• 제목/요약/키워드: Litter quality

검색결과 80건 처리시간 0.026초

하천수정화 근자연형 인공습지의 초기 인 제거 (Preliminary Phosphorous Removal Rate in a Natural-type Constructed Wetland for Stream Water Treatment)

  • 양홍모
    • 한국환경복원기술학회지
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    • 제5권6호
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    • pp.30-36
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    • 2002
  • A 0.19 hectare natural-type wetland for stream water treatment demonstration was constructed and planted with cattails from April 2001 to May 2001. Part of its bottom surfaces adjacent to levees have a variety of slope of 1 : 4~1 : 15. Two small open water areas were installed, in which emergent plants could not grow. Removal of nutrients from stream waters was a major objective of the wetland. Waters of Sinyang Stream flowing into Kohung Estuarine Lake were pumped and funneled into the wetland. The lake had been formed by a salt marsh reclamation project and was located southern coastal region of Korean Peninsula. Volumes and water quality of inflow and outflow were analyzed from July 2001 through December 2001. Inflow and outflow averaged $120.4m^3/day$ and $112.1m^3/day$, respectively. Hydraulic retention time was about 3.1 days. Average total phosphorous concentration of influent and effluent was $0.19mg/{\ell}$ and $0.075mg/{\ell}$, respectively. Total phosphorous loading rate of inflow and outflow averaged $12.05mg\;m^{-2}\;day^{-1}$ and $4.44mg\;m^{-2}\;day^{-1}$, respectively. Average total phosphorous removal rate in the wetland was $7.61mg\;m^{-2}\;day^{-1}$. Seasonal changes of phosphorous retention rates were observed. The wetland acted as effective phosphorous sinks in the initial stage of the constructed wetland.

Effects of controlled environmental changes on the mineralization of soil organic matter

  • Choi, In-Young;Nguyen, Hang Vo-Minh;Choi, Jung Hyun
    • Environmental Engineering Research
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    • 제22권4호
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    • pp.347-355
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    • 2017
  • This study investigated how the combined changes in environmental conditions and nitrogen (N) deposition influence the mineralization processes and carbon (C) dynamics of wetland soil. For this objective, we conducted a growth chamber experiment to examine the effects of combined changes in environmental conditions and N deposition on the anaerobic decomposition of organic carbon and the emission of greenhouse gases from wetland soil. A chamber with elevated $CO_2$ and temperature showed almost twice the reduction of total decomposition rate compared to the chamber with ambient atmospheric conditions. In addition, $CO_2$ fluxes decreased during the incubation under the conditions of ambient $CO_2$ and temperature. The decrease in anaerobic microbial metabolism resulted from the presence of vegetation, which influences the litter quality of soils. This can be supported by the increase in C/N ratio over the experimental duration. Principle component analysis results demonstrated the opposite locations of loadings for the cases at the initial time and after three months of incubation, which indicates a reduction in the decomposition rate and an increasing C/N ratio during the incubation. From the distribution between the decomposition rate and gas fluxes, we concluded that anaerobic decomposition rates do not have a significantly positive relationship with the fluxes of greenhouse gas emissions from the soil.

CONSIDERATIONS IN THE DEVELOPMENT OF FUTURE PIG BREEDING PROGRAM - REVIEW -

  • Haley, C.S.
    • Asian-Australasian Journal of Animal Sciences
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    • 제4권4호
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    • pp.305-328
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    • 1991
  • Pig breeding programs have been very successful in the improvement of animals by the simple expedient of focusing on a few traits of economic importance, particularly growth efficiency and leanness. Further reductions in leanness may become more difficult to achieve, due to reduced genetic variation, and less desirable, due to adverse correlated effects on meat and eating quality. Best linear unbiased prediction (BLUP) of breeding values makes possible the incorporation of data from many sources and increases the value of including traits such as sow performance in the breeding objective. Advances in technology, such as electronic animal identification, electronic feeders, improved ultrasonic scanners and automated data capture at slaughter houses, increase the number of sources of information that can be included in breeding value predictions. Breeding program structures will evolve to reflect these changes and a common structure is likely to be several or many breeding farms genetically linked by A.i., with data collected on a number of traits from many sources and integrated into a single breeding value prediction using BLUP. Future developments will include the production of a porcine gene map which may make it possible to identify genes controlling economically valuable traits, such as those for litter size in the Meishan, and introgress them into nucleus populations. Genes identified from the gene map or from other sources will provide insight into the genetic basis of performance and may provide the raw material from which transgenic programs will channel additional genetic variance into nucleus populations undergoing selection.

선택실험법을 이용한 해역수질 속성의 비시장적 가치 추정: 인천특별관리해역을 중심으로 (Using a Choice Experiment to Measure the Non-market Value of Sea Water Quality with a Focus on the Incheon Special Area Management Plan)

  • 진세준;박소연;유승훈
    • 해양환경안전학회지
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    • 제24권4호
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    • pp.451-458
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    • 2018
  • 인천연안은 인천광역시, 경기도 김포시 시흥시 안산시 일대로, 양식장에서 발생하는 쓰레기, 어업활동 후 버려진 어구 어망, 육상에서부터 한강을 타고 흘러오는 쓰레기 때문에 인천연안의 해양생태계의 변화가 우려되고 있다. 인천연안이 심각하게 오염되자 해양수산부는 인천연안을 특별관리해역으로 지정하여 해양환경 자산인 해역수질을 보존하고 있다. 이러한 배경 하에서 본 연구는 인천연안 해역수질의 비시장 가치를 선택실험법(choice experiment)을 이용하여 평가한다. 이를 위해, 전국 1,000 가구를 대상으로 면대면 설문조사를 실시하였고, 속성 각각의 한계지불의사액(MWTP, marginal willingness to pay)을 추정한다. 인천연안 해역수질의 속성별 가치(가구당 연간 한계지불의사액)를 추정한 결과, 가구당 연간 해역수질 1 %p 개선의 MWTP는 75원, 동물종의 다양성 증가의 MWTP는 135원, 식물종 다양성 증가의 MWTP는 309원, 해양쓰레기 1 %p 저감의 MWTP는 72원으로 나타났다. 모든 추정결과는 유의수준 1 %에서 유의한 것으로 나타났다. 본 논문의 주요 결과는 정책당국에 해양환경 관리정책 수립과 평가에 유용하게 활용될 수 있다.

리기다소나무와 낙엽송(落葉松) 인공조림지내(人工造林地內) 토양발생(土壤發生) 이산화탄소(二酸化炭素)에 관한 연구(硏究) (Soil Respiration in Pinus rigida and Larix leptolepis Plantations)

  • 손요환;김현우
    • 한국산림과학회지
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    • 제85권3호
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    • pp.496-505
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    • 1996
  • 경기도 양평지역의 유사한 입지에 인공조림된 40년생 리기다소나무와 낙엽송림에서 1995년 5월부터 11월까지 2주 간격으로 soda lime법으로 토양발생 이산화탄소량을 측정하였다. 뿌리호흡을 추정하기 위하여 처리구는 깊이 50-60cm로 주위에 도랑을 파서 뿌리를 끊고 주위의 뿌리가 침입하는 것을 방지하였다. 측정기간동안에 발생한 이산화탄소량은 연구대상 두 수종 간에서 통계적으로 유의한 차이가 있었다(p<0.01). 이산화탄소량은 리기다소나무 대조구에서 가장 높은 $0.38g/m^2/hr$를 보였고, 낙엽송 처리구에서 가장 낮은 $0.31g/m^2/hr$를 보였다. 이산화탄소 발생량이 리기다소나무 임지에서 낙엽송 임지에서보다 높은 것은 리기다소나무림에서 매년 공급되는 지상부 낙엽량이 많은 것과 직접적인 관련이 있는 것으로 보인다. 연간 이산화탄소 발생량은 23-27t/ha/yr로 추정되었다. 대기 및 토양온도와 이산화탄소 발생량 간에는 정의 상관관계가 있었으나 토양습도와 이산화탄소 발생량 간에는 유의한 상관관계가 발견되지 않았다. 대조구와 처리구 간의 이산화탄소 발생량 차이로 추정한 뿌리의 호흡은 전체 토양 발생 이산화탄소량 가운데 약 3%를 차지하고 있었다. 처리구의 도랑 깊이가 암석 등의 장애물로 인해 50-60cm로 한정되었고, 단근 후 곧바로 이산화탄소 발생량을 측정한 것 등이 뿌리 호흡을 과소 측정하게 하는 원인이 되었을 가능성이 있다. 세근을 포함한 지하부 유기물의 공급량 및 유기물의 성질 등 토양 발생 이산화탄소량에 영향을 주는 제반 인자들에 대한 보다 면밀한 장기간의 연구가 산림생태계 내 탄소의 순환을 이해하는데 필요한 것으로 사료된다.

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Effects of Supplementing Different Combinations of Nitrogen Supplements on Digestibility and Performance in Sheep Fed Wheat Straw Diets

  • Li, Yong;Li, Defa;Xing, Jianjun;Li, Shengli;Han, Yang;Han, In K.
    • Asian-Australasian Journal of Animal Sciences
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    • 제15권10호
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    • pp.1428-1432
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    • 2002
  • Thirty-six (20 wethers and 16 rams) adult Gansu highland finewool sheep with an average liveweight of $19.42{\pm}1.83kg$ were used. The sheep were allocated to 4 treatments and confined in individual feeding stalls. The 80 day feeding trial was divided into 2 periods of 38 and 42 days. The sheep had access to clean water and were fed chopped wheat straw ad libitum. Daily supplemented diets of 150 g for the first period and 200 g for the later period were provided. The 4 types of supplements were: Wheat bran type (I), which is the traditional feeding practice in the area and the control group; Linseed cake type (II); Linseed cake+poultry litter type (III); Poultry litter+distiller grains type (IV). The digestibility trial was conducted using a total collection method at the end of the first period in the feeding trial. The results showed that the digestibilities of DM, OM, CP, CF, NDF and ADF in group II and III were increased to more than 50%. CP and NDF digestibility in group II were significantly increased by 23.6% and 25.5% respectively over group I (p<0.01) and by 10.1% and 13.1% respectively over group III (p<0.05). The digestibility of DM, OM, CP, CF, NDF and ADF in group IV was lower than group I by 4.4 to 8.4% (p>0.05). Compared to group I, group II and III increased straw intake by 17.6% (p<0.01) and 10.8% (p<0.05). The ADG increased from 16.2 g in group I to 45.3 g and 32.8 g (p<0.01) in group II and III respectively. The ratio of supplement intake to gain decreased from 10.7 in group I to 3.9 and 5.4 (p<0.01) in group II and III respectively. The ratio of supplement cost to gain also decreased by 60.0% and 64.3%, respectively. The wool growth rate and wool strength in these 2 groups were noticeably improved. This significantly enhanced the wool's textile value. The above parameters in group IV were lower than in group I, except the ratio of supplement cost to gain. This research indicates that local low quality nitrogen resources could be used effectively and economically to improve the utilization of wheat straw fed to sheep on smallholder farms under harsh loess plateau conditions in the winter.

Effects of low-dose organic trace minerals on performance, mineral status, and fecal mineral excretion of sows

  • Ma, Lianxiang;He, Junna;Lu, Xintao;Qiu, Jialing;Hou, Chuanchuan;Liu, Bing;Lin, Gang;Yu, Dongyou
    • Asian-Australasian Journal of Animal Sciences
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    • 제33권1호
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    • pp.132-138
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    • 2020
  • Objective: To investigate the effects of low-dose trace mineral proteinates on reproductive performance, mineral status, milk immunoglobulin contents and fecal mineral excretion of sows. Methods: Eighty crossbred sows (Landrace×Large White) were randomly allocated to two groups in a 135-day trail, from breeding through 21 d postpartum. The two treatments were inorganic trace minerals (ITM): a basal diet+inorganic iron (Fe), copper (Cu), manganese (Mn), and zinc (Zn) at 90, 15, 25 and 90 mg/kg, respectively and organic trace minerals (OTM): a basal diet+proteinates of Fe, Cu, Mn, and Zn at 72, 12, 20, and 72 mg/kg, respectively. Results: Compared with ITM, OTM significantly increased (p<0.05) the number of piglets with birthweight >1 kg, the litter weaning weight, and milk Fe, Cu contents. No significant differences (p>0.05) were observed on sow hair mineral contents or immunoglobulin M (IgM), IgG, and IgA contents in colostrum and milk. In comparsion to ITM, OTM decreased fecal Fe, Cu, Mn, and Zn contents of gestating sows (p<0.01) and Fe, Mn, and Zn in lactating sows (p<0.01). Conclusion: These results indicate that low-dose mineral proteinates can increase the number of piglets with birthweight >1 kg, the litter weaning weight and certain milk mineral concentrations while reducing fecal mineral excretion.

습지에 의한 수질개선 효과 (Water Quality Improvement by Natural Wetland)

  • 김범철;김호섭;전만식;황길순
    • 생태와환경
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    • 제33권3호통권91호
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    • pp.295-303
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    • 2000
  • 10년 전부터 논농사가 중단되고 농업배수와 생활하수가 유입하여 식생이 번성한 습지에서 수질개선 효과를 측정하였다. 습지의 체류시간이 평균 1.2일로 매우 짧음에도 불구하고 SS와 질소의 제거효과는 높게 나타났다. 질산성질소의 제거효율은 평균 유입부하량의 61.4% (26.8 g/m$^{2}$/yr)로 조사항목 중 가장 높았으며, TN은 23.5% (45.1 g/m$^{2}$/yr), SS는 56% (1,515 g/m$^{2}$/yr)의 제거효율을 나타냈다. 습지에서의 유기물 제거효율은 낮았다. COD는 총 유입부하량의 14.2% (104 g/m$^{2}$/yr), VSS는 28.4% (28.4 g/m$^{2}$/yr)가 제거되었으나, DOC는 1.0% (7.6 g/m$^{2}$/yr)로 거의 제거되지 않았다. 평균 유입부하량이 32.5 g/m$^{2}$/yr이었던 TP는 대부분이 제거되지 않았으며 용존인의 경우는 유입된 인의 분해 및 퇴적물에서의 재용출에 의하여 습지로부터 유출되는 특성을 보였다. 습지에 설치된 enclosure에서는 물의 흐름이 차단되는 초기에 질산성질소를 제외하고 거의 모든 물질농도가 높아지는 것으로 나타났다. 이러한 현상은 체류시간이 길어지면서 다시 인을 제외한 SS, 유기물(VSS, COD, DOC)과 총질소는 감소하는 경향을 보였다. 식생과 습지 바닥에 축척되어 있는 식물고사체의 제거는 용존산소의 증가에 의한 질화작용으로 질산성질소의 농도가 증가할 뿐 습지의 정화효율에 미치는 영향은 적었다. 이것은 습지유출수의 유기물농도가 습지 내에 분포하는 식생보다는 퇴적된 유기물과 상부 수층간의 물질교환 평형에 의해 결정되는 것이며, 일부 퇴적층을 제거하고 체류시간을 늘인다고 해도 저질과의 평형농도 이상으로 수질을 개선할 수는 없다는 것을 의미한다. 한편 자연습지는 강우기의 유입수에 대하여 안정적인 처리효율을 보여 유역 비점원에서의 오염물질 유출방지에 활용이 가능할 것으로 보인다.

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하천수정화 연못-습지 시스템 부들 습지셀의 초기 질산성질소 제거 (Nitrate Removal Rate in Cattail Wetland Cells of a Pond-Wetland System for Stream Water Treatment)

  • 양홍모
    • 한국환경복원기술학회지
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    • 제5권6호
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    • pp.24-29
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    • 2002
  • Nitrate removal rate in three cattail wetland cells was investigated. They were a part of a pond-wetland system for stream water treatment demonstration. The system was composed of two ponds and six wetland cells. The acreage of each cell was approximately $150m^2$. The earth works for the system were finished from April 2000 to May 2000 and cattails were planted in the three cells in June 2000. Waters of Sinyang Stream flowing into Kohung Estuarine Lake were pumped into a primary pond, whose effluent was discharged into a secondary pond. The reservoir was formed by a tidal marsh reclamation project and located in southern coastal area of Korean Peninsula. Effluents from the secondary pond were funneled into the three cells. Volumes and water quality of inflow and outflow were analyzed from July 2000 through January 2001. Inflow and outflow averaged $20.2m^3/day$ and $19.8m^3/day$, respectively. Hydraulic retention time was about 1.6 days. Average influent and effluent nitrate concentration was $1.98mg/{\ell}$, $1.38mg/{\ell}$, respectively. Nitrate removal rate averaged $82.6mg\;m^{-2}\;day^{-1}$. Seasonal changes of nitrate retention rates were closely related to those of wetland cell temperatures. The average nitrate removal rate in the cells was a little lower, compared with that of $125.0mg\;m^{-2}\;day^{-1}$ for the wetlands operating in North America. This could be attributed to the initial stage of the cells and inclusion of three cold months into the seven-month study period. Root rhizosphere in wetland soils and litter-soil layers on cell bottoms could not developed. Increase of standing density of cattails within a few years will establish both root zones suitable for the nitrification of ammonia to nitrates and substrates beneficial to the denitrification of nitrates into nitrogen gases, which may lead to increase of the nitrate retention rate.

Evaluation of prooxidant-antioxidant balance in in vitro fertilization-conceived mice

  • Ahmadi, Hamid;Fathi, Fardin;Moeini, Ashraf;Amidi, Fardin;Sobhani, Aligholi
    • Clinical and Experimental Reproductive Medicine
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    • 제45권2호
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    • pp.82-87
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    • 2018
  • Objective: Concerns about the safety of assisted reproductive technology (ART) have been raised, as some studies have shown elevated incidence rates of childhood cancer, asthma, allergies, and other diseases in ART-conceived babies. Findings regarding the health of ART-conceived babies are controversial. The present study was conducted to evaluate the prooxidant-antioxidant balance (PAB) in in vitro fertilization (IVF)-conceived mice in comparison to naturally conceived offspring. Methods: Mice (6-8 weeks) were divided into two groups (IVF-conceived and naturally conceived) matched by sex, age, weight, and litter size. A 1-mL blood sample was taken and the sera were separated. The oxidant-antioxidant balance was evaluated using a fast and reliable PAB assay. The results were expressed as $mean{\pm}standard$ deviation. Results: The mean PAB values (HK units) in the IVF-conceived and naturally conceived groups were $59.70{\pm}22.30$ and $54.70{\pm}18.22$, respectively (p= 0.82). Conclusion: Since free radicals contribute to several pathological conditions and antioxidants play an important protective role against oxidative stress, evaluating the oxidant-antioxidant balance is very important. Although the results of this study showed that the quality of the defense mechanism against free radicals was not significantly different between the IVF-conceived and naturally conceived mice, other parameters of metabolic dysfunction need to be measured.