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• View249

  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.

• View232

  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.

• View202

  Effect of Tillage System and Fertilization Method on Biological Activities in Soil under Soybean Cultivation

  Eun-Ji Oh, Ji-Su Park, Jin Yoo, Suk-Jin Kim, Sun-Hee Woo, Keun-Yook Chung / Korean Journal of Environmental Agriculture / 2017 / v.36, no.4, 223-229

  https://doi.org/10.5338/KJEA.2017.36.4.42

  Abstract Full-Text PDF

  Abstract

  

  BACKGROUND:

  Tillage systems and fertilization play an important role in crop growth and soil improvement. This study was conducted to determine the effects of tillage and fertilization on themicrobial biomass Cand dehydrogenase activity of soils in a field under cultivation of soybean.

  METHODS AND RESULTS:

  An experimental plot, located in the temperate climate zone,was composed of two main sectors that were no-tillage (NT) and conventional tillage (CT), and they were subdivided into four plots, respectively, in accordance with types of fertilizers (non fertilizer, chemical fertilizer, hairy vetch, and liquid pig manure).Microbial biomass C and dehydrogenase activity were evaluated from May to July in 2016. The microbial biomass C and dehydrogenase activity of NT soils were significantly higher than those of CT in all fertilizer treatments, and they were further increased in hairy vetch treatment than the other fertilizer treatments in bothNTand CT. The dehydrogenase activity was closely related to microbial biomass C.

  CONCLUSION:

  It is concluded that application of green manure combined with no-tillage can provide viable management practices for enhancing microbial properties of soil.

• View185

  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.

• View125

  Change in Available Phosphate by Application of Phosphate Fertilizer in Long-term Fertilization Experiment for Paddy Soil

  Sun-Gang Yun, Myung-Sook Kim, Seok-Cheol Kim, Seong-Jin Park, Chang-Hoon Lee / Korean Journal of Environmental Agriculture / 2017 / v.36, no.3, 141-146

  https://doi.org/10.5338/KJEA.2017.36.3.27

  Abstract Full-Text PDF

  Abstract

  

  BACKGROUND:

  Phosphorus(P) is a vital factor for rice but excess input of phosphorus fertilizer can cause environmental risk and waste of fertilizer resources. We studied to assess the change of available phosphate, P balance, critical concentration of available phosphate under a rice single system.

  METHODS AND RESULTS:

  The changes of available phosphate of paddy soil were examined from long-term fertilization experiment which was started in 1954 at the National Academy ofAgricultural Science. The treatments were no phosphate fertilization(No fert., andN), phosphate fertilization(NPK, NPKC, and NPKCLS). The available phosphorus concentrations in treatmentswithout phosphate fertilizer (No fert. andN)were decreased continuously. But, after 47 years, available phosphate content in phosphate fertilizer treatment (NPK,NPKC, andNPKCLS) reached at the highest (245~331 mg kg^-1), showing a tendency to decrease afterward. The mean annual P field balance in these treatments (NPK,NPKC, andNPKCLS) had positive values that varied from16.6 to 17.5 kg ha^-1 year^-1, and ratio of residual P were increased. These showed that phosphate fertilizer in soil were converted into the form of residual phosphorus which was not easily extracted by available phosphate extractant. Also, Itwas estimated that the critical value of available phosphate for rice cultivationwas 120mg kg^-1 using Cate-Nelson equation.

  CONCLUSION:

  We concluded that no more phosphate fertilizer should be applied in rice single system if soil available phosphate is higher than the critical P value.

• View97

  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.

• View87

  Effects of Alternative Crops Cultivation on Soil Physico-chemical Characteristics and Crop Yield in Paddy Fields

  Kyunghwa Han, Hyunjun Cho, Heerae Cho, Hyubsung Lee, Junghun Ok, Mijin Seo, Kangho Jung, Yongseon Zhang, Youngho Seo / Korean Journal of Environmental Agriculture / 2017 / v.36, no.2, 67-72

  https://doi.org/10.5338/KJEA.2017.36.2.11

  Abstract Full-Text PDF

  Abstract

  

  BACKGROUND:

  Cultivation of alternative crops in paddy fields is necessary because of the decrease in rice consumption and the increase in excess stock of rice. The studywas conducted to investigate the effects of alternative crops cultivation in paddy fields on soil physico-chemical characteristics and crop yield.

  METHODS AND RESULTS:

  Soybean (Glycine max), red-clover (Trifolium pratense), and water convolvulus (Ipomoea aquatica) were selected for alternative crops in the first and/or second year and ricewas planted in the third year.When alternative cropswere cultivated in the previous year, soil bulk density, soil hardness, and water content were lower than those for rice cultivation. Water-depth decreasing rate and aggregate content were greater for the upland-upland-paddy cropping system than upland-paddy-paddy cropping system. Cultivation of red-clover andwater convolvulus for two years resulted in the high soil organic matter content. In the third year, available phosphate, exchangeable potassium, and soil cation exchange capacity were relatively high when soybean was cultivated in the previous year. In the first year, water convolvulus cultivation showed greater productivity than red-clover cultivation while the opposite pattern was found in the second year. Rice yield in the third year was greater for soybean or red-clover as a previous crop than for water convolvulus as a previous crop.

  CONCLUSION:

  The results suggest that cultivation of alternative crops in paddy fields can improve soil physical properties including bulk density, hardness, water content, and aggregate content as well as rice productivity.

• 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).

• View71

  Temporal Patterns of Pesticide Residues in the Keum, Mangyung and Dongjin Rivers in 2002

  Chan-sub Kim, Hee-Dong Lee, Yang-Bin Ihm, Kyeong-Ae Son / Korean Journal of Environmental Agriculture / 2017 / v.36, no.4, 230-240

  https://doi.org/10.5338/KJEA.2017.36.4.38

  Abstract Full-Text PDF

  Abstract

  

  BACKGROUND:

  To evaluate residues of environmentally concerned pesticides in water system, this monitoring was conducted over three rivers. The residual characteristics and discharging condition of these residues onwater system was investigated.

  METHODS AND RESULTS:

  Total twenty nine sampling sites were selected through main streams and branch streams of Keum, Mangyung and Dongjin rivers, and the water samples from them were regularly collected one month interval, especially biweekly fromMay toAugust in 2002. Of the pesticides monitored, six fungicides which include hexaconazole, isoprothiolane and iprobenfos were detectedwith frequencies of 0.3-50.9%and in their residue level of 0.1-4.7 g/L. Sixteen μ insecticides which include nine organophosphoruses, three carbamates, endosulfan, cypermethrin, buprofezin and fipronil were detected with frequencies of 0.3-32.5% and in their residue level of 0.01-2.8 μg/L. Nine herbicides which include alachlor molinate, anilofos, butachlor, dimepiperate, metolachlor, oxadiazon, pretilachlor and thiobencarbwere detectedwith frequencies of 0.8-22.9% and in their residue level of 0.01-9.07 μg/L.

  CONCLUSION:

  Detection frequencies and residue levels of insecticides and herbicides were the highest in waters sampled inMay and June. Almost pesticides detectedwere for the paddy rice and their residue levels were very low to compare with standard values.

• View63

  Short-Term Fertilization with Hairy Vetch, Compost and Chemical Fertilizer Affect Red Pepper Yield and Quality and Soil Properties

  Gopal Selvakumar, Pyoung Ho Yi, Seong Eun Lee, Seung Gab Han / Korean Journal of Environmental Agriculture / 2018 / v.37, no.1, 9-14

  https://doi.org/10.5338/KJEA.2018.37.1.10

  Abstract Full-Text PDF

  Abstract

  

  BACKGROUND:

  The use of green manure and compost as organic fertilizer may increase crop yield and soil fertility due to improved soil nutrient availability and soil organic matter content (SOM). This study aimed to investigate the effects of hairy vetch (Vicia villosa L.) and compost application on red pepper growth, yield, fruit quality and soil health.

  METHODS AND RESULTS:

  The treatments were no fertilizer (CON), chemical fertilizer (CF), hairy vetch (HV), and livestock compost+HV (LC+HV). Red pepper seedlings (70 days old) were transplanted and maintained in experimental plots for 140 days. Plant dry weight, microand macronutrient contents of plants and soil chemical properties were determined. All fertilizer treatments significantly increased plant dry weight. Fruit yield was significantly highest with HV treatment. As for nutrient content, plants in HV and LC+HV treatments have significantly higher K and Ca contents than the other treatments. Regarding soil properties, HV and LC+HV application significantly altered the soil chemical properties. Significantly higher SOM was observed in HV and LC+HV treated soils.

  CONCLUSION:

  The results of this study suggest that short-term application of hairy vetch and compost is an effective alternative to the conventional chemical fertilizer to increase fruit yield red pepper and improve soil health.

• View62

  Quali-Quantitative Analysis of Flavonoids for Mulberry Leaf and Fruit of ‘Suhyang’

  Wan-Taek Ju, O-Chul Kwon, Min-Ki Lee, Hyun-Bok Kim, Gyoo-Byung Sung, Yong-Soon Kim / Korean Journal of Environmental Agriculture / 2017 / v.36, no.4, 249-255

  https://doi.org/10.5338/KJEA.2017.36.4.39

  Abstract Full-Text PDF

  Abstract

  

  BACKGROUND:

  Globally, mulberry (Morus sp.) is exploited for feeding leaf to silkworms in order to obtain silk fiber or for animal feedstock production. Also, mulberry fruit is known to a by-product that was produced from mulberry tree after harvesting leaves for silkworm rearing, as a yield and consumption of mulberry fruit was increased, it has been fixing to a new income crop.Mulberry leaves and fruits are used for the health benefits of human beings. Mulberry contains various bioactive components, such as alkaloids and flavonoids. Mulberry flavonoids are an important part of the diet because of their effects on human nutrition. The flavonoids in mulberry leaf and fruit of ‘Suhyang’(Morus alba L.) were determined.

  METHODSANDRESULTS:

  Flavonoids formulberry leaf and fruit of ‘Suhyang’ were analysed using ultrahigh performance liquid chromatography coupled with diode array detection and quadrupole time-of-flight mass spectrometry (UPLC-DAD-QTOF/MS) technique. An UPLC-DAD-QTOF/MS system was used, and identification of mulberry leaves constituentswas carried out on the basis of the complementary information obtained fromLC spectra, MS ions, and MS/MS fragments. The mulberry leaf (16 flavonoids) and fruit (9 flavonoids) were isolated and analyzed from Suhyang using UPLC-DAD-QTOF/MS chromatogram. To the best of our knowledge, Quercetin 3-O-(6''-O-malonyl) glucoside and quercetin 3-O-rutinoside (rutin) was detected on the highest content in leaf and fruit, respectively and further researchwill be devoted to evaluate their biological activity.

  CONCLUSION:

  Obtaining information about the concentration of functional materials inmulberry leaves could contribute to the development and promotion of processed, functional products and offer possible industrial use of ‘Suhyang’, holding promises to enhance the overall profitability of sericulture.

• View58

  Acute Oral Toxicity of dsRNA to Honey Bee, Apis mellifera

  Hye Song Lim, Young Jun Jung, Il Ryong Kim, Jin Kim, Sungmin Ryu, Banni Kim, Jung Ro Lee, Wonkyun Choi / Korean Journal of Environmental Agriculture / 2017 / v.36, no.4, 241-248

  https://doi.org/10.5338/KJEA.2017.36.4.36

  Abstract Full-Text PDF

  Abstract

  

  BACKGROUND:

  RNAinterference (RNAi) eliminates or decreases gene expression by disrupting the target mRNA or by interfering with translation. Recently, RNAi technique was applied to generate new crop traits which provide protection against pests. To establish the environmental risk assessment protocol of RNAi LMO in lab scale, we developed dsRNA expression systemusing E. coli and tested acute oral toxicity assay to honey.

  METHOD AND RESULTS:

  The dsRNA expression vector, L4440, was chosen and cloned 240 bp of Snf7 and GFP gene fragment. To develop the maximum dsRNA induction condition in E. coli, we tested induction time, temperature and IPTG concentration inmedia. To estimate the risk assessment of dsRNA to honey bee, it has been selected and cultured with dsRNA supplement for 48 hours according to OECD guideline. As a result, the optimum condition of dsRNA induction was 37℃, 4 hours and 0.4 mM IPTG concentration and the difference between Snf7 and GFP dsRNA molecules from E. coli was not significant in survival and behavior to honey bee. Furthermore, blast search results indicated that effective match of predicted dsRNA fragments were not existed in honey bee genome.

  CONCLUSION:

  In this study,we developed and tested the acute oral toxicity of dsRNA using E. coli expression system to honey bee.

• View48

  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.

• View44

  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.

• View37

  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.

• View36

  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.

• View31

  Nutrient Leaching and Crop Uptake in Weighing Lysimeter Planted with Soybean as Affected by Water Management

  Ye-Jin Lee, Kyung-Hwa Han, Seul-Bi Lee, Jwa-Kyung Sung, Yo-Sung Song, Deog-Bae Lee / Korean Journal of Environmental Agriculture / 2017 / v.36, no.3, 147-153

  https://doi.org/10.5338/KJEA.2017.36.3.30

  Abstract Full-Text PDF

  Abstract

  

  BACKGROUND:

  Soil water content strongly depends on weather condition and irrigation, and it could influence on crop nutrient use efficiency. This study was performed to assess nutrient uptake of soybean by soil water condition.

  METHODS AND RESULTS:

  In this study, nutrient leaching and crop uptake as affacted bywatermanagement practice was investigated using weighing lysimeter which is located in National institute of agricultural science, Wanju, Jeonbuk province fromJune 2015 toOctober 2016. Water supply for soybean (cv. Daewon)wasmanagedwith irrigation and rainfall. Nitrate leaching was greatest in the rainfall treatment at early July 2016.Yield of soybean in the rainfall treatment was only 25%compared to the irrigation due to the drought at flowering and podding period. The uptake of nitrogen was considerably reduced by drought whereas the uptake of phosphorus and potassium was less affected by drought.

  CONCLUSION:

  It was proven that nitrogen loss and uptake were dependent on soil water condition. Therefore, irrigation water management to maintain available soil moisture capacity is critical to nitrogen uptake and yield of soybean.

• 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.

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  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.

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  Monitoring of Pesticides in the Yeongsan and Seomjin River Basin

  Young-Jun Lee, Jeong-Heui Choi, Sang Don Kim, Hee-Jung Jung, Hyung-Jin Lee, Jae-Han Shim / Korean Journal of Environmental Agriculture / 2015 / v.34, no.4, 274-281

  http://dx.doi.org/10.5338/KJEA.2015.34.4.37

  Abstract Full-Text PDF

  Abstract

  

  BACKGROUND:

  A lasting release of low levels of persistence chemicals including pesticides and pharmaceuticals into river has a bad influence on aquatic ecosystems and humans. The present study monitored pesticide residues in the Yeongsan and Seomjin river basins and their tributaries as a fundamental study for water quality standard of pesticides.

  METHODS AND RESULTS:

  Nine pesticides(aldicarb, carbaryl, carbofuran, chlorpyrifos, 2,4-D, MCPA, methomyl, metolachlor, and molinate) were determined from water samples using SPE-Oasis HLB(pH 2) and LC/MS/MS. Validation of the method was conducted through matrix-matched internal calibration curve, method detection limit(MDL), limit of quantification(LOQ), accuracy, precision, and recovery. MDLs of all pesticides satisfied the GV/10 values. Linearity(r²) was 0.9965- 0.9999, and a percentage of accuracy, precision, and recovery was 89.4-113.6%, 3.1-14.0%, and 90.8-106.2%, respectively. All pesticides exclusive of aldicarb were determined in the river samples, and there was a connection between the positive monitoring results and agricultural use of the pesticides.

  CONCLUSION:

  Monitoring outcomes of the present study implied that pesticides were a possible non-point pollutant source in the Yeongsan and Seomjin river basins and tributaries. Therefore, it is required to produce and accumulate more monitoring results on pesticides in river waters to set water quality standards, finally to preserve aquatic ecosystems.