• Journal of the Korea Organic Resources Recycling Association
• /
• v.25 no.1
• /
• pp.87-92
• /
• 2017

Objective of this experiment was to evaluate the effect on pepper growth to application of biochar pellet in case of development of soil carbon sequestration technology. The treatments consisted of control as a general agricultural practice method, pellet (100% pig compost), biochar pellets with mixture ratio of pig compost (9:1, 8:2, 6:4, 4:6, 2:8) for comparison of total carbon contents, $NH_4-N$ concentrations, and total biomass in the pots applied with biochar pellets after pepper harvesting. The application rates of biochar pellet was 8.8 g/pot regardless of their mixed rates based on recommended amount of application (440 kg/10a) for pepper cultivation. For the experimental results, Total carbon contents in the treatments were low from 1.8 to 2.6 fold as compared to the control. $NH_4-N$ concentrations were not significantly different among the treatment plots as compared to the control, but $NO_3-N$ was not detected in the all treatment plots. However, total biomass was not only significantly different between the control and 2:8 (biochar : pig compost) biochar pellet application plot even if the other treatments were low. Therefore, this biochar pellet application might be further modified for soil carbon sequestration in agricultural farming practices.

• The Korean Journal of Pesticide Science
• /
• v.12 no.4
• /
• pp.375-381
• /
• 2008

A new disease causing skin sooty dapple symptoms on fruits, leaves, and young shoot of Asian pear occurred in Korea. However, no chemical control approaches has been developed to control this disease. To investigate ecological aspects of this disease, we conducted field surveys in the high or low disease occurred orchards. The years with heavy rainfall caused severe occurrence of the skin sooty dapple disease than the years with lower rainfall during all growth stages of pear fruit. Different fruit-wrapping bags did not prevent occurrence of skin sooty dapple disease, and lesion numbers were higher in lower parts of fruit equatorial line inside of fruit-wrapping bags. There is a direct correlation between occurrence of the skin sooty dapple disease and frequency of fungicide application in the orchards. Among the tested commercial fungicides, thiophanate-methyl WP and penconazole WP completely inhibited the growth of the Cladosporium sp. in in vitro studies but little protection was observed in the field following fungicide applications. However, application of lime sulfur combined with the use of fruit-wrapping bags most effectively reduced incidence of the disease in the field. Our results suggest that skin sooty dapple disease could be a serious problem in sustainable organic pear farms and effective control methods for this disease urgently required.

• Membrane Journal
• /
• v.30 no.3
• /
• pp.190-199
• /
• 2020

The utilization of multiple water sources becomes important due to the master plan for development of water supply released by Ministry of Environment, Korea in 2018. In this study, therefore, the analysis of comprehensive effect in blending applicable water sources in Daesan where 100,000 ㎥/d seawater desalination plant will be constructed for industrial use was performed. The increase in mixing ratio of other water sources with seawater reduced salinity up to 50%, but negatively impacted the turbid and organic matter. Lab-scale reverse osmosis performance test also found that membrane fouling was exacerbated in blended water condition. The simulation results of reverse osmosis indicated 39% energy saving on average is expected at the one-to-one blending ratio, however, long-term performance test at the pilot-scale plant is highly required to evaluate the inclusive impact of mixing seawater and other water sources.

• The Journal of Engineering Geology
• /
• v.12 no.4
• /
• pp.471-484
• /
• 2002

Alluviums in the Keum River watershed cover an areal extent of $3,029{\;}\textrm{km}^2$ and contain about 8.1 billion tons of groundwater. However, the waters are severely polluted by nitrate, possibly due to the application of nitrogen fertilizer (>250 N kg/ha) on agricultural land. This paper aims to elucidate the pollution status and behaviors of nitrate in alluvial groundwaters in the Keum River watershed area, based on regional hydrogeochemical study. Most of the collected samples (n = 186) are polluted by nitrate (average = 42.2 mg/L, maximum = 295 mg/L). About 29% of the samples have the nitrate concentrations exceeding Korean Drinking Water Standard (44 mg/L $NO_3$). The distribution of nitrate concentrations in the study area is largely dependant on geochemical environments of alluvial aquifers. In particular, the decrease of redox potential of alluvial groundwaters showed a good correlation with the decreases of nitrate, iron, and manganese concentrations. Thus, the change of redox state in alluvial aquifers, likely reflecting their sedimentary environments, controls both the behavior and fate of nitrogen compounds and their natural attenuation (denitrification) in aquifers. A carbon-rich, silty layer within alluvium strata forms a reducing condition and possesses a buffering capacity on nitrate pollution.

• Journal of Korean Society of Environmental Engineers
• /
• v.34 no.3
• /
• pp.204-213
• /
• 2012

The objectives of this research were to estimate nitrogen budgets in agriculture and livestock in 2010, and to evaluate nitrous oxide ($N_2O$) emission by a local government. Input-output budgets for nitrogen were categorized into two sections including agriculture and livestock. Fertilizer, deposition, fixation, compost, irrigation, and feed were used as the nitrogen inputs while crop production, crop uptake, denitrification, volatilization, leaching, compost, and ocean disposal were used as the nitrogen outputs. Annual nitrogen input and output for agriculture and livestock were 1,148,848 N ton/yr and 610,380 N ton/yr respectively indicating the decrease of the nitrogen input and output, compared to our previous researches in 2005 and 2008. Total nitrogen input in 16 local government was estimated resulting that $N_2O$ emission was the highest for Jeonnam (2,574 ton/yr) and the lowest for Seoul (7 ton/yr).

• Journal of agriculture & life science
• /
• v.53 no.5
• /
• pp.153-165
• /
• 2019

This paper analyzes the priorities of introducing agricultural environmental conservation practices for the successful introduction of agricultural environmental conservation programs and promotes customized agricultural environment conservation practices packages suitable for the local environment. Agricultural environmental conservation practice consists of three fields: soil, water, and air, nine sub-fields, and 30 practice skills. Using the advantages of AHP and BWS appropriately for priority analysis, three areas and nine sub-fields are measured using AHP techniques, and the practical activities of each fields are measured by priorities using BWS techniques to enhance the differentiation and completeness of research. In addition, the criteria for evaluating priorities of practical activities used 'Environmental effectiveness' and 'Technical feasibility'. As a result of the priority evaluation, the 'Soil testing and reduction of fertilizer and livestock manure application' activities were evaluated as having the highest priority. Based on the results of the priorities for these practical activities, examples of customized practical activity packages by farming type and environmental conditions were presented.

• The Journal of Engineering Geology
• /
• v.32 no.4
• /
• pp.437-448
• /
• 2022

This work aims to assess the threat to human health of hazardous materials in groundwater that is used domestically and for drinking. Two distinct sub-assessments are considered: cancer and non-cancer risk. The studied groundwater is in an agricultural area of Gyeongnam Province, Korea, and is contaminated by arsenic at a mean level of 16.27 ㎍/L, far greater than the WHO guideline (10 ㎍/L for drinking water). We collected groundwater data from the National Groundwater Information Center (gims.go.kr) and assessed the risk to human health following the methodology of the United States Environmental Protection Agency. We considered three exposure scenarios: domestic use (scenario 1) and drinking use with different doses (scenarios 2 and 3). Scenario 1 had a median hazard quotient (HQ) of 0.77 and a cancer risk (CR) of 0.013. Scenario 2 had a median HQ of 0.08 and a CR of 3.69 × 10^-5, and the values for scenario 3 were 0.11 and 4.82 × 10^-5, respectively. Scenario 1 is likely the most hazardous to human health. Further study of the origin of arsenic in groundwater in the study area is required, as are remedial measures to mitigate its health effects.

• Proceedings of the Korea Water Resources Association Conference
• /
• 2020.06a
• /
• pp.252-252
• /
• 2020

대하천 주변 광역상수도 공급지역은 가뭄 발생시에도 안정적으로 물이용이 가능하나, 중소하천을 수원으로 하는 하천의 상류지역은 가뭄시 물공급 안정성이 취약하다. 따라서 중소하천을 대상으로 가뭄시 물 공급시설의 효율적 운영, 물부족 위험도 평가, 가용 수자원의 최적이용 등 종합적인 대책 마련을 위해서는 신뢰성 높은 수문량(하천유출량 및 수자원가용량) 예측이 필요하다. 기존의 가뭄시 하천유출량 예측정확도 평가는 통계적 회귀분석을 통한 가뭄지수 기반의 가뭄상황의 예측에 치중하여 불확실성이 크며 국내 유역의 복잡한 물이용체계를 고려하지 않아 시·공간적인 규모에 따라 상이한 결과를 나타내며 실측자료 기반의 하천유출량과 비교하면 정확도가 대부분 60% 이하로 나타난다(이상은 등, 2015). 본 연구에서는 상세 물이용체계를 고려한 정도높은 수자원가용량의 평가를 위하여 한강권역 내의 한탄강댐 상류 유역을 테스트베드로 선정하였다. 한탄강댐 상류유역은 다수의 복잡한 농업용 수리시설 운영에 따른 수자원가용량 예측정확도가 매우 낮은 지역으로 본 연구를 통해 정도 높은 수자원가용량 예측정확도를 확보하기에 적정한 유역이라 판단하였다. 수자원가용량을 평가하기 위한 모형은 한국건설기술연구원에서 개발된 CAT3.1(Catchment hydrologic cycle Assessment Tool 3.1)을 이용하였다. CAT 3.1은 중소하천 유역내의 인위적인 물이용체계(광역급수, 재이용, 지하수 취수, 하천수 취·배수 등)를 반영한 수문량(하천유출량 및 수자원가용량) 평가 및 예측이 가능한 모형으로 기존 개념적 매개변수 기반의 집중형 수문모형과 물리적 매개변수 기반의 분포형 수문모형의 장점을 최대한 집약하여 개발되었다. 한탄강댐 상류유역의 물리적 매개변수는 최대한 기 구축된 GIS 자료를 활용하여 추출하였다. 토지이용현황은 산림과 농업지역이 대부분을 차지하여 농업용수 공급이 대부분인 물이용체계를 가지고 있다. 따라서 한국농어촌공사에서 관리하는 11개 농업용 저수지에 대한 취수현황 및 제원, 국가지하수센터의 유역내 지하수사용량, 하폐수처리량을 기본 입력 자료로 사용하였다. 특히 농업용 저수지의 경우에는 저수지출구점을 기준으로 저수지 상류유역 및 한국농어촌공사에서 기 구축된 관개면적 공간자료를 기본으로 수혜구역을 세분화하여 모형을 적용하였다.

• Journal of Food Hygiene and Safety
• /
• v.22 no.4
• /
• pp.338-345
• /
• 2007

This study surveyed on the actual conditions of using sanitizers and disinfectants for improvements of sanitization on food utensils at 105 school and 20 industry foodservice operations. The questionnaire which was administered to 125 foodservices was used as a mail or visitation method. The answers of asking "Perception on temporary authorization system of sanitizers and disinfectants on food utensils" were 75% in contract managed school foodservices, 81.8% in self operated school foodservices, and 50% in industry. Main factors to choose sanitizers were sterilizing power (38.6%, 28.6%, 38.9%) and safety (32.6%, 46.1%, 33.3%) at every foodservices. Keeping ratio of sanitizers and disinfectants guidelines in contract managed school, self operated school and industry foodservices were 64.8%, 52% and 73.7%, respectively. If easy and practical guideline is developed, most foodservices replied to use if for disinfection of foodservices. Most of the foodservices were not only knowing sanitizers and disinfectants but also possessing a guideline. However, they didn't perform disinfection according to the guideline due to its complexity. Consequently, we suggest that it is necessary to provide an easy and practical "sanitizers and disinfectants guideline" and useful information.

• Korean Journal of Soil Science and Fertilizer
• /
• v.45 no.6
• /
• pp.1173-1178
• /
• 2012

Water competition among domestic, industrial and agricultural sectors has been gradually heightened recently in Korea as the lack of water supply is expected in the near future. About 46% of nation's water use is consumed in paddy farming to produce rice. And the conservation of water resource and quality in agricultural sector is a pending issue in the nation's long term water management plan. New paddy rice farming techniques that use significantly less irrigation water are urgently required. System of Rice Intensification (SRI) that is now well known to produce more rice with less water consumption has not been tried in Korea yet. And environmental effect of SRI on greenhouse gases (GHGs) has not been well investigated. The objective of this study was to measure the effect of SRI on GHGs as well as water use and rice yield in a Korean paddy condition. Three experimental runoff plots $5{\times}15m$ in size were prepared at an existing paddy field. Runoff, GHGs emission and water quality were measured during the 2011 growing seasons while a Japonica rice variety was cultivated. Rice plants grew better and healthier in SRI plots than in continuously flooded (CF) and intermittently drained (ID) plots. Rice yield from SRI plots increased 112.8 (ID)~116.1 (CF)% compared with CF and ID plots. Irrigation requirement of SRI plots compared to CF plot reduced by 52.6% and ID plot reduced by 62.0%, meaning that about 37.9~47.4% of irrigation water could be saved. GHGs emission from SRI plots reduced by 71.8% compared to that from CF plot and by 18.4% compared to that from ID plot, meaning that SRI could help contribute to ease the greenhouse gas accumulation in the atmosphere. It was believed that SRI is a promising paddy farming technique that could increase rice yield, and reduce irrigation water requirement and GHGs emission not just in Korea but also other rice farming countries all over the world. However, it was recommended that long term studies under different conditions including rice variety, soil texture, water source, climate need to be conducted for reliable data for the development of environmental policies related to GHGs emission control and management.