• Title/Summary/Keyword: organic cultivation in rice

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Status and Changes in Chemical Properties of Paddy Soil in Korea (우리나라 논토양의 화학성 현황과 변동)

  • Kang, Seong-Soo;Roh, Ahn-Sung;Choi, Seung-Chul;Kim, Young-Sang;Kim, Hyun-Ju;Choi, Moon-Tae;Ahn, Byung-Koo;Kim, Hyun-Woo;Kim, Hee-Kwon;Park, Jun-Hong;Lee, Young-Han;Yang, Sang-Ho;Ryu, Jong-Soo;Jang, Young-Sun;Kim, Myeong-Sook;Sonn, Yeon-Kyu;Lee, Chang-Hoon;Ha, Sang-Gun;Lee, Deok-Bae;Kim, Yoo-Hak
    • Korean Journal of Soil Science and Fertilizer
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    • v.45 no.6
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    • pp.968-972
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    • 2012
  • Soil chemical properties of agricultural soils in Korea were investigated at four-years interval in order of paddy, plastic film house, upland, and orchard soils since 1999. Paddy soil samples were taken from the surface 15 cm at 4,047, 2,010, 2,110 and 2,110 sites in all provinces of South Korea in 1999, 2003, 2007 and 2010, respectively. Soil chemical properties in Korea except Jeju province were measured. Soil pH and exchangeable calcium and available silicate contents increased with increasing the application rate of silicate fertilizer and with decreasing its application interval. Soil organic matter content also increased from $22.0g\;kg^{-1}$ in 1999 to $26.0g\;kg^{-1}$ in 2011. Average concentration of available phosphate in 2011 was higher than the upper limit of its optimal range for rice cultivation. However, exchangeable magnesium and available silicate contents were below the lower limit of their optimal ranges, which were 80% and 92% of them, respectively.

Heavy Metal Speciation in Compost Derived from the Different Animal Manures (이축분종(異畜糞種) 퇴비에서의 중금속 화학종분화(化學種分化))

  • Ko, H.J.;Choi, H.L.;Kim, K.Y.
    • Journal of Animal Science and Technology
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    • v.46 no.2
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    • pp.273-282
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    • 2004
  • Composting animal manure is one of feasible treatments that reserves some portion of nutrients of manure. Although the application of compost to arable land has many advantages, the repeated cultivation of the agriculture land will accumulate the level of heavy metals in the soil which is potentially hamful to people and animals. Therefore it is important to know the characteristics concentration and species of heavy metals in a variety of chemical fonns than just total content of the metal. Because the metals in different forms have different mobilities and bioavailabilites. The aim of this study was to examine the total content and the chemical forms of the heavy metals; Cr, Ni, Cu, Zn, As, Cd and Pb in the animal manure composted with sawdust or rice hull as a bulking agent. A total of 75 compost samples were collected throughout the country and classified into the three groups in accordance with the characteristics of raw materials: swine manure, poultry manure, and mixed(swine + poultry + cattle)manure. The compost samples were analyzed for total metal content and fractionated by sequential chemical extractions to estimate the quantities of metals: exchangeable, adsorbed, organically bound, carbonate and residual. The results showed that the heavy metal concentrations in all compost samples were lower than the maximum acceptable limits by the Korea Compost Quality Standards. The concentrations of heavy metals in the swine manure compost were higher than those of both the poultry and the mixed manure compost except for Cr. Zn and Cu concentrations of three different compost ranged from 157 to 839 mg Zn/kg DM(dry matter) and from 47 to 458 mg Cu/kg DM, depending on the composition of animal manures. The predominant forms for extracted metals were Cr, Ni, Zn, As and Ph, residual; Cu, organic; and Cd, carbonate. The results suggested that the legal standards for composts should be reexamined to revise the criteria on the total metal content as well as metal speciation.

Consumer Perceptions of Food-Related Hazards and Correlates of Degree of Concerns about Food (주부의 식품안전에 대한 인식과 안전성우려의 관련 요인)

  • Choe, Jeong-Sook;Chun, Hye-Kyung;Hwang, Dae-Yong;Nam, Hee-Jung
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.34 no.1
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    • pp.66-74
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    • 2005
  • This survey was conducted to assess the consumer perceptions of food-related hazard in 500 housewives from all over Korea. The subjects were selected by stratified random sampling method. The survey was performed using structured questionnaire through telephone interview by skilled interviewers. The results showed that 34.6% of the respondents felt secure and were not concerned about food safety, and 65.4% were concerned about food safety. Logistic regression analysis showed that the increasing concern on food brands, food additives (such as food preservatives and artificial color), and imported foodstuffs indicated the current increasing concern on food safety. Other related factors indicating the increasing concern on food safety were education level and care for children's health. The respondents who cared about food safety expressed a high degree of concern on processed foodstuffs such as commercial boxed lunch (93.3%), imported foods (92.7%), fastfoods (89.9%), processed meat products (88.7%), dining out (85.6%), cannery and frozen foods (83.5%), and instant foods (82.0%). The lowest degree of concern was on rice. All the respondents perceived that residues of chemical substances such as pesticides and food additives, and endocrine disrupters were the most potential food risk factors, followed by food-borne pathogens, and GMOs (Genetically Modified Organisms). However, these results were not consistent with scientific judgment. Therefore, more education and information were needed for consumers' awareness of facts and myths about food safety. In addition, the results showed that consumers put lower trust in food products information such as food labels, cultivation methods (organic or not), quality labels, and the place of origin. Nevertheless, the respondents expressed their desire to overcome alienation, and recognized the importance of knowing of the origin or the producers of food. They identified that people who need to take extreme precautions on food contamination were the producers, government officials, food companies, consumers, the consumer's association, and marketers, arranged in the order of highest to lowest. They also believed that the production stage of agriculture was the most important step for improving the level of food safety Therefore, the results indicated that there is a need to introduce safety systems in the production of agricultural products, as follows: Good Agricultural Practice (GAP), Hazard Analysis and Critical Control Point (HACCP), and Traceability System (75).