엽소진 Yeob So-jin , 김민경 Kim Min-kyeong , 안난희 An Nan-hee , 최순군 Choi Soon-kun

DOI:10.5389/KSAE.2023.65.4.001 JKWST Vol.65(No.4) 1-10, 2023

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As a result of climate change, non-point source pollution (NPS) from farmland with the steep slope during the rainy season is expected to have a significant impact on the water system. This study aimed to evaluate the effect of furrow mulching using alfalfa and PAM (Polyacrylamide) materials for each rainfall event, while considering the load characteristics of NPS. The study was conducted in Wanju-gun, Jeollabuk-do, in 2022, with a testbed that had a s lope of 13%, sandy loam soil, and maize c rops. The testbed was composed of four plots: bare soil (Bare), No mulching (Cont.), Vegetation mulching (VM), and PAM mulching (PM). Runoff was collected from each rainfall event using a 1/40 sampler and the NPS load was calculated by measuring the concentrations of SS, T-N, T-P, and TOC. During farming season, the reduction efficiency of NPS load was 37.1∼59.5% for VM and 38.2∼75.7% for PM. The analysis found that VM had a linear regression correlation (R2=0.28∼0.86, P-value=0.01∼0.1) with elapsed time of application, while PM had a quadratic regression correlation (R2=0.35∼0.80, P-value=0.1). These results suggest that the selection of furrow mulch materials and the appropriate application method play a crucial role in reducing non-point pollution in farmland. Therefore, further studies on the time-series reduction effect based on the application method are recommended to develop more effective preemptive reduction technologies.

김유안 Kim Yooan , 박주영 Park Jooyoung , 서교 Suh Kyo

DOI:10.5389/KSAE.2023.65.4.011 JKWST Vol.65(No.4) 11-23, 2023

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In Korea, open burning of agricultural residues is prevalent due to inadequate collection systems, which have caused environmental impacts such as GHGs and particulates. This illegal treatment of agricultural residues also results in economic loss, considering that agricultural residues can be utilized as resources such as pellets and energy sources. To understand the effect of avoiding open burning, this study evaluated the economic, environmental, and social effects of two alternative management options for agricultural residues: incineration and pelletizing. The study estimates the potential amount and dry weight by region for 18 items, taking various factors into account. Regarding the economic aspect, pelletizing facilities in all regions in Korea create economic benefits. This study shows that most regions have an environmental advantage by pelletizing residues. However, incineration creates more environmental benefits than pelletizing in metropolitan cities with relatively low density of residues. It is expected that the environmental, economic, and social findings of this study can be used to inform policies for bioenergy as the need for agricultural residue increases.

김귀훈 Kim Kwihoon , 전상민 Jun Sang-min , 강문성 Kang Moon Seong , 최진용 Choi Jin-yong

DOI:10.5389/KSAE.2023.65.4.025 JKWST Vol.65(No.4) 25-32, 2023

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KDS (Korean Design Standard) for agricultural drainage is a planning standard that helps determine the appropriate capacity and type of drainage facilities. The objective of this study was to analyze the inundation of the agricultural basin considering the current design standard and the critical rainfall duration. This study used the rainfall durations of 1-48 hour, and the time distribution method with the Chicago and the modified Huff model. For the runoff model, the NRCS (Natural Resources Conservation Service) unit hydrograph method was applied, and the inundation depth and duration were analyzed using area-elevation data. From the inundation analysis using the modified Huff method with different rainfall durations, 4 hours showed the largest peak discharge, and 11 hours showed the largest inundation depth. From the comparison analysis with the current method (Chicago method with a duration of 48 hours) and the modified Huff method applying critical rainfall duration, the current method showed less peak discharge and lower inundation depth compared to the modified Huff method. From the simulation of changing values of drainage rate, the duration of 11 hours showed larger inundation depth and duration compared to the duration of 4 hours. Accordingly, the modified Huff method with the critical rainfall duration would likely be a safer design than the current method. Also, a process of choosing a design hydrograph considering the inundation depth and duration is needed to apply the critical rainfall duration. This study is expected to be helpful for the theoretical basis of the agricultural drainage design standards.

윤성욱 Yun Sung-wook , 유찬 Yu Chan

DOI:10.5389/KSAE.2023.65.4.033 JKWST Vol.65(No.4) 33-43, 2023

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In this study, it was developed and verified an application method of fuzzy-logic theory to the rating process of agricultural fill dam safety. A fuzzy-logic is very famous logical system when some decision making is made on the status of a lack of information. Three proxies were selected and configured membership functions (MFs) and these MFs were activated in the process of fuzzification procedures. Fuzzified vlaues were passed through the rule-based inference system, then fire strength could classified among cases of the rule-based inference system. To obtain final results, Mandani-type was adapted in the defuzzification process. As the results, it was shown the developed system can give a correct results that was compared with Matlab - fuzzy inference function. More ever it could perform the detailed analysis and improvement on the infrastructure safety rating process using classical diagnosis method.

송호성 Song Hosung , 임성윤 Lim Seong-yoon , 김유용 Kim Yu-yong , 유석철 Yu Seok-cheol

DOI:10.5389/KSAE.2023.65.4.045 JKWST Vol.65(No.4) 45-52, 2023

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This study was conducted to examine the possibility of use as a structural material for ginseng cultivation facilities of recycled plastics. In order to determine the possibility that recycled plastic can replace timber used as a structural material for ginseng cultivation facilities, the specimens collected by elapsed time were compared with timber through bending tests. In addition, in order to analyze the effect of external environmental conditions on recycled plastic products, bending test was conducted with the specimens that had completed weathering test and accelerated heat aging test respectively. As a result, the bending strength of recycled plastic specimens with the elapsed time of 360 days was lower than that of timber. But bending strength of recycled plastic specimens exceeded the design allowable stress standard set by the Korea design standard (MOLIT, 2016). There was no degradation in quality of recycled plastic due to the external environment, and it was found that there would be no problem even if it was used as a structural material for ginseng cultivation facilities.