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  Adsorption Characteristics of Aqueous Ammonium Using Rice hull-Derived Biochar

  Yong-Su Choi, Joung-Du Shin, Sun-Il Lee, Sung-Chul Kim / Korean Journal of Environmental Agriculture / 2015 / v.34, no.3, 155-160

  http://dx.doi.org/10.5338/KJEA.2015.34.3.25

  Abstract Full-Text PDF

  Abstract

  

  BACKGROUND

  Objective of this study was to investigate adsorption characteristics of NH₄-N to biochar produced from rice hull in respective to mitigation of greenhouse gases.

  METHODS AND RESULTS

  NH₄-N concentration was analyzed by UV spectrophotometer. For adsorption experiment of NH₄-N to biochar, input amount of biochar was varied from 0.4 to 10 g/L with 30 mg/L NH₄-N solution. Its adsorption characteristic was investigated with application of Langmuir isotherm. Adsorption amount and removal rates of NH₄-N were decreased at 53.9% and increased at 20.2% with 10 g/L compared to 0.4 g/L, respectively. The sorption of NH₄-N to biochar produced from rice hull was fitted well by a Langmuir model. The largest adsorption amount of NH₄-N (q_m) and binding strength constant (b) were calculated as 0.4980 mg/g, and 0.0249 L/mg, respectively. It was observed that dimensionless constant (R_L) was 0.58.

  CONCLUSION

  It was indicated that biochar produced from rice hull is favorably absorbed NH₄-N, because this value lie within 0<R_L<1.

• Download145

  The applicability of burcucumber (Sicyos angulatus L.) as a substitute for nitrogen fertilizer

  Min-Suk Kim, Hyungi Min, Sun-Hee Hong, Jeong-Gyu Kim / Korean Journal of Environmental Agriculture / 2016 / v.35, no.1, 1-5

  http://dx.doi.org/10.5338/KJEA.2016.35.1.06

  Abstract Full-Text PDF

  Abstract

  

  BACKGROUND:

  Burcucumber(Sicyos angulatus L.) is an invasive plant species and disturbs ecosystems in Korea. The main method for prevention of burcucumber is cutting or pulling out. However, the studies accounting for the use of the by-product of burcucumber after cutting remain incomplete. Thus, the aim of this study was to investigate the applicability of burcucumber as a substitute for nitrogen fertilizer.

  METHODS AND RESULTS:

  Burcucmber plants only including stem, leaves, and petiole were collected from the Sky Park in Seoul and divided in to three categories based on the length of stem of burcucumber; 10-30 cm, 30-100 cm, and 100-200 cm. And they were input into soil with 20 kg-N/10 a. After 4 weeks aging, chemical properties of treated soils and the productivity of lettuce(Lactuca sativa L.) were examined. Both the inorganic nitrogen contents in soils and the growth of lettuce were increased with the decreases in length of burcucumber standing for young plant. And the inorganic nitrogen content and the productivity of lettuce were positively correlated(r= 0.9409).

  CONCLUSION:

  The C/N ratio of burcucumber was low, indicating fast decomposition and nitrogen supplying rate, resulting in the increase in lettuce growth. Burcucumber could be a good substitute for nitrogen organic fertilizer.

• Download139

  Banana Peel: A Green Solution for Metal Removal from Contaminated Waters

  KKIU Arunakumara, Buddhi Charana Walpola, Min-Ho Yoon / Korean Journal of Environmental Agriculture / 2013 / v.32, no.2, 108-116

  http://dx.doi.org/10.5338/KJEA.2013.32.2.108

  Abstract Full-Text PDF

  Abstract

  

  BACKGROUND:

  Certain crop-based waste materials have been recognized as cost-effective and highly efficient adsorbents for removal and recovery of different kind of heavy metals from aqueous solutions. The ability is strongly attributed to the carboxyl functional group of some pectin substances such as galacturonic acid often found in fruit peels. The present manuscript was aimed at assessing the potential applicability of banana peel for metal removal from contaminated waters.

  METHODS AND RESULTS:

  As revealed by laboratory investigations, banana peel contains pectin (10-21%), lignin (6-12%), cellulose (7.6-9.6%), and hemicelluloses (6.4-9.4%). The pectin extraction is reported to have glucose, galactose, arabinose, rhamnose, xylose, and galactouroninc acid. Several studies conducted under different conditions proved that banana peel is capable of adsorbing 5.71, 2.55, 28.00, 6.88, 7.97, and 5.80 mg/g of Cd²⁺, Co²⁺, Cu²⁺, Ni²⁺, Pb²⁺, and Zn²⁺, respectively, from aqueous solutions. Adsorption capacity is, however, dependent upon several factors including solution pH, dose of adsorbent and metal concentration, contact time and shaking speed.

  CONCLUSION(S):

  Since the annual world production of banana exceeds 100 million tons, about 40 million tons of banana peel (40% of total weight of the fresh fruit) remains vastly unused. Exploring a sound technology with banana peel would therefore, not only address the much needed sustainable tool for cleaning contaminated waters, but of course bring an additional value to the banana industry worldwide.

• Download113

  Method Development and Analysis of Carotenoid Compositions in Various Tomatoes

  Han-Kyul Kim, Jin-Hyuk Chun, Sun-Ju Kim / Korean Journal of Environmental Agriculture / 2015 / v.34, no.3, 196-203

  http://dx.doi.org/10.5338/KJEA.2015.34.3.23

  Abstract Full-Text PDF

  Abstract

  

  BACKGROUND:

  Purpose of this research is HPLC analysis method development of lycopene in tomato. And then, three components of carotenoid in four kinds of tomatoes (general tomato, cherry tomato, red and orange date tomato) were compared with each other.

  METHODS AND RESULTS:

  Lycopene in tomato was extracted with hexane likes other carotenoid components using 500 mg of dried powder sample. HPLC analysis conditions were column temperature (40℃), detection wavelength (454 nm), flow rate (1.0 mL/min) and injection volume (20.0 μL). Lycopene was analyzed by the gradient elution (60 → 100%) of the mobile phase solvents A[water: methanol=25: 75 (v/v)] and B[ethyl acetate].

  CONCLUSION:

  Three components of carotenoids (lutein, β-carotene, lycopene) were observed in tomatoes. The total carotenoid contents was the highest in red date tomato (662.0 mg/kg dry wt.) and the lowest in orange date tomato (111.3 mg/kg dry wt.). Lycopene contents in tomatoes was the highest percentage (93%) among all the carotenoids.

• Download113

  A Research of Soil Environmental Health in Urban Garden, Gwangju

  Gil-Sik Jang, Yun-Hee Kim, Young-Seop Choi, Seung-Ho Kim, Jong-Min Kim, Seok-Jin Bae, Young-Gwan Cho, Tae-Hyoung Koo / Korean Journal of Environmental Agriculture / 2016 / v.35, no.2, 87-96

  http://dx.doi.org/10.5338/KJEA.2016.35.2.14

  Abstract Full-Text PDF

  Abstract

  

  BACKGROUND:

  The objective of this study is to evaluate the soil quality to cultivate crops in urban garden.

  METHODS AND RESULTS:

  During the period of six month from March to August 2015, measured eight heavy metals, seven Organic items and Fluorine on seventeen urban sites and thirty-one suburban sites in Gwangju city.

  METHODS AND RESULTS:

  The average concentration and range of heavy metal in soil are 0.15 mg/kg(ND-0.6) for Cd, 14.9 mg/kg(1.5-33.3) for Cu, 4.4 mg/kg(0.4-71.8) for As, 0.05 mg/kg(ND-1.366) for Hg, 24.7 mg/kg(13.1-62.7) for Pb, 102.5 mg/kg(49.1-276.4) for Zn and 9.2 mg/kg(ND-90.1) for Ni but Cr⁶⁺ is not detected. The average value and range of soil fertility items are 253.5mg/kg(76.6-1766.0) for fluorine, 6.4(4.8-7.7) for pH, 20.3 g/kg(5.0-44.0) for orangic matters, 562.7 mg/kg (28.0-1672.0) for available phosphate, 0.6 cmol⁺/kg (0.1-2.3) for K, 9.7 cmol⁺/kg (2.7-22.0) for Ca, 3.0 cmol⁺/kg (0.9-7.4) for Mg, 1.0 ds/m(0.2-2.9) for conductivity. The concentration of Hg in Suburban area is 0.005 mg/kg lower than 0.134 mg/kg in urban area. Also, the concentration of As, Cd, Ni and Zn is lower than urban area as 32%, 37%, 51%, 71% respectively.

  CONCLUSION:

  According to SPI index of soil contamination, 39 sites are first degree and 8 sites are second degree and 1 site(41th) is fourth degree. Pb and Cd are not detected and As is detected tiny amounts in plants grown polluted soil, so heavy metals have not moved to plants.

• Download112

  Study for Residue Analysis of Fluxametamid in Agricultural Commodities

  Ji Young Kim, Yoon Ju Choi, Jong Soo Kim, Do Hoon Kim, Jung Ah Do, Yong Hyun Jung, Kang Bong Lee, Hyochin Kim / Korean Journal of Environmental Agriculture / 2019 / v.38, no.1, 1-9

  https://doi.org/10.5338/KJEA.2019.38.1.5

  Abstract Full-Text PDF

  Abstract

  

  BACKGROUND:

  Accurate and simple analytical method determining Fluxametamid residue was necessary in various food matrices. Additionally, fulfilment of the international guideline of Codex (Codex Alimentarius Commission CAC/GL 40) was required for the analytical method. In this study, we developed Liquid Chromatography-Tandem Mass Spectrometry (LC-MS/MS) method to determine the Fluxametamid residue in foods.

  METHODS AND RESULTS:

  Fluxametamid was extracted with acetonitrile, partitioned and concentrated with dichloromethane. To remove the interferences, silica SPE cartridge was used before LC-MS/MS (Liquid Chromatography-Tandem Mass Spectrometry) analysis with C₁₈ column. Five agricultural commodities (mandarin, potato, soybean, hulled rice, and red pepper) were used as a group representative to verify the method. The liner matrix-matched calibration curves were confirmed with coefficient of determination (r²) greater than 0.99 at calibration range of 0.001-0.25 mg/kg. The limits of detection and quantification were 0.001 and 0.005 mg/kg, respectively. Mean average accuracies were shown to be 82.24-115.27%. The precision was also shown to be less than 10% for all five samples.

  CONCLUSION:

  The method investigated in this study was suitable to the Codex guideline for the residue analysis. Thus, this method can be useful for determining the residue in various food matrices as routine analysis.

• Download93

  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.

• Download84

  Phytoremediation Potential of Kenaf (Hibiscus cannabinus L.), Mesta (Hibiscus sabdariffa L.), and Jute (Corchorus capsularis L.) in Arsenic-contaminated Soil

  M. Uddin Nizam, M. Wahid-U-Zzaman, M. Mokhlesur Rahman, Jang-Eok Kim / Korean Journal of Environmental Agriculture / 2016 / v.35, no.2, 111-120

  http://dx.doi.org/10.5338/KJEA.2016.35.2.15

  Abstract Full-Text PDF

  Abstract

  

  BACKGROUND:

  Arsenic (As)-contaminated groundwater used for long-term irrigation has emerged as a serious problem by adding As to soils. Phytoremediation potential of fiber crops viz., kenaf (Hibiscus cannabinus L.), mesta (Hibiscus sabdariffa L.), and jute (Corchorus capsularis L.) was studied to clean up As-contaminated soil.

  METHODS AND RESULTS:

  Varieties of three fiber crops were selected in this study. Seeds of kenaf, mesta, and jute varieties were germinated in As-contaminated soil. Uptake of As by shoot was significantly higher than that by root in the contaminated soil. In As-contaminated soil, kenaf and mesta varieties accumulated more As, than did jute varieties. In the plant parts above ground, mainly the shoots, the highest As absorption was recorded in kenaf cv. HC-3, followed by kenaf cv. HC-95. Kenaf varieties produced more biomass. In terms of higher plant biomass production, and As absorption, kenaf varieties showed considerable potential to remediate As-contaminated soil.

  CONCLUSION:

  The overall As absorption and phytoremediation potentiality of plant varieties were in the order of kenaf cv. HC-3 > kenaf cv. HC-95 > mesta cv. Samu-93 > jute cv. CVE-3 > jute cv. BJC-7370. All varieties of kenaf, mesta, and jute could be considered for an appropriate green plant-based remediation technology in As-contaminated soil.

• Download83

  Desalinization Effect of Off-season Crop Cultivation in Long-term Oriental Melon Cultivated Plastic Film House Soils

  Il-Su Byeon, Jong-Bae Chung / Korean Journal of Environmental Agriculture / 2015 / v.34, no.4, 253-259

  http://dx.doi.org/10.5338/KJEA.2015.34.4.39

  Abstract Full-Text PDF

  Abstract

  

  BACKGROUND:

  During the off-season, the cultivation of Chinese cabbage and water dropwort is often used to desalinize plastic film house soils. The objective of this study was to verify the effect of double-cropping systems on the salt removal in oriental melon cultivated plastic film house soils.

  METHODS AND RESULTS:

  Electrical conductivity (EC) and soluble salt contents were measured in soils collected from plastic film houses of oriental melon cultivation before and after the off-season crop cultivation. Also the same measurements were performed in the next oriental melon season to estimate the desalinization effect of double-cropping systems. During the cultivation of Chinese cabbage under open-field condition, EC_e of surface soil was reduced from 6.0 to 0.8 dS/m. Double-cropping of water dropwort in flooded soil was also efficient in removing the salts accumulated during oriental melon cultivation. In the house soils where salts were removed during the off-season crop cultivation, soil EC_e was maintained below 3 dS/m during the next oriental melon cultivation season.

  CONCLUSION:

  The off-season cropping under open-field or flooded condition was effective in desalinization of plastic film house soils. Since the salt removal effect is not expected to last for several years, the double-cropping system should be introduced every season to maintain soil EC below the critical level.

• Download82

  A Study on the Mitigation of Nitrous Oxide emission with the Horticultural Fertilizer of Containing Urease Inhibitor in Hot Pepper and Chinese Cabbage Field

  Ok Jung Ju, Gap June Lim, Sang Duk Lee, Tae Jin Won, Jung Soo Park, Chang Sung Kang, Soon Sung Hong, Nam Goo Kang / Korean Journal of Environmental Agriculture / 2018 / v.37, no.4, 235-242

  https://doi.org/10.5338/KJEA.2018.37.4.36

  Abstract Full-Text PDF

  Abstract

  

  BACKGROUND:

  About 81% of nitrous oxide (N₂O) emissions from agricultural land to the atmosphere is due to nitrogen (N) fertilizer application. Mitigation of N₂O emissions can be more effective in controlling biochemical processes such as nitrification and denitrification in the soil rather than decreasing fertilizer application. The use of urease inhibitors is an effective way to improve N fertilizer efficiency and reduce N₂O emissions. Several compounds act as urease inhibitors, but N-(n-butyl) thiophosphoric triamide (NBPT) has been used worldwide.

  METHODS AND RESULTS:

  Hot pepper and chinese cabbage were cultivated in five treatments: standard fertilizer of nitrogen-phosphorus-potassium(N-P-K, N-P₂O₅-K₂O: 22.5-11.2-14.9 kg/ha for hot pepper and N-P₂O₅-K₂O: 32.0-7.8-19.8 kg/ha for chinese cabbage), no fertilizer, and NBPT-treated fertilizer of 0.5, 1.0, and 2.0 times of nitrogen basal application rate of the standard fertilizer, respectively in Gyeonggi-do Hwaseong-si for 2 years(2015-2016). According to application of NBPT-treated fertilizer in hot pepper and chinese cabbage, N₂O emission decreased by 19-20% compared to that of the standard fertilizer plot.

  CONCLUSION:

  NBPT-treated fertilizer proved that N₂O emissions decreased statistically significant in the same growth conditions as the standard fertilization in the hot pepper and chinese cabbage cultivated fields. It means that NBPT-treated fertilizer can be applied for N fertilizer efficiency and N₂O emissions reduction.

• Download77

  Residues and Exposure Assessment of Carbendazim in Chamnamul on Field Trials for Revising Maximum Residue Limit in Korea

  Hee-Ra Chang, Hye-Min Gwak / Korean Journal of Environmental Agriculture / 2022 / v.41, no.3, 153-157

  https://doi.org/10.5338/KJEA.2022.41.3.18

  Abstract Full-Text PDF

  Abstract

  

  BACKGROUND:

  The residue dissipation pattern of pesticides for agricultural products during the pre-harvest period after the final application is important to prevent the maximum residue limit (MRL) violations in domestic and export markets. The MRL violations of carbendazim are observed more often in chamnamul by pesticide residue management surveys by the Ministry of Food and Drug Safety. The residue level at the pre-harvest interval (PHI) and the residue dissipation constant from the critical good agricultural practice (cGAP) trials could be estimated to meet the MRL and pose a health risk to consumers.

  METHODS AND RESULTS:

  Chamnamuls were harvested at 0, 1, 3, 5, 7, 10, and 14 days after application of carbendazim in accordance with critical GAP. The residue analysis in chamnanul was performed by HPLC-DAD with the C₁₈ column. The limit of quantitation of carbendazim was 0.04 mg/kg , and the recoveries were 74.4 - 95.8% at the two spiked levels (LOQ and 10LOQ) of carbendazim. The dissipation rates in chamnamul were calculated from the residues at the sampling days by statistical method at a 95% confidence level. The biological half-lives of residual carbendazim in the field trials 1 and 2 were 4.9 and 4.4 days, respectively.

  CONCLUSION(S):

  In this dissipation study, the residue concentrations at the recommended PHI were higher than the established MRL in Korea. Therefore, the MRL is proposed based on the residue data sets from the trials conducted at the same cGAP and the dietary exposure assessment.

• Download71

  Heavy Metal Accumulation in Edible Part of Eleven Crops Cultivated in Metal Contaminated Soils and Their Bio-concentration Factor

  Ga-Hee Lim, Kye-Hoon Kim, Byoung-Hwan Seo, Kwon-Rae Kim / Korean Journal of Environmental Agriculture / 2015 / v.34, no.4, 260-267

  http://dx.doi.org/10.5338/KJEA.2015.34.4.46

  Abstract Full-Text PDF

  Abstract

  

  BACKGROUND:

  The current study was conducted to examine the species specific accumulation of Cd and Pb in 11 crop species (Soybean, Sesame, Corn, Polished rice, Carrot, Potato, Garlic, Spring onion, Chinese leek, Red pepper, Eggplant), through cultivating them under the same condition with metal contaminated soils.

  METHODS AND RESULTS:

  Eleven crop species were cultivated in three different soils contaminated with Cd and Pb and harvested. Edible parts of each crop was pretreated and analyzed to determine Cd and Pb concentrations, and subsequently bioconcentration factors (BCFs) were calculated. In general, the crops of which seeds are used as food showed high concentrations of both Cd and Pb. For instance, Cd concentrations in crops cultivated in Soil A was in the order of soybean (0.432 mg kg^-1) > sesame (0.385) > polished rice (0.176) > carrot (0.116) > corn (0.060) > red pepper > (0.047) > potato (0.044) > egg plant (0.025) > garlic (0.023) > spring onion (0.016) > Chinese leek (0.011). BCFs showed the same order.

  CONCLUSION:

  From this study, it can be conclude that seeds plants should not be cultivated in Cd and Pb contaminated soils to secure food safety from metal contaminated soils.

• Download69

  Identification of Pitfalls Related to the Analysis of Liquid Chromatography-Tandem Mass Spectrometry and Liquid Chromatography-Time of Flight Mass Spectrometry

  Jin-Wook Kwon, Yoon-Jae Cho, Gyu-Seek Rhee / Korean Journal of Environmental Agriculture / 2015 / v.34, no.3, 230-237

  http://dx.doi.org/10.5338/KJEA.2015.34.3.33

  Abstract Full-Text PDF

  Abstract

  

  BACKGROUND

  To identify the sources of inaccuracy in LC/MS/MS methods used in the routine quantitation of small molecules are described and discussed.

  METHODS AND RESULTS

  Various UPLC coupled to triple quadrupole mass spectrometer and time of flight (TOF) were used to identify the potential sources of inaccuracy and inducing the pitfalls of qualification and quntitation during the veterinary drug residue analysis. Some of stable isotope labelled veterinary drugs, which were used as internal standards, presented “cross-talk”, regardless of manufactures of mass spectrometer and types of spectrometer. Group of sulfonamides also presented inaccuracy qualification and quantitation due to the multi-residue analytical method with the same fragment ions at the close retention times.

  CONCLUSION

  The phenomena of “cross-talk” occurring between subsequently monitored transition from stable isotope labelled and isotope non-labelled authentic chemical were identified. To prevent errors and achieve more accurate data during the analysis of small molecules by LC/MS/MS SRM method, Followings should be taken care of and kept checking; purity and concentration of stable isotope as an internal standard, prevention of carry-over during the separation in column, minimizing the ion suppression by matrix effect, identification of retention time, precursor ion and product ion, and full knowledge of data processing including smoothing and peak integration.

• Download68

  Estimation of Ammonia Emission with Compost Application in Plastic House for Leafy Perilla Cultivation

  Sung-Chang Hong, Jin-Ho Kim, Min-Wook Kim / Korean Journal of Environmental Agriculture / 2021 / v.40, no.3, 149-160

  https://doi.org/10.5338/KJEA.2021.40.3.18

  Abstract Full-Text PDF

  Abstract

  

  BACKGROUND:

  Concerns have been raised about the impact of recent high concentrations of fine dust on human health. Ammonia(NH₃) reacts with sulfur oxides and nitrogen compounds in the atmosphere to form ultrafine ammonium sulfate and ammonium nitrate (PM2.5). There is a growing need for accurate estimates of the amount of ammonia emitted during agricultural production. Therefore, in this study, ammonia emissions generated from the cultivation of leafy perilla in plastic houses were determined.

  METHODS AND RESULTS:

  Cow manure compost, swine manure compost, and poultry manure compost each at 34.6 ton ha^-1, the amount commonly used by farmers in the field, was sprayed on the soil surface. Just after spraying cow manure compost, swine manure compost, and poultry manure compost, the ammonia was periodically measured and analyzed to be 22.5 kg ha^-1, 22.8 kg ha^-1, and 85.2 kg ha^-1, respectively. The emission factors were estimated at 70.0 kg-NH₃ ton-N, 62.8 kg-NH₃ ton-N, and 234.1 kg-NH₃ ton-N, respectively. Most ammonia was released in the two weeks after application of the compost and then the amount released gradually decreased.

  CONCLUSION:

  Therefore, it is necessary to improve the emission factor through a study on the estimation of ammonia emission by type of livestock manure and major farming types such as rice fields and uplands, and to update data on the production, distribution, and sales of livestock manure.

• Download68

  Effect of Carbonized Biomass Derived from Pruning on Soil Carbon Pools in Pear Orchard

  Sun-il Lee, Jong-sik Lee, Gun-yeob Kim, Eun-jung Choi, Sang-uk Suh, Un-Sung Na / Korean Journal of Environmental Agriculture / 2016 / v.35, no.3, 159-165

  http://dx.doi.org/10.5338/KJEA.2016.35.3.26

  Abstract Full-Text PDF

  Abstract

  

  BACKGROUND:

  Carbonized biomass is increasingly used as a tool of soil carbon sequestration. The objective of this study was to evaluate soil carbon storage to application of carbonized biomass derived from pear tree pruning.

  METHODS AND RESULTS:

  The carbonized biomass was a mobile pyrolyzer with field scale, which a reactor was operated about 400~500℃ for 5 hours. The treatments were consisted of a control without input of carbonized biomass and two levels of carbonized biomass inputs as 6.06 Mg/ha, C-1 and 12.12 Mg/ha, C-2. It was shown that the soil carbon pools were 49.3 Mg/ha for C-1, 57.8 Mg/ha for C-2 and 40.1 Mg/ha for the control after experimental periods. The contents of accumulated soil carbon pool were significantly (P < 0.001) increased with enhancing the carbonized biomass input amount. The slopes (1.496) of the regression equations are suggested that carbon storage from the soil was increased about 0.1496 Mg/ha with every 100 kg/ha of carbonized biomass input amount.

  CONCLUSION:

  Our results suggest that application of carbonized biomass would be increased the soil carbon contents due to a highly stable C-matrix of carbonized biomass. More long-term studies are needed to be proved how long does carbon stay in orchard soils.

• Download68

  Soil carbon storage in upland soils by biochar application in East Asia

  Sun-Il Lee, Seong-Soo Kang, Eun-Jung Choi, Hyo-Suk Gwon, Hyoung-Seok Lee, Jong-Mun Lee, Sang-Sun Lim, Woo-Jung Choi / Korean Journal of Environmental Agriculture / 2021 / v.40, no.3, 219-230

  https://doi.org/10.5338/KJEA.2021.40.3.26

  Abstract Full-Text PDF

  Abstract

  

  BACKGROUND:

  Biochar is a solid material converted from agricultural biomass such as crop residues and pruning branch through pyrolysis under limited oxygen supply. Biochar consists of non-degradable carbon (C) double bonds and aromatic ring that are not readily broken down by microbial degradation in the soils. Due to the recalcitrancy of C in biochar, biochar application to the soils is of help in enhancing soil carbon sequestration in arable lands that might be a strategy of agricultural sector to mitigate climate change.

  METHODS AND RESULTS:

  Data were collected from studies on the effect of biochar application on soil C content conducted in East Asian countries including China, Japan and Korea under different experimental conditions (incubation, column, pot, and field). The magnitude of soil C storage was positively correlated (p < 0.001) with biochar application rate under field conditions, reflecting accumulation of recalcitrant black C in the biochar. However, The changes in soil C contents per C input from biochar (% per t/ha) were 6.80 in field condition, and 12.58 in laboratory condition. The magnitude of increment of soil C was lower in field than in laboratory conditions due to potential loss of C through weathering of biochar under field conditions. Biochar production condition also affected soil C increment; more C increment was found with biochar produced at a high temperature (over 450℃).

  CONCLUSION:

  This review suggests that biochar application is a potential measures of C sequestration in agricultural soils. However, as the increment of soil C biochar was affected by biochar types, further studies are necessary to find better biochar types for enhanced soil C storage.

• Download64

  Pollutant Runoff Reduction Efficiency of Surface Cover, Vegetative Filter Strip and Vegetated Ridge for Korean Upland Fields: A Review

  Se-In Park, Hyun-Jin Park, Hye In Yang, Han-Yong Kim, Kwang-Sik Yoon, Woo-Jung Choi / Korean Journal of Environmental Agriculture / 2018 / v.37, no.3, 151-159

  https://doi.org/10.5338/KJEA.2018.37.3.21

  Abstract Full-Text PDF

  Abstract

  

  BACKGROUND:

  In this review paper, the effects of surface cover (SCV), vegetative filter strip (VFS), and vegetated ridge (VRD) on the pollutant runoff from steep-sloping uplands were analyzed to compare the pollutant reduction efficiency in runoff (PRE_runoff) of the practices and to investigate how slope and rainfall parameters affect the PRE_runoff.

  METHODS AND RESULTS:

  The PRE_runoff of SCV, VFS, and VRD for pollutants including suspended solids and biological oxygen demand was compared by analysis of variance. The effect of slope and rainfall parameters on the PRE_runoff was explored by either mean comparison or regression analysis. It was found that the PRE_runoff differs with the practices due to different pollutant reduction mechanisms of the practices. Though the PRE_runoff was likely to be affected by site condition such as slope and rainfall (amount and intensity), more comprehensive understanding was not possible due to the limited data set.

  CONCLUSION:

  The PRE_runoff of SCV, VFS, and VRD differed due to the distinctive mechanisms of pollutant removal of the practices. It is necessary to accumulate experimental data across a variety of gradient of slope and rainfall for comprehensive understanding of the effects of the practices on pollutant runoff from steep-sloping uplands.

• Download64

  Assessment of Electrical Conductivity of Saturated Soil Paste from 1:5 Soil‐Water Extracts for Reclaimed Tideland Soils in South‐Western Coastal Area of Korea

  Hyun‐Jin Park, Hye In Yang, Se‐In Park, Bo‐Seong Seo, Dong‐Hwan Lee, Han‐Yong Kim, Woo‐Jung Choi / Korean Journal of Environmental Agriculture / 2019 / v.38, no.2, 69-75

  https://doi.org/10.5338/KJEA.2019.38.2.15

  Abstract Full-Text PDF

  Abstract

  

  BACKGROUND:

  Measurement of electrical conductivity of saturated soil paste (EC_e) for assessment of soil salinity is time‐consuming, and thus conversion of EC of 1:5 soilwater extract (EC_1:5) to EC_e using a dilution factor may be of help to monitor salinity of huge number of soil samples. This study was conducted to evaluate the dilution factor for reclaimed tideland (RTL) soils of South Korea.

  METHODS AND RESULTS:

  Soil samples (n=40) were collected from four RTLs, and analyzed for EC_1:5, EC_e, and cation compositions of 1:5 soil‐water extract. The dilution factor (8.70) was estimated by regression analysis between EC_1:5 and EC_e, and the obtained dilution factor was validated by applying to an independent data set (n=96) of EC_1:5 and EC_e. The EC_e measured and predicted was strongly correlated (r²=0.74, P<0.001), but EC_e was overestimated by 16% particularly for the soils with high clay content and low sodium adsorption ratio (SAR).

  CONCLUSION:

  This study suggests that using the dilution factor to convert EC_1:5 to EC_e is feasible method to monitor changes in the soil salinity of the study RTL. However, overestimation of EC_e should be cautioned for the soils with high clay content and low SAR.

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  Ammonia Adsorption Characteristic of Reusable PAN/zeolite Fibers Made by Electrospinning

  Yeon Hee Ro, Woo Jin Chung, Soon Woong Chang / Korean Journal of Environmental Agriculture / 2020 / v.39, no.4, 281-288

  https://doi.org/10.5338/KJEA.2020.39.4.33

  Abstract Full-Text PDF

  Abstract

  

  BACKGROUND:

  Generally, ammonia occurs from agricultural waste disposal. Ammonia is known as a harmful substance to the human body and has a bad influence such as eutrophication on the ecosystem. It is possible to remove the ammonia by ammonia adsorption method using natural zeolite, without external influence. However, due to the natural zeolite shape, it is hard to reuse.

  METHODS AND RESULTS:

  Electrospinning method can produce fiber with constant diameter. Moreover, electrospinning method has no limitation for selecting the material to make the fiber, and thus, it is valuable to reform the surface of adsorbent. In this study, reusable membrane was made by electrospinning method. The highest removal efficiency was shown from the membrane with 20% of zeolite included, and it has been verified that it is possible to reuse the membrane through chemical treatment. The highest ammonia removal efficiency was about 92.4%.

  CONCLUSION:

  In this study, ammonia adsorption characteristics of zeolite fibers were studied. Electrospinning method can produce zeolite fiber with even distribution. Ammonia can be removed efficiently from ion exchange ability of the natural zeolite. The result of adsorption isotherm indicated that both Freundlich model and Langmuir model provided the best fit for equilibrium data. And study on desorption has demonstrated that the ion exchange from zeolite was reversible when 0.01 M NaCl and KCl solution were used.