• 한국농공학회지
• /
• 제11권3호
• /
• pp.1731-1738
• /
• 1969

1. For the purpose of analyzing the plan of new reclamation project and its evaluation, actual studies for the existing polders are required. 2. The variations of the salt content of soil, yields and staus of its plantation have been studied for six areas reclaimed in relatively recent years, including Kangwha, Daechon, Chopo, Eushin, Kwangyang and Chinkyo. 3. The annual yields from the project were only 52 percent in the first year as compared with kilograms per 10 a. in the Hachirogata polder in Japan. 4. Such a low productivity in the existing polders in Korea is chiefly by the high ground water table, unfavourable conditions of subdrainage in the root zone, and saline damages of existing high salt content. That is because the depth of drainage ditches is too shallow and layout distance between every drainage ditches is also too long. 5. In order to overcom such a uncertiainties, the drainagedistance suitable for these areas has been Calculated by using the Donnans formula. Applying to the formula, drainage facilities are so densie that land use capability may be decreased. 6. For the purpose of ensuring the effective desalinization and high land use capability, feasible interval to establish the culvert has been studied in accordance with both formulas of Donnan and Hoogan. 7. In order to accomplish the early desalinization in both areas of new reclamation or existing polders, the problems of internal drainages should be resolved. for this puprose in addition to the endeavour of the personnels actually engaged in such works. The actual support of the related agencies for financial assitance is required.

• 한국농공학회지
• /
• 제31권1호
• /
• pp.96-105
• /
• 1989

This laboratory study was performed to produce basic data for the estimation of water requirements for desalinization, through analyzing changes of the electrical conductivity and the exchangeable sodium percentage during the desalinization of reclaimed tidelands. Desalinization experiments were carried out by two water management practices, namely, the leaching method by subsurface drainage and the rinsing method by surface drainage, using samples of silt loam soil and silty clay loam soil collected in reclaimed tidelands. The results obtained from this study were summarized as follows : 1. The sample soils used in this study were saline-sodic soils with the high electrical conductivity and the high exchangeable sodium percentage. 2. Changes of the electrical conductivity and the exchangeable sodium percentage with water requirements for desalinization showed a similar tendency in the desalinization experiment by the same water management practice. 3. The regression equation between the relative electrical conductivity(EC/EC) and water requirements for desalinization(Dw/Ds) could be described by Dw/Ds=O. 29x(EC/EC.) -0.982 (Leaching method), Dw/Ds=3. 678X0. 030(EC/EC ) (Rinsing method). 4. The regression equation between the relative exchangeable sodium percentage (ESP/ESP ) and water requirements for desalinization (Dw/Ds) could be expressed in Dw/Ds = 0.039 x (ESP/ESP. ) - 1. 134 (Leaching method), Dw/Ds=7. 197X0. 024(ESP/ESP ) (Rinsing method). 5. It was estimated that water requirements for the adequate desalinization would be Dw/Ds=0.3 (Leaching method) and Dw/Ds=3.0 (Rinsing method)

• 한국작물학회지
• /
• 제42권1호
• /
• pp.112-118
• /
• 1997

본 연구는 신간탁지 제염에 대한 기초자료를 얻고자 해남간탁지의 토양을 대상으로 제염효과를 분석하고 제염정도에 대한 보리의 생장반응을 조사하였다. 1. 공시토양은 점토함량이 16％이고 함량이 75％인 철사질양토이며 pH는 8.0이고 포화용액의 전기전도도는 59mS / cm인 염류알칼리토양이었다. 2. 토양포화용액의 전기전도도를 4mS / cm이하로 낮추기 위한 제염용수량은 5cm 깊이의 토양에서는 140mm였고, 20cm 깊이의 토양에서는 240mm였다. 3. 제염과정중 토양포화용액의 pH값은 8.0에서부터 8.3까지 높아졌다. 4. 보리종자의 출아률은 80mm이상의 제염용수량에서 76％이상으로 유의적인 변화가 없었다. 5. 보리의 초장은 파종후 1과와 2과에서는 120mm이상의 제염용수량에서, 그리고 파종후 3과와 4과에서는 160mm이상의 제염용수량에서 정상으로 신장하였다. 6. 보리 엽면적과 생체종 파종후 2과에는 120mm이상의 제염용수량에서, 파종후 3과에는 160mm이상의 제염용수량에서 염해의 발생이 없었다. 7. 이상의 결과로 보아 신간탁지에서 보리의 초기 생장기의 정상생육을 위한 토양포화용액의 전기전도도는 20cm 깊이의 토양에서 9mS / cm 이하가 되어야 할 것으로 판단된다.

• 한국지하수토양환경학회지:지하수토양환경
• /
• 제20권6호
• /
• pp.55-61
• /
• 2015

Based on the literature study for the determination of perchlorate in soil we chose the ion chromatography as a measurement method and decided to use 70 mM KOH as an eluent to avoid the interference derived from the co-elution of pyrophosphate (P₂O₇⁴⁻), tripolyphosphate (P₃O₁₀⁵⁻). Also we proposed to use air dried soil through 0.15 mm sieve and distilled water as an extractant. Under the these basic concepts, we carried out the experiments to set up the detail procedure like solid to liquid ratio (S/L ratio), extraction time, device for extraction and indicating factors for quality control (e.g. precision, accuracy, MDL, LOQ). In case of time and device for extraction, 5 hours of mechanical shaking or 1 hour of centrifugation showed better precision and accuracy than that of sonication for 1 hour According to these results, we proposed the extraction method combining 5 hours of mechanical shaking with 1 hour of centrifugation. From the aspect of S/L ratio, the ratio of 1/2 or 1/3 showed resonable precision and accuracy. In case of the ratio of 1/2, there would be some problems in the separation process when the proportion of fine particle is high. Therefore, we proposed the extraction ratio of solid to liquid as 1/3 instead of 1/2. With the consideration of cost effectiveness and soil salinity, we proposed the use of cartridge for removing the interfering anions like chloride, sulfate and carbonate in specific sample such as saline soil.

• 한국토양비료학회지
• /
• 제22권4호
• /
• pp.280-284
• /
• 1989

서남해안(西南海岸)에 분포(分布)되어 있는 간척가능지(干拓可能地) 442,000ha에 대(對)한 토성별(土性別) 분포현황(分布現況)과 물리화학적(物理化學的) 특성(特性)을 조사(調査) 분석(分析)하고 토양(土壤) 성숙(成熟)에 따라 일어나는 상상(像想) 침하량(沈下量)에 대(對)하여 연구(硏究)한 결과(結果)를 요약(要約)하면 다음과 같다. 1. 기존간척지(旣存干拓地) 257,000ha의 토성별(土性別) 분포면적(分布面積)은 미사식양질(微砂埴壤質) 53.0%, 미사사양질(微砂砂壤質) 36.0%, 사질(砂質) 6.0%, 사양질(砂壤質) 5.0% 이다. 2. 간척가능지(干拓可能地) 442,000ha의 토성별(土性別) 분포면적(分布面積)은 미사식양질(微砂埴壤質) 51.0%, 사질(砂質) 20.0%, 사양질(砂壤質) 15.0%, 징사식양질(徵砂埴壤質) 14.0%이며 지역별(地域別) 분포(分布)는 경기(京機)와 전남(全南)은 미사질계토양(微砂質系土壤), 전북(全北)은 조립질토양(粗粒質土壤), 충남지역(忠南地域)은 각종토성(各種土性)이 고르게 분포(分布)되어 있다. 3. 간척가능지토양(干拓可能地土壤)은 염도(鹽度)(EC) 46~51mmhos/cm, E.S.P 25~60%, pH 7.5~8.0으로 U.S.Salinity Lab의 염류토양(鹽類土壤) 분류(分類)로 함염(含鹽)Alkali토와(土) 유사(類似)하다. 4. 간척가능지(干拓可能地)를 농경지(農耕地)로 개발(開發)할때 예상(豫想)되는 침하량(沈下量)은 미사질양토(微砂質壤土) 18.0%, 치사질식양토(徵砂質埴壤土) 21.0%이다.

• 한국환경생태학회지
• /
• 제16권1호
• /
• pp.10-21
• /
• 2002

본 연구에서는 임해매립지에 식재된 조경수목의 피해도와 식재환경으로서 그 영향요인을 분석하고자 하였다. 중부권역과 남부권역의 8개 임해매립지에 식재된 총 42종 1,233주의 수목피해도와 총 6수종 130주의 가지길이 생장량을 조사하였고, 토양의 염분함량, 토양경도, 토양산도, 배수시설 설치여부 등의 토양환경 요인과 해안으로부터의 이격거리 등 임해매립지에서의 식재 환경요인을 분석하였다. 분석결과, 상록침엽수종의 평균 피해도는 32%로 낙엽수종의 평균 피해도 52%보다 낮았다. 피해도가 낮은 수종은 해송, 섬잣나무, 가이즈까 향나무, 아왜나무, 동백나무, 후박나무 등이었고, 피해도가 높은 수종은 단풍나무, 목련, 배롱나무, 감나무, 계수나무, 마가목, 왕벚나무, 소나무, 모과나무, 자귀나무, 느티나무 등이었다. 임해매립지 식재수목의 피해는 토양염분의 영향보다는 강한 해풍, 높은 토양경도, 척박한 토양의 영향이 큰 것으로 판단된다. 수목이 피해를 받는 토양 염분농도 0.03% 이하를 유지하기 위해서는 갯벌토양에서 뿌리 분가지 최소 1.7m의 성토가 필요한 것으로 분석되었으며. 토심 77cm가지 뿌리가 뻗어있는 것으로 조사된 근권층의 토양경도는 4.Skg/㎥로 높았다. 토양산도도 총 25개 시료 중 22개 시료가 pH 3.72~5.85의 산성토양으로 분석되었다. 동일 수종의 경우, 해안에서 이격거리가 큰 경우, 배수시설이 설치되어 있는 경우에 그 피해도가 낮게 나타났다.

• 한국작물학회:학술대회논문집
• /
• 한국작물학회 2001년도 추계 학술대회지
• /
• pp.204-205
• /
• 2001

• 한국작물학회:학술대회논문집
• /
• 한국작물학회 2005년도 춘계학술발표회 요지
• /
• pp.46-47
• /
• 2005

• Mycobiology
• /
• 제47권2호
• /
• pp.230-241
• /
• 2019

The Great Sebkha of Oran is a closed depression located in northwestern of Algeria. Despite the ranking of this sebkha among the wetlands of global importance by Ramsar Convention in 2002, no studies on the fungal community in this area have been carried out. In our study, samples were collected from two different regions. The first region is characterized by halophilic vegetation and cereal crops and the second by a total absence of vegetation. The isolated strains were identified morphologically then by molecular analysis. The biotechnological interest of the strains was evaluated by testing their ability to grow at different concentration of NaCl and to produce extracellular enzymes (i.e., lipase, amylase, protease, and cellulase) on solid medium. The results showed that the soil of sebkha is alkaline, with the exception of the soil of cereal crops that is neutral, and extremely saline. In this work, the species Gymnoascus halophilus, Trichoderma gamsii, the two phytopathogenic fungi, Fusarium brachygibbosum and Penicillium allii, and the teleomorphic form of P. longicatenatum observed for the first time in this species, were isolated for the first time in Algeria. The halotolerance test revealed that the majority of the isolated are halotolerant. Wallemia sp. and two strains of G. halophilus are the only obligate halophilic strains. All strains are capable to secrete at least one of the four tested enzymes. The most interesting species presenting the highest enzymatic index were Aspergillus sp. strain A4, Chaetomium sp. strain H1, P. vinaceum, G. halophilus, Wallemia sp. and Ustilago cynodontis.

• Asian-Australasian Journal of Animal Sciences
• /
• 제18권1호
• /
• pp.32-37
• /
• 2005

Under a typical Mediterranean environment in southern Australia, the evaporation rate increases significantly in hot summers, resulting in highly saline drinking water for grazing animals. Also in the cropping areas, dryland salinity is a problem. Grazing animals under these environments can ingest excessive amount of salt from feed, drinking water and soil, which can lead to a reduction in growth rate. To understand the impact of high salt intake on grazing deer, two experiments were conducted to assess the effect of salt levels in drinking water on feed intake and growth rate of red and fallow weaner deer. The results revealed that fallow deer did not show any abnormal behaviour or sickness when salt level in drinking water was increased from 0% to 2.5%. Feed intake was not affected until the salt content in water exceeded 1.5%. Body weight gain was not affected by 1.2% salt in drinking water, but was reduced as salt content in water increased. Compared with deer on fresh water, the feed intake of red deer on saline water was 11-13% lower when salt level in drinking water was 0.4-0.8%. An increase in salt level in water up to 1% resulted in about a 30% reduction in feed intake (p<0.01). Body weight gain was significantly (p=0.004) reduced when salt level reached 1.2%. The deer on 1% salt tended to have a higher (p=0.052) osmotic pressure in serum. The concentration of P, K, Mg and S in serum was affected when salt level in water was over 1.0%. The results suggested that the salt level in drinking water should be lower than 1.2% for fallow weaner deer and 0.8% for red weaner deer to avoid any reduction in feed intake. Deer farmers need to regularly test the salt levels in drinking water on their farms to ensure that the salt intake of grazing deer is not over the levels that deer can tolerate.