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• View204

  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.

• View174

  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.

• View149

  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.

• View81

  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.

• View77

  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).

• View69

  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.

• View38

  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.

• View38

  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.

• View35

  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.

• View29

  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.

• View26

  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.

• View26

  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

  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.

• View23

  Effect of Phyllite Application on Physical and Chemical Properties of Soil, Growth and Inorganic Nutrient Uptake of Crops

  Hyun-Tae Kim, Se-Won Kang, Dong-Cheol Seo, Sung-Dong Moon, Ju-Sik Cho / Korean Journal of Environmental Agriculture / 2016 / v.35, no.2, 97-103

  http://dx.doi.org/10.5338/KJEA.2016.35.2.20

  Abstract Full-Text PDF

  Abstract

  

  BACKGROUND:

  Clay mineral is well known to improve physico-chemical of soil. The objective of this study was to investigate the growth characteristics and inorganic nutrient contents of crops with application levels of phyllite.

  METHODS AND RESULTS:

  Both young radish and lettuce were selected as target crops for this study. The experiment was conducted in a wagner pot(1/5000a) in glass house at Sunchon National University. Treatment conditions were divided P0NPK(No phyllite + NPK), P5NPK(phyllite 5 Mg/ha + NPK), P10NPK(phyllite 10 Mg/ha + NPK) and P15NPK(phyllite 15 Mg/ha + NPK) by crops, respectively. Bulk density and porosity of soil in control without treatment conditions were ranged from 1.02 ∼1.04 g/cm³ and 56.5∼57.0%, respectively, and those for treatments with phyllite were in the ranged from 0.94∼1.00 g/cm³ and 58.4∼63.5%, respectively. Dry weights of young radish and lettuce were higher in P15NPK treatment than those in other treatments. The amounts of T-N, T-P and K uptake in young radish with phyllite application treatments were increased 36∼115, 18∼67 and 20∼76% than without phyllite application treatment, respectively. In lettuce treatments, amounts of T-N, T-P and K uptake were intended to all tested treatments similar with result of young radish treatment.

  CONCLUSION:

  Therefore, these results confirm that phyllite application to the soil improves physico-chemical of soil in addition to improving growth of young radish and lettuce.

• View22

  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.

• View21

  Stability of Matrine and Oxymatrine from the Biopesticide from Sophora flavescens under Aquatic and Soil Environment

  Jin Hyo Kim, Geun-Hyoung Choi, Sung-Jin Lim, Byung-Jun Park / Korean Journal of Environmental Agriculture / 2015 / v.34, no.1, 1-5

  http://dx.doi.org/10.5338/KJEA.2015.34.1.01

  Abstract Full-Text PDF

  Abstract

  

  BACKGROUND:

  The stabilities of the two alkaloidal insecticides of S. flavescens including matrine and oxymatrine are important factor to establish expiry date and usage manual for crop protection. However, the environmental stability of the compounds had not been studied with the extract and its commercial biopesticide.

  METHODS AND RESULTS:

  The environmental stabilities of the two alkaloids were performed with extract of S. flavescens, and its two commercial biopesticides both in controlled aquatic and soil conditions. The half-lives of the total matrines for the extract and its two commercial biopesticides were estimated over 200 days both under aerobic and anaerobic water condition. Under dry soil condition, the initial decay rates of the matrines were calculated 0.0804-0.1275 (t_1/2 5.4-8.6 days), and the half-lives under wet soil condition were calculated 33.0-231 days. Total soil bacteria on the wet soil ranged 6.0-8.0 log CFU/g-soil during the experiments period.

  CONCLUSION:

  The aquatic mixture of the extract showed excellent stability both with the extract and its biopesticides, however, the stability of soil mixture were shorter than the aquatic mixture, suggesting that soil metal consider as a catalyst for the degradation of the two alkaloids.

• View20

  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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  Synergistic and Antagonistic Interactions for Pesticide mixtures to Honeybee Larvae Toxicity

  Min Kyoung Paik, Jeong Taek Im, Kyongmi Chon, Kyung-Hun Park, Yong-Soo Choi, Myeong-Lyeol Lee, Chul-Han Bae, Jin-Ho Kim, Byeong Chul Moon / Korean Journal of Environmental Agriculture / 2016 / v.35, no.4, 241-246

  https://doi.org/10.5338/KJEA.2016.35.4.32

  Abstract Full-Text PDF

  Abstract

  

  BACKGROUND:

  Recently, the widespread distribution of pesticides in the hive has been of concern about pesticide exposure on honeybee (Apis mellifera L.) health. Larval toxicity was adapted to assess the synergistic and antagonistic interaction of cumulative mortality to the honeybee larvae of the four most common pesticides detected in pollen.

  METHODS AND RESULTS:

  Acetamiprid(3.0 ㎕/L), chlorothalonil (803.0 ㎕/L), coumaphos (128.0 ㎕/L), and tau-fluvalinate (123.0 ㎕/L) were tested in combination; binary, ternary and four component mixture. Larvae were exposed to four pesticides mixed in diet at the average levels detected in pollen. As a result, synthetic toxicity was observed in the binary mixture of acetamiprid with coumaphos. The binary and ternary component mixtures of tested pesticides have mostly demonstrated additive effect in larval bees. The significant antagonistic effects were found in four parings of mixtures including chlorothalonil added to acetamiprid/tau-fluvalinate or acetamiprid/coumaphos/tau-fluvalinate, and tau-fluvalinate added to acetamiprid/chlorothalonil or acetamiprid/coumaphos/chlorothalonil.

  CONCLUSION:

  Interactions between combinations of four pesticides showed mostly additive or antagonistic effects in larval bees. Therefore, predicting the larval mortality of pesticides mixtures on the basis of the results of single pesticide may actually overestimate the risk. We suggest that pesticide mixture in pollen be evaluated by adding their toxicity together for complete data on interactions.

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  Ecological Characteristics of Vascular Plants by Habitat Types of Dry Field in Jeolla-do, Korea

  Kwang-Jin Cho, Myung-Hyun Kim, Min-Kyeong Kim, Young-Eun Na, Young-Ju Oh, Lak-Jung Choe / Korean Journal of Environmental Agriculture / 2014 / v.33, no.2, 86-102

  http://dx.doi.org/10.5338/KJEA.2014.33.2.86

  Abstract Full-Text PDF

  Abstract

  

  BACKGROUND:

  According to the types of human interference, there are various plants that have strong vitality and ability to breed in the dry field. Recently, climate change alters the geographical distribution and phenology of the plant species. So, we need to understand present occurrence pattern and ecological characteristics of these plants.

  METHODS AND RESULTS:

  The plant species data were obtained from 8 regions in Jeolla-do. Flora investigation was done from May 2013 to September 2013. Habitat type of dry field in Jeolla-do was classified into 3 types (inside of dry field: IDF, embankment around the end of a dry field: EDF, levee slope of dry field: LS). The vascular plants of study area were listed 296 taxa which contain 68 families, 203 genera, 244 species, 43 varieties and 9 forms. The vascular plants of three different habitat types were IDF 174 taxa, EDF 249 taxa and LS 136 taxa. The occurrence rate of Therophyte was arranged by the order of IDF(67.6%), EDF(51.9%), LS(54.3%). Naturalized rate was analysed as IDF 27.9%, EDF 21.0%, LS 18.6%. Urbanization index was analysed as IDF 11.8%, EDF 13.7%, LS 10.0%.

  CONCLUSION:

  With these results, we found that three habitat types were ecological difference affected by the human impacts. Also, we found environmental indicators through the ecological characteristics of flora for the type of habitat of dry field. These indicators will help assess the agriculture environmental variability and the floral change according to the climate change in dry field.

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  Determination of Analytical Method for the Insecticide Clothianidin and its Metabolites in Soil and Surface Water

  Young-Joon Choi, Chan-Hyeok Kwon, Byung-Soo Han, Young-Deuk Lee / Korean Journal of Environmental Agriculture / 2014 / v.33, no.2, 69-77

  http://dx.doi.org/10.5338/KJEA.2014.33.2.69

  Abstract Full-Text PDF

  Abstract

  

  BACKGROUND:

  The purpose of this study was to investigate the effects of clothianidin on the soil in terms of clothianidin dissipation and degradation to evaluate its safety in order to provide an analytical foundation for clothianidin and the 5 metabolites related to it.

  METHODS AND RESULTS:

  High-performance liquid chromatography(HPLC) was used to separate clothianidin and its metabolites in this study. In soil, after suppressing dissociation-proned ions with weak alkalic NH₄OH and extracting the metabolites with methanol, clothianidin, Methylaminoimidazole(MAI), Methylnitroguanidine(MNG), Thiazolylmethylurea(TZMU) and Thiazolylnitroguanidine(TZNG). Thiazolylmethylguanidine(TMG) were extracted with the addition of neutral NH₄OAC to increasing the intensity of ions. Compounding elements were separated by using Hydrometrix (ChemElut^TM) and ion-exchanging Solid-phase extraction(SPE) Strong cation-exchanger(SCX) and C18 were used. The recovery rates of clothianidin and 5 metabolites in soil and water ranged from 87.4% to 104.3%. A standard deviation of our analysis for the soil and water samples were less than 5%.

  CONCLUSION:

  Well accepted detection limits for clothianidin and 5 metabolites in soil samples based on a dissipation analysis is 0.005 mg/kg and 0.001 mg/L in water samples. The dissipation concentration of this study was decided to be enough to evaluate the dissipation levels of clothianidin and its metabolites.