p-ISSN 1225-3537e-ISSN 2233-4173
Yeonhee Lee, Gnu Nam, Hyesung Yeom, Bokyeong Kim, Changhyun Shin, Jae-Young Kim / Korean Journal of Environmental Agriculture / 2024 / v.43, 1-10
Abstract
This study was performed to evaluate the potential damage caused by a chemical accident through the analysis of off-site consequence (OCA) and the presence of ammonia residues in crops. The assessment of OCA was carried out for worst-case and alternative-case scenarios. To determine the ammonia residues in crops, samples were collected from both sweetpotato (SW) and wormwood (WW) crops in 9 separate groups within the affected area, and the ammonium levels were quantified using ion chromatography. As a result of the OCA, for the worst- and alternative-case scenarios, the impact distances were estimated at 1.6 km and 666 m from the accident site, respectively. In the impacted zone, SW samples exhibited ammonia concentrations ranging from 69.6 to 218.0 mg/kg, which were up to 16.9 times higher than those in the unaffected areas. Meanwhile, WW samples in both the worst- and alternative-case scenarios showed lower ammonia, with concentrations varying from 62.2 to 77.8 mg/kg and 49.0 to 67.8 mg/kg, respectively. These results indicate that the ammonium residue in crops outside the affected area is at least 49 mg/kg due to the inherent ammonium in plants, the application of nitrogen fertilizer, and various nitrogen sources. Thus, it may not be possible to predict the actual impact range accurately. However, the simultaneous assessment of OCA and the residue analysis offers valuable insights into the initial contamination levels of the accident-affected area.
Jae-Hyun Park, Gyu-Hyeon Park, Dong-Hoon Sagong / Korean Journal of Environmental Agriculture / 2024 / v.43, 11-21
In grape nursery stock production, grafting success and nursery quality depend on the grafting materials, method, attention paid to grafting, grafting time, ambient conditions, and post-transplanting management. Recently, various grafting methods have been employed in grapevine propagation. This study aimed to determine the most effective grafting methods for producing high-quality grape nursery stock of ‘Campbell Early’/3309C. Grafting operations were conducted in early April using four grafting techniques, i.e., tongue grafting, veneer grafting, cleft grafting, and omega machine grafting. The data showed that the omega machine grafting was fast and yielded a high proportion of nursery stock for sale. Tongue grafting resulted in the highest grafting success, tree height, and percentage of nursery stock for sale and special grade nursery stock. The veneer grafting produced a high shoot diameter and a low percentage of low grade (unsaleable in Korea) nursery stock. The percentage of low-grade nursery stock and the expected yield of low-grade nursery trees were high in both tongue and cleft grafting. Based on the results from this study, the most effective grafting method of grape ‘Campbell Early’/3309C nursery stock in the nursery production company was the veneer grafting or omega machine grafting.
Jin-Ho Kim, Jong-Sik Lee, Kyu-Hyun Park, Chan-Wook Lee, Sung-Chang Hong, Min-Wook Kim, Hye-Min Lee / Korean Journal of Environmental Agriculture / 2024 / v.43, 22-31
Short Lived Climate Forcers (SLCF) are substances with relatively short lifetime in the atmosphere. Recently, it has become an object of attention, because SLCF such as black carbon (BC), methane (CH4), tropospheric ozone (O3), and hydrofluorocarbons (HFCs) have a warming effect on climate, and some of them have detrimental impacts on human health and agriculture. In this study, it is necessary to provide basic data for establishing countermeasures in the agricultural sector against ozone, and the emission characteristics of ozone evaluated through various existing studies. As SLCF, the Radiative Forcing from increases in tropospheric ozone is estimated to be 0.35±0.15 Wm–2. Ozone damages photosynthesis, plant structure and function, as well as productivity. A common symptom of ozone injury is small stipple-like lesions on the leaf surface. Recently matured leaves are more susceptible than very young and old leaves. The optimum condition for ozone formation are high temperature and solar radiation, low relative humidity and wind speed. With these condition, early summer before the rainy season will be the worst time in Korea. It is important to understand the pollution level of ozone and various problems, which will be brought with climate change. It will be another element for agricultural management in the future.
Keon Sang Ryoo / Korean Journal of Environmental Agriculture / 2024 / v.43, 32-51
The soil in north Gyeongsangbuk-do is mostly made up of sand, which lacks various essential minerals for growing crops, and also increases the pollution of the surrounding water when it rains. Therefore, the applicability of water pollution reduction and soil restoration was examined by using compost prepared by mixing MgO and mineral sources in a weight ratio of 1:2 with the existing Korean cattle compost. MgO used is a powder obtained by activating MgCO3 natural stone at 800℃ for 2 hours, and the mineral source was made by adding white soil to a sulfuric acid solution and heating it at 80℃ for 1 h and then recovering the sulfuric acid solution. After spraying the prepared compost on 20 farmland, water pollution and soil fertility were measured through analysis of water and soil items such as TOC, BOD, T-N, and T-C before and after spraying. When newly prepared compost was applied to the soil, the concentrations of TOC, BOD, T-N, and TP were reduced by 19.09%, 28.0%, 30.9%, and 27.5%, respectively, compared to commercial compost. On the basis of these results, it was confirmed that newly prepared compost is better than commercial compost for the water pollution reduction effect and the inhibition of green algae generation. Through soil analysis, the levels of EC and effective phosphoric acid in the soil were lower in the newly prepared compost than in the commercial compost. It is expected that soil fertility can be increased by reducing the rate of nutrient loss caused by rainfall.
Jae-Hyun Park, Han-Gil Kim, Yong-Han Yoon, Jin-Hee Ju / Korean Journal of Environmental Agriculture / 2024 / v.43, 52-60
This study focused on the effectiveness of companion planting applied to rooftop urban agriculture as a means to implement eco-friendly agricultural technology in cities. This study analyzed the effects of companion planting various aromatic plants, such as rosemary (Rosmarinus officinalis), marigold (Tagetes erecta), perilla (Perilla frutescens), and garlic chives (Allium tuberosum), with pepper (Capsicum annuum) as the main crop. This study was conducted on the rooftop of Konkuk University’s Global Campus in Chungju from May to August 2023. This study measured the effects of companion planting on soil temperature and moisture changes, plant growth and physiological characteristics, pest control effectiveness, and fruit productivity. As a result of examining the characteristics of the rooftop soil, it was found that a favorable soil environment was created for peppers to grow well in the experimental plots where peppers and garlic chives were planted together. In addition, as a result of investigating the growth and physiological characteristics of peppers, they grew best in the treatment plots where peppers and garlic chives were planted together. Traces of pest feeding were relatively lower in the experimental plots where garlic chives and perilla were co-planted than in rosemary and marigold. This suggests that these companion plants are more effective as trap plants for attracting leaf-feeding pests. Therefore, based on the overall results, companion planting of peppers and garlic chives in rooftop urban agriculture seems desirable for the growth, physiology, fruit productivity, and biological control of peppers.
Jae-Hyun Park, Dong-Hoon Sagong / Korean Journal of Environmental Agriculture / 2024 / v.43, 61-71
This study was conducted to investigate the effect of indole butyric acid (IBA) alone and in combination with dimethyl sulfoxide (DMSO) on the rate of grafting take, rooting, sprouting, grafting success and yield of nursery stock for sale of grape ‘Heukboseok’ potted nursery stock that were cutting-grafted to various rootstocks. This experiment was composed three factors. 1st factor is eight types of rootstocks as 18808, Teleki 5C (5 C), Teleki 8B (8 B), Millardet et Grasset 101-14 (101-14), Couderc 3306 (3306 C), Couderc 3309 (3309 C), Selection Oppenheim 4 (SO 4), Riparia Gloire de Montpellier (RG). 2nd factor is three levels of DMSO concentration as 0%, 5%, and 10%. 3rd factor is three levels of IBA concentration as 500, 1,000, and 1,500 mg/L. The grafting was performed in the end of March with the omega machine grafting. DMSO and IBA were applied through thirty seconds dip to the rootstock base. The data showed that the rate of grafting take, rooting, and sprouting were the highest in the 101-04, 3309 C, and 18808 rootstocks, respectively. The rate of grafting success was the highest in 18808 rootstock, and the rate of yield of potted nursery stock for sale of 18808 and 3309 C were higher than other rootstocks. The DMSO concentration was correlated to the rate of grafting take, sprouting and grafting success. However, the IBA concentration was not correlated to the rate of sprouting, grafting success and yield of potted nursery stock for sale. Based on the results from this study, the 3309 C rootstock had the highest graft compatibility with the ‘Heukboseok’, and the combination effect of DMSO and IBA were different by the rootstock.
Young-Sun Kim, Seung-Jae Lim / Korean Journal of Environmental Agriculture / 2024 / v.43, 72-81
This study was conducted to evaluate the effects on growth and turfgrass quality of perennial ryegrass in the sandy soil blended with bottom ash produced after combusting dry livestock manure (BAL). Treatments were designed as follows; No-fertilizer (NF, 100% sand), Control [3 N active ingredient (a.i.) g/m2, 100% sand], 3%BAL (3N a.i. g/m2, 3%BAL+97% sand), 5% BAL (3N a.i. g/m2, 5%BAL+95% sand), 7% BAL (3N a.i. g/m2, 7%BAL+93% sand) and 10% BAL (3N a.i. g/m2, 10%BAL+90% sand). Compared to NF and the control, BAL treatments increased soil pH, electrical conductivity (EC), available phosphate (Av-P2O5), and exchangeable potassium (Ex-K). There were no significant differences in turf color index, chlorophyll content, shoot length, clipping yield, or shoot dry weight between BAL treatments and the control. However, root dry weight, P and K concentrations, and nutrient uptake were higher in the BAL treatments compared to the control. The BAL application rate was positively correlated with root growth and nutrient uptake (p≤0.05). These results indicated that the application of BAL as a soil amendment improved root growth and nutrient uptake by supplying phosphate and potassium in the sandy soil.
Hyun Ho Noh, Chang Jo Kim, So-Hee Kim, Seung-Hwa Yu, Younkoo Kang, Chun-Gu Lee, Sang-Hyeob Lee, Kee Sung Kyung / Korean Journal of Environmental Agriculture / 2024 / v.43, 82-91
This study was carried out to measure droplet size and to predict drift distances using DRIFTSIM model under various nozzle and spraying pressure conditions. The XR nozzle produced approximately 50% of droplets small enough to drift significantly, with increased drift distances when the spraying height was reduced. The DG nozzle generated relatively larger droplets and exhibited shorter drift distances. The TP nozzle showed similar characteristics to the XR nozzle but had reduced drift distances when the height was lowered. The AI nozzle primarily produced larger droplets, making it the most effective in minimizing drift. This study confirms the impact of spraying pressure and height on droplet size and drift distance. The XR and TP nozzles generated a higher proportion of small droplets, increasing drift potential, while the AI nozzle was the most effective in reducing drift. The DG nozzle was identified as the most suitable nozzle, considering both drift reduction and crop surface adhesion efficiency. Therefore, adjusting spraying pressure and height can significantly minimize drift-related issues.
Tae-Young Lee, Tae-Wooung Kim, Young-Sun Kim / Korean Journal of Environmental Agriculture / 2024 / v.43, 92-100
This study was conducted to investigate the effects of livestock manure liquid fertilizer such as aerobic liquid fertilizer (AF) and anaerobic liquid fertilizer (AAF) on the growth and productivity of lettuce (Lactuca sativa) and Chinese cabbage (Brassica campestis). Treatments were as follow; control, AF-1 (AF 1 L/m2), AF-2 (AF 2 L/m2), AF-3 (AF 4 L/m2), AAF-1 (AAF 1 L/m2), AAF-2 (AAF 2 L/m2), and AAF-3 (AAF 4 L/m2). The EC of commercial substrates in AF and AAF treatments were higher than that of the control. As applied AF and AAF in the lettuce and Chinese cabbage, growth factors like chlorophyll content, leaf number, leaf width, leaf length, fresh weight and dry weight, and the nutrient availability of nutrient content and nutrient uptake increased than those of the control. The application amount of AF and AAF was correlated with growth factors and nutrient availability positively (p≤0.05) in both lettuce and Chinese cabbage. These results indicated that fertigation of AF and AAF was improved the growth of lettuce and Chinese cabbage by promoting an uptake amount of nutrient.
Ji Hyeon Baek, Pyeong Ho Lee, Yeonjong Koo / Korean Journal of Environmental Agriculture / 2024 / v.43, 101-108
Methane emissions in paddy soils occur through the decomposition of organic matter by anaerobic bacteria, including methanogenic bacteria, under anaerobic conditions maintained by waterlogged soil environments. These methanogenic bacteria produce methane via the acetoclastic pathway or the hydrogenotrophic pathway, making it challenging to determine the primary pathway for methane production. In this study, we supplied potassium acetate (KOAc) instead of additional hydrogen supplements to limit methane production through the hydrogenotrophic pathway, thereby analyzing the conversion of acetate to methane in paddy soils. We investigated the effect of acetate ions on methane production at various concentrations and confirmed methane production upon acetate addition. Furthermore, genetic cluster analysis revealed that Archaea clusters likely respond to acetate ions to produce methane. Soil reaction analysis based on regional soil characteristics revealed significant variations in methane production in response to acetate ions, indicating that methane production pathways in paddy soils may vary regionally.
Young-Sun Kim, Seung-Jae Lim, Ji-Hae Kang, Kyoungmok Lee, Geung-Joo Lee / Korean Journal of Environmental Agriculture / 2024 / v.43, 109-116
This study was conducted to evaluate the effects of application of slow release fertilizer such as methylene urea (MU) and isobutylene diuera (IBDU) on the growth and quality of creeping bentgrass (Agrostis palustris Huds.). Treatments were designed as follows; No-fertilizer (NF), Control [straight fertilizer (SF) 3N active ingredient (a.i.) g/m2/month], MU (MU 3N a.i. g/m2/month), and IBDU (IBDU 3N a.i. g/m2/month). As compared to NF, turf color index, chlorophyll content, clipping yield, and nutrient (N, P, K) uptake amount of MU and IBDU treatment were not significantly different (p≤0.05). The growth rate of MU or IBDU were 43.1% and 43.7% within 10 days after treatment (DAT) of fertilizers, respectively, that decreased than that of control, while 34.5% and 34.9% for 10-20 DATs, increased. These results indicated that as applied of MU and IBDU in the creeping bentgrass, the growth rate of turfgrass was lower than that of SF, and nutrient available period of slow release fertilizers increased.
Do-Gyun Park, Hye-Won Kim, Hyoung-Seok Lee, Min-Ji Lee, Hye-Ran Park, Taek-Keun Oh, Sun-Il Lee / Korean Journal of Environmental Agriculture / 2024 / v.43, 117-127
Biochar is increasingly recognized as a sustainable practice to enhance soil carbon balance and reduce greenhouse gas emissions. Produced through the pyrolysis of biomass in limited oxygen, biochar has shown promise in agriculture. However, its effects on the Net Ecosystem Carbon Balance (NECB), Total Global Warming Potential (GWP), and Net GWP, especially during autumn and spring Kimchi cabbage growing seasons, require further research. This study investigates the impact of rice hull biochar on NECB, CO2, and N2O emissions during these seasons. The Biochar application rates were control=0 ton/ha, B1=1 ton/ha, B3=3 ton/ha, and B5=5 ton/ha. In autumn, Total GWP, including CO2 emissions, ranged from 3.55 to 3.93 t/ha, showing no significant impact from increased biochar application. However, Net GWP decreased substantially with higher biochar inputs, ranging from -6.84 t/ha in the control to -16.59 t/ha in the B5 treatment, indicating enhanced carbon sequestration. During spring, Total GWP increased slightly with more biochar, from 1.63 to 1.97 t/ha, but Net GWP consistently decreased, from -8.80 to –18.74 t/ha. These results suggest that while Total GWP varies seasonally, biochar improves NECB and reduces Net GWP, highlighting its potential for mitigating climate change through sustainable agricultural practices.
Binod Prasad Luitel, Hee-Jin Lee, Min-Seon Choi, Tae-Jun Lim / Korean Journal of Environmental Agriculture / 2024 / v.43, 128-136
The expression of green color at the tip of peeled ’Hongsan’ garlic cloves is one of the pertinent issues for growers to maximize cultivation area and support regional marketing of the product. The purpose of this study was to find the effects of planting depth and sunshine drying on the expression of greenness at the tip of peeled ‘Hongsan’ cloves. Garlics cloves were planted at three soil depths – 5 cm (control), 7.5 cm and 10 cm and the harvested garlics were assessed their greenness on the tip of peeled cloves at one, two, five and ten days after sunshine drying in the field. The results have revealed that planting depth at control, 7.5 cm and 10 cm following sunshine drying of one day after garlic harvest (AGH) showed the greenness (1–4 scale) values of 2.7, 1.9 and 1.7 in the tip of peeled cloves, respectively. The shallower the planting depth, greener the tip of the peeled cloves in ‘Hongsan’ garlic. As the number of days for sunshine drying prolonged AGH, the intensity of greenness increased at all planting depths. The intensity of greenness at the tip of peeled cloves increased from 2.7 to 3.1 as the number of sunshine drying days AGH increased from the first to the tenth at control. Meanwhile, garlic yield between the planting depths was non-significant (p≤0.05) though there are significant differences in emergence of the garlics. Thus, greenness at the tip of peeled ‘Hongsan’ garlics can be regulated by manipulating soil depth and sunshine drying days AGH in field conditions.
Tae-Uk Jeong, Do-Kyu Song, Beom-Ku Lee, Jeong-Ok Park, Kyeong-Ah Kim, Eun-Chul Yoo / Korean Journal of Environmental Agriculture / 2024 / v.43, 137-148
To comprehend the status of sewer odor-related complaints in Busan Metropolitan City and create a complaint map, we collected and analyzed three years' worth of complaint data, mapping coordinates based on inputted addresses. Sewer odor complaints consistently totaled 1,274 cases over the three years, with a notable concentration in downtown areas. Yeongdo-gu recorded the highest number of complaints in 209 cases (16.4%), while Jung-gu exhibited elevated complaint rates per thousand residents and per square kilometer. Complaints were more frequent in the summer, particularly in June, with 207 cases, compared to the winter season. Recognizing the need for diverse analyses and foundational data for sewer odor reduction, it is deemed necessary to establish a standardized manual incorporating various checklists, in addition to unifying the management of complaint reception desks across districts. As Yeongdo-gu had the highest complaint frequency, a detailed investigation focused on 50 locations examined four sulfur compounds in sewer odors. The contribution analysis revealed hydrogen sulfide as the predominant odorant, constituting 82.74% of the total, reaffirming its significance in sewer odor. Analyzing sulfur compound concentrations by land use indicated higher hydrogen sulfide levels (133.61 ppb) in commercial areas compared to residential and industrial zones. Based on these data, civil complaint map and concentration map of sewer malodor were made using Geocoding tool program, QGIS, R leaflet package and sewerage network diagram layer. With sewer malodor complaints persistently occurring annually, it is expected that the sewer map can serve as foundational data for efficient sewer odor management. In addition, it is judged that continuous and extensive sewer malodor investigation and plateform-type system construction should be conducted focusing on the original citer areas such as Jung-Gu, Seo-gu and Dong-gu, where the frequency of civil complaints was realtively high.
Hyesu Lee, Jin Ha Sim, Ji Young Kim, Gui-Hyun Jang, Miok Eom / Korean Journal of Environmental Agriculture / 2024 / v.43, 149-158
Carbimazole is used for the treatment of hyperthyroidism. Methimazole, which is produced after the rapid metabolization of carbimazole in the body, can adversely affect endocrine hormones and cause gastrointestinal problems. Methimazole is prescribed as a veterinary drug to treat thyroid disease in cats. However, there is suspicion that it is being used for rapid fattening of non-thyroidal livestock, such as cows and pigs, posing serious health risks to consumers. Currently, there are no analytical methods for the detection of methimazole in livestock and fishery products in Korea. Thus, in this study, we developed a method to efficiently analyze methimazole in livestock and fishery products through liquid chromatography with tandem mass spectrometry. Methimazole was extracted with 80% acetonitrile and purified using C18 powder, followed by fat removal using acetonitrile-saturated hexane. The coefficient of linearity, average recovery, and coefficient of variation of the analytical method were verified according to the CODEX guidelines. The developed method was employed to monitor methimazole residue levels in livestock and fishery products, but no residues were detected. The proposed method can serve as a foundation for improving the safety management of domestic- and imported-livestock and fishery products.
Yu Jin Seo, Hoo Bin Han, Eun Hea Jho / Korean Journal of Environmental Agriculture / 2024 / v.43, 159-173
Hye-Ran Eun, So-Hee Kim, Mun-Ju Jeong, Ye-Jin Lee, Su-Min Kim, Yoon-Hee Lee, Yi-Gi Min, Hyun Ho Noh, Yongho Shin / Korean Journal of Environmental Agriculture / 2024 / v.43, 174-187
The effectiveness of adjuvants was evaluated in enhancing deposition within target spray area and reducing off-target pesticide drift during UAV-based pesticide applications. Tricyclazole, a widely used fungicide formulation in rice cultivation, was selected to measure deposition behavior using a Cellulose Deposition Sampler (CDS). The results demonstrated that the inclusion of paraffin and lecithin type adjuvants increased average depositions in CDS and rice plant samples (panicle and green leaf blade). Drift patterns were influenced by wind direction, and higher wind speeds were associated with increased drift rates. Compared to the untreated control, the relative drift reduction ratio ranged from –1.3 to 34.6% for the paraffin adjuvant and from 33.8 to 65.9% for the lecithin adjuvant, with greater drift reduction observed at higher wind speeds. Pesticide residue levels in harvested brown rice remained below the maximum residue limit (MRL) across all treatments, ensuring food safety of adjuvants. These findings indicate that the use of adjuvants in UAV-based applications can effectively reduce drift, improve application efficiency, and promote environmental sustainability in agricultural practices.
Mohamed R. Fouad, Ahmed F. El-Aswad, Maher I. Aly / Korean Journal of Environmental Agriculture / 2024 / v.43, 188-199
This study investigate the uptake and translocation of fenitrothion insecticide and thiobencarb herbicide in rice plants. This study is carried out under laboratory conditions, two concentrations (1 and 10 μg/g) and lysimeter conditions at a concentration of 25 μg/g. Significant differences in pesticide uptake by rice were observed between the two laboratory treatments (1 and 10 μg/g) across all time intervals, as well as in the cumulative amounts. After reaching maximum concentrations, a decrease in uptake was noted, likely due to biodegradation and plant growth dilution. The average bioconcentration factor (BCF) of thiobencarb was higher than that of fenitrothion, indicating a greater ability of rice plants to absorb and accumulate thiobencarb. The BCFs for both fenitrothion and thiobencarb were higher at lower concentrations (4.85 and 5.67) compared to higher concentrations (0.55 and 0.89), suggesting that the uptake capacity was saturated at low concentrations, limiting the rice plants' ability to accumulate the pesticides at varying initial concentrations under laboratory conditions. The recovery rates of fenitrothion and thiobencarb from soil and rice plant samples, as determined by HPLC, exceeded 80%. After 10-week period, fenitrothion and thiobencarb were not detectable in soil or rice under field conditions. Additionally, two metabolites of fenitrothion were tentatively detected in rice plants, while two metabolites of thiobencarb were detected in soil, with concentrations of 1.5 and 1.0 μg/g for metabolites I and II, respectively. One thiobencarb metabolite (metabolite I) was detected in rice plants at a concentration of 5 μg/g.
Hye-Min Lee, Hye-Won Kim, Jin-Ho Kim, Min-Wook Kim / Korean Journal of Environmental Agriculture / 2024 / v.43, 200-210
This study examines air pollutant emissions from agricultural activities in paddy fields and cropland areas in Buan and Gochang, South Korea. From June 2022 to May 2024, air quality monitoring stations collected data on particulate matter (PM-10, PM-2.5) and gaseous pollutants (NO2, SO2, O3). The findings indicate that particulate matter levels were notably higher in spring and fall, due to farming activities like herbicide application and crop harvesting. In contrast, gaseous pollutant levels remained within national air quality standards, although SO2 displayed unique seasonal patterns, particularly in the paddy field areas, where concentrations were higher in the mornings and afternoons. A comparison between urban and agricultural areas showed similar patterns for particulate matter, influenced by external factors like dust storms, but agricultural areas exhibited higher concentrations during farming seasons. The study emphasizes the importance of establishing dedicated air quality monitoring systems in agricultural regions, as the emission characteristics differ significantly from urban areas. Future research is needed to investigate the chemical composition of finding particulate matter in these regions to develop more effective pollution control strategies and improve overall air quality management in agricultural areas.
Chae Yeong Park, Su Jung Lee, Sun Young Gu, Jung Mi Lee, Gui Hyun Jang, Miok Eom / Korean Journal of Environmental Agriculture / 2024 / v.43, 211-222
A simultaneous analytical method was developed for the quantification and confirmation of nereistoxin and nereistoxin-related pesticides in agricultural products. These pesticides were extracted with a 2% L-cysteine solution in 0.05 N HCI and hydrolyzed using ammonium hydoxide and 3% nickel(II) chloride solution, purified using dispersive solid phase extraction (d-SPE) kit, and then analyzed by LC-MS/MS. To prevent the matrix effect, all analytes were quantified using matrix-matched calibrations, as assessed by the determination coefficient (R2) of the range from 0.9951-1.000. The LOD and LOQ were satisfactory for determining low residual levels of the pesticides in agricultural products. The accuracy and precision of the method were evaluated based on recoveries with five replicates at three fortification levels (LOQ, 10×LOQ and 50×LOQ). The mean recoveries of nereistoxin and nereistoxin-related pesticides in agricultural products were 75.3-108.0% with a coefficient of variation of 0.8-7.0%. All the optimized results were excellent, as assessed by the Ministry of Food and Drug Safety guidelines and the Codex Alimentarius Commission guidelines for pesticide residue analysis. This study provides fundamental data for setting the residue definition and maximum residue limits for nereistoxin and nereistoxin-related pesticides in agricultural products.
Kyeong-Hun Park, Jun-Hyoung Bang, Chang-Young Yoon, Sojeong Hwang, Bo-Seon Kim, Juyeong Kim, Bala Murali Krishna Vasamsetti, Kyongmi Chon / Korean Journal of Environmental Agriculture / 2024 / v.43, 223-232
Buprofezin is a thiadiazine insecticide that functions as an insect growth regulator, exerting its insecticidal effect by inhibiting chitin biosynthesis. In Korea, it is commonly used as a pesticide to control planthoppers, greenhouse whiteflies, and scale insects on various crops. Despite its low water solubility, buprofezin has a high affinity for soil particles and can accumulate in sediments within aquatic environments, posing a potential risk to non-target aquatic species. This study evaluated the acute toxicity of buprofezin on two species: the OECD standard species Chironomus riparius and the native species Glyptotendipes tokunagai. Acute toxicity tests were conducted following OECD guideline 235, and median lethal concentrations (LC50) were calculated using the US EPA probit analysis software. The results showed a 24-hour LC50 of 1.587-2.560 mg/L and a 48-hour LC50 of 0.471-1.421 mg/L for C. riparius, while G. tokunagai demonstrated higher sensitivity, with a 24-hour LC50 of 0.679-1.143 mg/L and a 48-hour LC50 of 0.536-0.936 mg/L. These findings suggest that both C. riparius and the native G. tokunagai are suitable species for assessing pesticide risk in aquatic environments.
Hyun Ho Noh, So-Hee Kim, Dong Ju Kim, Eun Been Oh, Jeong Do Choi, Jee Hyo Moon, Chang Jo Kim, Kee Sung Kyung / Korean Journal of Environmental Agriculture / 2024 / v.43, 233-241
This study analyzed the effect of lecithin adjuvant on droplet size and drift reduction during pesticide application, and evaluated its effectiveness by predicting drift distances using the DRIFTSIM model. A flat fan nozzle (XR8002) was used to compare the droplet sizes of water and lecithin adjuvant mixtures, measured with a laser diffraction system. Droplet size parameters (DV10, DV50, DV90) were compared, and the drift distance for each solution was predicted using the DRIFTSIM model. The results showed that the lecithin adjuvant significantly increased droplet size compared to water. At 40 psi, the DV10, DV50, and DV90 of the lecithin mixture increased by 42.7%, 35.4%, and 35.5%, respectively, compared to water. This trend was also observed at higher pressures. Drift predictions indicated that the lecithin adjuvant mixture reduced drift distances by up to 35% compared to water. In particular, droplets smaller than 100 μm, which are more prone to drift and evaporation, were significantly reduced in the lecithin mixture, demonstrating its effectiveness in drift reduction. Additionally, lowering the spray height from 2 m to 1 m further shortened the drift distance, emphasizing the importance of height control in drift reduction. Overall, lecithin adjuvant can be an effective tool for increasing droplet size and reducing pesticide drift, contributing to minimizing environmental impact and enhancing pesticide efficiency during application. These findings suggest that lecithin adjuvant has potential as a sustainable pesticide management strategy in agricultural practices.
