• 한국환경보건학회지
• /
• 제36권4호
• /
• pp.323-336
• /
• 2010

We evaluated the properties of a fixed-bed column reactor for high-concentration tetrachloroethylene (PCE) removal. The anaerobic bacterium Clostridium bifermentans DPH-1 was able to dechlorinate PCE to cis-1,2-dichloroethylene (cDCE) via trichloroethylene (TCE) at high rates in the monoculture biofilm of an upflow fixed-bed column reactor. The first-order reaction rate of C. bifermentans DPH-1 was relatively high at $0.006\;mg\;protein^{-1}{\cdot}l{\cdot}h^{-1}$, and comparable to rates obtained by others. When we gradually raised the influent PCE concentration from $30\;{\mu}M$ to $905\;{\mu}M$, the degree of PCE dechlorination rose to over 99% during the operation period of 2,000 h. In order to maintain efficiency of transformation of PCE in this reactor system, more than 6 h hydraulic retention time (HRT) is required. The maximum volumetric dechlorination rate of PCE was determined to be $1,100\;{\mu}mol{\cdot}d^{-1}l$ of reactor $volume^{-1}$, which is relatively high compared to rates reported previously. The results of this study indicate that the PCE removal performance of this fixed-bed reactor immobilized mono-culture is comparable to that of a fixed-bed reactor mixture culture system. Furthermore, our system has the major advantage of a rapid (5 days) start-up time for the reactor. The flow characteristics of this reactor are intermediate between those of the plug-flow and complete-mix systems. Biotransformation of PCE into innocuous compounds is desirable; however, unfortunately cDCE, which is itself toxic, was the main product of PCE dechlorination in this reactor system. In order to establish a system for complete detoxification of PCE, co-immobilization of C. bifermentans DPH-1 with other bacteria that degrade cDCE aerobically or anaerobically to ethene or ethane may be effective.

• Asian-Australasian Journal of Animal Sciences
• /
• 제26권4호
• /
• pp.509-516
• /
• 2013

This study estimated the fermentation characteristics and nutrient value of corn-lablab bean mixture silages relative to corn silages. The effects of feeding corn-lablab bean mixture silages on nutrient apparent digestibility and milk production of dairy cows in northern China were also investigated. Three ruminally cannulated Holstein cows were used to determine the ruminal digestion kinetics and ruminal nutrient degradability of corn silage and corn-lablab bean mixture silages. Sixty lactating Holstein cows were randomly divided into two groups of 30 cows each. Two diets were formulated with a 59:41 forage: concentrate ratio. Corn silage and corn-lablab bean mixture silages constituted 39.3% of the forage in each diet, with Chinese wildrye hay constituting the remaining 60.7%. Corn-lablab bean mixture silages had higher lactic acid, acetic acid, dry matter (DM), crude protein (CP), ash, Ca, ether extract concentrations and ruminal nutrient degradability than monoculture corn silage (p<0.05). Neutral detergent fiber (NDF) and acid detergent fiber (ADF) concentrations of corn-lablab bean mixture silages were lower than those of corn silage (p<0.05). The digestibility of DM, CP, NDF, and ADF for cows fed corn-lablab bean mixture silages was higher than for those fed corn silage (p<0.05). Feeding corn-lablab bean mixture silages increased milk yield and milk protein of dairy cows when compared with feeding corn silage (p<0.05). The economic benefit for cow fed corn-lablab bean mixture silages was 8.43 yuan/day/cow higher than that for that fed corn silage. In conclusion, corn-lablab bean mixture improved the fermentation characteristics and nutrient value of silage compared with monoculture corn. In this study, feeding corn-lablab bean mixture silages increased milk yield, milk protein and nutrient apparent digestibility of dairy cows compared with corn silage in northern China.

• The Plant Pathology Journal
• /
• 제29권2호
• /
• pp.125-135
• /
• 2013

In agro-ecosystems worldwide, some of the most important and devastating diseases are caused by soil-borne necrotrophic fungal pathogens, against which crop plants generally lack genetic resistance. However, plants have evolved approaches to protect themselves against pathogens by stimulating and supporting specific groups of beneficial microorganisms that have the ability to protect either by direct inhibition of the pathogen or by inducing resistance mechanisms in the plant. One of the best examples of protection of plant roots by antagonistic microbes occurs in soils that are suppressive to take-all disease of wheat. Take-all, caused by Gaeumannomyces graminis var. tritici, is the most economically important root disease of wheat worldwide. Take-all decline (TAD) is the spontaneous decline in incidence and severity of disease after a severe outbreak of take-all during continuous wheat or barley monoculture. TAD occurs worldwide, and in the United States and The Netherlands it results from a build-up of populations of 2,4-diacetylphloroglucinol (2,4-DAPG)-producing fluorescent Pseudomonas spp. during wheat monoculture. The antibiotic 2,4-DAPG has a broad spectrum of activity and is especially active against the take-all pathogen. Based on genotype analysis by repetitive sequence-based-PCR analysis and restriction fragment length polymorphism of phlD, a key 2,4-DAPG biosynthesis gene, at least 22 genotypes of 2,4-DAPG producing fluorescent Pseudomonas spp. have been described worldwide. In this review, we provide an overview of G. graminis var. tritici, the take-all disease, Pseudomonas biocontrol agents, and mechanism of disease suppression.

• 한국초지조사료학회지
• /
• 제16권4호
• /
• pp.283-290
• /
• 1996

This experiment was carried out to determine the effects of soil condition that previous crop cultivated after [TO: Soil of corn cultivated, T1 : Soil of rye monoculture cultivated(l50kg/ha), T2 : Soil of mixedculture cultivated(Rye : Red clover = 120 : 3koa). T3 : Soil of mixed-culture cultivated(Rye : Red clover = 90 : 6kg/ ha), T4 : Soil of mixedculture cultivated(Rye : Red clover = 60 : 9kg/ha), T5 : Soil of mixedculture cultivated (Rye: Red clover = 30 : 12kg/ha), T6 : Soil of red clover monoculture cultivated(l5kgha)) on the growth characteristics and nutrient yield of silage corn. The results are summarized as follows. 1. The plant length of silage corn was high in order of T6>T5>T4 treatment. In the leaf length, T5 and T6 treatment showed short compared to the other treatments, but they were wider than the other treatments in leaf width. In the number of leaf, T6 treatment was the highest as 14 leaves per plant, while T1 treatment showed lower than the other treatments as 12.6 leaves per plant. 2. In the stem hardness, ear length, ear width and ear full degree, soil treatment of red clover mono-culture cultivation(T6) showed higher than the other treatment as 5.1 1kg/$cm^2$, 20.8~~1, 7.7cm and 97%. respectively (P<0.01, 0.05). Ihe leaf of summer depression did not many occurrence, but T6 treatment was lower than the other treatment as 0.8 leaf per plant. 3. ADF and NDF composition were not affected by soil condition. Crude protein composition of T6 treatment was the highest as 7.8%. while TI treatment was the lowest as 6.9%. Fresh weight yield(59,083kg/ha), dry matter yield(21,743kg/ha), crude protein yield(l,369kg/ha) and TDN yield(15,800kg/ha) at T6 treatment were much more increased by 41.9, 47.5, 57.4 and 49% than TI treatment(39,410, 14,259, 827 and 10,056kg/ha).

• 한국잡초학회지
• /
• 제13권2호
• /
• pp.151-158
• /
• 1993

벗풀 단독(單獨) 재배시(栽培時)의 종내(種內) 및 벼와의 종간경합(種間競合) 특성(特性)을 파악(把握)하기 위하여 포장(圃場)과 폿트에서 일련(一聯)의 실험(實驗)을 수행(遂行)하여 다음과 같은 결과(結果)를 얻었다. 1. 벗풀 단독(單獨) 재배시(栽培時) $0.5m^2$당(當) 1본식(本植)한 구(區)에 비(比)해 초장(草長)과 화경수(花莖數)는 10주(株)부터, 엽수(葉數)와 엽장(葉長)은 5주(株)부터 종내경합(種內競合)이 시작(始作)되었고 지상부(地上部) 건물중(乾物重)과 형성(形成)된 지하경수(地下莖數)는 5주(株)부터 현저(顯著)한 감소(減少) 현상(現象)을 나타내면서 종내경합(種內競合)이 시작(始作)되었다. 2. 벼의 이앙(移秧) 본수(本數)를 일정(一定)하게 하고 벗풀 밀도(密度)를 달리한 종간경합실험(種間競合實驗)에서 벼의 초장(草長)은 벗풀을 $0.5m^2$당(當) 15주(株) 재식(栽植)할 때 짧아졌으며, 경수(莖數)는 벗풀 5주(株) 재식구(栽植區)부터 억제(抑制)되었다. 벗풀의 생장량(生長量), 지상부(地上部) 건물중(乾物重)그리고 형성(形成)된 지하경수(地下莖數)는 벗풀 재식밀도(栽植密度)가 증가(增加)함에 따라 감소(減少)되었다. 3. 벗풀의 재식주수(栽植株數)를 일정(一定)하게 하고 벼의 재식밀도(栽植密度)를 달리한 종간경합실험(種間競合實驗)에서 벗풀의 생장량(生長量), 지상부(地上部) 건물중(乾物重), 지하경수(地下莖數) 및 벼의 초장(草長)과 경수(莖數)는 벼 재식본수(栽植本數)가 증가(增加)함에 따라 감소(減少)되었다. 4. 작기별(作期別) 종간경합실험(種間競合實驗)에서 뱃풀 단독재식구(單獨栽植區)에 대한 벗풀과 벼 혼식구(混植區)의 생장비율(生長比率)로 비교(比較)해 본 벗풀의 생장(生長)은 만기이앙(晩期移秧) 재배구(栽培區)보다 조기(早期) 및 보통기이앙(普通期移快) 재배구(栽培區)에서 더 억제(抑制)되었고, 벼의 초장(草長) 및 경수(莖數)는 그의 반대(反對)였다.

• 한국잡초학회지
• /
• 제9권2호
• /
• pp.168-173
• /
• 1989

올챙고랭이의 종내(種內) 및 벼와의 종간경합특성(種間競合特性)을 밝히기 위하여 1/2,000a 규격의 폿트와 포장(團場)에서 일연(一連)의 시험(試驗)을 수행(遂行)하였다. 1. 올챙고랭이 밀도별(密度別) 종내경합(種內競合) 특성(特性) 단식구(單植區)보다 벼 입묘하(立苗下)에서 올챙고랭이 종내경합(種內競合) 시발밀도(始發密度)가 낮아졌으며, 올챙고랭이의 경수증가(莖數增加)에 의한 종내경합(種內競合)은 벼 입묘유무조건(立苗有無條件) 모두에서 폿트당(當) 5주(株)부터 시작(始作)되었다. 건물중(乾物重)은 단식(單植)의 경우 폿트당(當) 10주(株)부터, 그리고 벼 입묘하(立苗下)에서는 15주(株)부터 종내경합(種內競合)이 시작(始作)되었다. 2. 벼 밀도변화(密度變化)에 따른 올챙고랭이의 종간경합(種間競合) 특성(特性) 벼의 초장(草長)은 폿트당(當) 벼 2.6주(株), 분얼수는 2.5주(株) 밀도(密度)부터 감소현상(減少現象)이, 건물중(乾物重)은 2주(株)의 밀도(密度)부터 증가율(增加率)의 순화현상(純化現象)이 초래(招來)되었고, 올챙고랭이의 치명적(致命的)인 종간경합(種間競合)은 폿트당(當) 벼 2.5~3주(株)의 밀도(密度)까지에서 나타났으며, 초장(草長)보다는 경수분화(莖數分化)나 건물생산면(乾物生産面)에서 유의적(有意的)이었다. 3. 벼의 작기간변화(作期間變化)에 따른 올챙고랭이의 종간경합(種間競合) 특성(特性) 초장(草長)은 배와 올챙고랭이 모두 단식(單植)보다는 혼식(混植)에서 증가(增加)되었고 작기(作期)가 늦어질수록 올챙고랭이의 초장(草長)은 짧아졌으나 벼는 길어지는 경향(傾向)이었다. 벼의 분얼수와 올챙고랭이 경수(莖數)의 비율(比率)은 모든 처리(處理)에서 1 : 3 정도(程度)의 일율성(一律性)을 보였고, 작기(作期)가 늦어질수록 감소경향(減少傾向)이 심(甚)하였으며, 지상부(地上部) 거물중(乾物重)역시 만기조건(晩期條件)에서 떨어졌으며 변동폭(變動幅)은 벼보다 올챙고랭이에서 현저하였다. 4. 올챙고랭이 밀도변동(密度變動)에 의한 벼와의 종간경합(種間競合) 특성(特性) 올챙고랭이의 밀도증가(密度增加)로 올챙고랭이에 대한 벼의 초장우위성(草長優位性)(차광기능(遮光機能))은 감소(減少)되는 경향(傾向)이었으며 올챙고랭이의 면적당(面積當) 경수(莖數)와 지상부(地上部) 건물중(乾物重)은 증가(增加)하는 대신 벼의 분얼수와 지상부(地上部) 건물중(乾物重)은 감소(減少)하는 경향(傾向)이었다.

• Journal of Ecology and Environment
• /
• 제34권4호
• /
• pp.333-345
• /
• 2011

Aquatic macrophytes, often also called hydrophytes, are key components of aquatic and wetland ecosystems. This review is to briefly summarizes various macrophyte classifications, and covers numerous aspects of macrophytes' role in wetland ecosystems, namely in nutrient cycling. The most widely accepted macrophyte classification differentiates between freely floating macrophytes and those attached to the substrate, with the attached, or rooted macrophytes further divided into three categories: floating-leaved, submerged and emergent. Biogeochemical processes in the water column and sediments are to a large extent influenced by the type of macrophytes. Macrophytes vary in their biomass production, capability to recycle nutrients, and impacts on the rhizosphere by release of oxygen and organic carbon, as well as their capability to serve as a conduit for methane. With increasing eutrophication, the species diversity of wetland macrophytes generally declines, and the speciose communities are being replaced by monoculture-forming strong competitors. A similar situation often happens with invasive species. The roles of macrophytes and sediment microorganisms in wetland ecosystems are closely connected and should be studied simultaneously rather than in isolation.

• 한국유기농업학회지
• /
• 제24권3호
• /
• pp.525-537
• /
• 2016

본 연구는 유기조사료를 효율적으로 생산하기 위해 대표적인 동계 사료작물인 청보리에 콩과 사료작물(헤어리베치와 사료용 완두)의 혼파와 발효우분을 시용하여 생산성과 사료가치를 평가하고, 토양의 지력 향상과 가축분뇨의 자원화를 위한 발효우분의 적정 시용수준을 구명하여 단위면적당 유기한우 사육능력을 추정하고자 2012~2015년에 실시하였다. 콩과 사료작물의 혼파에 따른 3년 평균 청보리의 건물, 조단백질 및 TDN 수량은 5.55~5.82, 0.49~0.52 및 3.51~3.72 톤/ha으로 단파로 재배했을 경우의 4.44, 0.36 및 2.92톤/ha 보다 유의하게 증가하였으나 혼파구 간에는 차이가 없었고, 발효우분의 질소시용량이 증가함에 따라 무비구에 비해 이들 생산량이 증가하였으며 평균 ha 당 100 kg/ha 이상의 질소시용 시에 무비구보다 유의한 증가를 나타내었다(p<0.05). 청보리의 3년 평균 조단백질 함량, ADF 함량 및 상대 조사료가치(RFV) 등은 단파구(각각 7.89%, 29.71% 및 104.89)보다 콩과 사료작물의 혼파구(각각 8.81~9.02%, 31.71~32.69% 및 105.44~108.83)에서 유의하게 높게 나타났고 NDF와 TDN 함량은 콩과 사료작물의 혼파구가 반대로 유의하게 낮았다(p<0.05). 콩과 사료작물의 혼파에 따른 청보리의 조단백질과 TDN 함량에 유기한우 사육능력(체중 450 kg, 400 g 일당증체 목표)은 2.15~3.66과 2.13~3.39두(평균 2.14~3.54두)로 단파구의 각각 1.93~2.79와 2.18~2.91두(평균 2.06~2.85두)보다 높은 사육능력을 보였으며 이러한 경향은 우분 질소 시용수준이 증가됨에 따라 더욱 뚜렷하였다. 이상의 결과를 종합해 볼 때, 청보리를 재배 시에 콩과 사료작물을 혼파함으로써 단파재배 보다 발효우분의 질소시용수준을 ha 당 50 kg 이상 줄이면서도 건물수량을 포함한 생산성과 유기한우 사육능력 증대는 물론 조단백질 함량 등 사료가치를 향상을 시켜 한우 사양시 조사료자원의 다양화뿐 아니라 저투입에 의한 양질의 유기조사료 생산으로 유기축산물 생산에도 크게 기여하리라 사료된다.

• 한국잡초학회지
• /
• 제9권3호
• /
• pp.177-182
• /
• 1989

1. 비료성분별(肥料成分別)의 올챙고랭이 종간경합특성(種間競合特性) 질소시비량(窒素施肥量) 증가(增加)로 두 식물종(植物種) 모두 초장(草長), 경수(莖數), 건물중(乾物重)이 증대(增大)되었으나 초장(草長)과 경수증가(莖數增加)는 올챙고랭이보다 벼가 민감하였다. 또한 가리시비량(加里施用量) 증가(增加)로 벼는 전반적인 생장(生長)이 촉진(促進)되었으며, 올챙고랭이는 경수(莖數)와 건물중(乾物重) 형성(形成)에서 효과적(效果的)이었다. 2. 수심차이(水深差異)에 따른 올챙고랭이의 종간경합특성(種間競合特性) 두 식물(植物) 모두 밭 조건(條件)보다는 담수심(湛水深)이 깊어질수록 초장(草長)이 커졌으나, 경수(莖數)(분얼수)와 건물중(乾物重)에 있어서는 올챙고랭이의 경우 밭 조건(條件)일수록 벼에 대한 우위성(優位性)이 있었으나 수심(水深) 6~8cm 이상에서는 두 식물종(植物種) 모두 분얼수 및 건물중(乾物重)이 심하게 감소(減少)하였다. 3. 광제한(光制限)에 따른 올챙고랭이의 종간경합특성(種間競合特性) 광제한(光制限)으로 단식(單植)보다 혼식(混植)에서 두 식물(植物) 모두 경수분화(莖數分化)가 비슷한 비율(比率)로 감소(減少)되는 경향(傾向)이었으나 채광역(採光域)의 경엽장(莖葉長)과 경엽중(莖葉重)의 증가폭(增加幅)은 벼보다 올챙고랭이가 컸다. 차광역(遮光域)의 지하부증(地下部重)은 벼보다 올챙고랭이가 단식(單植)보다 혼식(混植)에서 현저히 감소(減少)하는 경향(傾向)이었다.

• 한국초지조사료학회지
• /
• 제16권2호
• /
• pp.133-138
• /
• 1996

To investigate the effects of inorganic phosphate ($P_2O_5$ 200kg/ha), fermented cow manures($P_2O_5$ 200kg/ha, 400kg/ha) and poultry manures($P_2O_5$ 200kg/ha, 400kg/na) levels mixed with sawdust on the soil changes and productivity of alfalfa monoculture, a field experiment arranged by randonmized complete block design was conducted at National Livestock Research Institute in Suwon, September, 1993 to December 1995. The results are as follows. S1. Soil pH was changed from 5.40(before experiment) to 6.17(fermented cow manure, $P_2O_5$ 400kg/ha), 6.76 (fermented poultry manure, $P_2O_5$400kg/ha) and 6.3l(inorganic phosphate, $P_2O_5$ 200kg/ha) at 0~5cm depth of subsoil, respectively. Organic contents after experiment were lower as a range of 2.41%~3.15% than those before experiment. 2. Total nitrogen contents of each treatment showed as 0.13%~0.16% at 0~5cm depth of subsoil comparing with before experiment(0.15%). Available phosphate content of inorganic phosphate($P_2O_5$200kgha) was highest as 405ppm. lowest as 125ppm(fermented poultry manure, $P_2O_5$ 200kg/ha) than before trial(205ppm). 3. K and Ca contents of after experiment were appeared to 0.22%~0.78% and 6.45%~9.45% comparing with before experiment(0.10% and 3.56%), respectively. 4. During two years, average DM yield of fermented cow rnanure($P_2O_5$ 400kg/ha) was highest as 11, 731kg/ha and lowest as 9, 017kg/ha at fermented poultry manure plot($P_2O_5$ 200kg/ha) with as sawdust, but no significant difference was found among treatment(P>0.05). 5. CP production, NEL and TDN yield of fermented cow manure($P_2O_5$ 400kg/ha) were highest as 2, 282kg/ha 69, 900kg/ha and 6, 392kg/ha, respectively, but no significant difference among treatment(P>0.05). 6. In inorganic contents of alfalfas, there was not show same tendency in accordance with treatments. As a results mentioned above, it was possible to use 200kg $P_2O_5/ha$ of fermented cow or poultry manure with sawdust instead of inorganic phosphae fertilizer.