Current Issue 2020. Vol.39, Iss.1

Orginal Articles

• The Study of Soil Chemical Properties and Soil Bacterial Communities on the Cultivation Systems of Cnidium officinale Makino

  Kiyoon Kim, Kyeung Min Han, Hyun-Jun Kim, Kwon Seok Jeon, Chung Woo Kim, Chung Ryul Jung / Korean Journal of Environmental Agriculture / 2020 / v.39, no.1, 1-9

  https://doi.org/10.5338/KJEA.2020.39.1.1

  Abstract Full-Text PDF

  Abstract

  

  BACKGROUND:

  The aim of this study was to investigate the soil chemical properties and soil bacterial community of the cropping system for Cnidium officinale Makino.

  METHODS AND RESULTS:

  The bacterial community was analyzed for the relative abundance and principal coordinated analysis (PCoA analysis) by using by Illumina Miseq sequencing. The correlation analysis between soil chemical properties and soil bacterial community were analyzed by Spearman’s rank correlation and DISTLM analysis. Soil bacterial community (phylum and class) showed two distinct clusters consisting of cluster 1 (first cropping) and cluster 2 (continuous cropping) from 2 different cultivation methods of Cnidium officinale Makino. PCoA and DISTLM analyses showed that soil pH and Ca significantly affected soil bacterial community in cultivation area of Cnidium officinale Makino. In addition, Spearman’s rank correlation showed significant correlation between relative abundance (Acidobacteria and Actinobacteria) and soil factors (soil pH and Ca).

  CONCLUSION:

  The results of this study were considered to be important for determining the correlation between soil properties and soil bacterial community of the cropping method for Cnidium officinale Makino. Furthermore, the results will be helpful to investigate the cause of continuous cropping injury of the Cnidium officinale Makino by examining the changes of soil properties and soil bacterial communities.

• Risk Assessment about Heavy Metals Contamination in Agricultural Products at Abandoned Mine Area

  Jae-Min An, Soon-Young Chang, Hyang-Ran Hwang, Dae-Han Park, Bom-Nae Lee, Saet-Byeol Kim, Gwang-Hee Lee / Korean Journal of Environmental Agriculture / 2020 / v.39, no.1, 10-19

  https://doi.org/10.5338/KJEA.2020.39.1.2

  Abstract Full-Text PDF

  Abstract

  

  BACKGROUND:

  This study was to carry out risk assessment of contamination of cadmium (Cd), lead (Pb), and inorganic arsenic (I-As) in agricultural products of 25 crops from the abandoned mine areas. The 36 typical investigation sites located in Gyeongbuk provincial area were selected by considering the heavy metal levels, that had been known that the amount of the heavy metals exceeded the contamination level based on the previous survey.

  METHODS AND RESULTS:

  Cadmium, lead, and total arsenic (T-As) concentrations were determined using microwave device and ICP-MS. Inorganic arsenic was determined by HPLC-ICP-MS. The limits of quantification for heavy metals were 0.59 μg/kg for Cd, 0.42 μg/kg for Pb, 0.55 μg/kg for T-As, and sum of As (Ⅲ) (1.74 μg/kg) and As (Ⅴ) (2.25 μg/kg) for I-As, respectively. The contents of Cd, Pb, and I-As (only rice) were N.D.-0.958 mg/kg, N.D.-0.227 mg/kg, and 0.082 mg/kg, respectively, in the agricultural products. For risk assessment, dietary exposures of heavy metals through usual intake were 5.20×10^-4-7.15×10⁰ μg/day for Cd, 7.00×10^-5-7.75×10^-1 μg/day for Pb, and 1.17×10¹ μg/day for I-As, taking 0.01-14.37%, 0.01-2.05%, and 15.16% as risk indices, respectively.

  CONCLUSION:

  It requires to consider the critical levels of heavy metals in agricultural products due to unexpectedly high levels in a few places, while concentrations of heavy metals in the samples were relatively low in most areas.

• Melon Growth Enhancement by Fucoidan and Fucoidan Decomposing Bacteria

  Sohee Yang, Yeji Gil, Heejeong Oh, Yeonjong Koo / Korean Journal of Environmental Agriculture / 2020 / v.39, no.1, 20-25

  https://doi.org/10.5338/KJEA.2020.39.1.3

  Abstract Full-Text PDF

  Abstract

  

  BACKGROUND:

  Marine algae is a productive organism that is consumed as a nutritious food. However, large amounts of unused portions of the algae are incinerated as trash or dumped in the sea, causing pollution. Recycling algae is important for saving resources and conserving the environment. In this study, the fucoidan which is a major carbohydrate of marine algae was tested as a source of fertilizer for farming.

  METHODS AND RESULTS:

  The growth rate of the melon was examined after treating fucoidan and the melon growth factors, weight and length of stem were measured. To discover the mechanism of melon growth promotion of fucoidan, bacteria that decomposed fucoidan were isolated from soil and abalone. Bacillus wiedmannii and Stenotrophomonas pavanii were isolated from terrestrial soil and Pseudomonas sp. was isolated from abalone. Among these three bacteria, Pseudomonas sp. had the highest and most specific fucoidan-decomposing activity. When Pseudomonas sp. was treated with fucoidan on melon-growing soil, the growth of melon was relatively improved compared to the treatment with fucoidan alone.

  CONCLUSION:

  We found that fucoidan, the main carbohydrate of marine algae, promoted melon growth. Fucoidan-decomposing microorganisms were isolated from terrestrial soil and marine organism, and we found that these bacteria stimulated the effect of melon growth promotion of marine algae. This is the first report that confirms the fertilizer effect of marine algae and shows the use of bacteria with marine algae.

• Detection and Potential Abundances of Anammox Bacteria in the Paddy Soil

  Anamika Khanal, Seul Lee, Ji-Hoon Lee / Korean Journal of Environmental Agriculture / 2020 / v.39, no.1, 26-35

  https://doi.org/10.5338/KJEA.2020.39.1.4

  Abstract Full-Text PDF

  Abstract

  

  BACKGROUND:

  Microbes that govern a unique biochemical process of oxidizing ammonia into dinitrogen gas, such as anaerobic ammonium oxidation (anammox) have been reported to play a pivotal role in agricultural soils and in oceanic environments. However, limited information for anammox bacterial abundance and distribution in the terrestrial habitats has been known.

  METHODS AND RESULTS:

  Phylogenetic and next-generation sequencing analyses of bacterial 16S rRNA gene were performed to examine potential anammox bacteria in paddy soils. Through clone libraries constructed by using the anammox bacteria-specific primers, some clones showed sequence similarities with Planctomycetes (87% to 99%) and anammox bacteria (94% to 95%). Microbial community analysis for the paddy soils by using Illumina Miseq sequencing of 16S rRNA gene at phylum level was dominated by unclassified Bacteria at 33.2 ± 7.6%, followed by Chloroflexi at 20.4 ± 2.0% and Acidobacteria at 17.0 ± 6.5%. Planctomycetes that anammox bacteria are belonged to was 1.5% (± 0.3) on average from the two paddy soils.

  CONCLUSION:

  We suggest evidence of anammox bacteria in the paddy soil. In addition to the relatively well-known microbial processes for nitrogen-cycle, anammox can be a potential contributor on the cycle in terrestrial environments such as paddy soils.

• Assessment of Hydrochemistry and Irrigation Water Quality of Wicheon Watershed in the Gyeongsangbuk-do

  Gi-Chang Lee, Moung-Sub Park, Jae-Sik Kim, Tae-Kwon Jang, Hyo-Sun Kim, Hwa-Sung Lee, Jin-Chang Son / Korean Journal of Environmental Agriculture / 2020 / v.39, no.1, 36-43

  https://doi.org/10.5338/KJEA.2020.39.1.5

  Abstract Full-Text PDF

  Abstract

  

  BACKGROUND:

  Wicheon watershed has the largest irrigation area among the mid-watershed of Nakdong river. However, no investigation of irrigation water quality has been conducted on the Wicheon watershed, which evaluates the effects on the soil quality and crop cultivation. Therefore, this study aims to provide various assessments of water quality of Wicheon watershed as the scientific basic data for efficient agricultural activities.

  METHODS AND RESULTS:

  Water sampling was performed in five locations of the first tributaries of Wicheon. Wicheon watershed showed clean water quality with very low organic matters and safe water quality from metals at all points of investigation. It was estimated that the natural chemical components of Wicheon watershed were originated from water-rock interaction in Gibbs diagram. All samples were concentrated in the type of Ca-HCO₃-Cl in the Piper diagram. The quality of irrigation water was evaluated with sodium adsorption ratio (SAR), residual sodium carbonate (RSC), permeability index (PI), and percent sodium (%Na). The values of these water quality indices were in the range of 0.37-0.67, –2.11-–0.24, 41.13-84.52% and 11.28-21.84%, respectively, and were classified as good grades at all sites.

  CONCLUSION:

  The water quality of Wicheon watershed was very low in salt, indicating good irrigation water suitable for growing agricultural products. We hope that the results of this study will be used as the basic data for the cultivation of agricultural products and promotion of their excellence.

• A Study on Rapid Residual Analysis of Benzo(a)pyrene in Agricultural Products and Soils

  Hee-Gon Kim, Hun-Ju Ham, Kyong-Suk Hong, Hee-Chang Shin, Jang Hyun Hur / Korean Journal of Environmental Agriculture / 2020 / v.39, no.1, 44-49

  https://doi.org/10.5338/KJEA.2020.39.1.6

  Abstract Full-Text PDF

  Abstract

  

  BACKGROUND:

  Benzo(a)pyrene is a highly toxic substance which has been listed as a Group I carcinogen by the International Agency for Research on Cancer. There have been numerous studies by researchers worldwide on benzo(a)pyrene. Soxhlet, ultrasound-assisted, and liquid–liquid extractions have been widely used for the analysis of benzo(a)pyrene. However these extraction methods have significant drawbacks, such as long extraction time and large amount of solvent usage. To overcome these disadvantages, we aimed to establish a rapid residual analysis of benzo(a)pyrene content in agricultural products and soil samples.

  METHODS AND RESULTS:

  A Quick, Easy, Cheap, Effective, Rugged, and Safe (QuEChERS) method was used as the pretreatment procedure. For rapid residual analysis of benzo(a)pyrene, a modified QuEChERS method were used, and the best codition was demonstrated after various performing instrument analysis. The extraction efficiency of this method was also compared with Soxhlet extraction, the current benzo(a)pyrene extracting method. Although both methods showed high recovery rates, the rapid residual analysis method markedly reduced both the measurement time and solvent usage by approximately 97% and 96%, respectively.

  CONCLUSION:

  Based on these results, we suggest the rapid residual analysis method established through this study, faster and more efficient analysis of residual benzo(a)pyrene in major agricultural products such as rice, green and red chili peppers and also soil samples.

• Effects of Biochar on Early Growth and Nutrient Content of Vegetable Seedlings

  Sung-Chang Hong, Seon-Young Yu, Kyeong-Sik Kim, Gyu-Hyun Lee, Sae-Nun Song / Korean Journal of Environmental Agriculture / 2020 / v.39, no.1, 50-57

  https://doi.org/10.5338/KJEA.2020.39.1.7

  Abstract Full-Text PDF

  Abstract

  

  BACKGROUND:

  Biochar is used in various environmental fields, such as water quality and soil restoration, and affects soil fertility and nutrient cycling. Also, when crops are grown on biochar-applied soil, their characteristics may be affected. Biochar is used especially with commercial vegetable seedlings.

  METHODS AND RESULTS:

  The objective of this study was to determine the effects of biochar content in seeding mixes on early growth of lettuce (Lactuca sativa L.), Chinese cabbage (Brassica rapa L.), and red pepper (Capsicum annuum L.). Treatments consisted of a control (0: 10, ratio of biochar to seeding mixes (w/w)), 1: 9 (biochar 10%), 3: 7 (biochar 30%), 5: 5 (biochar 50%), and 7: 3 (biochar 70%). The biochar was made from risk husk and had a C/N ratio of 104. As the mixing ratio of biochar increased, pH increased whereas EC and nitrogen content decreased. The highest phosphorus content was with the treatment of 30% biochar, while there were significant increases in the weight of lettuce seedlings and concentrations of T-N, P₂O₅, K₂O, MgO, and Na with the treatments of 30% and 50% biochar. Although the weight of Chinese cabbage seedlings increased with the treatment of 10% biochar, the increase was not statistically significant. Also, there was an increase in the weight of red pepper seedlings with the treatment of 30% biochar, but the increase was not statistically significant. With increases in the biochar mixing ratio, the K₂O concentration of red pepper seedlings increased, but the concentrations of P₂O₅, CaO, MgO, and Na decreased. It was believed that this was because of absorption inhibition by calcium-phosphate formation in the seeding mixes owing to increased pH.

  CONCLUSION:

  In conclusion, adding biochar to seeding mixes is considered to be an important mean for growing healthy vegetable seedlings. More field experiments are needed to verify the effect of biochar on vegetable crop growth over the entire growing season.

• Degradation Characteristics of Non-degradable Dye in Aqueous Solution by Ozonation

  Se-Wook Hwang, Jong-Hwan Park, Su-Lim Lee, Ju-Hyun Eom, Sung-Ki Ryu, Ik-Won Choi, Seong-Heon Kim, Se-Won Kang, Ju-Sik Cho, Dong-Cheol Seo / Korean Journal of Environmental Agriculture / 2020 / v.39, no.1, 58-64

  https://doi.org/10.5338/KJEA.2020.39.1.8

  Abstract Full-Text PDF

  Abstract

  

  BACKGROUND:

  Most of the researches on the dye removal using ozonation have been focused on the removal efficiency. However, the research on their removal characteristics and mechanism according to the reaction time has been still insufficient.

  METHODS AND RESULTS:

  In this study, the effects of initial pH and dye concentration with reaction time on the degradation characteristics of methyl orange (MO) and methylene blue (MB) by ozonation were evaluated. The degradation efficiency of MB by ozonation increased with increasing pH. On the other hand, the degradation efficiency of MO by ozonation did not show a significant difference with varing pH. The both MO and MB by ozonation were decomposed within 30 min irrespective of the dye concentration, but the decomposition rates of dyes were faster at lower initial dye concentration. The decomposition efficiency of total organic carbon (TOC) in each dye solution by ozonation was low, which was found to be effective for partial decomposition such as decolorization rather than complete degradation of the dye.

  CONCLUSION:

  Overall, ozonation was an effective method for removing nondegradable dyes. However, it is necessary to study the optimization of dye degradation under various environmental conditions for ozonation.

• Effects of Tillage on Organic Matters and Microbial Communities in Organically Cultivated Corn Field Soils

  Dalrae Ahn, Nan-Hee An, Da-Hye Kim, Byeong-Hak Han, Jaehong You, InCheol Park, Jae-Hyung Ahn / Korean Journal of Environmental Agriculture / 2020 / v.39, no.1, 65-74

  https://doi.org/10.5338/KJEA.2020.39.1.9

  Abstract Full-Text PDF

  Abstract

  

  BACKGROUND:

  Soil carbon sequestration has been investigated for a long time because of its potential to mitigate the greenhouse effect. No- or reduced tillage, crop rotations, or cover crops have been investigated and practiced to sequester carbon in soils but the roles of soil biota, particularly microorganisms, have been mostly ignored although they affect the amount and stability of soil organic matters.

  METHODS AND RESULTS:

  In this study we analyzed the organic matter and microbial community in organically cultivated corn field soils where no-tillage (NT) or conventional tillage (CT) had been practiced for about three years. The amounts of organic matter and recalcitrant carbon pool were 18.3 g/kg dry soil and 4.1 g C/kg dry soil, respectively in NT soils, while they were 12.4 and 2.5, respectively in CT soils. The amounts of RNA and DNA, and the copy numbers of bacterial 16S rRNA genes and fungal ITS sequences were higher in NT soils than in CT soils. No-tillage treatment increased the diversities of soil bacterial and fungal communities and clearly shifted the bacterial and fungal community structures. In NT soils the relative abundances of bacterial phyla known as copiotrophs, Betaproteobacteria and Bacteroidetes, increased while those known as oligotrophs, Acidobacteria and Verrucomicrobia, decreased compared to CT soils. The relative abundance of a fungal phylum, Glomeromycota, whose members are known as arbuscular mycorrhizal fungi, was about two time higher in NT soils than in CT soils, suggesting that the higher amount of organic matter in NT soils is related to its abundance.

  CONCLUSION:

  This study shows that no-tillage treatment greatly affects soil microbial abundance and community structure, which may affect the amount and stability of soil organic matter.

• Residue Dissipation Patterns of Indoxacarb and Pymetrozine in Broccoli under Greenhouse Conditions

  Seung-Hyun Yang, Jae-In Lee, Hoon Choi / Korean Journal of Environmental Agriculture / 2020 / v.39, no.1, 75-82

  https://doi.org/10.5338/KJEA.2020.39.1.10

  Abstract Full-Text PDF

  Abstract

  

  BACKGROUND:

  This study was carried out to establish pre-harvest residue limits (PHRLs) of indoxacarb and pymetrozine in broccoli under greenhouse conditions, based on dissipation patterns and biological half-lives of pesticides during 10 days after application.

  METHODS AND RESULTS:

  The field studies were conducted in two different greenhouse, located in Chungju-si (Field 1) and Gunsan-si (Field 2). Samples were collected at 0, 1, 2, 3, 5, 7 and 10 days after spraying pesticide suspension. The analytical methods for indoxacarb and pymetrozine using HPLC-DAD were validated by recoveries ranging of 94.3-105.4% and 81.8-96.0%, respectively, and MLOQ (Method Limit of Quantification) of 0.05 mg/kg. Biological half-lives of indoxacarb and pymetrozine were 2.9 and 3.2-3.8 days in broccoli, respectively. The lower 95% confidence intervals of dissipation rate constant of indoxacarb were determined as 0.1508 (Field 1) and 0.2017 (Field 2), whereas those of pymetrozine were calculated as 0.1489 (Field 1) and 0.1577 (Field 2).

  CONCLUSION:

  The significant differences were not observed between the dissipation rates of indoxacarb and pymetrozine in broccoli. The major factor affecting residue dissipation was the dilution effect by fast growth. The PHRLs for 10 days prior to harvest were recommended as 30.06 (Field 1) and 18.07 (Field 2) mg/kg for indoxacarb, and 4.84 (Field 1) and 4.43 (Field 2) mg/kg for pymetrozine, respectively.