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Korean Journal of Environmental Agriculture

p-ISSN 1225-3537
e-ISSN 2233-4173

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Current Issue 2017. Vol.36, Iss.2 Cover image Contents list Print articles

Orginal Articles

  • Effects of Alternative Crops Cultivation on Soil Physico-chemical Characteristics and Crop Yield in Paddy Fields

    Kyunghwa Han, Hyunjun Cho, Heerae Cho, Hyubsung Lee, Junghun Ok, Mijin Seo, Kangho Jung, Yongseon Zhang, Youngho Seo / Korean Journal of Environmental Agriculture / 2017 / v.36, no.2, 67-72

    https://doi.org/10.5338/KJEA.2017.36.2.11
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    BACKGROUND:

    Cultivation of alternative crops in paddy fields is necessary because of the decrease in rice consumption and the increase in excess stock of rice. The studywas conducted to investigate the effects of alternative crops cultivation in paddy fields on soil physico-chemical characteristics and crop yield.

    METHODS AND RESULTS:

    Soybean (Glycine max), red-clover (Trifolium pratense), and water convolvulus (Ipomoea aquatica) were selected for alternative crops in the first and/or second year and ricewas planted in the third year.When alternative cropswere cultivated in the previous year, soil bulk density, soil hardness, and water content were lower than those for rice cultivation. Water-depth decreasing rate and aggregate content were greater for the upland-upland-paddy cropping system than upland-paddy-paddy cropping system. Cultivation of red-clover andwater convolvulus for two years resulted in the high soil organic matter content. In the third year, available phosphate, exchangeable potassium, and soil cation exchange capacity were relatively high when soybean was cultivated in the previous year. In the first year, water convolvulus cultivation showed greater productivity than red-clover cultivation while the opposite pattern was found in the second year. Rice yield in the third year was greater for soybean or red-clover as a previous crop than for water convolvulus as a previous crop.

    CONCLUSION:

    The results suggest that cultivation of alternative crops in paddy fields can improve soil physical properties including bulk density, hardness, water content, and aggregate content as well as rice productivity.

  • Decreases Nitrous Oxide Emission and Increase Soil Carbon via Carbonized Biomass Application of Orchard Soil

    Sun-il Lee, Gun-yeob Kim, Eun-jung Choi, Jong-sik Lee, Hyun-cheol Jung / Korean Journal of Environmental Agriculture / 2017 / v.36, no.2, 73-79

    https://doi.org/10.5338/KJEA.2017.36.2.13
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    BACKGROUND:

    Carbonized biomass is a carbon-rich solid product obtained by the pyrolysis of biomass. It has been suggested to mitigate climate change through increased carbon storage and reduction of greenhouse gas emission. The objective of this studywas to evaluate carbon dioxide (CO2) and nitrous oxide (N2O) emissions from soil after carbonized biomass addition.

    METHODSANDRESULTS:

    The carbonized biomasswas made froma pyrolyzer, which a reactorwas operated about 400~500 for 5 hours. The ℃ treatmentswere consisted of a control without input of carbonized biomass and two levels of carbonized biomass inputs as 6.06Mg/ha for CB-1 and 12.12 Mg/ha for CB-2. Emissions of CO2 and N2O from orchard soil were determined using closed chamber for 13 weeks at 25℃of incubation temperature. Itwas shown that the cumulative CO2 were 209.4 g CO2/m2 for CB-1, 206.4 g CO2/m2 for CB-2 and 214.5 g CO2/m2 for the control after experimental periods. The cumulative CO2 emission was similar in carbonized biomass input treatment compared to the control. Itwas appeared that cumulativeN2Oemissions were 4,478 mg N2O/m2 for control, 3,227 mg N2O/m2 for CB-1 and 2,324 mg N2O/m2 for CB-2 at the end of experiment. Cumulative N2Oemission contents significantly decreased with increasing the carbonized biomass input.

    CONCLUSION:

    Consequently the carbonized biomass frombyproducts such as pear branch residue could suppress the soil N2O emission. The results fromthe study imply that carbonized biomass can be utilized to reduce greenhouse gas emission from the orchard field.

  • Sediment Toxicity Assessment of Pesticides using Chironomus riparius Acute and Chronic Effect

    Jung-eun Park, Eun-Jin Hwang, Hee-Ra Chang / Korean Journal of Environmental Agriculture / 2017 / v.36, no.2, 80-86

    https://doi.org/10.5338/KJEA.2017.36.2.18
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    BACKGROUND:

    Pesticides is exposed in an aquatic environment and effected to benthic animals. Especially, sediment-associated pesticides is required for determination of sediment toxicity on aquatic organisms. This study was conducted to evaluate the impact of six pesticides (chlorfluazuron, difenoconazole, dithianon, flufenoxuron, flutianil, pendimethalin) on Chironomus riparius in aquatic ecosystems.

    METHODSANDRESULTS:

    Chlorfluazuron, difenoconazole, dithianon, flufenoxuron, flutianil and pendimethalin were used as a model compounds, which have a sediment-associated potential (Koc>3). Acute and chronic toxicity tests on Chironomus riparius were performed at six concentrations of each pesticidewith four replicates of each based onOECDtest guideline 235 and 218. The calculated 48-h EC50 values of chlorfluazuron, flutianil, pendimethalin, difenoconazole, dithianon and flufenoxuron were 6.72, 2.55, 2.27, 0.77, 0.30 and 0.11 mg/L, respectively. Flufenoxuronwas the lowest 48-h EC50 value in this study. TheNoObserved EffectiveConcentration (NOEC) and the Lowest Observed Effect Concentration (LOEC) of flufenoxuron for Chironomus riparius in 28-days test were 30 and 60 μg/kg, respectively.

    CONCLUSION:

    Pesticides of the sediment-associated have the potential effect for Chironomus riparius in aquatic ecosystems. Therefore, sediment toxicity assessment of these pesticides should be further investigated to evaluate the impact to benthic organisms.

  • Comparison of Flavonoid Characteristics between Blueberry (Vaccinium corymbosum) and Black Raspberry (Rubus coreanus) Cultivated in Korea using UPLC-DAD-QTOF/MS

    Young Jin Kim, Heon-Woong Kim, Min-Ki Lee, Seon-Hye Lee, Hwan-Hee Jang, Yu-Jin Hwang, Jeong-Sook Choe, Sung-Hyun Lee, Youn-Soo Cha, Jung-Bong Kim / Korean Journal of Environmental Agriculture / 2017 / v.36, no.2, 87-96

    https://doi.org/10.5338/KJEA.2017.36.2.14
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    BACKGROUND:

    The objective of this study was to identify and compare the main phenolic compounds (anthocyanins, flavonoids, phenolic acids) in blueberry and black raspberry cultivated in Korea using ultra-performance liquid chromatography –diode array detection–quadrupole time-of-flight mass spectrometry (UPLC-DAD-QTOF/MS).

    METHODS AND RESULTS:

    Twenty-nine flavonoids were identified by comparison of ultraviolet and mass spectra with data in a chemical library and published data. Blueberry contained flavonols including kaempferol, quercetin, isorhamnetin, myricetin, and syringetin aglycones. Isorhamnetin 3-O-robinobioside, kaempferol 3-O-(6''-Oacetyl) glucoside, quercetin, quercetin 3-O-arabinofuranoside (avicularin), quercetin 3-O-(6''-O-malonyl) glucoside, and quercetin 3-O-robinobiosidewere detected for the first time in blueberry. The flavonoids in raspberry consisted of quercetin aglycone and its glycosides. The mean total flavonoid content in blueberry [143.0mg/100 g dryweight (DW)]was 1.5-times that in raspberry (95.4mg/100 gDW). The most abundant flavonoid in blueberry was quercetin 3-O-galactoside (hyperoside, up to 76.1 mg/100 g DW) and that in raspberry was quercetin 3-O-glucuronide (miquelianin, up to 55.5 mg/100 g DW). Miquelianin was not detected in blueberry.

    CONCLUSION:

    Flavonol glycosides were the main flavonoids in blueberry and black raspberry cultivated in Korea. The composition and contents of flavonoids differed between blueberry and black raspberry, andmay be affected by the cultivar and cultivation conditions.

  • Effects of Water Stress on Carotenoid and Proline Contents in Kale (Brassica oleracea var. acephala) leaves

    Hyo-Joon Lee, Jin-Hyuk Chun, Sun-Ju Kim / Korean Journal of Environmental Agriculture / 2017 / v.36, no.2, 97-105

    https://doi.org/10.5338/KJEA.2017.36.2.16
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    BACKGROUND:

    Environmental stress has amajor effect on the growth and yields of vegetables, and can significantly affect nutritionally important phytochemicals, causing large economic losses.

    METHODS AND RESULTS :

    The present study was aimed at exploring the effects of water stress on the carotenoid and proline contents in kale leaves to understand drought tolerance of kale plants. Kale was randomly divided into two groups at 57 days after sowing (DAS).One of the groups was well-watered (WW) and the other was water stressed (WS). Harvesting of kale leaves was started one day after treatment (58DAS) and continued for 10 days (~67DAS).We investigated the status of plant growth (leaf number, length,width, freshweight) of kale throughout the study.Carotenoid (lutein, α-carotene, zeaxanthin, β-carotene) and proline contents were analyzed by high-performance liquid chromatography (HPLC). Our results showed that the total carotenoid contents ranged from 926.0 to 1,212.0 mg/kg dry wt. (at 3 and 2 days, respectively) in WW treatment and 887.8 to 1,157.4 mg/kg dry wt. (at 10 and 4 days, respectively) inWS treatment. The ratio of individual carotenoid to the total carotenoid contents of kale leaves was 51.4 for lutein, 4.44 for zeaxanthin, 2.76 for α-carotene, and 41.4% for β-carotene. Total carotenoid contents showed a significant reduction from7 days (1,037.2mg/kg dry wt.) to 10 days (887.8mg/kg dry wt.) inWS treatment. The lutein content did not show a significant difference in WWbetween 7 and 10 days after treatment but showed a significant difference in WS treatment. The α-carotene content showed no significant difference between the treatments.However, zeaxanthin contentwas higher during 4–10 days and β-carotene content was lower during 6–10 days inWS than inWWon each harvest day. InWW, the proline content showed no significant difference, but in WS, the proline content started to increase at 7 days and almost doubled in 10 days.

    CONCLUSION :

    The marked increase in zeaxanthin and proline contents in kale leaves indicated that the two phytochemicals are associatedwith drought tolerance in the plant.

  • Effect of Cold Stress on Carotenoids in Kale Leaves (Brassica oleracea)

    So-Jung Hwang, Jin-Hyuk Chun, Sun-Ju Kim / Korean Journal of Environmental Agriculture / 2017 / v.36, no.2, 106-112

    https://doi.org/10.5338/KJEA.2017.36.2.19
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    BACKGROUND:

    Kale (Brassica oleracea) biosynthesizes various phytochemicals including glucosinolates, flavonoids, and carotenoids. Phytochemicals of plants are influenced by light, temperature, carbon dioxide, and growing conditions. Specifically, carotenoids are affected by temperature, light, and oxygen. The aim of this study was to investigate the effect of cold stress (day/night: 25℃/20℃, 20℃/15℃, 15℃/10℃) on carotenoids in kale leaves.

    METHODS AND RESULTS:

    Kale was grown in pots for up to 50 days after sowing (DAS) in a greenhouse. For cold acclimation experiments, kale grown in growth chambers for 3 days andwas subjected to low temperature for 4 days. The conditionsmaintained in the growth chamberswere as follows: photoperiod, 12/12 h (day/night); light, fluorescent; and relative humidity, 60%. Carotenoid (lutein, α-carotene, zeaxanthin, β-carotene) contents were analyzed by high-performance liquid chromatography (HPLC). The total carotenoid content gradually increased during cold acclimation for 3 days. When kale was subjected to cold stress, the total carotenoid content was high at 25℃/20℃ treatment, but low at 15℃/10℃ treatment. The total carotenoid content of kale leaves continuously grown in greenhouse decreased from50 to 57DAS (1,418 and 1,160 mgkg-1 drywt., respectively). The lutein, α-carotene, and β-carotene contents were very low and the zeaxanthin contentswere very high at 15℃/10℃treatment.When kale was subjected to cold stress, the ratio of individual to the total carotenoid contents of kale leaves was 4553% for -carotene and 210% for zeaxanthin.

    CONCLUSION:

    The β-carotene and zeaxanthin contents in kale leaves indicate their sensitiveness toward cold stress.

  • Comparison of Solidification Pre-treatment Methods for the Determination of δ13C of Dissolved Organic Carbon:

    Byeong-Jun Jeon, Hyun-Jin Park, Woo-Jung Choi, Yong-Se Park, Sang-Mo Lee, Kwang-Sik Yoon / Korean Journal of Environmental Agriculture / 2017 / v.36, no.2, 113-118

    https://doi.org/10.5338/KJEA.2017.36.2.12
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    BACKGROUND:

    The carbon (C) isotope ratio (δ13C) of dissolved organic C (DOC) is an indicator of water pollution source. In this study, the potential use of two pre-treatments for the δ13C analysis, alkaline persulfate oxidation coupledwith carbonate precipitation (precipitation) and freeze drying (drying), were compared to suggest a more feasible pre-treatment method.

    METHODS AND RESULTS:

    Two reference materials with different δ13C values were used for the experiments; chemical grade glucose (-12.0±0.02‰) and pig manure compost extract (-23.3±0.04‰). In the precipitation method, themeasured δ13C values were consistently lower than the theoretically calculated values as dissolved CO2 could not be removed due to the alkaline property of the reagents and the dissolution of air CO2 into the alkaline solution. The dryingmethod also resulted inmore negative δ13C than the calculated δ13C; however, the difference was systematic (3.9±0.3‰) and therewas a strong correlation (δ13Ccalculated=0.87×δ13Cmeasured-0.624, r2=0.98) between the calculated andmeasured δ13C. Calibration of δ13Cusingthe relationship between the calculated and themeasured δ13C values produced reliable and accurate δ13C values.

    CONCLUSION:

    Our results suggest that the dryingmethod is more accurate pre-treatment method to minimize the influence of air CO2 compared to the precipitationmethod for the determination of δ13C of DOC.

  • Arsenic Speciation and Risk Assessment of Miscellaneous Cereals by HPLC-ICP-MS

    Jae-Min An, Kyong-Suk Hong, Sung-Youn Kim, Dae-Jung Kim, Ho-Jin Lee, Hee-Chang Shin / Korean Journal of Environmental Agriculture / 2017 / v.36, no.2, 119-128

    https://doi.org/10.5338/KJEA.2017.36.2.20
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    BACKGROUND:

    Miscellaneous cereal have been largely consumed in Korea as due to their physiological functions beneficial to human health. The cereals are currently a social concern because they have been found to contain heavymetals. Thus,monitoring heavymetals in the cereals is an important requirement for food safety analysis. In this study, we determined arsenic concentration in the cereals randomly harvested from different markets.

    METHODS AND RESULTS:

    Inorganic arsenic was determined by ICP-MS coupled with HPLC system. The HPLC-ICP-MS analysis was optimized based on the limit of detection and recover test to reach 0.13-1.24 μg/kg and 94.3–102.1%, respectively. The concentrations of inorganic arsenic equivalent to daily exposure were levels of 19.91 μg/day inmixed grain, 1.07 μg/day in glutinous rice, 0.77 μg/day in black brown rice, 0.13 μg/day in barley and 0.11 μg/day in soybeans.

    CONCLUSION:

    The levels of arsenic in miscellaneous cerealswere found lower than the recommended The Joint FAO/WHOExpert Committee on FoodAdditives (JECFA) levels, suggesting that the cerealsmarketed inKorea are not potential concern in risk assessment.

  • Phylogeny of Marine Yeasts Isolated from Coastal Seawater in the East Sea of Korea

    Il-Seok Chin, Yong-Hwan Kim, Won-Kap Yun, Nyun-Ho Park, Jong-Shik Kim / Korean Journal of Environmental Agriculture / 2017 / v.36, no.2, 129-134

    https://doi.org/10.5338/KJEA.2017.36.2.17
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    BACKGROUND:

    Yeasts are used in a variety of industries. However,most industries are biased toward Saccharomyces cerevisiae ; so we sought to explore non-conventional yeasts (NCY). This study aimed to isolate yeasts from seawater collected from the East Sea of Korea and to analyze the NCY.

    METHODS AND RESULTS:

    We first collected seawater and performed pure isolation using four kinds of medium (GPY, DOB+CSM,DG18, and SCG). In total, 314 strains and 17 genera were isolated by ITS sequencing, including Aureobasidium pullulans (236 strains), Cryptococcus (19 strains), Cystobasidium (18 strains), and Rhodotorula (9 strains). Upon in-depth analysis, A. pullulans, the most dominant genus (236 strains), was divided into Group II (147 strains), Unknown I (8 strains), and Unknown II (49 strains).

    CONCLUSION:

    In this study, a total of 314 strains were isolated from seawater; many of these yeasts have been found and reported in seawater previously. In-depth analysis of A. pullulans, showed the dominance of Group I (21 strains) and Group II (147 strains).We also discovered Unknown I (8 strains) and Unknown II (49 strains), which have not been reported previously.

  • Endophytic Yeasts Colonize Roots of Ulmus parvifolia Jacq. and Quercus salicina Blume

    Jong-Shik Kim, Dae-Shin Kim / Korean Journal of Environmental Agriculture / 2017 / v.36, no.2, 135-139

    https://doi.org/10.5338/KJEA.2017.36.2.15
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    BACKGROUND:

    Identification and characterization of endophytic yeasts inhabiting the roots of Ulmus parvifolia Jacq. and Quercus salicina Blume require biotechnological and culture-based techniques.

    METHODS AND RESULTS:

    Homogenized U. parvifolia and Q. salicina root sampleswere spread onto four types of agar medium containing ancgtibiotics, L-sorbose, and Triton X-100. In total, 25 yeast strains were isolated and subjected to phylogenetic analysis based on their internal transcribed spacer region sequences. The results revealed that the yeast genera Cyberlindnera (12 isolates) and Cryptococcus (1 isolate) were associated with roots of U. parvifolia; and the genera Rhodotorula (8 isolates), Trichosporon (3 isolates), and Kluyveromyces (1 isolate) were associated with roots of Q. salicina. Additionally, a Kluyveromyces isolate produced a detectable level of bioethanol. The yeast strains reported hereinmay be used in industrial production of biosurfactants and bioethanol.

    CONCLUSION:

    Our findings revealed that the endophytic yeast genera Cyberlindnera and Cryptococcus predominated in roots of U. parvifolia; and the genera Rhodotorula (8 isolates), Trichosporon (3 isolates), and Kluyveromyces (1 isolate) predominated in roots of Q. salicina. Additionally, Kluyveromyces isolates produced a detectable level of bioethanol.