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Open Access Journal

Korean Journal of Environmental Agriculture

p-ISSN 1225-3537
e-ISSN 2233-4173

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The Korean Journal of Environmental Agriculture is an official publication of the Korean Society of Environmental Agriculture. It is published quarterly a year, March 31, June 30, September 30, and December 31, and distributed to more than 700 members including individuals and institutions. The abbreviated title is ‘Korean J. Environ. Agric.’ The journal was launched on June 30 in 1982, the Print ISSN was issued on October 30, 1992 (Volume 11, No. 2) while the Online ISSN was issued on December 31, 2010 (Volume 29, No. 4). Whole document of a part of the articles in this journal are listed in the Google Scholar, Korea Citation Index (KCI) and ScienceCentral. The full text is freely available from http://www.korseaj.org.

Creative Commons Attribution Non-Commercial License

This is an Open-Access article distributed under the terms of the Creative Commons Attribution Non-Commercial License (http://creativecommons.org/licenses/by-nc/3.0) which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited.

Current Issue 2017. Vol.36, Iss.1more..

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

  • Changes in Composition and Content of Flavonoids by Processing Type in Rapeseed (Brassica napus) Flowers
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    BACKGROUND:

    Increased value added by rapeseed (Brassica napus) by-product and the development of a usable rapeseed functional tea.

    METHODS AND RESULTS:

    To develop a usable rapeseed functional tea, the total flavonoid content in the varieties Youngsan, Tammi, Tamra, Naehan, Hanra, Mokpo No. 68, and Mokpo No. 111 was investigated. Effect of three treatments, i.e., drying, leaching, and roasting, on flavonoid contents or flower was tested using multiple processingmethods per treatment. Total flavonoid content decreased under the various drying methods, confirming that flavonoid content is heat-dependent. This findingwasmore pronounced for freezing and oven-drying (15.3 and 13.8 mg/g DW, respectively), with a 10% difference in the total flavonoid content between the two methods. Under leaching conditions, the flavonoid content decreasedwith increasing treatment time.Notably, roasting methods did not result in loss of flavonoid content. The total flavonoid content in the rapeseed varieties decreased in the following order: Youngsan, Tammi, Tamra, Naehan, Hanra, Mokpo No. 68, andMokpo No. 111.

    CONCLUSION:

    The flavonoid content in rapeseed flower was higher in Youngsan than in the other varieties, under processing conditions such as freeze-drying, leaching at 90℃ for 5 min, and roasting.

  • Thermal Stability of Representative Bioactive Compounds in Biopesticide Derived from Castor Oil or Wormseed Extract under Controlled Temperature
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    BACKGROUND:

    Castor oil and wormseed extract are important active ingredients for biopesticide, and ricinoleic acid in castor oil and three monoterpenes (ascaridole, carvacrol and p-cymene) in wormseed extract are known bioactive substances. However, their stabilities had not been studied, even though the stability was the core property for estimation of shelf-life of biopesticide. Aimed to investigate the thermal stabilities of the bioactive substances in castor oil and wormseed extracts.

    METHODS AND RESULTS:

    The contents of ricinoleic acid and three monoterpenes (ascaridole, carvacrol and p-cymene) were analyzed by gas chromatography (GC). The thermal stabilities of the bioactive substance were measured at 0℃, 23℃, 30℃, 40℃, 45℃and 54℃for 84 d. The half-lives of ricinoleic acid in biopesticides was ranged from 28.9 d to 57.8 d at 30℃, and the stability of pure castor oil were located in the range (t1/2=46.2 d for Indian product and 27.7 d for Korean product) at the same temperature. The half-lives of the total monoterpenes in biopesticides were ranged from 3.9 d to 27.7 d at 30℃. Among the monoterpenes, the stability ascaridole and p-cymene were decreased in acidic condition. All the bioactive substances showed similar stability on the different thermal conditions.

    CONCLUSION:

    The half-lives ofmost bioactive substance fromcastor oil andwormseed extractswere less than 100 d. To increase the stability of bioactive substance in biopesticide, stabilizing additives like antioxidant and oxygen remover should be considered to extend of the shelf-life.

  • Adsorption Characteristics of Copper using Biochar Derived from Exhausted Coffee Residue
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    BACKGROUND:

    There is very limited knowledge of the effects of biochar derived fromexhausted coffee residue on metal adsorption processes. Furthermore, only limited information is available on the adsorption mechanism of copper. The aimof this studywas to evaluate the absorption behaviors of copper by biochar derived from exhausted coffee residue.

    METHODS AND RESULTS:

    Biochars produced by pyrolysis of exhausted coffee residue at 300℃(CB300) and 600℃ (CB600) were characterized and investigated as adsorbents for the removal of copper from aqueous solution. The results indicated that the adsorption equilibrium was achieved around 2 h and the pseudo-second-order kinetic model fit the data better than the pseudo-first-order kinetic model. The maximum Cu adsorption capacities of CB600 by Freundlich and Langmuir isothermswere higher than those of CB300. The adsorption data were well described by a Langmuir isotherm compare to Freundlich isotherm.

    CONCLUSION:

    Our results suggest that exhausted coffee residue can be used as feedstock materials to produce high quality biochar, which could be used as adsorbents to removal copper.

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