• Journal of The Korean Society of Grassland and Forage Science
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• v.39 no.2
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• pp.89-96
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• 2019

This study was conducted to investigate 106 grassland farms in six provinces including Chungcheongbuk-do, Gangwon-do, Gyeonggi-do, Gyeongsangbuk-do, Gyeongsangnam-do, Jeju-do, and Jeollanam-do to present their problems and causes by surveying the actual state of grassland farms during three years(2014~2016). The grassland survey was divided into three categories; used as the perennial grasses and annual forage crops (Complied with Grassland Act), not used as the perennial grasses and annual forage crops (Not complied with Grassland Act) and failed to meet the farmer and some items are missing or inaccurate (Insufficient contents). Among the surveyed grassland farm, 68 farms (64.2 %) were complied with Grassland Act but 30 farms (28.3 %) were not complied with Grassland Act. Especially, the 8 farms (26.7 %) not complied with Grassland Act used the grassland as other purposes such as tree growing, golf club and swine farm etc.. Therefore, strict on-site investigation by local governments is required to prevent the grassland from being used by illegal purposes. And there's a strong likelihood that 5 farms (62.5 %) avoided the survey violate the positive law. Grassland grades used by the local administrative agencies were not influenced by the factors affecting the yield (existence and non-existence of overseeding and fertilization by grassland grade, soil pH and organic matter content). This results suggest that there is a fundamental problem on the current grassland grade system based on the yield and the irregular time of investigation and lack of on-site investigation are another causes for inaccurate grassland grade. Therefore, the new method evaluating grassland grades which is not based on yield and the thorough on-site investigation by local administrative agencies are necessary when the grassland grade is evaluated.

• Journal of the Korean Institute of Landscape Architecture
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• v.51 no.3
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• pp.21-36
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• 2023

As a solution to environmental issues, such as climate change response, the carbon neutrality strategy, urban heat islands, fine dust, and biodiversity enhancement, the value of urban green spaces and trees are becoming important, and various studies dealing with the effects of trees for environmental improvement are being conducted. This study comprehensively considers the preceding studies on planting tree species, planting structure, planting density, and planting base to propose a direction for the planting renewal of green areas in urban parks and applies the findings to a renewal plan to improve the urban environment through landscaping trees. A field survey was conducted on the planting status of Seoul Children's Grand Park, a large-scale neighborhood park in Seoul, and based on the survey data, a planting function evaluation was conducted, and areas needing improvement in planting function were identified. The planting function evaluation was carried out considering the park function setting, planting concept according to spatial function, and planting status. As a result of the study, the direction of planting renewal according to functional change was derived for each stage of planting function evaluation. Increasing the green area ratio is a priority in setting up park functions, but user convenience should also be considered. As a concept of planting, visual landscape planting involves planting species with beautiful tree shapes, high carbon absorption, and fine dust reduction effects. Ecological landscape planting should create a multi-layered planting site on a slope. Buffer planting should be created as multi-layered forests to improve carbon absorption and fine dust reduction effects. Green planting should consist of broad-leaved trees and herbaceous layers and aim for the natural planting of herbaceous species. For plant species, species with high urban environment improvement effects, local native species, and wild bird preferred species should be selected. As for the planting structure, landscape planting sites and green planting sites should be composed of trees, shrubs, and trees and herbaceous layers that emphasize ecology or require multi-layered buffer functions. A higher standard is applied based on the planting interval for planting density. Installing a rainwater recycling facility and using soil loam for the planting base improves performance. The results of this study are meaningful in that they can be applied to derive areas needing functional improvement by performing planting function evaluation when planning planting renewal of aging urban parks and can suggest renewal directions that reflect the paradigm of functional change of created green areas.

• Research in Plant Disease
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• v.10 no.3
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• pp.188-193
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• 2004

The symptom expressions such as yellowish and mosaic spots in overwintering barley have been considered to be a damage by cold or water. However, it had revealed that the symptom expressions were caused by viruses throughout three year nationwide surveys. Barley yellow mosaic virus (BaYMV), Barley mild mosaic virus (BaMMV), and Soil-borne wheat mosaic virus (SBWMV) was detected in 2001-2003 and Barley yellow dwarf virus-MA V (BYDV -MA V) from field samples collected on March in 2003. The results of investigation showed that the incidence of BaYMV was more than 70％ and that of BaMMV and SBWMV was 15.7-37.4％ and 0.7-10.1 ％ in three year surveys, respectively. The incidence of BYDV-MAV was approximately 1 ％ in 2003 only. The distribution of BaYMV was relatively uniform throughout barley fields in Korea, but the incidence of the virus in Gyunggi Province was as low as 19％ compared to 65-85％ in the rest of regions. On the other hand, 70％ of BaMMV was found to be in the west south regions of Korea, Jeonbuk and Jeonnam Provinces. Taken together, both BaYMV and BaMMV were thought to be dominant casual agents in overwintering barley by either single or mixed infections. Previous survey data for BaYMV from 1994 to 1996 indicated that the incidence of the virus was approximately 40％ in Jeonbuk, Jeonnam, and Gyungnam Provinces. Thus, comparing with the results from the recent nationwide survey, the incidence of BaYMV had been rapidly increasing in overwintering barley fields in the southern part of Korea.

• Economic and Environmental Geology
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• v.38 no.5 s.174
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• pp.547-561
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• 2005

General characteristics of groundwater contamination by As were reviewed with several recent researches, and its occurrence in groundwater of Korea was investigated based on a ffw previous studies and a groundwater quality survey in Nonsan and Geumsan areas. In Bangladesh, which has been known as the most serious arsenic calamity country, about $28\%$ of the shallow groundwaters exceeded the Bangladesh drinking water standard, $50{\mu}g/L$, and it was estimated that about 28 million people were exposed to concentrations greater than the standard. Groundwater was characterized by circum-neutral pH with a moderate to strong reducing conditions. Low concentrations of $SO_4^{2-}$ and $NO_3^-$, and high contents of dissolved organic carbon (DOC) and $NH_4^+$ were typical chemical characteristics. Total As concentrations were enriched in the Holocene alluvial aquifers with a dominance of As(III) species. It was generally agreed that reductive dissolution of Fe oxyhydroxides was the main mechanism for the release of As into groundwater coupling with the presence of organic matters and microbial activities as principal factors. A new model has also been suggested to explain how arsenic can naturally contaminate groundwaters far from the ultimate source with transport of As by active tectonic uplift and glaciatiion during Pleistocene, chemical weathering and deposition, and microbial reaction processes. In Korea, it has not been reported to be so serious As contamination, and from the national groundwater quality monitoring survey, only about $1\%$ of grounwaters have concentrations higher than $10{\mu}g/:L.$ However, it was revealed that $19.3\%$ of mineral waters, and $7\%$ of tube-well waters from Nonsan and Geumsan areas contained As concentrations above $10{\mu}g/:L.$. Also, percentages exceeding this value during detailed groundwater quality surveys were $36\%\;and\;22\%$ from Jeonnam and Ulsan areas, respectively, indicating As enrichment possibly by geological factors and local mineralization. Further systematic researches need to proceed in areas potential to As contamination such as mineralized, metasedimentary rock-based, alluvial, and acid sulfate soil areas. Prior to that, it is required to understand various geochemical and microbial processes, and groundwater flow characteristics affecting the behavior of As.

• Journal of Sericultural and Entomological Science
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• v.14 no.2
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• pp.125-154
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• 1972

The major purpose of this survey is to collect the related information on technical aspects for solving the problems which are facing producing farmers and regions, provide scientific facts to farmers related personals and institutions and aimed at contributing the development of sericultural sector in Korea. The results are as follows; (1) The area of mulberry field per a farmer which was selected as sample ranges from 3.0 to 370a with its average 45. 1a. And yet, the average of new cultivated areas is above than that of ordinary ones by 56.3 to 33.8a. The largest area is Honam hill area with 101. 1a and e smallest is Muzinzang with 20.8a. Shortly, a large number of farmer belongs to 11 to 50a with 66.5 per cent. (2) The ratio of clay and loam soils which are inadequte for growing of mulberry trees is 28.3 per cent and particulary high in new cultivated area with 36.2 per cent. And yet, base soil is occupied with 45 per cent of heavy clay and particularly even 54.2 per cent in new cultivated area. On the other hand, the number of areas which the contents of organic matters is relatively low, with 48.2 per cent is near the half, but the ratio of mulberry fields which seems to contain organic matters abundantly is only 7.2 per cent. (3) The varieties of mulberry trees are Ilgirae, Gaeryangseoban, Suwonsang No.4 and Nosang. The ,ratio of the varieties are 33.3%, 25.7%, 18.0% and 10.5%, respectively. Consequently the four varieties enumerated above occupies 93.5 per cent. (4) The mulberry fields are almost composed of exclusive mulberry fields and its ratio was 92.3 per cent. The number of planted trees per 10a arrange from 480 to 1,390 and its average is 846. But most of them nearly belong to 701 to 1,000 with 91.3per cent. (5) The second year's autumn after planting is generally adopted as the first harvesting season, and its ratio is 73.0 per cent, but autumn of the years and next spring are not few, and its ratio are 12.7 and 8.7 per cent. The first harvesting method is relatively normal with 88.8 per cent of ratio. From the viewpoint of harvesting method, picking leaves was applied with 97.7 per cent of ratio in young larvae rearing and picking shoot and picking shoot after harvest with branches were applied with 80.0 per cent of ratio in grown larvae rearing. The ratio of applying the harvesting method of picking leaves were 97.7 and 91.7 per cent in young larva and grown larva in autumn rearings. But there was also picking leaves absolutely with 7.1 per cent of ratio(Chunwon was 47 per cent) and yet, the farmers applying cutting before shooting in spring was no more than 17.8 percent.

• Journal of East-West Nursing Research
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• v.1 no.1
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• pp.50-71
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• 1997

The intention of this study is to apprehend the con. tents and methods of herb remedies that are commonly conducted when there are health-problem cases of ENT, eyes, teeth and skin. Methods of this study are divided into two stages : 1) For a period of six months from December 1994 to June 1995, some 40 persons who are believed to be well versed with herb remedies have been randomly chosen, and we made a survey on herb remedies by symptoms: and 2) we have endeavored to make their grounds evident through the studies on literatures with the focus on the basic data collected. Their results are as follows: 1) When one feels a pain in ears, such herb remedies are employed as pouring the vapor into ears, which is made by steaming Alaska pollack, or as applying or wiping with the juices of radish or the ginkgo, or' alum. Applying the radish juice is effective for sterilization and fever removal: and applying the ginkgo juice is effective for cleanliness. But, plastering alum, sesame oil or castor oil, or pouring the vapor of Alaska pollack into ears are perhaps effective but do not have any pharmacologic grounds. 2) When one bleeds at the nose, such kinds of herb remedies are applied as stimulating nose or head with cold water, pressing nose or ridge of nose, or filling up nares with mashed mugworts. In addition, they have utilized garlic or leeks. Such methods as stimulating with cold water or just pressing nose and ridge of nose is based on reasonable grounds, i.e. vasoconstriction and vascular compression ; and applying mashed garlic on the sole of foot is good for the circulation of Qui ; and the use of mugworts and leeks is based upon the pharmacological function of hemostasis. 3) When one feels a sore throat such kinds of herb remedies are employed as gargling or rinsing throat with brine, drinking hot gruel or water, or drinking the juice of mugwort, radish, ginger or Chinese quince. Gargling with brine or drinking the juice of mugwort, radish or ginger is based upon the pharmacological function of pain alleviation, fever removal, and detoxication. 4) When a boil is formed in mouth, such herb remedies are applied as spreading honey, brine or alum water, and taking gall nut, Chinese matrimony vine, lotus root, etc, for drugs. Spreading honey, brine or water that is made by infusing gallnut, Chinese matrimony vine, lotus root is based upon such functions as hematosis, astriction, antibacterial, and antiphlogistic, Alum, eggplant and licorice are said to be effective, but their pharmacological effects have no grounds. 5) When one has conjunctivitis such herb remedies are commonly applied as irrigation with brine and dropping breast milk in eyes. Moreover, such other drugs are used as plantain. shepherd's purse, and purslane, etc. The use of brine, breast milk, plantain, shepherd's purse and purslane is based upon such functions as sterilization, antiphlogistic, disinfection and pain relieving. Eriocaulon sieboldianum, bean stem, bean pod and narcissus leaves are said to be effective, but their pharmacological action have no basis. When one has a stye, such herb remedies are applied as extracting eyelashes, stimulating by a massage of middle finger, third finger or big toe, as well as sear ing with a heated bamboo comb that is fine-toothed. Other than these, plantain and nightshade's nuts are used as drugs for it. Extracting eyelashes corresponds with exclusing suppurative node and draining the stye of pus ; and the use of plantain is based upon disinfection: and nightshade's nuts are said to be effective, however, their pharmacological action has no grounds. 6) For a treatment of toothache, such herb remedies are commonly employed as rinsing mouth with brine and holding cold water or gasoline in the mouth ; and as the drugs that are believed to be effective have been Welsh onion, ginger and castor-oil, plant, etc. The use of Welsh onion is based upon pain killing, antiinflammatory actions, and the use of ginger is based upon detoxication and disinfection ; and seeds of castor-oil plants are said to be effective, but they have no pharmacological basis. 7) When one has hives, such herb remedies are commonly applied as rubbing burned straw in affected parts, exposing to its smoke, rubbing with salt, sweeping down with a broom, and spreading and drinking boiled water of trifoliate orange. The use of cassia tora seeds, walnut, aloe and radish is said to be effective. The use of cassia tor a seeds has the functions of intestinal order, anti-paralysis, etc. The use of walnut has resulted in an increase of blood by invigorating spirits ; and the use of aloe is based upon disinfection, antibiotic, anti-salt, antihistamine and detoxication action. But, the effects of radish juice and straw's smoke have no pharmacological grounds. 8) When one gets a boil, such herb remedies are commonly used as applying a plaster, paste of flour mixed with yolk, soy sauce or honey, as well as spreading pounded elm tree. Other remedies that have been said to be effective are ; heating with mugwort, brine, wild rocambole, aloe, onion, squid's bone, etc. The use of mugwort is based upon pain killing, astringent antiinflammatory and tranquility. Wild rocambole is based upon the generation and maintenance functions of cell-joining textures ; elm tree upon antiphlogistic ; aloe upon fever removal and antiphlogistic ; onion on pain killing, fever removal, antiphlogistic and tranquility ; squid's bone on astriction: and brine or vinegar on sterilization. Pine resin and gardenia seed are said to be effective, but they have no pharmacological basis. 9) When one cuts his skin, such herb remedies are commonly employed as spreading mugwort's juice or squid's bone powder, or pressing the wounds. In addition, kalopanax, onion and fine soil are employed. The use of mugwort, kalopanax and squid's bone is based upon such functions as hemostasis, sedation, pain killing, antibacterial ; and fine soil is said to be effective, but it has no pharmacological basis. 10) When one suffers from whitlow, such herb remedies are commonly utilized as heating with boiled soy sauce, spreading soybean paste, or dipping into eggs, etc. Other drugs that have been employed are onion root, brine, eggplant, potato, loach, etc. The use of onion is based upon pain killing and antiphlogistic functions ; and that of brine upon antiphlogistic function. The use of soy sauce or soybean paste, fomentation, eggplant, potato and loach is said to be effective, but it has no pharmacblogic ground. 11) For the treatment of frostbite, such herb remedies are commonly used as dipping the affected part into frozen soybean sack, using boiled water of eggplant stem, garlic caulis, onion, hot pepper, caulis. Onion is based upon antiphlogistic and tranquility actions garlic upon disintection, metabolic exacerbation, tonic and aphrodisiac actions and the use of eggplant and hot pepper is based upon help blood circulation, dissolution and excretion of waste matters in vein. 12) For the treatment of burn, such herb remedies or drugs are commonly used as cleansing with Korean gin, spreading eggs, cleansing with cold water and soap water ; and as brine, cactus, moss, soybean paste, oil, etc. The cleansing with Korean gin, cold water, soap water, brine, vinegar is based upon cleaning and sterilizing functions ; and the use of cucumber is based upon nu. trition provision, and strengthening of resisting power by adjustment of metabolism. The use of potato, cactus, moss, oil and eggs is said to be effective, but their phamacological functions are not clarified. In view of the above results, we can realize that the drugs that have been employed in herb remedies are quite diverse. However, in regard to majority of herb remedies that have been employed by symptoms, the pharmacological functions of their drugs have not been clarified, and they are merely known as effective. Furthermore, they have not been recorded in the literature as yet ; and we confirm that there have been many herb remedies that were executed without the proper knowlege of their effects. It is now our view that the results of this survey may be utilized for consulting data in regard to the use of herb remedies.

• Korean Journal of Environment and Ecology
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• v.35 no.2
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• pp.154-163
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• 2021

This study was carried out to present the habitat distribution status and the habitat distribution prediction of Sophora koreensis, which is the Korean Endemic Plant included in the EN (Endangered) class of the IUCN Red List. The habit distribution survey of Sophora koreensis confirmed 19 habitats in Gangwon Province, including 13 habitats in Yanggu-gun, 3 habitats in Inje-gun, 2 habitats in Chuncheon-si, and 1 habitat in Hongcheon-gun. The northernmost habitat of Sophora koreensis in Korea was in Imdang-ri, Yanggu-gun; the easternmost habitat in Hangye-ri, Inje-gun; the westernmost habitat in Jinae-ri, Chuncheon-si; and the southernmost habitat in Sungdong-ri, Hongcheon-gun. The altitude of the Sophora koreensis habitats ranged from 169 to 711 m, with an average altitude of 375m. The area of the habitats was 8,000-734,000 m², with an average area of 202,789 m². Most habitats were the managed forests, such as thinning and pruning forests. The MaxEnt program analysis for the potential habitat of Sophora koreensis showed the AUC value of 0.9762. The predictive habitat distribution was Yanggu-gun, Inje-gun, Hwacheon-gun, and Chuncheon-si in Gangwon Province. The variables that influence the prediction of the habitat distribution were the annual precipitation, soil carbon content, and maximum monthly temperature. This study confirmed that habitats of Sophora koreensis were mostly found in the ridge area with rich light intensity. They can be used as basic data for the designation of protected areas of Sophora koreensis habitat.

• Korean Journal of Weed Science
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• v.12 no.3
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• pp.271-291
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• 1992

This study was conducted to survey the situation of direct rice seeding in Honam province in Korea to investigate problems and seek countermeasure of weed control in direct rice seeding. The total area of direct rice seeding in the south-western part of Korea (Chonbuk, Chonnam, and Chungnam) was 1650.8ha (732.1ha for direct seeding in dry field and 918.7ha for direct seeding in flooding field) in 1992. The followings are summary of the study. 1. In case of direct rice seeding in dry field, butachlor EC and G at 3 to 5 DAS was mostly selected by farmers to control weeds in dry field. Benthiocarb or chlornitrofen was also used in few cases. At 10 to 14 DAS just before rice emergence, tank misture of butachlor EC and paraquat was treated by some farmers. At 35 to 40 days, after flooding mixture of sulfonylurea derivatives was sequentially applied. Surviving weeds including barnyardgrass were finally controlled by mixture of bentazon+quinclorac WP foliage application. 2. In case of direct rice seeding in flooding field, weed control were mostly unsuccessful partially due to wrong selection of herbicide and missing the optimum application time. Three relatively successful weed control in the survey were summarized as follows. 1) Oxadiazon EC, butachlor or benthiocarb were treated just after puddling(5 to 7 days before seeding). then mixture of bentazone+quinclorac WP or sulfonylurea derivatives was sequently applied to control remaining weeds at 20 days after seeding. 2) Mixtures of bensulfuronmethyl+dimepiperate G, pyrazosulfuronethyl+molinate G, or bensulfuronmethyl+mefenacet+dymron G were applied at 11 days after puddling when barnyardgrass were at 2.0 leaf stage. Phytotoxicity was not found in case of mixture of bensulfuronmethyl+dimepiperate G but found in the other two cases but disappeared later. 3) Mixtures of bensulfuronmethyl+quinclorac G., pyrazosulfuronethyl+quinclorac G or betazone and quinclorac G were treated after 18 to 20 days after puddling when barnyardgrass was within 3.0 leaf stage. It showed good weed control in both annuals and perrenials without phytotoxicity. On the contrary, other sulfonylurea derivatives such as middle periodic herbicide showed poor weed control against barnyardgrass, so that sequential treatment of bentazone+quinclorac WP mixture was required. 3. Herbicidal characteristics and optimum application time of 45 rigistered herbicides in Korea were analyzed to discover new substitute for quinclorac mixture, that showed excellent weed control against barnyardgrass at its 3 leaf stage or older. The analysis revealed that 70% of herbicides were for preemergence and the others were post periodic herbicide. Most farmers favor to apply herbicide when rice seedlings completely rooted, at this time barnyardgrass are at 2.5-3.0 leaf stage. Therefore herbicide of which optimum application time had long is required. In this study. 6 middle periodic herbicides among sulfonylurea derivatives and 2 quinclorac mixture were selected and evaluated their weeding spectrums at different leaf stage of barnyardgrass in both soil application in flooding condition and foliage application in dry paddy field. The order of weeding spectrum in magnitude was as follows : bentazone+quinclorac WP> bentazone + quinclorac G>bensulfuronmethyl + quinclorac G>pyrazosulfuronethyl + quinclorac G> pyrazosulfuronethyl + Molinate G>bensulfuronmethyl + mefenacet + dymron G>bensulfuronmethyl + mefenacet G>bensulfuron methyl+benthiocarb G. The above results coincided with that of the survey. In conclusion, there is no proper substitute for quinclorac mixrure, which can control barnyardgrass at 3.0 leaf stage or even older. Therefore quinclorac should be supplied continuously to farmers in order to anchor direct rice seeding in Korea. Author suggested the followings to eastablish direct rice seeding technology effectively and quickly : 1) A tentatively named "The research committee for direct rice seeding" which was composed of farmers. researchers and goberment. should be eastablished to cooperate effectively. 2) Development of a pricise direct rice seeding machine for both dry and flooding paddy field. which is workable regardless of condition and varieties of seeds. 3) Study on protecting rice seed and seedling from sparrows. 4) Systematic studies of weed control techniques in direct rice seeding to standardize herbicide application. 5) Studies on farm-land reformation. techniques of precise land preparation. and direct rice seeding using an airplane.

• Korean Journal of Agricultural and Forest Meteorology
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• v.15 no.2
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• pp.85-101
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• 2013

In order to search for distribution characteristics on C4 plants at the paddy fields, uplands, orchard and roadside in South Korea, vascular plants were investigated. Flora investigation had been carried out from May 2002 to October 2006 at 241 plots. In the results of survey, the flora of these areas consist of 74 families, 231 genera and 352 species totally. The class frequencies were arranged by the order of Magnoliopsidae (255 species), Monocotyledoneae (89 species), Pteropsida (7 species) and Sphenopsida (1 species). The number of species in each investigated agricultural field types was 55 families with 203 species in paddy field, 49 families with 218 species in uplands, 44 families with 115 species in orchard and 48 families with 202 species in roadside respectiviely. Representative species compositions of these four agricultural field types were characterized by Artemisia princeps, Persicaria thunbergii in paddy field, Artemisia princeps, Erigeron annuus in upland and roadside, Commelina communis, Digitaria ciliaris in orchard, respectively. Therefore, indicative species in agricultural ecosystem was Artemisia princeps. Among the investigated 352 species, $C_4$ plants identified were 38 species, and the occurrence ratio of $C_4$ monocotyledonous plants were higher in paddy field, orchard and roadside than upland. Such differences in the occurrence ratio of $C_4$ plants under diverse agricultural field types reflect differences in environmental condition such as micro-climate, soil moisture under various agricultural fields. Dominant $C_4$ monocotyledonous plants were Digitaria ciliaris and Commelina communis, while $C_4$ dicotyledonous plants were Amaranthus mangostanus and Chenopodium album var. centrorubrum in agricultural fields. Naturalized plants were identified as 47 species and occurrence ratio were higher in upland and roadside than other agricultural field types. Among the investigated naturalized plants, $C_4$ plants were Amaranthus mangostanus and Amaranthus retroflexus. Distribution characteristics of representative $C_4$ plants in agricultural field types, revealed that the projected increase in temperature due to climate change may provide better conditions for the growth of $C_4$ plants. Thus, the necessity of long-term monitoring should be conducted on the diffusion of $C_4$ plants that may threaten influence agroecosystem in Korea.

• Korean Journal of Organic Agriculture
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• v.24 no.1
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• pp.73-85
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• 2016

This study was carried out to allelopathic effects of aqueous extracts on Coronopus didymus in order to investigate the competitive dominant in plant ecosystem and possibility application in natural herbicide. Number of species and species diversity for close to patch of C. didymus was decreased gradually site #1 (7, 1.76), site #2 (5, 1.34) and site #3 (5, 1.25). It was generally decreased the relative germination ratio (r=-0.731, p<0.01), the mean germination time, the relative elongation ratio (r=-571, p<0.01, r=-0.730, p<0.01), the relative fresh weight (r=-0.743, p<0.01), development of root hairs of receptor plants by concentration of the aqueous extracts from C. didymu. But they were different from the growing regions, the kind of receptor plants and the treatment of the aqueous extracts. Especially, it was differently effected among growing regions that inhibited more radicle than shoot by the aqueous extracts concentration of C. didymus. Total phenolic compound in the aqueous extracts of C. didymus analyzed about $23.0{\pm}1.1mg/g$. Total phenolic compounds of soil in survey area was increased gradually site #1 ($0.072{\pm}0.002mg/g$), site #2 ($0.082{\pm}0.003mg/g$) and site #3 ($0.092{\pm}0.004 mg/g$). We think that the aqueous extracts of C. didymu showed allelopathic effects on other plants. Therefore, C. didymu hold the competitive dominant of plant ecosystem in Jeju Island and possibility application of natural herbicide.