• 제목/요약/키워드: soil chemistry

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Effects of Compost and Gypsum on Soil Water Movement and Retention of a Reclaimed Tidal Land

  • Lee, Jeong-Eun;Yun, Seok-In
    • 한국토양비료학회지
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    • 제47권5호
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    • pp.340-344
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    • 2014
  • Compost and gypsum can be used to ameliorate soil physicochemical properties in reclaimed tidal lands as an organic and inorganic amendment, respectively. To evaluate effects of compost and gypsum on soil water movement and retention as a soil physical property, we measured the soil's saturated hydraulic conductivity and field capacity after treating the soil collected in a reclaimed tidal land with compost and gypsum. Saturated hydraulic conductivity of soil increased when compost was applied at the conventional application rate of $30Mg\;ha^{-1}$. However, the further application of compost insignificantly (P > 0.05) increased saturated hydraulic conductivity. On the other hand, additional gypsum application significantly increased soil saturated hydraulic conductivity while it decreased soil field capacity, implying the possible effect of gypsum on flocculating soil colloidal particles. The results in this study suggested that compost and gypsum can be used to improve hydrological properties of reclaimed tidal lands through increasing soil water retention and movement, respectively.

Soil salinity shifts the community structure and diversity of seed bacterial endophytes of salt-sensitive and tolerant rice cultivars

  • Walitang, Denver I.;Ahmed, Shamim;Jeon, Sunyoung;Pyo, Chaeeun;Sa, Tongmin
    • 한국작물학회:학술대회논문집
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    • 한국작물학회 2017년도 9th Asian Crop Science Association conference
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    • pp.244-244
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    • 2017
  • Soil salinity due to accumulation of salts particularly sodium chloride affects agricultural lands and their vegetation. Generally, rice is a moderately sensitive plant with some cultivars with varying tolerance to salinity. Though there are physiological differences between salt-sensitive and salt-tolerant rice cultivars, both are still affected especially during high salinity and prolonged exposure. This also ultimately affects their indigenous bacterial endophytes particularly those that inhabit the rice seed endosphere. This study investigates the dynamic structure of seed bacterial endophytes of salt-sensitive and tolerant rice cultivars grown in different levels of soil salinity. Endophytic bacterial diversity was studied Terminal-Restriction Fragment Length Polymorphism (T-RFLP) analysis. Results revealed a very interesting pattern of diversity and shifts in community structure of bacterial endophytes in the rice seeds. There is a general decrease in diversity for the salt-sensitive rice cultivar, IR29 as soil salinity increases. For the salt-tolerant cultivars, IC32 and IC37, diversity interestingly increased at moderate salinity then decreased at high soil salinity. The patterns of community structure is also strikingly different for the salt-sensitive and salt-tolerant rice cultivars. IR29 has a more even distribution of abundance, but under soil salinity, the community shifted where Curtobacterium, Pantoea, Flavobacterium and Microbacterium become the more dominant bacterial communities. For IC32 and IC37, the dominant bacterial groups under normal stress conditions were also the dominant bacterial groups during salt stress conditions. Their seed bacterial community is dominated by endophytes belonging to Microbacterium, Flavobacterium, Pantoea, Kosakonia and Enterobacter. Stenotrophomonas and Xanthomonas have not changed in terms of abundance under different salinity stress level in the salt-sensitive and salt-tolerant rice cultivars. This study showed that soil salinity greatly influenced the seed bacterial communities of rice seeds irrespective of their physiological tolerance to salinity.

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An overview of applicability of WEQ, RWEQ, and WEPS models for prediction of wind erosion in lands

  • Seo, Il Whan;Lim, Chul Soon;Yang, Jae Eui;Lee, Sang Pil;Lee, Dong Sung;Jung, Hyun Gyu;Lee, Kyo Suk;Chung, Doug Young
    • 농업과학연구
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    • 제47권2호
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    • pp.381-394
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    • 2020
  • Accelerated soil wind erosion still remains to date to cause severe economic and environmental impacts. Revised and updated models to quantitatively evaluate wind induced soil erosion have been made for specific factors in the wind erosion equation (WEQ) framework. Because of increasing quantities of accumulated data, the WEQ, the revised wind erosion equation (RWEQ), the wind erosion prediction system (WEPS), and other soil wind erosion models have been established. These soil wind erosion models provide essential knowledge about where and when wind erosion occurs although naturally, they are less accurate than the field-scale. The WEQ was a good empirical model for comparing the effects of various management practices on potential erosion before the RWEQ and the WEPS showed more realistic estimates of erosion using easily measured local soil and climatic variables as inputs. The significant relationship between the observed and predicted transport capacity and soil loss makes the RWEQ a suitable tool for a large scale prediction of the wind erosion potential. WEPS developed to replace the empirical WEQ can calculate soil loss on a daily basis, provide capability to handle nonuniform areas, and obtain predictions for specific areas of interest. However, the challenge of precisely estimating wind erosion at a specific regional scale still remains to date.

토주실험에서 동물용 의약품의 이동 특성 (Mobility Characteristics of Veterinary Antibiotics in Soil Column)

  • 황선영;한만희;조재영
    • Journal of Applied Biological Chemistry
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    • 제55권4호
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    • pp.241-246
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    • 2012
  • 본 연구에서는 토양에 대한 동물용 의약품의 흡 탈착 특성과 토주 실험을 이용한 동물용 의약품의 이동 특성을 조사하였다. 토양 중에서 동물용 의약품 흡 탈착은 Freundlich 흡 탈착등온식에 부합하였다. 흡착상수($K_F$) 값은 oxytetracycline > amoxicillin > sulfathiazole 순으로 나타났다. 100일 동안의 토주실험을 진행한 결과, tetracycline 계열의 oxytetracycline은 토양 내 흡착력이 강해 지하로의 이동이 거의 이루어지지 않는 반면, sulfonamide 계열의 sulfamethoxazole은 토양 흡착은 거의 이루어지지 않고 대부분 중력수를 통한 지하로의 이동량이 매우 높게 나타났다. 이는 oxytetracycline은 토양 중 존재하는 2가 양이온 $Ca^{2+}$ 등과 강하게 흡착되어 토양내 잔류량이 높게 나타날 것이며, amoxicillin과 sulfathiazole은 환경중 유거수나 지하수로 용탈가능성이 높음을 보여주는 지표이다.

Enzyme and Microbial Activities in Paddy Soil Amended Continuously with Different Fertilizer Systems

  • Gadagi, Ravi;Park, Chang-Young;Im, Geon-Jae;Lee, Dong-Chang;Chung, Jong-Bae;Singvilay, Olayvanh;Sa, Tong-Min
    • 한국환경농학회지
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    • 제20권5호
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    • pp.325-329
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    • 2001
  • Soil enzyme and microbial activities are affected by fertilizer and compost applications and can be used as sensitive indicators of ecological stability. Microbial population and soil enzymes viz., dehydrogenase, urease, acid phosphatase and aryl-sulphatase were determined in the long-term fertilizer and compost applied paddy soil. Soil samples were collected from the four treatments (control, compost, NPK and compost+NPK). Long-term NPK+compost application significantly increased activities of urease, dehydrogenase and acid phosphatase than all other treatments. The compost application enhanced activities of urease, dehydrogenase and acid phosphatase than the NPK application. However, arylsulfatase activity was not significantly different between compost and fertilizer application. The highest microbial population was recorded in the NPK+compost treatment. The compost application also resulted in higher microbial population than the NPK application. The above results indicate that ecological stability could be maintained by application of compost alone or with NPK.

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Distribution of Cd, Cu and Zn in a Sewage Sludge-treated Calcareous Soil

  • Lee, Sang-Mo;Cho, Chai-Moo;Yoo, Sun-Ho
    • Journal of Applied Biological Chemistry
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    • 제42권3호
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    • pp.134-139
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    • 1999
  • The distributions of Cd, Cu, and Zn concentration in soil treated with one (1988) or two (1988 and 1993) applications of sewage sludge at rates of 0, 25, 50, and $100Mg\;ha^{-1}$ (dry weight basis) were determined to assess the accumulation and mobility of the heavy metals. The heavy metals accumulated almost entirely in 0 to 15 cm soil depths. Small amounts of the metals moved out of the tillage zone (0-15 cm depth) into the subsoil, but even at the high rate of sewage sludge, little movement of heavy metals occurred below 100 cm depth. The water-extractable Cd, Cu, and Zn concentrations were very low regardless of the rate of sewage sludge application. Availability of metals as determined by DTPA extraction showed the percentage of DTPA-extractable/total concentration increased with sewage sludge application. In the 0-15 cm depth of sewage sludge treated soil, the percentage of DTPA-extractable/total concentration was higher than 46% for Cd, but the value was less than 27% and 17% for Cu and Zn, respectively. The Cd, Cu, and Zn added to this calcareous clay soil by sewage sludge application were not very mobile, and the amount of plant available form was very small.

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Effects of Heavy Metals Pollution in Soil and Plant in the Industrial Area, West ALGERIA

  • Tahar, Kebir;Keltoum, Bouhadjera
    • 대한화학회지
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    • 제55권6호
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    • pp.1018-1023
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    • 2011
  • Alzinc is a ursine situated in the Ghazaouet town western part of the republic of Algeria. The purpose of this study was to determine the degree of contamination which soil and plants are burdened with some heavy metals: Pb, Zn, Ni, Cu, Cd, Mn, Cr, Fe and As, then the accumulation of heavy metals in the soil and plant adjacent of area the alzinc ursine was detected and the interdependence of pollution among all three regions of the environment determined. This paper analyzes the heavy metal contents within a 2-years period in the soil and plants at the beginning of the vegetation period. The presence of Pb, Zn, Ni, Cu, Cd, Mn, Cr, Fe and As, in the samples were analyzed using Inductively Coupled Plasma-Atomic Emission Spectrometry (ICP-AES). Measurements of heavy metal contents were performed at three locations in soil and vegetative parts of three-plant types (plant alimentary) period during summer. The plant samples from the immediate environment of the dumpsite were highly contaminated with Zn, Cd and Mn. Three plants species: grape, artichoke and pepper, particularly, grape met some of the conditions to be classified as accumulators for Zn, Cu, Cd and Fe, consequently, she revealed a health risk for human and livestock due to the spread of the metal pollution from waste dumpsites to agricultural areas.

잠재 산성황산염토양의 개량에 관한 연구 (Study on the Improvement of Potential Acid Sulfate Soil)

  • 한강완;전재철;조재영;김금희;안열
    • 한국토양비료학회지
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    • 제29권3호
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    • pp.249-254
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    • 1996
  • 잠재성 산성황산여토양의 개량을 위해 표면배수실험, 배수실험, 토양간혼용, 매몰효과를 실험한 결과는 다음과 같다. 1. 잠재 산성황산염토양의 물관리방법에 있어 표면 배수효과는 없었으며, 배수효과는 1일 이상 배수처리구들 보다 1일 간격 배수 처리시 토양 pH가 다소 높게 유지되었으며 벼 생육상태도 양호하였다. 2. 산화된 잠재성 산성황산염토양을 개량하는데 있어 숙답토와의 동비율 혼합구 및 숙답토 30cm 복토구에서는 수도생육피해가 없어 물리적 개량법으로 이용할 수 있었다. 3. 잠재 산성황산염토양을 파낸 후 효과적인 처리방안으로는 숙답토로 30cm이상 복토한 구 및 숙답토 50%이상 혼합토양구에서 수도피해가 없었으므로 숙답에 성토하는 경우 30cm이상 복토처리가 요구된다.

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