• 한국토양비료학회지
• /
• 제50권4호
• /
• pp.318-324
• /
• 2017

Lime bordeaux mixture (LBM) and lime sulfur mixture (LSM) are representative environmental friendly organic materials for prevention of insect pests in South Korea. Recently, those have been widely used as an alternative for chemical pesticides in eco-friendly farms. However, South Korea has not established even recommendation of LBM and LSM considering the stability of heavy metals in soil. The aim of this study was to evaluate the accumulation of hazardous heavy metals in soil and plant with long-term application of LBM and LSM. Firstly, we investigated the amount of LBM and LSM used per year in several eco-friendly farms to determine a standard application rate of both materials. The pepper plant was grown on the pot in greenhouse for 14 weeks. Both materials were applied at 0, 1, 3, and 9 times of standard application rates (2.56 and $1.28L\;ha^{-1}$ of LBM and LSM per year, respectively). Dry matter yield of pepper and heavy metals (As, Cd, Cu, Hg, Ni, Pb, and Zn) concentration in soil and pepper plant were measured after 14 weeks. Yield of pepper plant did not significantly chang with up to application rate of 1 times, thereafter it markedly decreased with more than 3 times. With increasing LBM and LSM application, the concentration of Cu and Zn in soil significantly increased. Especially, Zn concentration in pepper significantly increased with increasing application rates of both materials. This might resulted in significant decrease in dry matter yield of pepper. The concentrations of those heavy metals in soil did not exceed safety levels ($150mg\;kg^{-1}$ for Cu and $300mg\;kg^{-1}$ for Zn) established by the Korean Soil Environmental Conservation Act as well as concentration of heavy metals in pepper plant by Korean Ministry of Food and Drug Safety. However, particular attention should be paid for heavy metal safety and crop productivity when using LBM and LSM in the organic farm.

• 대한수의학회지
• /
• 제15권1호
• /
• pp.39-45
• /
• 1975

The authors believe that farm livestok will be greatly affected by the marked increasing use of organic phosphate. This study was carried out to observe the clinical signs and histopathological changes of mouse, guinea pig, hamster and rabbit that were orally administered with diazinon used usually as agricultural insecticide, and cholinesterase (ChE) activity was histochemically examined in the liver, heart, kidney, adrenal gland, duodenum and salivary gland of these experimental animals administered with diazinon. The results obtained were as follows: 1. Clinical signs such as dullness, severe salivation, ataxia, dyspnea, irregular slight convulsion and inappetance and as the histopathological changes cloudy swelling, congestion and hemorrhage of parenchymal organs, catarrh or local necrsois of the gastrointestinal tract, congestion or hemorrhage of the other organs were observed. Especially, hemorrhage of adrenal glands (rabbit, guinea pig) and pulmonary congestion and hemorrhage were necessarily constant. 2. In the histochemical study, ChE activity appeared intensely in the liver, heart, medulla of adrenal glands and salivary glands (submaxillary and parotid) of control animals, but ChE activity was negative or markedly decreased in experimental animals administered with diazinon. There was no marked difference between the control and experimental animals in ChE activity of the kidney. 3. Histochemical observation of ChE activity was helpful to explain the clinical signs and histopathological changes and was regarded as a diagnostic method for organic phosphate poisoning.

• 한국유기농업학회지
• /
• 제7권1호
• /
• pp.35-48
• /
• 1998

고추 연작지에서의 녹비작물의 효과를 구명하기 위하여 자운영을 포함한 5개 녹비작물을 동계간에 재배한 결과 자운영은 월동한 개체가 정연없이 동계간에 모두 동사하였으며, 나머지 4종류 녹비작물의 건물중은 호밀> 밀> 보리> 이탈리안 라이그라스의 순이었는데, 호밀의 경우 ha당 건물중이 4.1통이었다. 녹비작물 재배는 고추의 연작장해, 특히 고추 연작지에서 가장 문제가 되는 고추 역병(Phytophthora capsis)의 발생을 경감시키는 효과가 있는 것으로 나타났으며, 果長과 果直徑이 증가하여 고품질의 고추생산이 가능하였다. 1년차로 퇴비만을 사용한 경우 고추의 생육과 수량은 화학비료를 사용한 구에 비하여 떨어지는 결과를 보였으나 퇴비 사용량이 증가할수록 그 차이가 줄어들었으며, 토양중의 유기물 함량이 높아져 퇴비의 지속적 肥效가 인정되었다. 고추영농의 경우 저투입지속농업(LISA)과 일반관행농업을 비교해 보면, 수익-비용 분석결과를 중심으로 한 주요 경제적요인과 기술적요인 양측 모두 뚜렷한 차이가 있었다. 따라서 LISA에 의한 고추영농을 발전시키려면 단순히 기술진보 뿐만 아니라 다양한 현실적 목표를 조화시킬 수 있는 LISA 고추영농에 필요한 다목표 의사결정모형을 개발할 필요가 있는 것으로 나타났다.

• 한국응용곤충학회지
• /
• 제49권4호
• /
• pp.417-422
• /
• 2010

국내에 문제가 되는 담배가루이(Bemisia tabaci)의 살충성 Lecanicillium lecanii Btab01 균주의 생육 특성과 살충력을 검정하였다. PDA, TSA, SDA+Y배지에서 L. lecanii Btab01은 $20{\sim}25^{\circ}C$에서 균사성장이 가장 빨랐으며 $28^{\circ}C$이상에서 성장이 억제되었다. L. lecanii Btab01는 고체배양과 액체배양 시 담배가루이 약충에 대해 살충률에 큰 차이를 보이지는 않았다(93.9%, 98.3%). 농도별로는 $10^5$, $10^6$, $10^7$, $10^8$ cfu/ml에서 각각 5.8%, 33.8%, 77.3%, 98.5%의 살충률을 보였고 각각 16.1일, 7.3일, 5.1일, 3.5일의 $LT_{50}$값을 나타내었다. L. lecanii Btab01을 약충에 처리 후 포화습도 조건을 0 시간 24 시간, 168 시간 유지하였을 때, 0%, 20.3%, 100%의 살충률을 보였다. 균주에 0.5% 식용유를 첨가하였을 때 포자의 발아가 2 배 가량 증가하였으며 균주에 0.1% 식용유를 첨가하여 약충에 처리했을 때(98.6%)가 첨가하지 않았을 때(79.9%)보다 살충력이 향상됨을 알 수 있었다.

• 한국환경농학회지
• /
• 제4권2호
• /
• pp.78-87
• /
• 1985

제지(製紙)슬러지가 논 토양(土壤)의 화학성(化學性)과 수도생육(水稻生育)에 미치는 영향(影響)을 검토(檢討)하기 위하여 슬러지의 시용량(施用量)을 300, 600, 900 및 1,200㎏/10a 으로 달리하고 각(各) 시용수준별(施用水準別)로 C/N 율(率)을 30 : 1 로 조절(調節)하여 pot 시험(試驗)을 실시(實施)함으로써 토양중(土壤中) 질소(窒素)의 형태변화(形態變化), 유기태질소(有機態窒素)의 무기성분(無機成分) 및 중금속함량변화(重金屬含量變化)를 경시적(經時的)으로 조사(調査)한 결과(結果)를 요약(要約)하면 다음과 같다. 1) 토양중(土壤中) amino sugar 및 amino acid 태질소(態窒素), 유기물(有機物) CEC 및 유효규산(有效珪酸)의 함량(含量)은 슬러지구(區)가 3요소구(要素區)에 비(比)하여 증가(增加)하였다. 2) 항온(恒溫) 6주후(週後) 유기태질소(有機態窒素)의 무기화율(無機化率)은 3요소구(要素區)가 12.2%, 슬러지 300㎏/10a 구(區) 12.6%, 슬러지 300㎏/10a의 C/N 율조절구(率調節區) 15.1%, 슬러지 600㎏/10a 구(區) 9.7%, 슬러지 600㎏/10a의 C/N 율조절구(率調節區)는 15.2%로 나타났다. 3) 토양중(土壤中) 동(銅) 및 납의 함량(含量)은 각각(各各) $0{\sim}0.2100$ 및 $0{\sim}0.0013$ ppm 범위(範圍)였으며 크롬 및 카드뮴은 검출(檢出)되지 않았고 토양중(土壤中) 이들 중금속함량(重金屬含量)은 처리간(處理間)에 차이(差異)가 없었다.

• 한국식물병리학회:학술대회논문집
• /
• 한국식물병리학회 2003년도 정기총회 및 추계학술발표회
• /
• pp.100.1-100
• /
• 2003

A dctA gene encoding a protein with identity to a C4-dicarboxylate/H+ was cloned from a beneficial biocontrol bacterium, P. chororaphis O6. Expression of the dctA was induced in minimal medium by several organic acids and was repressed by glucose. Highest expression was observed in early-log cells grown on fumarate and succinate with decline as cells approached late-log phase. The dctA transcript accumulated weakly when cells were grown on malate but strong expression was observed with benzoate. Expression of the dctA transcript was repressed in early-log cells upon addition of glucose to fumarate, but was detected as the cell culture aged. A dctA-deficient mutant of O6, constructed by marker exchange mutagenesis, did not grow on minimal medium containing succinate, benzoate, or fumarate, and growth on malate was delayed. The dctA mutant and wild type grew equally on glucose. The dctA mutant on cucumber roots in sterilized potting soil was colonized at levels comparable to those of the wild type, but induction level of disease resistance by the mutant against target leaf spot disease was decreased. These results may indicate that the dctA is essential for utilization of certain organic acids and its expression is controlled by the availability of sugars. In addition, the dctA is not essenitial for cucumber root colonization, but important for induction of disease resistance.

• Journal of Ecology and Environment
• /
• 제43권1호
• /
• pp.22-30
• /
• 2019

Background: Piton du Milieu (PdM) impounding reservoir is suspected to be eutrophic based on the elevated level of orthophosphate and nitrate. Water supplies from three adjacent rivers are primarily thought to contribute to the nutrient enrichment of the reservoir. It is also suspected that there is leaching of orthophosphate, nitrate and organic matter into the rivers during rainfall events and also as a result of anthropogenic activities within the catchment area. The aim of this study was to ascertain the impact of nutrient loading on the water quality of PdM water and on the population of freshwater microalgae in the reservoir. The enumeration and identification of algae from PdM were performed by differential interference contrast microscopy. Dissolved oxygen (DO) and pH were determined by electrometric methods, whereas nutrient levels, silica and total organic carbon (TOC) were determined by instrumentation techniques. Results: Annual mean orthophosphate, nitrate and total organic carbon input from the three feeders within the catchment area of PdM reached levels as high as 0.09 mg/L, 0.4 mg/L and 2.62 ppm respectively. Over a 12-month period, mean TOC concentration in the reservoir was 2.32 ppm while the mean algal cell count was 4601 cells/mL. The dominant algal species identified were Oscillatoria, Cyclotella, Navicula and Cosmarium. Conclusion: This study highlights the trophic state of the reservoir water and clearly points to the need for constant monitoring in order to avoid the occurrence of an impending harmful algal bloom.

• 한국유기농업학회지
• /
• 제30권1호
• /
• pp.103-118
• /
• 2022

Photorhabdus is a bacterial symbiont of entomopathogenic nematodes of the genus Heterorhabditis in the family Heterorhabditidae. Photorhabdus is known to have nematicidal activity in addition to insecticidal activity. P. temperata isolated from Korean indigenous H. megidis Gwangju strain also produced high control efficacy against root-knot nematode Meloidogyne incognita and root-lesion nematode Pratylenchus penetrans. P. temperata has drawn interest as a potential bionematicide for the control of root-knot nematodes thereby. For the registration as an organic agricultural material, the toxicity of P. temperata was assessed by the acute toxicity test in carp (Cyprinus carpio) and acute oral and dermal toxicity tests in Sprague-Dawley rat (Rattus norvegicus) in compliance with the guidelines of the Rural Development Administration (RDA). In the acute toxicity test in fish, neither lethality nor abnormal responses of carp were observed. Body length and weight of carp and changes in DO concentrations and pH values were not significantly different between the treated group and the untreated control. In the acute oral and dermal toxicity tests, clinical signs, abnormal behavior, mortality, and pathological findings were not observed in all the experimental rats. The weight increment of all rats was normal. Acute toxicity results of P. temperata in fish and rats belonged to categories III, IV, and IV of RDA, respectively. Toxicity results of the present study indicated that P. temperata could be a safe and promising bionematicide against root-knot nematodes and root lesion nematode.

• 접착 및 계면
• /
• 제10권3호
• /
• pp.134-140
• /
• 2009

분자설계를 통하여 측쇄를 변화시킨 아크릴공중합체를 합성하여 아크릴공중합체 점착제와 초박형웨이퍼와의 젖음성 및 점착물성을 조사하였다. 선형 아크릴공중합체를 에폭시계 Tetra-DX 가교제와 반응시켜 3차원 망상구조를 형성하고 가교의 영향을 조사하였다. 계면상호작용보다는 아크릴공중합체의 측쇄변화가 젖음성에 더 큰 영향을 미쳤다. 가교도가 증가할수록 probe tack, peel strength가 감소하는 경향을 나타냈다. 가교에 의해 SAFT 내열성이 증가하였지만 가교제의 함량이 증가하면 오히려 SAFT 내열성이 감소하였다.

• 한국작물학회:학술대회논문집
• /
• 한국작물학회 1998년도 21세기 한반도 농업전망과 대책(한국작물학회.한국육종학회 공동주관 심포지움 회보)
• /
• pp.1-23
• /
• 1998

Sustainable agriculture in Korea will gain important momentum by implementing The Direct Payment Scheme for Environmentally Friendly Agriculture in 1999. The farmers who want to participate in the program will be paid 530,000won/ha directly by the Government in return for engaging sustainable agriculture. The policy scheme which is a pilot program will be restricted to environmentally regulated areas to apply such as water supply protection zone, environmental protection districts and national parks. As a consequence of the policy, the supply of transitional organic agricultural products is expected to increase significantly. However the increased supply of low input agricultural products may have difficulties to find an appropriate marketing channel which is differentiated from the general agricultural product market. Development of an open market system for mass transaction of the low imput agricultural products is necessary. Also various government programs and projects which are designed for clean environment and regional community development must be integrated into the sustainable agriculture program to have synergy effects.