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• View225

  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.

• View187

  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.

• View162

  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.

• View105

  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.

• View83

  Effect of Phosphate Application on Cadmium Extractability and its Uptake by Rice Cultivated in Contaminated Paddy Soil

  Hyun Ho Lee, Keun Ki Kim, Yong Bok Lee, Youn Sig Kwak, Suk Chul Kim, Sang-beom Lee, Chang Ki Shim, Chang Oh Hong / Korean Journal of Environmental Agriculture / 2016 / v.35, no.4, 235-240

  https://doi.org/10.5338/KJEA.2016.35.4.35

  Abstract Full-Text PDF

  Abstract

  

  BACKGROUND:

  To determine effect of phosphate (P) application on Cadmium (Cd) extractability and its uptake by rice plant in Cd contaminated paddy soil, dipotassium (K₂HPO₄) which was the most effective of P materials to decrease Cd extractability in previous study was selected as P fertilizer.

  METHODS AND RESULTS:

  Dipotassium phosphate was applied at the rates of 0, 78, 234, and 390 kg P₂O₅/ha, and then rice was cultivated in submerged paddy soil from Jun. to Oct. in 2015. Cadmium concentrations in grain, straw, and root of rice plant decreased significantly with increasing application rate of K₂HPO₄. The trend of 1 M NH₄OAc extractable Cd concentration in soil was similar to that of Cd uptake by rice plant. One M NH₄OAc extractable Cd concentration was negatively related to soil pH and negative charge. Alleviation of Cd phytoavailability of rice in paddy soil might be attributed to increase in pH and negative charge of soil. Using a quadratic response model, amount of grain yield were related to K₂HPO₄ application rates as Grain yield = 5.38 + 2.39 ×10^-3 K₂HPO₄ – 6.65 × 10^-6 K₂HPO₄ ² (model R² = 0.968). Using this equations, the greatest grain yield (5.6 Mg/ha) was at the rate of 180 kg P₂O₅/ha. At this application rate of P, the Cd concentration in grain was 0.53 mg/kg, implying ca. 23% lower than the control.

  CONCLUSION:

  From the view point of heavy metal safety and crop productivity, it might be good P management to apply P fertilizer with 4 times higher rate than recommendation (45 kg/ha).

• View74

  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.

• View67

  Effect of Agricultural Practice and Soil Chemical Properties on Community-level Physiological Profiles (CLPP) of Soil Bacteria in Rice Fields During the Non-growing Season

  Jinu Eo, Myung-Hyun Kim, Young Ju Song / Korean Journal of Environmental Agriculture / 2019 / v.38, no.4, 219-224

  https://doi.org/10.5338/KJEA.2019.38.4.30

  Abstract Full-Text PDF

  Abstract

  

  BACKGROUND:

  Soil bacteria play important roles in organic matter decomposition and nutrient cycling during the non-growing season. The purpose of this study was to investigate the effects of soil management and chemical properties on the utilization of carbon sources by soil bacteria in paddy fields.

  METHODS AND RESULTS:

  The Biolog EcoPlate was used for analyzing community-level carbon substrate utilization profiles of soil bacteria. Soils were collected from the following three types of areas: plain, interface and mountain areas, which were tested to investigate the topology effect. The results of canonical correspondence analysis and Kendall rank correlation analysis showed that soil C/N ratio and NH₄⁺ influenced utilization of carbon sources by bacteria. The utilization of carbohydrates and complex carbon sources were positively correlated with NH₄⁺ concentration. Cultivated paddy fields were compared with adjacent abandoned fields to investigate the impact of cultivation cessation. The level of utilization of putrescine was lower in abandoned fields than in cultivated fields. Monoculture fields were compared with double cropping fields cultivated with barley to investigate the impact of winter crop cultivation. Cropping system altered bacterial use of carbon sources, as reflected by the enhanced utilization of 2-hydroxy benzoic acid under monoculture conditions.

  CONCLUSION:

  These results show that soil use intensity and topological characteristics have a minimal impact on soil bacterial functioning in relation to carbon substrate utilization. Moreover, soil chemical properties were found to be important factors determining the physiological profile of the soil bacterial community in paddy fields.

• View57

  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.

• View54

  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.

• View48

  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.

• View39

  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.

• View39

  The Applicability of the Acid Mine Drainage Sludge in the Heavy Metal Stabilization in Soils

  Min-Suk Kim, Hyungi Min, Byeongjoo Lee, Sein Chang, Jeong-Gyu Kim, Namin Koo, Jeong-Sik Park, Gwan-In Bak / Korean Journal of Environmental Agriculture / 2014 / v.33, no.2, 78-85

  http://dx.doi.org/10.5338/KJEA.2014.33.2.78

  Abstract Full-Text PDF

  Abstract

  

  BACKGROUND:

  Recent studies using various industrial wastes for heavy metal stabilization in soil were conducted in order to find out new alternative amendments. The acid mine drainage sludge(AMDS) contains lots of metal oxides(hydroxides) that may be useful for heavy metal stabilization not only waste water treatment but also soil remediation. The aim of this study was to investigate the applicability of acid mine drainage sludge for heavy metals stabilization in soils

  METHODS AND RESULTS:

  Alkali soil contaminated with heavy metals was collected from the agricultural soils affected by the abandoned mine sites nearby. Three different amounts(1%, 3%, 5%) of AMDS were applied into control soil and contaminated soil. For determining the changes in the extractable heavy metals, CaCl₂ and Mehlich-3 were applied as chemical assessments for metal stabilization. For biological assessments, lettuce(Lactuca sativa L.) and chinese cabbage(Brassica rapa var. glabra) were cultivated and accumulation of heavy metals on each plant were determined. It was revealed that AMDS reduced heavy metal mobility and bioavailability in soil, which resulted in the decreases in the accumulation of As, Cd, Cu, Pb, and Zn in each plant.

  CONCLUSION:

  Though the high level of heavy metal concentrations in AMDS, any considerable increase in the heavy metal availability was not observed with control and contaminated soil. In conclusion, these results indicated that AMDS could be applied to heavy metal contaminated soil as an alternative amendments for reducing heavy metal mobility and bioavailability.

• View35

  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.2019.38.2.11

  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.

• View30

  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.

• View29

  Persistent Organic Pollutants (POPs) Residues in Greenhouse Soil and Strawberry Organochlorine Pesticides

  Sung-Jin Lim, Young-Tak Oh, You-Sung Jo, Jin-Ho Ro, Geun-Hyoung Choi, Ji-Yeon Yang, Byung-Jun Park / Korean Journal of Environmental Agriculture / 2016 / v.35, no.1, 6-14

  http://dx.doi.org/10.5338/KJEA.2016.35.1.05

  Abstract Full-Text PDF

  Abstract

  

  BACKGROUND:

  Residual organochlorine pesticides (OCPs) are chemical substances that persist in the environment, bioaccumulate through the food web, and pose a risk of causing adverse effect to human health and the environment. They were designated as persistent organic pollutants (POPs) by Stockholm Convention. Greenhouse strawberry is economic crop in agriculture, and its cultivation area and yield has been increased. Therefore, we tried to investigate the POPs residue in greenhouse soil and strawberry.

  METHODS AND RESULTS:

  Extraction and clean-up method for the quantitative analysis of OCPs was developed and validated by gas chromatography (GC) with electron capture detector (ECD). The clean-up method was established using the modified quick, easy, cheap, effective, rugged, and safe(QuEChERS) method for OCPs in soil and strawberry. Limit of quantitation (LOQ) and recovery rates of OCPs in greenhouse soil and strawberry were 0.9-6.0 and 0.6-0.9 μg/kg, 74.4-115.6 and 75.6-88.4%, respectively. The precision was reliable sincerelative standard deviation (RSD) percentage (0.5-3.7 and 2.9-5.2%) was below 20, which was the normal percent value. The residue of OCPs in greenhouse soil was analyzed by the developed method, and dieldrin, β-endosulfan and endosulfan sulfate were detected at 1.6-23, 2.2-28.4 and 1.8-118.6 μg/kg, respectively. Those in strawberry were not detected in all samples.

  CONCLUSION:

  Dieldrin, β-endosulfan and endosulfan sulfate in a part of investigated greenhouse soil were detected. But those were not detected in investigated greenhouse strawberry. These results showed that the residue in greenhouse soil were lower level than bioaccumulation occurring.

• View27

  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.

• View26

  Effect of KOH Concentrations and Pyrolysis Temperatures for Enhancing NH₄-N Adsorption Capacity of Rice Hull Activated Biochar

  HuiSeon Kim, Seok-In Yun, NanHee An, JoungDu Shin / Korean Journal of Environmental Agriculture / 2020 / v.39, no.3, 171-177

  https://doi.org/10.5338/KJEA.2020.39.3.20

  Abstract Full-Text PDF

  Abstract

  

  BACKGROUND:

  Recently, biomass conversion from agricultural wastes to carbon-rich materials such as biochar has been recognized as a promising option to maintain or increase soil productivity, reduce nutrient losses, and mitigate greenhouse gas emissions from the agro-ecosystem. This experiment was conducted to select an optimum conditions for enhancing the NH₄-N adsorption capacity of rice hull activated biochar.

  METHODS AND RESULTS:

  For deciding the proper molarity of KOH for enhancing its porosity, biochars treated with different molarity of KOH (0, 1, 2, 4, 6, 8) were carbonized at 600℃ in the reactor. The maximum adsorption capacity was 1.464 mg g^-1, and an optimum molarity was selected to be 6 M KOH. For the effect of adsorption capacity to different carbonized temperatures, 6 M KOH-treated biochar was carbonized at 600℃ and 800℃ under the pyrolysis system. The result has shown that the maximum adsorption capacity was 1.76 mg g^-1 in the rice hull activated biochar treated with 6 M KOH at 600℃ of pyrolysis temperature, while its non-treated biochar was 1.17 mg g^-1. The adsorption rate in the rice hull activated biochar treated with 6 M KOH at 600℃ was increased at 62.18% compared to that of the control. Adsorption of NH₄-N in the rice hull activated biochar was well suited for the Langmuir model because it was observed that dimensionless constant (R_L) was 0.97 and 0.66 at 600℃ and 800℃ of pyrolysis temperatures, respectively. The maximum adsorption amount (q_m) and the bond strength constants (b) were 0.092 mg g^-1 and 0.001 mg L^-1, respectively, for the rice hull activated biochar treated with 6 M KOH at 600℃ of pyrolysis.

  CONCLUSION:

  Optimum condition of rice hull activated biochar was 6M KOH at 600℃ of pyrolysis temperature.

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  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.

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  Assessment of Human Bioavailability Quotient for the Heavy Metal in Paddy Soils Below Part of the Closed Metalliferous Mine

  Min-Kyeong Kim, Sung-Chang Hong, Myung-Hyun Kim, Soon-Kun Choi, Jong-Sik Lee, Kyu-Ho So, Goo-Bok Jung / Korean Journal of Environmental Agriculture / 2015 / v.34, no.3, 161-167

  http://dx.doi.org/10.5338/KJEA.2015.34.3.30

  Abstract Full-Text PDF

  Abstract

  

  BACKGROUND

  For the heavy metal cotamination sites, it is very important to estimate the human bioavailability quotients for heavy metals in paddy soils released from mine tailings, which is a major source of contamination in Korea, and to assess the human health risks of heavy metals.

  METHODS AND RESULTS

  This experiment was carried out to investigate the human bioavailability quotient of the heavy metals in paddy soils below part of the closed metalliferous mine. For estimating the human bioavailability quotients for heavy metals, 30 paddy soils below part of the closed mine were collected, and analyzed for Cd, Cu, Pb, Zn, and As using simple bioavailability extraction test(SBET). The quantities of Cd, Cu, Pb, Zn and As extracted from paddy soils below part of the mine by using the SBET analysis were 28.1, 17.3, 34.1, 14.6 and 2.3% respectively. Specially, the maximum values of Cd, Pb and Zn were 73.3, 81.5 and 58.1% of human bioavailability quotient, respectively, and varied considerably among the sampling sites. The human bioavailability quotient of Cd, Cu, Pb and Zn in soils near the closed mine showed significant positive correlation among soil pH value, O.M. and Ex. Ca. contents, while it correlated negatively between soil Ex. K and Ex. Mg contents in paddy soils. Also, its of Cd, Cu, Pb and Zn in paddy soils showed significant positive correlation with 0.1M HCl extractable and total contents, while in soils, it correlated negatively with As content in soil near the closed mine.

  CONCLUSION

  The results of the simple bioavailability extraction test (SBET) indicate that regular ingestion of soils by the local population could be closed a potential health threat due to long-term heavy metals exposure in these mine areas.

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  The Distribution and Behavior of Medically-derived ¹³¹I in the Yeongsan River Basin

  Tae-Woo Kang, Young-Un Han, Won-Pyo Park, Kwang-Duck Song, Soon-Hong Hwang, Tae Gu Kang, Kyung Hyun Kim / Korean Journal of Environmental Agriculture / 2018 / v.37, no.4, 243-250

  https://doi.org/10.5338/KJEA.2018.37.4.33

  Abstract Full-Text PDF

  Abstract

  

  BACKGROUND:

  Recently, the use of ¹³¹I for diagnosis and treatment of thyroid cancer has been increasing, and the radionuclide is continuously released into aquatic ecosystem. This study was carried out to investigate the ¹³¹I concentrations in mainstreams, tributaries, and sewage wastewater treatment plants (SWTPs) of the Yeongsan River Basin and to identify their origins from the assessment of behaviors in the rivers.

  METHODS AND RESULTS:

  The water samples were collected from 19 sites including mainstreams (13), tributaries (4) and SWTPs (2). The ¹³¹I concentration was measured using a gamma-ray spectrometry with a HPGe detector. The ¹³¹I in SWTPs was detected mostly in the discharged effluent at the sampling sites. However, from the surface water of the rivers, ¹³¹I was found only at two sites from each sampling period of the first (MS4 and MS10) and the second half (MS4 and MS7) of the year 2017. The concentrations of ¹³¹I in the effluent discharged from SWTPs were in the range of 0.0870 to 3.87 Bq/L for SWTP1, and <MDC to 0.534 Bq/L for SWTP2. The concentrations of the isotope detected in surface water of the rivers were between 0.0908 to 0.174 Bq/L. The behavior assessment of ¹³¹I in the river revealed that it was not detected in the upper streams of the mainstreams and tributaries, while continuous detection was found in the SWTPs and downstream sites affected by the effluent. However, the concentration of ¹³¹I decreased downstream, eventually becoming undetectable. Such behavior was closely related to the behavior found in the SWTPs.

  CONCLUSION:

  These results indicated that medically-derived ¹³¹I was discharged to the river via sewage effluent at the SWTPs. It is necessary to evaluate the influence of aquatic ecosystems through continuous monitoring in the future.