Korean Journal of Environmental Agriculture

Current Issue 2023. Vol.42, Iss.3

Orginal Articles

• Survey of Antibiotic Resistant Bacteria in Lake Gyeongpo, Korea

  Dukki Han / Korean Journal of Environmental Agriculture / 2023 / v.42, no.3, 169-176

  https://doi.org/10.5338/KJEA.2023.42.3.20

  Abstract Full-Text PDF

  Abstract

  

  The emergence and spread of antibiotic-resistant bacteria have been increasing with anthropogenic contamination. Understanding the prevalence and distribution of these resistant bacteria in environments is crucial for effectively managing anthropogenic pollutants. Lake Gyeongpo in the Gangwon Province of South Korea is known for its diverse ecological features and human interactions. The lake is exposed to pollutants from nonpoint sources, including urban areas, agricultural practices, and recreational activities, which can introduce antibiotics and foster antibiotic resistance in bacteria. The present study investigates Lake Gyeongpo as a potential reservoir for antibiotic-resistant bacteria in a natural ecosystem. A total of 203 bacterial isolates were collected from six sampling locations in Lake Gyeongpo during May, July, and November 2022. Most isolates were taxonomically identified as Pseudoalteromonas, Bacillus, Shewanella, and Vibrio spp.; their abundance showed a spatiotemporal distribution. An antibiotic susceptibility test was conducted on 75 isolates using the disk diffusion method with six drugs according to the CLSI guideline; 42 isolates were resistant to one or more antibiotics. Among these, 15 isolates were identified as multidrug resistant bacteria. This finding suggests the potential anthropogenic impact on Lake Gyeongpo and provides valuable insights into the dissemination of antibiotic resistance caused by anthropogenic pollutants.

• Application Effect of Rendering Livestock Carcass-Based Carbonized Material in Chinese Cabbage Cultivation

  Tae-Uk Jeong, Jae-Hoon Lee, Jun-Suk Rho, Dong Yeol Lee, Jeong-Min Lee, Jong-Hwan Park, Dong-Cheol Seo / Korean Journal of Environmental Agriculture / 2023 / v.42, no.3, 177-183

  https://doi.org/10.5338/KJEA.2023.42.3.21

  Abstract Full-Text PDF

  Abstract

  

  Rendering, is attracting attention as a technology that can stably and quickly process livestock carcasses. However, large amounts of livestock carcass solid residues are discharged in this process and limited methods are available for recycling them. In this study, rendered animal carcass solid residues were pyrolyzed to produce carbonized materials (350℃; RACR-C) and their chemical properties were investigated. Further, RACR-C were applied to cabbage cultivation for investigating their crop growth characteristics and soil improvement effects. RACR-C contained large amounts of fertilizer components such as nitrogen and phosphorus, and showed no toxic effects on the seedling growth of crops. The content of water-soluble nutrients released from RACR-C under the reaction time increased rapidly within 30 min, but was insignificant compared to the total content. Thus, most fertilizer components in RACR-C were not readily soluble in water. The optimal application amount for applying RACR-C to cabbage cultivation based on the changes in cabbage growth, inorganic content, and soil chemistry was 200 kg/10a. Overall, pyrolysis of solid residues after rendering livestock carcass to produce carbonized material as a soil improver is an effective method to recycle the waste discharged from the rendering process.

• Sorption Characteristics of Procymidone and 3,5-Dichloroaniline on Microplastic Films

  Ji Won Yang, Youn-Jun Lee, Eun Hea Jho / Korean Journal of Environmental Agriculture / 2023 / v.42, no.3, 184-192

  https://doi.org/10.5338/KJEA.2023.42.3.22

  Abstract Full-Text PDF

  Abstract

  

  Microplastics are generated by the breakdown of plastic wastes in agricultural soil and residual pesticides in agricultural soil can adsorb on microplastics. In this study, the sorption characteristics of procymidone (PCM) and one of its metabolites, 3,5-dichloroaniline (DCA), on low-density polyethylene (LDPE) and polyvinyl chloride (PVC) microplastics were investigated. The sorption and desorption tests were carried out for 72 h using LDPE or PVC microplastic films to study the sorption isotherms of PCM and DCA and kinetics for sorption and desorption of PCM. The results show that the sorption data of PCM and DCA were better described by the Freundlich isotherm model (R2=0.7568-0.9915) than the Langmuir isotherm model (R2=0.0545-0.5889). The sorption potential of PVC for both PCM and DCA was greater than that of LDPE. The sorption data of PCM on PVC and LDPE were fitted better to the pseudo-second-order kinetic model than the pseudo-first-order kinetic model. The PCM sorption on LDPE was about three times faster than that on PVC. Both microplastic films released the sorbed PCM back to water, and more PCM was released from PVC than LDPE, but the desorption rate was faster with LDPE than PVC. Overall, the results show that different microplastics have different sorption characteristics for different chemicals. Also, the sorbed chemicals can be released back to environment suggesting the potential of contaminant spread by microplastics. Thus, the management practices of microplastics in agricultural soil need to consider their interaction with the chemical contaminants in soil.

• Residue Monitoring and Dietary Risk Evaluation of Fungicide Propiconazole in Leafy Vegetables under Greenhouse Conditions

  Lawal Abdulkareem, Ji-Eun Oh, Se-Yeon Kwak, Sang-Hyeob Lee, Jae-Won Choi, Aniruddha Sarker, Kee Sung Kyung, Tae Hwa Kim, Jang-Eok Kim / Korean Journal of Environmental Agriculture / 2023 / v.42, no.3, 193-202

  https://doi.org/10.5338/KJEA.2023.42.3.23

  Abstract Full-Text PDF

  Abstract

  

  Residue monitoring of propiconazole (PCZ) in cabbage, shallot, and spinach was conducted under multi-trial greenhouse conditions. This study aimed to understand the fate of the applied fungicide in these vegetables. Furthermore, the associated health risk of PCZ in leafy vegetables was assessed through dietary risk assessment. Commercially available PCZ (22% suspension concentrate) was administered thrice according to the OECD fungicide application interval guideline. The plant samples were extracted using a slightly modified QuEChERS technique and analyzed using gas chromatography-tandem mass spectrometry. The average PCZ recovery was between 84.5% and 117.6%, with a <5% coefficient of variance. The dissipation of PCZ residue in cabbage, shallot, and spinach after 14 days was 96%, 90%, and 99%, respectively, with half-lives of <5 days. Meanwhile, dietary risk assessments of PCZ residues in the studied vegetables using the risk quotient (RQ) were significant < 100 (RQ < 100). Thus, the population groups considered in this study were not at substantial risk from consuming leafy vegetables sprayed with PCZ following critical, good agricultural practices.

• Column Comparison for the Separation of Ferimzone Z and E Stereoisomers and Development of Trace Residue Analysis Method in Brown Rice Using HPLC-MS/MS

  Mun-Ju Jeong, So-Hee Kim, Hye-Ran Eun, Ye-Jin Lee, Su-Min Kim, Jae-Woon Baek, Yoon-Hee Lee, Yongho Shin / Korean Journal of Environmental Agriculture / 2023 / v.42, no.3, 203-210

  https://doi.org/10.5338/KJEA.2023.42.3.24

  Abstract Full-Text PDF

  Abstract

  

  Ferimzone Z is a fungicide for effectively controlling rice blast. Under light irradiation conditions, it undergoes a rapid conversion to its E-stereoisomer. Given the importance of isomers in risk assessments of residues in crops, an analytical method was developed for individual isomer quantification. A comparative analysis performed using two columns in HPLC-MS/MS demonstrated that the isomers were successfully separated using the Cadenza column. For the brown rice sample preparation, 5 g of the homogenized sample was saturated with 7 mL of water. The sample was then extracted with a 10 mL mixed solvent of acetonitrile and ethyl acetate (1:1, v/v) that contained 0.1% formic acid, and it was subsequently partitioned with magnesium sulfate and sodium chloride. The upper layer was purified using dSPE containing C18 and PSA sorbents. The established method was subjected to method validation, and it showed recovery rates of 90.6-98.8% (RSD ≤ 3.9%) at concentrations of 0.01, 0.1, 2 mg/kg, with a soft matrix effect (%ME) ranging from -3.1% to +6.5%. his method can be employed in monitoring studies of brown rice to determine the conversion ratio from the Z isomers to the E isomers.

• Nutrient Balance during Crop (Forage Barley) Cultivation in Winter Season: A Weighing Lysimeter Study

  Jin-Hee An, Chan-Wook Lee, Jung-Hun Ok, Hye-Jin Pack, Yo-Sung Song, Ye-Jin Lee / Korean Journal of Environmental Agriculture / 2023 / v.42, no.3, 211-219

  https://doi.org/10.5338/KJEA.2023.42.3.25

  Abstract Full-Text PDF

  Abstract

  

  Nutrient balance is an environmental indicator for assessing the potential of sustainable agriculture. Improving the use of arable land is crucial for reducing the nutrient balance. This study monitored soil water content, seepage water, crop growth, and nutrient balance in weighing lysimeters during forage barley (Hordeum vulgare L., “Yeongyang”) cultivation from October to April. The study was conducted from 2020 to 2022, and the treatments included forage barley cultivation (clay loam, CL-FC; sandy loam, SL-FC) and bare soils. During the regeneration period (March to April), the soil moisture contents of bare and forage barley-cultivated soils were approximately 30-40% and 18.1-21.8%, respectively. The daily evapotranspiration of forage barley was 6.09 mm. The nitrogen balances for SL-FC and CL-FC were -0.43 to -2.93 g m^-2 and -0.79 to 0.75 g m^-2, respectively, which can be attributed to the higher nutrient uptake of forage barley in SL-FC than in CL-FC. Consequently, the forage barley cultivation in SL-FC can potentially reduce nutrient leaching during the spring rainy season. Furthermore, nutrient balance can be reduced by cultivating forage crops during the winter season.

• Evaluation of Total Residues of Imidacloprid in Livestock Products from Domestic Markets by using a Simultaneous Analytical Method Based on QuEChERS

  Seung Won Lee, Ji Hyun Yoon, Ji Yu Kim, Da Jung Lim, Hyung Wook Jo, Joon Kwan Moon, Hye-Min Gwak, Hee-Ra Chang, In Seon Kim / Korean Journal of Environmental Agriculture / 2023 / v.42, no.3, 220-230

  https://doi.org/10.5338/KJEA.2023.42.3.26

  Abstract Full-Text PDF

  Abstract

  

  Imidacloprid is a neonicotinoid insecticide widely used for insect control in a variety of crops. The evaluation of imidacloprid total residues in animal feeds derived from crop by-products is required to ensure the safety of livestock products. We performed simultaneous LC/MS/MS analyses of imidacloprid and its metabolites in five different livestock products including beef, pork, chicken, milk and egg from domestic markets. The methods for sample preparation and instrumental analysis were established by modifying QuEChERS method to meet the Codex guidelines. The methods generated 0.0035 mg/kg of the limit of determination (LOD), 0.01 mg/kg of the limit of quantitation (LOQ) and standard calibration linearity with >0.983 of the coefficients of determination (R²). The methods exhibited the recovery values of imidacloprid and its metabolites ranging from 65.66 to 119.27% without any interference between matrices. Imidacloprid total residues in the livestock products were found as values lower than the LOQ and maximum residue limits (MRLs). This study suggests that the methods are successfully applicable for the safety evaluation of imidacloprid total residues in livestock products from domestic markets.

• Variation of CO₂ Concentration in Greenhouses and Effects on Growth and Yield in Alstroemeria with CO₂ Supplementation

  Seonjin Lee, WonSuk Sung, Donguk Park, Pilsoo Jeong / Korean Journal of Environmental Agriculture / 2023 / v.42, no.3, 231-238

  https://doi.org/10.5338/KJEA.2023.42.3.27

  Abstract Full-Text PDF

  Abstract

  

  We analyzed the variations in the CO₂ concentration and temperature between a CO₂-enriched and control greenhouse. We cultivated Alstroemeria ‘Hanhera’ in the two greenhouses and assessed the growth parameters (stem length, stem thickness, and the number of flowers) and yield. The CO₂-enriched greenhouse had a CO₂ generator that produced CO₂ at rate of 0.36 kg/h and its windows were programmed to open when the temperature exceeded 20℃ and close when it dropped below 15℃. The control greenhouse had no additional CO₂ supplementation, and its windows were programmed to open when the temperature exceeded 20℃ and close at approximately 17:00. In the morning, CO₂ concentration remained above 500 ppm in the CO₂-enriched greenhouse, which was higher than that in the control greenhouse (approximately 370 ppm). The ventilation effect only through the side windows to reduce the temperature in both greenhouses did not appear dynamically. CO₂ supplementation promoted plant growth, resulting in a significant increase in plant yield of over 60% compared to that of the control greenhouse. Our findings suggest that elevated CO₂ concentration in the morning can significantly promote the growth and development of Alstroemeria during the winter.

• Influence of M.7 Apple Rootstock on Productivity and Fruit Quality of High Density ‘Fuji’, ‘Hongro’ and ‘Sansa’ Apple Trees

  Young Soon Kwon, Jeong-Hee Kim, Dong-Hoon Sagong, Jong Taek Park / Korean Journal of Environmental Agriculture / 2023 / v.42, no.3, 239-252

  https://doi.org/10.5338/KJEA.2023.42.3.28

  Abstract Full-Text PDF

  Abstract

  

  Most apple trees in South Korea are grafted on M.9 and M.26 rootstocks; however, these rootstocks are susceptible to fire blight. Although M.7 rootstocks are moderately resistant to fire blight, they tend to exhibit excessive vigor, which is unsuitable for high-density planting, unless weak cultivars are used. This study investigated the vegetative growth, yield, and fruit quality of apple trees grafted onto M.7, M.9, or M.26 rootstocks to assess the feasibility of establishing high-density apple orchards domestically using the M.7 rootstock a period of seven years (1-7 years after planting). Rootstocks were tested using three cultivars with contrasting induced vigor and harvesting times: vigorous and late-maturing ‘Fuji,’ moderate vigor and middle-maturing ‘Hongro,’ and low vigor and early-maturing ‘Sansa.’ The planting density was maintained constant, with 190 trees per 10 a. Primary thinning (leaving only the king fruit on clusters) was performed, whereas secondary thinning (controlling crop load) was not. Vegetative growth, accumulated yield per 10 a, and yield efficiency varied depending on cultivars and rootstocks; however, the cultivars had a more notable effect on fruit quality than the rootstocks. Biennial bearing often occurred in the M.26 rootstock. ‘Fuji’/M.7 was overly vigorous for high-density planting. The fruit quality and accumulated yield per 10 a of M.7 were similar to those of M.9 with the ‘Hongro’ and ‘Sansa’ cultivars. In particular, ‘Hongro’/M.7 did not show tree vigor reduction due to heavy crop load, and the degree of biennial bearing in ‘Sansa’/M.7 was not particularly high. These results indicated that high-density apple planting using the M.7 rootstock was achievable using the ‘*Corresponding author: Dong-Hoon Sagong Hongro’ and ‘Sansa’ cultivars.

• Reduction of Hexavalent Chromium by Shewanella sp. HN-41 in the Presence of Ferric-Citrate

  Hyemin Park, Jin-Hyeob Kwak, Ji-Hoon Lee / Korean Journal of Environmental Agriculture / 2023 / v.42, no.3, 253-258

  https://doi.org/10.5338/KJEA.2023.42.3.29

  Abstract Full-Text PDF

  Abstract

  

  In the environment, chromium often exists in a highly mobile and toxic form of Cr(VI). Therefore, the reduction of Cr(VI) to less toxic Cr(III) is considered an effective remediation strategy for Cr(VI)-contamination. In this study, the biological reduction of hexavalent chromium was examined at the concentrations of 0.01 mM, 0.1 mM, and 1 mM Cr(VI) by the dissimilatory metal-reducing bacterium, Shewanella sp. HN-41 in the presence of ferric-citrate. With the relatively condensed cell densities, the aqueous phase Cr(VI) was reduced at the proportions of 42%, 23%, and 31%, respectively for the 0.01 mM, 0.1 mM, and 1 mM Cr(VI) incubations, while Fe(III)-citrate was reduced at 95%, 88%, and 73%, respectively. Although the strain HN-41 was not considered to reduce Cr(VI) as the sole electron acceptor for anaerobic metabolism in the preliminary experiment, it has been presumed that outer-membrane c-type cytochromes such as MtrC and OmcA reduced Cr(VI) in the presence of ferric-citrate as the electron acceptor. Since this study indicated the potential of relatively high cell density for Cr(VI) reduction, it might propose a bioremediation strategy for Cr(VI) removal from contaminated waters using engineered systems such as bioreactors employing high cell growths.