than those of Site II. This is probably due to green manure cultivation. By the large, for high cash upland crops and intensive agricultural use of silty reclaimed tidal land, site-specific soil ripening such as flooding desalination and green manure cultivation could be useful.

• Journal of The Korean Society of Agricultural Engineers
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• v.55 no.2
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• pp.47-57
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• 2013

This study is to assess the reduction of non-point source pollution loads for rice straw mulching of upland crop cultivation at a watershed scale. For Byulmi-cheon watershed (1.21 $km^2$) located in the upstream of Gyeongan-cheon, the HSPF (Hydrological Simulation Program-Fortran) and SWAT (Soil and Water Assesment Tool), physically based distributed hydrological models were applied. Before evaluation, the model was calibrated and validated using 9 rainfall events. The Nash-Sutcliffe model efficiency (NSE) for streamflow using the HSPF was 0.62~0.76 and the determination coefficient ($R^2$) for water quality (sediment, total nitrogen T-N, and total phosphorus T-P) were 0.72, 0.62, and 0.63 respectively. The NSE for streamflow using the SWAT were 0.43~0.81 and the $R^2$ for water quality (sediment, T-N, and T-P) were 0.54, 0.87, and 0.64 respectively. From the field experiment of 16 rainfall events, the rice straw cover condition reduced surface runoff average 10.0 % compared to normal surface condition. By handling infiltration capacity (INFILT) in HSPF model, the value of 16.0 mm/hr was found to reduce about 10.0 % reduction of surface runoff. For this condition, the reduction effect of sediment, T-N, and T-P loads were 87.2, 28.5, and 85.1 % respectively. By handling soil hydraulic conductivity (SOL_K) in SWAT model, the value of 111.2 mm/hr was found to reduce about 10.0 point reduction of surface runoff. For this condition, the reduction effect of sediment, T-N, and T-P loads were 80.0, 83.2, and 78.7 % respectively. The rice straw surface covering was effective for removing surface runoff dependent loads such as sediment and T-P.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.19 no.2
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• pp.24-29
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• 2020

In South Korea, agricultural mechanization has been carried out in paddy field, but not in the upland field during recent decades. Among crops such as root vegetables, leafy vegetables from upland field, corn is used as forage for livestock as well as food for men. The corn harvester needs to be developed to replace men's labor in rural area to follow the recent needs in the farm industry. The corn harvester is comprised of three parts such as cutting part, feeding part and pick-up part. The feeding part is so long for cut corns to be delivered from the cutting part to the pick-up part. Structurally, the load from the long moment arm is likely to be big. Thus, the setup to measure the stress on the duct of the feeding part was configured with the data acquisition system. The strain gages were attached on several points that seem to be loaded a lot comparatively. The stress was measured and the measured stresses were divided by the yield stress to get the safety factor. And then, we made sure the safety factors were above 1 on the all points. In conclusion, the feeding part of the corn harvester which convey the cut corn from the cutting part from the pick-up part can be regarded to be made safe structurally.

• Korean Journal of Soil Science and Fertilizer
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• v.25 no.3
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• pp.263-269
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• 1992

These studies was conducted to investigate the influence of ALLELOPATHIC effects of upland weeds on crops and soil microorganisms. The aqueous extract of weed residues were used to identify physiological controll of plant and microorganisms. The results obtained are as follows : 1. The aqueous extract of weeds controlled germination and growth of plant, especially the 5%-extract of Potulaca oleracea suppressed the growth of soybean about 8~12%. 2. The 5%-extract of Potulaca oleracea inhibited effect of phytosynthesis of soybean about 60%. 3. The move the concetration of phenolic compounds in soil, the less a number of actinomycetes and bacteria. 4. The number of soil microorganism(fusarium oxysporum spp.) were decresed as to the concentration of vanillic acid was increased.

• Journal of The Korean Society of Agricultural Engineers
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• v.58 no.5
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• pp.81-90
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• 2016

Due to droughts and water shortages causing severe damage to crops and other vegetations, much attention has been given to efficient irrigation for upland farming. However, little information has been known to measure soil moisture levels in a field scale and apply their spatial variability for proper irrigation scheduling. This study aimed to characterize the spatial variability and temporal stability of soil water contents at depths of 10 cm, 20 cm and 30 cm on flat (loamy soil) and hill-slope fields (silt-loamy soil). Field monitoring of soil moisture contents was used for variogram analysis using GS+ software. Kriging produced from the structural parameters of variogram was applied for the means of spatial prediction. The overall results showed that the surface soil moisture presented a strong spatial dependence at the sampling time and space in the field scale. The coefficient variation (CV) of soil moisture was within 7.0~31.3 % in a flat field and 8.3~39.4 % in a hill-slope field, which was noticeable in the dry season rather than the rainy season. The drought assessment analysis showed that only one day (Dec. 21st) was determined as dry (20.4 % and 24.5 % for flat and hill-slope fields, respectively). In contrary to a hill-slope field where the full irrigation was necessary, the centralized irrigation scheme was appeared to be more effective for a flat field based on the spatial variability of soil moisture contents. The findings of this study clearly showed that the geostatistical analysis of soil moisture contents greatly contributes to proper irrigation scheduling for water-efficient irrigation with maximal crop productivity and environmental benefits.

• Korean Journal of Agricultural Science
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• v.47 no.2
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• pp.315-326
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• 2020

In this study, a real-time crop recognition system was developed for an unmanned farm machine for upland farming. The crop recognition system was developed based on a stereo camera, and an image processing framework was proposed that consists of disparity matching, localization of crop area, and estimation of crop height with coordinate transformations. The performance was evaluated by attaching the crop recognition system to a tractor for five representative crops (cabbage, potato, sesame, radish, and soybean). The test condition was set at 3 levels of distances to the crop (100, 150, and 200 cm) and 5 levels of camera height (42, 44, 46, 48, and 50 cm). The mean relative error (MRE) was used to compare the height between the measured and estimated results. As a result, the MRE of Chinese cabbage was the lowest at 1.70%, and the MRE of soybean was the highest at 4.97%. It is considered that the MRE of the crop which has more similar distribution lower. the results showed that all crop height was estimated with less than 5% MRE. The developed crop recognition system can be applied to various agricultural machinery which enhances the accuracy of crop detection and its performance in various illumination conditions.

• Korean Journal of Remote Sensing
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• v.14 no.4
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• pp.343-352
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• 1998

Spectral reflectance data of upland crops at OSMI bands were collected and evaluated for the feasibility of crop discrimination knowledge-based on crop calendar. Effective bands and their ratio values for discriminating corn from two other legumes were defined with OSMI equivalent bands and their ratio values. For corn discrimination from two other legumes, peanut and soybean, June 22 among measurements dates was the best since all OSMI equivalent bands and their ratio values in June 22 were highly significant for corn separability. Phenological growth stage of a silage corn (rs510) could be estimated as a function of spectral reflectance in vegetative stage. Five growth stage prediction models were generated by the SAS procedures REG and STEPWISE with OSMI equivalent bands and their ratio values in vegetative stage.

• Korean Journal of Soil Science and Fertilizer
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• v.48 no.6
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• pp.677-682
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• 2015

Although it is not a landscape crop according to MIFAFF(ministry of agriculture, food and rural affairs), yellow mustard is considered a superb landscape crop because of its growth and flower characteristics. We sowed yellow mustard as a landscape and green manure crop in upland soil (four types of soil texture) in spring. And we studied its flowering characteristics, dry weight, and nitrogen yield. The growths of yellow mustard were possible in every soil ranging from sandy soil to clay loam. Its height was 54.1 ~ 76.1cm and the number of node per hill was 11.3 ~ 17.0. Its flowers had a light yellow. It took about 44 ~ 50 days to flower, and flowered for 22~25 days. The dry weight of yellow mustard was $2.27{\sim}3.60tonha^{-1}$ with highest in sandy loam and loam. Among the nutrients of yellow mustard, nitrogen(T-N) was $12.6{\sim}20.8gkg^{-1}$, and C/N ratio was 21.6~37.7. The nitrogen yield of yellow mustard was $35{\sim}62kgha^{-1}$. In conclusion, because of its flowering characteristics and dry weight, yellow mustard was considered appropriate for both green manure and landscape crop uses.

• Korean Journal of Soil Science and Fertilizer
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• v.50 no.6
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• pp.644-652
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• 2017

Clover, a legume crop, is a landscape crop and green manure crop that can be sowing in spring. Clover serves various roles such as landscape composition, weeds suppressing, prevention of soil loss and nutrients on sloping, atmosphere purification, and supplying nitrogen in soil. Thus, in order to utilize this crop in agricultural land, we observed its effect on growth and carbon uptake in upland soil. The plant height of clover species increased with late harvesting time and was 46.0~55.0 cm at 90 days after seeding (DAS) and the longest in red clover. The dry matter increased at 85 DAS, after that, decreased slightly. The dry matter of white clover and red clover was $3.0Mg\;ha^{-1}$ and $3.1Mg\;ha^{-1}$, respectively, and crimson clover was $2.5Mg\;ha^{-1}$, significantly lower than other clover. Crops bloomed at 90 DAS were white clover and crimson clover, the period from sowing to flowering was 78 days for crimson clover and 85 days for white clover. The nitrogen content of the clover species was $12.0{\sim}29.3g\;kg^{-1}$, with the highest of $29.3g\;kg^{-1}$ for white clover. The carbon content of clover species was similar in all clover species, but carbon uptake was high in white clover and red clover, and lowest in crimson clover. The carbon uptake of the plant increased to 85 DAS and then decreased. Based on the clover growth and carbon uptake, white clover and red clover were promising when sown in spring.

• Journal of The Korean Society of Agricultural Engineers
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• v.61 no.5
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• pp.49-55
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• 2019

This study attempted to investigate the changes in the perception of local government officials about agricultural infrastructure improvement projects due to the financial policy changes. A total of 141 local government officials were surveyed on the priority, the current status of the agricultural infrastructure improvement projects. Irrigation facilities renovation project and Small drainage improvement project had generally high priority, while Support project of cultivation basis for upland crops in paddy, Large scale land readjustment project, and Upland infrastructure improvement project had low priorities. After the introduction of the block grant system, agricultural infrastructure improvement projects had often been conducted by collecting opinions from local residents. The officials in charge of local governments recognized that the agricultural infrastructure improvement projects were reduced due to lack of financial resources and project potential sites. In response to the changes in the agricultural infrastructure improvement projects, most of the surveys showed that the influence of cities and provinces was strengthened. In addition, respondents most needed to improve the subsidy rate and there were a large number of cases requiring differential support to meet the characteristics of the local government. Therefore, it will be necessary to present a new perspective on the agricultural infrastructure improvement projects and to suggest differentiated projects for each regions.