Current Issue 2019. Vol.38, Iss.4

Orginal Articles

• Effect of Agricultural Practice and Soil Chemical Properties on Community-level Physiological Profiles (CLPP) of Soil Bacteria in Rice Fields During the Non-growing Season

  Jinu Eo, Myung-Hyun Kim, Young Ju Song / Korean Journal of Environmental Agriculture / 2019 / v.38, no.4, 219-224

  https://doi.org/10.5338/KJEA.2019.38.4.30

  Abstract Full-Text PDF

  Abstract

  

  BACKGROUND:

  Soil bacteria play important roles in organic matter decomposition and nutrient cycling during the non-growing season. The purpose of this study was to investigate the effects of soil management and chemical properties on the utilization of carbon sources by soil bacteria in paddy fields.

  METHODS AND RESULTS:

  The Biolog EcoPlate was used for analyzing community-level carbon substrate utilization profiles of soil bacteria. Soils were collected from the following three types of areas: plain, interface and mountain areas, which were tested to investigate the topology effect. The results of canonical correspondence analysis and Kendall rank correlation analysis showed that soil C/N ratio and NH₄⁺ influenced utilization of carbon sources by bacteria. The utilization of carbohydrates and complex carbon sources were positively correlated with NH₄⁺ concentration. Cultivated paddy fields were compared with adjacent abandoned fields to investigate the impact of cultivation cessation. The level of utilization of putrescine was lower in abandoned fields than in cultivated fields. Monoculture fields were compared with double cropping fields cultivated with barley to investigate the impact of winter crop cultivation. Cropping system altered bacterial use of carbon sources, as reflected by the enhanced utilization of 2-hydroxy benzoic acid under monoculture conditions.

  CONCLUSION:

  These results show that soil use intensity and topological characteristics have a minimal impact on soil bacterial functioning in relation to carbon substrate utilization. Moreover, soil chemical properties were found to be important factors determining the physiological profile of the soil bacterial community in paddy fields.

• Hydroponic Nutrient Solution and Light Quality Influence on Lettuce (Lactuca sativa L.) Growth from the Artificial Light Type of Plant Factory System

  Jeong-Wook Heo, Kyeong-Hun Park, Seung-Gil Hong, Jae-Su Lee, Jeong-Hyun Baek / Korean Journal of Environmental Agriculture / 2019 / v.38, no.4, 225-236

  https://doi.org/10.5338/KJEA.2019.38.4.31

  Abstract Full-Text PDF

  Abstract

  

  BACKGROUND:

  Hydroponics is one of the methods for evaluating plant production using the inorganic nutrient solutions, which is applied under the artificial light conditions of plant factory system. However, the application of the conventional inorganic nutrients for hydroponics caused several environmental problems: waste from culture mediums and high nitrate concentration in plants. Organic nutrients are generally irrigated as a supplementary fertilizer for plant growth promotion under field or greenhouse conditions. Hydroponic culture using organic nutrients derived from the agricultural by-products such as dumped stems, leaves or immature fruits is rarely considered in plant factory system. Effect of organic or conventional inorganic nutrient solutions on the growth and nutrient absorption pattern of green and red leaf lettuces was investigated in this experiment under fluorescent lamps (FL) and mixture Light-Emitting Diodes (LEDs).

  METHODS AND RESULTS:

  Single solution of tomatoes (TJ) and kales (K) deriving from agricultural by-products including leaves or stems and its mixed solution (mixture ration 1:1) with conventional inorganic Yamazaki (Y) were supplied for hydroponics under the plant factory system. The Yamazaki solution was considered as a control. ‘Jeockchima’ and ‘Cheongchima’ lettuce seedlings (Lactuca sativa L.) were used as plant materials. The seedlings which developed 2~3 true leaves were grown under the light qualities of FL and mixed LED lights of blue plus red plus white of 1:2:1 mixture in energy ratio for 35 days. Light intensity of the light sources was controlled at 180 μ mol/m²/s on the culture bed. The single and mixture nutrient solutions of organic and/or inorganic components which controlled at 1.5 dS/m EC and 5.8 pH were regularly irrigated by the deep flow technique (DFT) system on the culture gutters. Number of unfolded leaves of the seedlings grown under the single or mixed nutrient solutions were significantly increased compared to the conventional Y treatment. Leaf extension of ‘Jeockchima’ under the mixture LED radiation condition was not affected by Y and YK or YTJ mixture treatments. SPAD value in ‘Jeockchima’ leaves exposed by FL under the YK mixture medium was approximately 45 % higher than under conventional Y treatment. Otherwise, the maximum SPAD value in the leaves of ‘Cheongchima’ seedlings was shown in YK treatment under the mixture LED lights. NO₃-N contents in Y treatment treated with inorganic nutrient at the end of the experiment were up to 75% declined rather than increased over 60 % in the K and TJ organic treatment.

  CONCLUSION:

  Growth of the seedlings was affected by the mixture treatments of the organic and inorganic solutions, although similar or lower dry weight was recorded than in the inorganic treatment Y under the plant factory system. Treatment Y containing the highest NO₃-N content among the considered nutrients influenced growth increment of the seedlings comparing to the other nutrients. However effect of the higher NO₃-N content in the seedling growth was different according to the light qualities considered in the experiment as shown in leaf expansion, pigmentation or dry weight promotion under the single or mixed nutrients.

• Effect of Incorporation of Hairy Vetch on Nitrous Oxide Emission from Soils Cultivated with Maize

  Hae Ri Han, Hyun Ho Lee1, Chang Oh Hong / Korean Journal of Environmental Agriculture / 2019 / v.38, no.4, 237-244

  https://doi.org/10.5338/KJEA.2019.38.4.32

  Abstract Full-Text PDF

  Abstract

  

  BACKGROUND:

  Impact of incorporating hairy vetch into soil on mitigating nitrous oxide (N₂O) emissions from maize field in South Korea has not been investigated, whereas impacts on soil properties and nutrients for crops have been investigated. Therefore, this study was conducted to examine N₂O emission from upland soil incorporated with hairy vetch for one year in maize field.

  METHODS AND RESULTS:

  Hairy vetch was grown in an upland soil from November, 2017 to May, 2018 and incorporated into soil on May 25 of 2018. Control and conventional treatment (NPK) were included for comparison. Gas samples were collected weekly for a year to examine N₂O emissions from the soil. Chemical nitrogen (N) fertilizer stimulated N₂O emission in short term resulting in the greatest cumulative N₂O emission in NPK (6.72 kg N₂O ha^-1) compared to the control (4.04 kg N₂O ha^-1) and hairy vetch-incorporated field (5.43 kg N₂O ha^-1), and the greatest yield of maize from NPK, because total N input was much greater by NPK (186 N kg ha^-1) than by hairy vetch (81.6 N kg ha^-1).

  CONCLUSION:

  Incorporation of hairy vetch reduced N₂O emissions from the maize compared to the NPK–treated field. However, further research on improving crop productivity with incorporation of hairy vetch is needed.

• Effect of Weathering of Bottom Ash on Mitigation of Green House Gases Emission from Upland Soil

  Do Young Heo, Chang Oh Hong / Korean Journal of Environmental Agriculture / 2019 / v.38, no.4, 245-253

  https://doi.org/10.5338/KJEA.2019.38.4.33

  Abstract Full-Text PDF

  Abstract

  

  BACKGROUND:

  Weathering of bottom ash (BA) might induce change of its surface texture and pH and affect physical and chemical properties of soil associated with greenhouse gas emission, when it is applied to the arable soil. This study was conducted to determine effect of weathering of BA in mitigating emission of greenhouse gases from upland soil.

  METHODS AND RESULTS:

  In a field experiment, methane (CH₄), carbon dioxide (CO₂), and nitrous oxide (N₂O) emitted from the soil was periodically monitored using closed chamber. Three month-weathered BA and non-weathered BA were applied to an upland soil at the rates of 0, 200 Mg ha^-1. Maize (Zea mays L.) was grown from July 1_st to Oct 8_th in 2018. Both BAs did not affect cumulative CH₄ emission. Cumulative CO₂ emission were 23.1, 19.8, and 18.8 Mg/ha/100days and cumulative N₂O emission were 35.8, 20.9, and 17.7 kg/ha/100days for the control, non-weathered BA, and weathered BA, respectively. Weathering of BA did not decrease emission of greenhouse gases significantly, compared to the weathered BA in this study. In addition, both BAs did not decrease biomass yields of maize.

  CONCLUSION:

  BA might be a good soil amendment to mitigate emissions of CO₂ and N₂O from arable soil without adverse effect on crop productivity.

• Microbiological Quality of Agricultural Water in Jeollabuk-do and the Population Changes of Pathogenic Escherichia Coli O157:H7 in Agricultural Water Depending on Temperature and Water Quality

  Injun Hwang, Hyeonheui Ham, Daesoo Park, Hyobeen Chae, Se-Ri Kim, Hwang-Yong Kim, Hyun Ju Kim, Won-Il Kim / Korean Journal of Environmental Agriculture / 2019 / v.38, no.4, 254-261

  https://doi.org/10.5338/KJEA.2019.38.4.34

  Abstract Full-Text PDF

  Abstract

  

  BACKGROUND:

  Agricultural water is known to be one of the major routes in bacterial contamination of fresh vegetable. However, there is a lack of fundamental data on the microbial safety of agricultural water in Korea.

  METHODS AND RESULTS:

  We investigated the density of indicator bacteria in the surface water samples from 31 sites collected in April, July, and October 2018, while the groundwater samples were collected from 20 sites within Jeollabuk-do in April and July 2018. In surface water, the mean density of coliform, fecal coliform, and Escherichia coli was 2.7±0.55, 1.9±0.71, and 1.4±0.58 log CFU/100 mL, respectively, showing the highest bacterial density in July. For groundwater, the mean density of coliform, fecal coliform, and E. coli was 1.9±0.58, 1.4±0.37, and 1.0±0.33 log CFU/ 100mL, respectively, showing no significant difference between sampling time. The survival of E. coli O157:H7 were prolonged in water with higher organic matter contents such as total nitrogen (TN), and nitrate-nitrogen (NO₃-N). The reduction rates of E. coli O157:H7 in the water showed greater in order of 25, 35, 5, and 15℃.

  CONCLUSION:

  These results can be utilized as fundamental data for prediction the microbiological contamination of agricultural water and the development of microbial prevention technology.

• Estimation of Nitrogen Mineralization of Organic Amendments Affected by Nitrogen Content in Upland Soil Conditions

  Jin-Soo Lim, Bang-Hyun Lee, Seung-Hee Kang / Korean Journal of Environmental Agriculture / 2019 / v.38, no.4, 262-268

  https://doi.org/10.5338/KJEA.2019.38.4.35

  Abstract Full-Text PDF

  Abstract

  

  BACKGROUND:

  To investigate mineralization characteristics of organic resources in the soil, five materials (rice straw, cow manure sawdust compost, microorganism compost, mixed oil-cake, and amino acid fertilizer) were treated according to the nitrogen content, and an indoor incubation experiment was conducted for 128 days. The results of this analysis were applied to determine the nitrogen mineralization pattern of these organic resources.

  METHODS AND RESULTS:

  During the constant temperature incubation period, the nitrogen net mineralization rate of the organic resources was the highest in the amino acid fertilizer with the highest nitrogen content, and the lowest in the rice straw with the lowest nitrogen content. A positive correlation (0.96) was observed between the potential nitrogen mineralization rate and total nitrogen content. The mineralization rate constant, k, was negatively correlated with the organic matter (-0.96) and carbon content (-0.97). The nitrogen mineralization rate during the first cropping season, as estimated by the model, was 6.6%, 11.6%, 30.9%, 70.7%, and 81.0% for the rice straw, the cow manure sawdust compost, the microorganism compost, the mixed oil-cake, and the amino acid fertilizer, respectively.

  CONCLUSION:

  The nitrogen mineralization rate varies depending on the type of organic resources or the nitrogen content; thus, it can be used as an index for determining the nitrogen supply characteristics of the organic resource. Organic resources such as compost with low nitrogen content or those undergoing fermentation contain organic nitrogen. Organic nitrogen is stabilized during the composting process. Therefore, as the nitrogen mineralization rate of these resources is lower than that of non-fermented organic resources, it is desirable to use the fermented organic materials only to improve soil physical properties rather than to supply nutrients for the required amount of fertilizer.

• Investigating Survival of Erwinia amylovora from Fire Blight-Diseased Apple and Pear Trees Buried in Soil as Control Measure

  Ye Eun Kim, Jun Young Kim, Hyeong Jin Noh, Dong Hyeung Lee, Su San Kim, Seong Hwan Kim / Korean Journal of Environmental Agriculture / 2019 / v.38, no.4, 269-272

  https://doi.org/10.5338/KJEA.2019.38.4.36

  Abstract Full-Text PDF

  Abstract

  

  BACKGROUND:

  Since 2015, fire blight disease caused by Erwinia amylovora has been devastating apple and pear orchards every year. To quickly block the disease spreading, infected apple and pear trees have been buried in soil. However, concern on the possibility of the pathogen survival urgently requires informative data on the buried host plants. Therefore, this study was conducted to investigate the survival of the pathogen from the buried host plants.

  METHODS AND RESULTS:

  Apple trees buried in 42 months ago in a Jecheon site and pear trees buried in 30 months ago in an Anseong site were excavated using an excavator. Plant samples were taken from stems and twigs of the excavated trees. The collected 120 samples were checked for rotting and used for bacterial isolation, using TSA, R2A, and E. amylovora selection media. The purely isolated bacteria were identified based on colony morphology and 16S rDNA sequences. Wood rotting and decay with off smells and discoloring were observed from the samples. A total of 17 genera and 48 species of bacteria were identified but E. amylovora was not detected.

  CONCLUSION:

  Our investigation suggests that the survival of E. amylovora doesn’t seem possible in the infected hosts which have been buried in soil for at least 30 months. Therefore, the burial control can be considered as a safe method for fire blight disease.

• Soil Chemical Properties of Reclaimed Tide Lands Under Government Management in Korea: Results of 4-years monitoring

  Jin-Hee Ryu, Su-Hwan Lee, Yang-Yeol Oh, Jeong-Tae Lee / Korean Journal of Environmental Agriculture / 2019 / v.38, no.4, 273-280

  https://doi.org/10.5338/KJEA.2019.38.4.37

  Abstract Full-Text PDF

  Abstract

  

  BACKGROUND:

  The reclaimed lands for agricultural use managed by the Korean government is consisted of 17,145 hectares of lands under construction and 13,384 hectares of completed lands. In order to utilize these reclaimed lands as competitive agricultural complexes, the government is preparing to develop comprehensive development plans for multiple purposes. For rational land-use planning and soil management, information of the soil chemical properties is necessary.

  METHODS AND RESULTS:

  From 2013 to 2016, soil samples were collected from 85 representative sampling sites of the reclaimed lands and analyzed for soil chemical properties including electric conductivity (EC), pH, soil organic matter (SOM), and nutrients. The annual mean soil EC ranged from 5.1 to 8.3 dS m^-1 and have continued to decrease over the years (estimation equation with EC as dependent and year as independent variable was y = 0.0736x² - 1.4985x + 9.8305, R² = 0.9753). The pH ranged from 7.3 to 7.6, which was higher than the optimum range (5.5~7.0) for agricultural soils. Soil organic matter (8 to 11 g kg^-1) was lower level than the optimum range (20~30 kg^-1). Available silicate (Av.SiO₂) ranged from 169 to 229 mg kg^-1, which was close to the minimum content (≥157 mg kg^-1) for rice paddy field. Available phosphate (Av.P₂O₅) content (24~39 mg kg^-1) was lower than the optimum range (80~120 mg kg^-1) for rice paddy field.

  CONCLUSION:

  For efficient agricultural use of reclaimed lands under government management, our results suggest that the application of organic matter and supplying deficient nutrients as well as desalinization is required.

• Variation of Pesticide Residues in Strawberries by Washing and Boiling Processes

  Se-Yeon Kwak, Sang-Hyeob Lee, Hye-Rin Jeong, Ae-Ji Nam, Aniruddha Sarker, Hyo-Young Kim, Chae-Uk Lim, Hyun-Jeong Cho, Jang-Eok Kim / Korean Journal of Environmental Agriculture / 2019 / v.38, no.4, 281-290

  https://doi.org/10.5338/KJEA.2019.38.4.38

  Abstract Full-Text PDF

  Abstract

  

  BACKGROUND:

  As the demand for strawberries increases, people are paying attention to food safety in strawberry, especially pesticide residues. To remove the pesticides from strawberry, various washing and processing technique in households are additionally required.

  METHODS AND RESULTS:

  Strawberries were washed with water, detergent, alcohol, and ultrasonication and processed to strawberry jam. The mean reduction efficiency according to the washing solvent and method was found to be higher in the order of detergent (42.5%) > alcohol (41.7%) > water (41.3%) > ultrasoniation with alcohol (40.2%) > ultrasoniation with water (38.6%) > ultrasoniation with detergent (36.9%), but there was no significant difference among the treatments. The residue levels of pesticides during processing to jam decreased by 11.9-94.4% for etoxazole, fluopyram, procymidone, spiromesifen, and prochloraz, while the other pesticides were concentrated by boiling, or rather increased by 11.8-40.2%. However, when the residue levels were converted to residual amounts in consideration of the change in weight after processing, the residual amounts of the tested pesticides were reduced by 59.8-98.4% during processing. The processing factor (PF) were different for each pesticide, but PFs were < 1 for all washing solvents and methods, and 0.06-1.40 when processed into jam.

  CONCLUSION:

  To ensure the consumption of pesticide-free strawberry, the most efficient washing method is to immerse the strawberry in fresh water for few minutes, followed by rinsing them under running water.

• Application of Molybdenum Enhances Nitrogen Fixation and Transfer, and Biomass Production under a Hairy Vetch/Barley Mixture Cropping System

  Tae-Young Kim, Song-Yeob Kim, Young Eun Yoon, Jang Hwan Kim, Yong Bok Lee / Korean Journal of Environmental Agriculture / 2019 / v.38, no.4, 291-295

  https://doi.org/10.5338/KJEA.2019.38.4.39

  Abstract Full-Text PDF

  Abstract

  

  BACKGROUND:

  Mixed cropping of hairy vetch and Barley is widely used as a green manure for reducing chemical fertilizers while maintaining soil fertility in paddy soil. We investigated the effect of Molybdenum (Mo) fertilizer on vetch N₂ fixation, biomass production and transfer N from vetch to barley under a hairy vetch-barley mixed cropping system.

  METHODS AND RESULTS:

  The barley and hairy vetch were sowed at a rate of 135 and 23 kg/ha, respectively, without chemical fertilizer application but with Mo fertilizer at 0, 0.5, 1.0, 2.0, and 4.0 kg/ha as a treatment. The percentage of hairy vetch N derived from air N₂ fixation (%Ndfa) and N transfer from hairy vetch to barley (%Ndfv) was determined by the ¹⁵N natural abundance method. Although application of Mo at 2.0 kg/ha significantly increased biomass of both barley and hairy vetch, the biomass was decreased at application of Mo 4.0 kg/ha. At the application of Mo 2.0 kg/ha, the percentage of Ndfa and Ndfv was 81.7 and 53.9, respectively, which are significantly higher than that of the treatments without Mo.

  CONCLUSION:

  These results highlight that application of Mo fertilizer can be an effective measures to improve N fixation in hairy vetch and biomass production in both barley and hairy vetch.

• Transciptomic Analysis of Larval Fat Body of Plutella xylostella under Low Temperature

  Kwang-Ho Kim, Dae-Weon Lee / Korean Journal of Environmental Agriculture / 2019 / v.38, no.4, 296-306

  https://doi.org/10.5338/KJEA.2019.38.4.40

  Abstract Full-Text PDF

  Abstract

  

  BACKGROUND:

  Temperature is known to be the main factor affecting development, growth and reproduction of organisms and also a physical factor directly related to insect survival. Insects as ectothermal species should be responsive to climate changes for their survival and develop various survival strategies under the unfavorable temperature such as low temperature. The purpose of this study is to identify genes contributing to adaptation of low temperature.

  METHODS AND RESULTS:

  To identify genes contributing to adaptation of low temperature, the transcriptomic data were obtained from fat body in Plutella xyostella larvae via next generation sequencing. We identified structural proteins, heat shock proteins, antioxidant enzymes, detoxification proteins, and cryoprotectant mobilization and biosynthesis-related proteins. Genes encoding chitinase, cuticular protein, Hsp23, chytochrome protein, Glutathione S transferase, and phospholipase 2 were up-regulated under low temperature. Proteins related to energy metabolism such as UDP-glycosy ltransferase, trehalase and trehalose transporter were downregulated.

  CONCLUSION:

  When insect pests were exposed to low temperature, changes in gene expression of fat body could provide some hints for understanding temperature adaptation strategies.

• The Performances of Sediment Trap for Reducing Water Pollutants and Soil Loss from Rainfall Runoff in Cropland

  Se-In Park, Hyun-Jin Park, Han-Yong Kim / Korean Journal of Environmental Agriculture / 2019 / v.38, no.4, 307-313

  https://doi.org/10.5338/KJEA.2019.38.4.41

  Abstract Full-Text PDF

  Abstract

  

  BACKGROUND:

  An intensive farming system may be of the most important source for agricultural non-point source (NPS) pollution, which is a major concern for agricultural water management in South Korea. Various management practices have therefore been applied to reduce NPS loads from upland fields. This study presents performances of sediment trap for reducing NPS and soil loss from rainfall runoff in cropland.

  METHODS AND RESULTS:

  In 2018 and 2019, three sediment traps (L1.5 m × W1.0 m × D0.5 m = 0.75 m³) and their controls were established in the end of sloped (ca. 3%) upland field planted with maize crops. Over the seasons, runoff water was monitored, collected, and analyzed at every runoff. Soils deposited in sediment traps were collected and weighed at the season end. Sediment traps reduced runoff amount (p<0.05) and NPS concentrations, though the decreased NPS concentrations were not always statistically significant. In addition, sediment traps had a significant prevention effect on soil loss from rainfall runoff in a sloped cropland.

  CONCLUSION:

  The results suggest that the sediment trap could be a powerful and the best management practice to reduce NPS pollution and soil loss in a sloped upland field.

• Effect of the Harvest Season on the Yield and Growth of Unripe Fruit and Biennial Flowering of ‘Miyagawa’ Satsuma Mandarin in Open Field Cultivation

  Seok-Beom Kang, Young-Eel Moon, Kyung-Rok Yankg, Jae-Ho Joa, Hae-Jin Lee / Korean Journal of Environmental Agriculture / 2019 / v.38, no.4, 314-320

  https://doi.org/10.5338/KJEA.2019.38.4.42

  Abstract Full-Text PDF

  Abstract

  

  BACKGROUND:

  As consumption of unripe mandarin increases, its cultivation has increased in open field cultivation areas. Because unripe mandarin must be harvested before ripening and color change, the optimum harvest time must be determined. This study investigated the effect of the harvest season on the yield of unripe fruit and biennial flowering of ‘Miyagawa’ satsuma mandarin.

  METHODS AND RESULTS:

  Two areas of unripe mandarin orchard were selected, and the yield, fruit growth, working time, and flowering of trees the following year were investigated. Fruit was harvested at 40, 60, 80, 100, and 120 days after full bloom and at general ripening. Fruit yield of unripe mandarin increased with later harvest time from 100^th to 120^th day except normal ripening. The next year, biennial occurred with normal ripening and harvesting, but not at the 120^th day after full bloom. At the 40^th day (earliest harvest time), summer and autumn shoots were present, but not after the 100^th day. The 40^th day required the most harvesting time; because the time gradually decreased with later harvest, the harvest time was shortest on the 120^th day, and general ripening occurred shortly after the 120^th day.

  CONCLUSION:

  Harvesting of unripe mandarin 100–120 days after full bloom was ideal to reduce harvesting time, enhance yield, and enable flowering the following year.

• Study for Residue Analysis of Pinoxaden in Agricultural Commodities

  Ji Young Kim, Eun Kyung Yoon, Jong Soo Kim, Nu Ri Seong, Sang Soon Yun, Yong Hyun Jung, Jae Ho Oh, Hyochin Kim / Korean Journal of Environmental Agriculture / 2019 / v.38, no.4, 321-331

  https://doi.org/10.5338/KJEA.2019.38.4.43

  Abstract Full-Text PDF

  Abstract

  

  BACKGROUND:

  Pinoxaden is the phenylpyrazoline herbicide developed by Syngenta Crop Protection, Inc. and marketed on 2006. The maximum residue levels for wheat and barley were set by import tolerance. Thus, Ministry of Food and Drug Safety (MFDS) official analytical method determining Pinoxaden residue was necessary in various food matrixes. Satisfaction of international guideline of CODEX (Codex Alimentarius Commission CAC/GL 40) and National Institute of Food and Drug Safety Evaluation-MFDS (2017) are additional pre-requirements for analytical method. In this study, liquid chromatography-tandem mass spectrometry (LC-MS/MS) method was investigated to analyze residue of Pinoxaden (M4), which is defined as pesticide residue in Korea, in foods.

  METHODS AND RESULTS:

  Pinoxaden (M4) was extracted followed by acid digestion (2hr reflux with 1N HCl) and pH adjusting (pH 4-5 with 3% ammonium solution). To remove oil, additional clean-up step with hexane saturated with acetonitrile was required to high oil contained sample before purification. HLB cartridge and nylon syringe filter were used for purification. Then, samples were analyzed by LC-MS/MS using reserve phase column C₁₈. Five agricultural group representative commodities (mandarin, potato, soybean, hulled rice, and red pepper) were used to verify the method in this study. The liner matrix-matched calibration curves were confirmed with coefficient of determination (r²) > 0.99 at calibration range 0.002-0.2 mg/kg. The limits of detection and quantitation were 0.004 and 0.01 mg/kg, respectively, which were suitable to apply Positive List System (PLS). Mean average accuracies of pinoxaden (M4) were shown to be 74.0-105.7%. The precision of pinoxaden and its metabolites were also shown less than 14.5% for all five samples.

  CONCLUSION:

  The method investigated in this study was suitable to CODEX (CAC/GL 40) and National Institute of Food and Drug Safety Evaluation-MFDS (2017) guideline for residue analysis. Thus, this method can be useful for determining the residue in various food matrixes in routine analysis.

• The Effect of Food Waste Compost on Tomato (Lycoperscion Esculentum.L) Growth and Soil Chemical Properties

  Young Don Lee, Khalid Abdallah Huseein, Jae Hong Yoo, Jin Ho Joo / Korean Journal of Environmental Agriculture / 2019 / v.38, no.4, 332-337

  https://doi.org/10.5338/KJEA.2019.38.4.44

  Abstract Full-Text PDF

  Abstract

  

  BACKGROUND:

  From year 2005, landfill for food waste has been prohibited. Also, according to London agreement in year 2013, ocean discharge for livestock manure, sewage sludge, and food waste has been regulated. Alternative way for food waste disposal is incineration. However, due to high moisture content, additional input for energy is needed. Therefore, effective way for food waste disposal such as application of food waste compost is needed.

  METHODS AND RESULTS:

  Seven different treatments (livestock compost, food waste compost, food waste + livestock compost, livestock compost + chemical fertilizer, food waste compost + chemical fertilizer, food waste + livestock compost + chemical fertilizer and control) were applied to tomato crop. All treatments were replicated with completely randomized design. Tomato growth treated with LC+NPK showed the highest values at 6 weeks for all parameters such as leaf length (11.80 cm), leaf width (6.88 cm), and chlorophyll (61.12 O.D.), compared to other treatments. Subsequently the FWC+LC+NPK treatment was followed (11.51 cm, 6.40 cm, 59.50 O.D. for leaf length, leaf width, and chlorophyll, respectably). EC, OM contents, and CEC in the soil treated with the composts significantly increased.

  CONCLUSION:

  To evaluate the effect of food waste compost application on tomato growth and soil chemical properties, we carried out field experiment treated with 7 treatments with 3 replicates. The LC+NPK treatment showed highest values for all parameters. Some parameters such as shoot length and total length for tomato were not significantly different between the LC+NPK and the FWC+LC+NPK treatments.

• Occurrence of Pesticide Residues in Han River Basin in 2012 and 2014

  Chan-Sub Kim, Hee-Dong Lee, Kyeong-Ae Son, Eun-Young Lee, Jin-A Oh / Korean Journal of Environmental Agriculture / 2019 / v.38, no.4, 338-351

  https://doi.org/10.5338/KJEA.2019.38.4.45

  Abstract Full-Text PDF

  Abstract

  

  BACKGROUND:

  To investigate distribution and seasonal variation of concentration and flux of pesticides in Han river basin, water samples were examined at 24 sites in 2012 and 2014.

  METHODS AND RESULTS:

  Water samples were collected four times per year and subjected to liquid-liquid partition extraction followed by GC-ECD/NPD analysis. Of fifteen pesticides detected, iprobenfos, diazinon, isoprothiolane, endosulfan sulfate and oxadiazon were detected in a higher frequency, while fenoxanil, carbofuran, fenitrothion, butachlor and metolachlor were only detected in a sample. Pesticides with high occurrences, iprobenfos, diazinon, isoprothiolane, endosulfan sulfate and oxadiazon were detected in residue level of 0.01-0.46, 0.01-0.24, 0.03-0.85, 0.02-0.06 and 0.05-0.24 μg/L, respectively. Carbofuran and acetanilide herbicides were found at lower frequencies, but their concentrations were one order of magnitude higher than those of the others.

  CONCLUSION:

  Discharge of pesticides in downstream area were mainly contributed from rice farming and suburban horticulture, while pesticide occurrences in upstream area, such as Donggang river basin were caused by highland agriculture for cabbage and potato production. Despite the influx of pesticides from tributaries through intensive agriculture areas, pesticide concentration in the main stream water was low due to the dilution effect from the upstream. Therefore, the water quality was considered to be good at the most downstream, the effluent of Paldang dam.