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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.

• Download121

  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.

• Download106

  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.

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  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.

• Download93

  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.

• Download83

  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.

• Download79

  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.

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  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.

• Download72

  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.

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  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.

• Download62

  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.

• Download60

  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.

• Download55

  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.

• Download54

  Feasibility of Coal Combustion Ash on Acidity Regulation for Agricultural Use

  Sejin Oh, Min Woo Kang, Sung-Chul Kim, Sang Soo Lee / Korean Journal of Environmental Agriculture / 2019 / v.38, no.1, 10-16

  https://doi.org/10.5338/KJEA.2019.38.1.3

  Abstract Full-Text PDF

  Abstract

  

  BACKGROUND:

  Coal ashes generated from thermal power plants have been known as beneficial materials for agricultural use because of their nutrient elements. However, there is limitation to recycle them due to their alkalinity. The objective of this study was to evaluate the effectiveness or safety of the coal ashes for their heavy metals on agricultural recycling when adjusted to pH of 5 with sulfuric acid.

  METHODS AND RESULTS:

  Concentration of hydrogen which is needed to adjust pH of coal ash was estimated by using a buffering curve and then the amount of sulfuric acid was changed by the estimation before incubation. Each of fly ash (FA) and bottom ash (BA) was collected from both thermal plants of Yeongdong (YD) and Yeongheung (YH). The pH values of coal ashes increased to 4.76 (from 4.34) after incubation with sulfuric acid for 56 days, closer to the targeted pH. Coal ashes also increased the contents of available phosphorus by 2-fold (165 mg/kg) and 11-fold (1,137 mg/kg) for YDBA and YDFA, respectively, compared to the control.

  CONCLUSION:

  The utilization of coal ash with its acidity regulation would be very beneficial to agriculture sector and further suggest promising environmental safety against heavy metals.

• Download53

  Relation of Organic Matter Content and Nitrogen Mineralization of Soils Collected from Pepper Cultivated Land

  Yejin Lee, Seulbi Lee, Yangmin Kim, Yosung Song, Deogbae Lee / Korean Journal of Environmental Agriculture / 2019 / v.38, no.3, 119-123

  https://doi.org/10.5338/KJEA.2019.38.3.26

  Abstract Full-Text PDF

  Abstract

  

  BACKGROUND:

  Estimation of soil nitrogen supply is essential to manage nitrogen fertilization in arable land. In Korea, nitrogen fertilization is recommended based on the soil organic matter content because it is difficult to assess nitrogen (N) mineralization of upland soils directly. In this study, the relationship between soil organic matter (SOM) content and N mineralization was investigated to explore the limitation of using SOM in predicting soil N mineralization.

  METHODS AND RESULTS:

  Soil samples from the 0 to 10 cm depth were collected from 18 individual pepper cultivated fields in Tae-an and Chung-yang provinces before fertilization. N mineralization in the soils was quantified using incubation for 70 days at 30℃. The mineralizable soil N (MSN) was positively correlated with SOM, and the relation equation between MSN and SOM was‘MSN(kg 10a^-1) = 0.2933*SOM(g kg^-1) + 0.0897 (r²=0.6224, p<0.001)’. However, the differences of N mineralization among the soils with the similar concentrations of soil organic matter were about 3 to 4.6 times, suggesting that the other soil factors such as total N concentration or EC should affect N mineralization.

  CONCLUSION:

  We concluded that SOM alone could not reflect the capacity of soil to supply N that is used for recommendation of N fertilization rate. Therefore, other soil properties should be considered to improve N fertilization management in arable land for sustainable agriculture.

• Download53

  Variation of Pesticide Residues in Strawberries by Washing and Boiling Processes

  Se-Yeon Kwak, Sang-Hyeob Lee, Hye-Rin Jeong, Ae-Ji Nam, Aniruddha Sarker, Hyo-Young Kim, Chae-Uk Lim, Hyun-Jeong Cho, Jang-Eok Kim / Korean Journal of Environmental Agriculture / 2019 / v.38, no.4, 281-290

  https://doi.org/10.5338/KJEA.2019.38.4.38

  Abstract Full-Text PDF

  Abstract

  

  BACKGROUND:

  As the demand for strawberries increases, people are paying attention to food safety in strawberry, especially pesticide residues. To remove the pesticides from strawberry, various washing and processing technique in households are additionally required.

  METHODS AND RESULTS:

  Strawberries were washed with water, detergent, alcohol, and ultrasonication and processed to strawberry jam. The mean reduction efficiency according to the washing solvent and method was found to be higher in the order of detergent (42.5%) > alcohol (41.7%) > water (41.3%) > ultrasoniation with alcohol (40.2%) > ultrasoniation with water (38.6%) > ultrasoniation with detergent (36.9%), but there was no significant difference among the treatments. The residue levels of pesticides during processing to jam decreased by 11.9-94.4% for etoxazole, fluopyram, procymidone, spiromesifen, and prochloraz, while the other pesticides were concentrated by boiling, or rather increased by 11.8-40.2%. However, when the residue levels were converted to residual amounts in consideration of the change in weight after processing, the residual amounts of the tested pesticides were reduced by 59.8-98.4% during processing. The processing factor (PF) were different for each pesticide, but PFs were < 1 for all washing solvents and methods, and 0.06-1.40 when processed into jam.

  CONCLUSION:

  To ensure the consumption of pesticide-free strawberry, the most efficient washing method is to immerse the strawberry in fresh water for few minutes, followed by rinsing them under running water.

• Download52

  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.

• Download51

  Relative Effectiveness of Bone Meal as a Phosphorus Fertilizer Compared with Fused Phosphate

  Jong-Bae Chung, Byeong-Ryong Jeong / Korean Journal of Environmental Agriculture / 2017 / v.36, no.1, 1-6

  https://doi.org/10.5338/KJEA.2017.36.1.01

  Abstract Full-Text PDF

  Abstract

  

  BACKGROUND:

  Bone meal is commonly used as a phosphorus (P) fertilizer in organic farming. Effectiveness of bone meal was compared with mineral P fertilizer to elucidate the optimum application rates of bone meal in crop production.

  METHODSANDRESULTS:

  The effects of bonemeal and fused phosphate on plant growth and P uptake were determined in a pot experimentwithmaize (Zeamays L.) in a clay loam soil. Bone meal and fused phosphate were applied at 150 and 300 mg P₂O₅/kg soil, and maize was grown for 3 consecutive growth periods of 4 to 5 weeks each. As compared with fused phosphate, total shoot growth of maize per pot was 3-6% lower in bone meal fertilization, and the difference was not significant in the application of 300 mg P₂O₅/kg. At the same P application rate, uptake of P by maize plants was 7-9% lower in bone meal treatment. The P use efficiency in bone meal treatments ranged from11.9-13.6%, equivalent to 73-84% of the efficiency for fused phosphate treatments.

  CONCLUSION:

  The equivalence of immediate effectiveness of bone meal as a P fertilizer was at least 90% compared with fused phosphate in the pot experimentwithmaize. The results indicate that bone meal could be a reasonable alternative to chemical P fertilizers.

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  Free Amino Acid Composition of Korean Spinach (Spinacia oleracea) Cultivars as Influenced by Different Harvesting Time

  Young-Eun Yoon, Saranya Kuppusamy, Song Yeob Kim, Jang Hwan Kim, Yong Bok Lee / Korean Journal of Environmental Agriculture / 2016 / v.35, no.2, 104-110

  http://dx.doi.org/10.5338/KJEA.2016.35.2.21

  Abstract Full-Text PDF

  Abstract

  

  BACKGROUND:

  There is lack of comprehensive compositional data of the amino acid profile of spinach with regard to different cultivars. A more detailed knowledge in this aspect will be of benefit in the future selection of spinach genotypes with improved nutritional quality.

  METHODS AND RESULTS:

  The effects of cultivar type (Jeoncheonhu, Sagyejul, Namdongcho and Mustang) and harvest time (79^th, 116^th and 145^th days after sowing or DAS) on the concentrations of free amino acids in field-grown spinach (Spinacia oleracea) were examined. About 35 different free amino acids were detected and quantified by the amino acid analyzer. Glutamic acid and proline were identified as the major amino acids, while α -aminoadipic acid and α-aminobutyric acid were present in much lower concentrations. Spinach constituted 1468.4 mg/100 g total free amino acids (TAA), of which essential amino acids, neutral/acidic amino acids and sulphur containing amino acids constituted around 15, 45 and 2% of the TAA, respectively. The most limiting amino acids among the leafy vegetables – cysteine was recorded only in Mustang harvested at 116 DAS. Free amino acid contents did not differ significantly among the spinach cultivars and also at different harvest times.

  CONCLUSION:

  The data show that, either of the spinach cultivars, preferably Mustang harvested on or after 116 DAS can serve as a significant source of nutritionally relevant amino acids to meet the demand of the growing populations.