• Proceedings of the Korean Society of Organic Agriculture Conference
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• 2009.12a
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• pp.285-285
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• 2009

벼 유기재배에 있어서 녹비작물을 이용하여 화학비료를 대신하고 있으나 녹비를 이용하기 위해서는 월동 전에 파종하고 이듬해 벼 이앙 전에 토양에 환원을 해야 하는 번거로움이 있다. 따라서 벼 재배 직전에 유기자재를 이용하여 화학비료를 대신하고자 했을 경우 유기자재를 전층시비와 표층시비의 차이에 따른 토양중의 이화학적 특성과 벼의 수량특성의 변화를 구명하였다. 벼 유기재배시 토양양분공급용으로 이용되고 있는 유기자재 4종을 공시하여 유기자재의 질소 성분량(7kg/10a)을 기준으로 하여 이앙 20일전에 시비방법별로 전층시비와 표층시비 2처리로 구분하여 전량 기비시비하고 경운한 다음 동진1호를 시험품종으로 하여 2년 연속 시비처리와 벼를 재배하면서 일어나는 토양의 이화학적 특성과 벼 생육 및 특성의 변화를 시기별로 조사하였다. 시험 전 토양의 화학성은 표층시비구의 염류농도, 가리와 석회의 함량이 다소 높아서 염류농도가 전층 시비구 보다 높은 조건의 토양이었다. 유기자재별 무기화 정도는 전층시비보다 표층시비를 할 때 약 20~30일 정도 빨랐다. 토양 중의유기물 잔존함량은 시비방법간의 큰 차이는 없었으나 표층시비를 할 경우 후기로 갈수록 다소 증가되는 경향이었으나, 전질소 잔존함량은 감소되었다. 토양 액상과 공극율은 전층시비>표층시비였으며, 입단 형성력도 같은 경향이었다. 토양 효소활성은 PME의 활성은 유기자재를 전층처리하였을 때 촉진되었으며, $\beta$-Glucosidase의 활성은 전층보다 표층처리시 활성이 높았다. 시비방법에 따른 벼의 수량 특성은 시비방법별로는 표층시비를 할 경우 전층시비보다 4~7%의 높은 특성을 보였으며, 관행대비 1년차에는 3~9%의 낮았으나, 2년 연속처리를 할 경우 대조구와 비슷해 지는 경향이었다.

• Korean Journal of Environmental Agriculture
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• v.24 no.3
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• pp.253-260
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• 2005

Salt accumulation in the plastic film house soils under continuous cultivation condition causes problems such as salt damages to plants, nitrate accumulation in vegetables, groundwater contamination, etc. due to excess application of fertilizers. Objective of this research was to find an optimum adsorbent to reduce salt concentration in the soil solution of plastic film house soils, where crop injuries have been observed due to the salt accumulation. The soils were significantly high in available P $(1,431{\sim}6,516mg\;kg^{-1}),\;NO_3-N\;(117.60{\sim}395.73mg\;kg^{-1})$, exchangeable Ca $(4.06{\sim}11.07\;cmol_c\;kg^{-1})$ and Mg $(2.59{\sim}18.76\;cmol_c\;kg^{-1})$, as compared to those of the average upland soils in Korea. Soils were treated with each of adsorbent such as ion-exchange resin, zeolite, rice bran, etc. at 2% level and prepared into saturated-paste samples. After equilibrium, soil solution was vacuum-extracted from the soil and measured for changes of the pH, EC, and concentrations of $Ca^{2+},\;Mg^{2+},\;K^+,\;Na^+,\;{NH_4}^+,\;{PO_4}^{3-}\;and\;{NO_3}^-$. Rice bran effectively removed ${PO_4}^{3-}\;and\;{NO_3}^-$ in the soil solution up to 100%. Efficiency was decreased in the orders of rice bran > ion-exchange resin > zeolite. Removal efficiencies of zeolite and ion-exchange resin for $Ca^{2+}$ were ranged from 1 to 65% and from 7 to 61%, respectively. Ion-exchange resin was also effective for removing $Mg^{2+},\;K^+,\;Na^+,\;and\;{NH_4}^+$. Overall results demonstrated that rice bran and ion-exchange resin could be applicable for salt accumulated soil to remove the respective anion and cation.

• Korean Journal of Organic Agriculture
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• v.21 no.4
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• pp.647-657
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• 2013

This experiment was done to evaluate the effects of green manure cropping in green house soil on the changes of soil nutrients and soil microorganisms. The biomass of green manure crop was the highest in ryegrass and nitrogen absorption was the highest in hairy vetch. After cropping, soil phosphate content was the lowest in ryegrass, however, biomass C was the highest of all the green manures. Nitrogen uptake of plant and nitrogen content of the soil after the experiment showed a negative correlation. Total N content of soil was increased in hairy vetch plot, but decreasing tendency showed in the ryegrass and common crabgrass plots. In this results are summarized that green manure cropping greatly reduced salt accumulation in green house.

• Proceedings of the Korean Society of Organic Agriculture Conference
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• 2009.12a
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• pp.304-305
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• 2009

시설재배지의 토양화학성 변화는 작물재배 기간 시비한 화학비료에서 유래된 무기성분 뿐만아니라, 가축분퇴비의 질소성분의 토양잔류량이 요소비료 보다 9.4배 많아 염류집적 주 요인이라는 보고('05 경기도)가 시사하는 봐와 같이 유기자원으로 시용하는 가축분 등의 부산물비료의 무기화에서 유래된 비료성분이 토양염류집적 및 토양환경악화에 더 큰 영향을 미칠 수 있다. 시설재배지의 유기물자원 시용기준이 토양의 특성에 관계 없이 작물에 따라 양적인 시험성적이 주로되어 있으며, 토양검정에 의한 시용기준도 유기물함량에 따라 볏짚, 우분, 돈분 및 계분으로 돠어 있다. 일반노지와 달리 시설재배지에서는 유기물함량이 토양의 비옥도 및 작물생육에 영향을 미치는 것 보다는 토양의 전기전도도(EC)가 더 중요한 작물생육 조건이 될 수 있다. 따라서 토양의 특성에 따라 물질순환에 의한 유기자원 시용기준으로 개선할 필요성이 있다. 시설재배지의 장기적인 토양관리를 위하여 유기물자원에 의한 토양환경 개선 효과를 구명하고자. 무처리, 가축분부산 물비료 관행 시용 기준 대비 볏짚 등 5개의 유기자원을 토양의 무기태질소 함량 대비 유기자원의 탄소함량을 C/N율 10 조절량을 시용하여 시험하였고, 또한 토양의 전기전도도(EC)가 상이한 3개( <2.0 dS/m, 2.0~6.0 dS/m, 6.0 dS/m<)토양에 유기물자원(우드칩)을 C/N율 10, 20, 30 조절하여 수박을 시험작물로 비닐하우스에서 재배하여 수행하였다. 시험 후 토양의 전기전도도(EC)는 시험 전에 비하여 시험 후 토양에서 가축분부산물비료는7% 증가되었으나 유기물자원 처리는 26~33% 경감되는 효과가 있었다. 수박의 과중은 무처리를 제외하고 처리간에 차이가 없었다. 유기물자원 C/N율 조절간에는 시험전 토양의 EC에 따라 차이가 있어 C/N 10 조절에서는 26~44%, C/N 20 조절에서는 30~51%, C/N 30 조절에서는 27~48% 경감효과가 있었으며, 3토양의 평균 토양EC 경감율은 C/N 10, 20, 30 조절에서 각각 34, 39 및 38 % 이었다. 수박의 생육 및 과중은 토양의 C/N율 조절간에는 차이가 없었으나, 토양의 EC 간에는 토양의 EC가 6.0dS/m 이상 토양에서 가장 낮았다. 따라서 탄소원의 유기자원을 C/N율 조절에 의한 시용기준 개선으로 토양의 무기태질소와 토양의 전기전도도(EC)를 경감시켜 친환경적 토양관리와 수박의 수량과 품질을 향상시킬 수 있을 것으로 평가되었다.

• The Korean Journal of Ecology
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• v.23 no.1
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• pp.33-37
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• 2000

Mass loss and changes of mineral nutrients during decomposition of Lepista nuda for 7 weeks from October 7 to December 28 in 1998 were investigated in an oak stand in Kongju, Korea. Content of nitrogen, phosphorus, potassium, calcium and magnesium of the fresh L. nuda was 67.8, 4.1, 47.3, 0.4 and 1.5 ㎎/g, respectively. Content of nitrogen, phosphorus and potassium in L. nuda were much higher than those in leaf litter. After 7 weeks, remaining mass was 35%. Nitrogen, phos- phorus and potassium increased till 5 weeks and then decreased rapidly, however, calcium and magnesium steadily increased during the experimental period. Nitrogen and phosphorus showed a short period of immobilization, and calcium showed no immobilization period during decomposition. After 7 weeks, remaining N, P, K, Ca and Mg was 26.6, 37.5, 28.5, 35.0 and 91.0% of the initial content, respectively. Nutrients could be relocated spatially during the formation and decomposition of fruiting body of Basidiomycetes.

• Applied Biological Chemistry
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• v.51 no.1
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• pp.1-5
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• 2008

Salt accumulation in soils of greenhouse due to the massive application of nitrogen fertilizers causes salt stress on the various crops, a serious problem in domestic agriculture. Since the majority of the salinity is nitrate, the excess nitrate should be removed; therefore, a bacterial strain having high capacity of nitrate uptake and identified as Enterobacter amnigenus GG0461 was isolated from the soils of greenhouse. Optimum conditions for the bacterial growth and nitrate uptake were investigated. GG0461 was able to grow without nitrate; however, nitrate facilitated the growth. The rate of nitrate uptake increased at alkaline pH and both growth and nitrate uptake were maximal at pH 8-9. When the initial pH of culture medium was increased to pH 8 or 9, it was decreased to neutral upon bacterial growth and nitrate uptake. These results imply that the major factor mediating bacterial nitrate uptake is a nitrate/proton antiporter. The fact was supported by the effect of nitrate addition in the absence of nitrate, since the addition of nitrate greatly increased the nitrate uptake and rapidly decreased pH of media.

• Journal of Applied Biological Chemistry
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• v.54 no.2
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• pp.79-83
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• 2011

Over-application of nitrogen fertilizer keeps increasing the salinity in the soils of greenhouse in domestic agriculture. In order to remove the excess amounts of soil nitrate, soil microorganisms which have high capacity of nitrate uptake were isolated from the upland soils and their nitrate uptake activities were measured. Strain GS2 was able to remove 50 mM nitrate within 12 h. After sequence comparison analysis of 16S rRNA gene, the strain was identified and named as Bacillus sp. GS2. When the growth and nitrate uptake activities were measured, maximal values were obtained at $30-40^{\circ}C$ and $37^{\circ}C$, respectively; however, both were optimal at pH 6-8. In the media containing 50 mM nitrate, Bacillus sp. GS2 removed 43 mM nitrate which is corresponding to 86% removal. Similar amounts of nitrate removal were observed at the nitrate concentrations up to 300 mM, showing a saturation in nitrate uptake at concentrations above 50 mM. These results imply that Bacillus sp. GS2 can be a good candidate for the microbial remediation of accumulated environmental nitrate because of its excellent growth and nitrate uptake activity.

• Applied Biological Chemistry
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• v.44 no.2
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• pp.92-96
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• 2001

Soil physical-chemical properties and phosphorous adsorption characteristics were investigated to obtain the informations of the appropriate fertilization and soil management in Baicheng region, China, where agricultural circumstances at present forces to consider the use of land for crop production. Soils were collected from one uncultivated and three cultivated lands on August 1993. Soil $_PH$ was very higher in uncultivated land than in cultivated land, their values were 10.2 and 7.4, respectively. Regardless of cultivation, soil organic matter contents were below 2%, and concentrations of available soil phosphorus expressed as Bray 1 P and Olson P were less than 10 mg P $kg^{-1}$, however, cation exchange capacity was higher than 20 cmol(+) $kg^{-1}$. For uncultivated soil, the values of exchangeable sodium percent and calcium saturation percent were higher than 100%. The major cation of soil saturation paste extracts was Na regardless of land use type. Based on electrical conductivity and sodium adsorption ratio of saturation paste extracts, uncultivated soil was classified as saline-sodic soil and cultivated soil was classified as sodic or normal soil. The maximum adsorption capacity of phosphorus calculated by Langmuir isotherm ranged from 406 to 521 mg P ,$kg^{-1}$. The constraints of soils in Baicheng regions for agricultural cops werw high salt concentration, unfavorable soil chemical composition such as low concentration of available phosphorous, and poor drainage due to soil dispersion by high Na concentration. Therefore, the soil in Baicheng region, need the application of phosphorus fertilizer to increase the soil fertility and the proper soil management to improve the soil physical property especially permeability and soil structure.

• Journal of Soil and Groundwater Environment
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• v.11 no.5
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• pp.51-58
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• 2006

In this study, uptake and toxicity of disel (TPH) by poplar specie, $P.\;nigra{\times}P.\;maximowiczii$ were assessed in laboratory soil column experiments. Poplar cuttings were grown for 2 months and exposed to various concentration (0, 200, 500, 1000, 2000 mg/kg) of disel for a period of 60 days. For disel removal experiments, disel was effectively removed in the range of lower concentration. but, the removal rate of disel was rapidly decreased as increasing initial disel concentrations. For the this reason, toxicity effetcs were evaluated by measuring in poplar cutting mass variation and monitoring transpiration. Exposure on higher disel concentration resulted in decrease of biomass and transpiration accompanied by chlorosis and abscission, indicating toxic effect of disel on the poplar tree. And also, we have observed that both removal efficiency of disel and the microbial activity were higher at the bottom of the soil column. It was suggested that the plant formed the root zone at contaminated soil, stimulated microbial activity by plant root exudates, and played an important role in enhanced biodegradation of disel.

• Korean Journal of Soil Science and Fertilizer
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• v.8 no.1
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• pp.19-23
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• 1975

In order to find out the effect of long-term annual additions of organic matter on the physico-chemical properties of paddy soil, the soil with and without compost application has been analysed. 1. There was no significant difference in the particle size distribution between compost and uncompost treatment, however, hydraulic conductivity, sedimention volume were remarkedly increased in compost. 2. Bulk density and soil strength were decreased in organic matter additions, but porosity increased. 3. Relative to Atterberg Limits, liquid limit, plastic limit, and elastic index were increased in compost. 4. Aggregate size distribution was slightly increased in additions of organic matter. 5. Regarding to chemical properties, pH, organic matter content, C.E.C. and extractable cation were increased in organic matter additions.