• 한국환경복원기술학회지
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• 제12권1호
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• pp.52-66
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• 2009

The increase of rice productivity, the decrease of rice demand, aging farmers, and the market-opening of rice along with the domestic and international conditions changes have been led to the increase of the abandoned rice paddy fields. Such abandoned rice paddy fields have been left in many areas and most of them have become wetlands. The purpose of this study is methodology of selection to the wetland for development in the abandoned rice paddy fields along with surroundings. The selection of habitat suitability index assessment study to conservation and restoration was done through hydrology, wild animals habitation, wetland vegetation, outside disturbance, and natural purification capacity assessment. In addition, the same method was applied to assessment items and standards for both the restoration site selection and the type of restoration. Both assessment items and standards were applied to the sites, drawn on the maps, and overlayer for the comprehensive map, and then the wetland suitability index was applied to the suitable site. The development technique was applied to 10 sites near the Banwol Stream watershed in Gunpo, Gyeonggi province. The selection of conservation, restoration, and the optimal sites can lead to not only the biodiveristy increase in agricultural or semi natural areas but also to the establishment of ecological networks in national level.

• 한국농림기상학회지
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• 제3권1호
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• pp.37-43
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• 2001

Crop status monitoring and yield prediction at higher spatial resolution is a valuable tool in various decision making processes including agricultural policy making by the national and local governments. A prototype crop forecasting system was developed to project the size of rice crop across geographic areas nationwide, based on daily weather pattern. The system consists of crop models and the input data for 1,455 cultivation zone units (the smallest administrative unit of local government in South Korea called "Myun") making up the coterminous South Korea. CERES-rice, a rice crop growth simulation model, was tuned to have genetic characteristics pertinent to domestic cultivars. Daily maximum/minimum temperature, solar radiation, and precipitation surface on 1km by 1km grid spacing were prepared by a spatial interpolation of 63 point observations from the Korea Meteorological Administration network. Spatial mean weather data were derived for each Myun and transformed to the model input format. Soil characteristics and management information at each Myun were available from the Rural Development Administration. The system was applied to the forecasting of national rice production for the recent 3 years (1997 to 1999). The model was run with the past weather data as of September 15 each year, which is about a month earlier than the actual harvest date. Simulated yields of 1,455 Myuns were grouped into 162 counties by acreage-weighted summation to enable the validation, since the official production statistics from the Ministry of Agriculture and Forestry is on the county basis. Forecast yields were less sensitive to the changes in annual climate than the reported yields and there was a relatively weak correlation between the forecast and the reported yields. However, the projected size of rice crop at each county, which was obtained by multiplication of the mean yield with the acreage, was close to the reported production with the $r^2$ values higher than 0.97 in all three years.

• 한국작물학회지
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• 제48권3호
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• pp.224-231
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• 2003

This study was conducted to investigate the varietal differences in leaf senescence during ripening stage and its relation to grain yield of rice. During grain filling period leaf senescence was evaluated by SPAD readings (an indirect indicator of chlorophyll content) for 74 varieties including local, improved domestic, and introduced varieties in the field condition. Leaf senescence was varied greatly among 74 varieties. Jodongji and Dadajo known as local rice varieties had significantly lower SPAD value than the other varieties and became senescent rapidly. However, SPAD value of the flag leaf and 2nd leaf of SNU-SG1 were much higher than the other varieties and leaves of SNU-SG1 also showed a tendency of delayed senescence compared to the other varieties. There were significantly positive correlation between cumulated SPAD value of upper leaf(flag leaf and 2nd leaf) during 35 days after heading and grain yield divided by sunshine hour during 40 days of grain filling and compensated for temperature effect, and cumulated SPAD value of the 4th leaf showed negative correlation with the yield. That is, the delayed senescence of the upper leaves and the rapid senescence of lower leaves were positively associated with grain yield increase.

• 한국농공학회논문집
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• 제48권3호
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• pp.35-45
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• 2006

Fallow paddy areas have been increased due to the import of cheap agricultural product, and the unbalance between farming cost and rice price since 1990. In domestic, rice production control that decrease paddy field area has been introduced for the control of rice demand and supply and stabilization of rice price since 2003. Because of the desire of paddy field's owner to create benefit by using paddy for other object, fallow paddy would be continuously increased. In the other aspect, many people in the world is suffering from hunger because of the shortage of food. In case of Korea, continuous drought and flood damages will be potential concern of stable food supply. From this viewpoint, the increasing fallow paddy area needs to be protected from the devastation by weed breeding for the re-cultivation. In this study, fallow paddy managed with the shallow pools and shallows was selected fur monitoring and analyzing of water quality and plant body change. As the results, the managed fallow paddy found to be effective in the purification of water quality and the control of plant growth.

• 한국환경농학회지
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• 제19권5호
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• pp.433-441
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• 2000

A feasibility study was performed to examine the agronomic application of treated sewage on paddy rice culture by field experiment for two consecutive years. The domestic sewage was treated by the constructed wetland system which was in subsurface flow type and consisted of sand and macrophyte. The effluent of the wetland system was used for irrigation water. The effluent was diluted to maintain the total nitrogen concentration below $26mg{\cdot}L^{-1}$ in the first year and used without dilution in the second year experiment. Growth components and yields were compared against the CONTROL plot where conventional method was applied. And also, soil characteristics of the plots before and after reclaimed sewage irrigation were analyzed. Generally, addition of the treated sewage to the irrigation water showed no adverse effects on paddy rice culture, and even enhancement was noticed in both growth and yield. Irrigation of treated sewage after concentration adjusted with conventional fertilization showed the better result, and the yield exceeded that of CONTROL case where clean water was irrigated. Soil characteristics changed after irrigation, and significant EC increasing was observed for the reclaimed sewage irrigation plots. From this study, it appears that reuse of treated sewage, as supplemental irrigation water could be a feasible and practical alternative. For full-scale application, further study is recommended on the specific guideline of major water quality components in treated sewage for irrigation and public health.

• 한국농공학회지
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• 제42권3호
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• pp.66-75
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• 2000

Effect of reclaimed sewage on the paddy rice culture was examined by field experiment for two consecutive years. The domestic sewage was treated by the constructed wetland and the effluent of the treatment wetland was used for irrigation water. The reclaimed sewage was diluted before irrigation in the first year and it was used without dilution in the second year experiment. Growth components and yields were compared against the control plot where conventional method was applied. And also soil characteristics of the plots before and after reclaimed sewage irrigation were analyzed Generally addition of the reclaimed sewage irrigation didn't affect paddy rice culture adversely and even enhancement was observed. Fertilization was thought to be important factor for rice culture rather than irrigation water quality. Conventional fertilization and reclaimed sewage irrigation which contained high nutrient concentration resulted in better growth and more yield. Unlike widespread concern lodging did not happen even in the case of irrigation with average 90mg/L of T-N and conventional fertilization. Soil characteristics changed after irrigation and significant EC increasing was observed for the reclaimed sewage irrigation plots. From soil analyses salt accumulation could be a more potential problem than nutrients like nitrogen and phosphorus in the use of reclaimed sewage irrigation. Overall reclaimed sewage irrigation was thought to be one of practical alternatives for the ultimate disposal of sewage in rural area.

• 한국약용작물학회지
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• 제17권6호
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• pp.415-420
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• 2009

This study was carried out to select economical byproduct composts as the substitute for the traditional organic fertilizer, Yacto, in the cultivation of ginseng seedlings, and to investigate the application method of a selected compost. Among tested byproduct composts, popped rice hull compost was the best substitute for Yacto, while the application of domestic animal manure composts resulted in red skinned roots of ginseng seedlings. Optimal mixing ratio of the popped rice hull compost with virgin soil (fine sand) were 3~4 : 1 in bulk, showing the same root yield compared to that of conventional seedbed soil. When the popped rice hull compost was lower than $1\;{\pm}\;0.1%$ in nitrogen content, the expeller cake of oil seed was added to seedbed soil to rise nitrogen content until $1\;{\pm}\;0.1%$.

• 한국식품과학회지
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• 제34권3호
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• pp.380-384
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• 2002

For the screening of gamma-irradiated grains, domestic rice, glutinous rice, barley, and wheat were irradiated with 0.1, 0.3, 0.5, 0.7, and 1.0 kGy and screened using the DEFT/APC (Direct Epifluorescent Filter Technique/Aerobic Plate Count) method. The log DEFT/APT units increased with the dose increment in all samples, whereas the log APC unit decreased gradually. For rice, barley, and wheat, unirradiated and irradiated samples with below 0.3 kGy had 2.0 or lower logarithmic units, whereas those with 0.5 kGy or higher had 2.0 or higher logarithmic units. For glutinous rice, the sample irradiated with 0.5 kGy showed 1.92 logarithmic unit and those with 0.7 kGy or higher had 2.0 or higher logarithmic units. These results suggest that if the grains show 2.0 or higher logarithmic units, they could be assumed to have been irradiated at a dose level of at least 0.5 kGy. In conclusion, grains could be easily screened through the DEFT/APC method.

• 인간식물환경학회지
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• 제24권6호
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• pp.551-561
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• 2021

Background and objective: Vietnam is prioritizing agricultural production for food export capacity in all national policies. As a result, for three decades, its agriculture has been making quite many remarkable achievements. Methods: The most successful one is that the nation has become one of the world's leading rice exporters and ensures its national food security. Through these endeavors, the Mekong River Delta (MRD), in particular, has emerged as a key region in ensuring national food security and rice export. Results: The new era can now see Vietnamese agriculture turning to place special emphasis on commodity quality and the improvement of the living environment. This is evidenced, for example, by the phenomenon that the MRD, as a rice basket of the whole country, is making moves back to nature-based agriculture with attempts to restore the natural ecology, including preserving and restoring local traditional rice seeds, adopting natural farming practices and minimizing the use of chemical fertilizers and pesticides. Conclusion: The case studies of nature-based farming practices in the MRD indicate that, while the national agriculture is generally developing large-scale production, the small-scale farming in the region, integrated with tourist and educational activities on-site, is meeting the demands of a highly potential domestic niche market. Moreover, this model appears to be a sustainable farming approach that defines itself as a working green livelihood for the region.

• 한국초지학회:학술대회논문집
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• 한국초지조사료학회 2002년도 창립 30주년 International Symposium
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• pp.5-56
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• 2002

The problems in the current domestic forage production were evaluated, and the prospective improvement was suggested in this paper. Grassland development in forest, production of high quality forages in upland and paddy land, efficient utilization of rice straw, development of new varieties of forages suitable for our environmental conditions and imported forages were described Among them, preferential production and utilization of forages using paddy field after rice harvest . should be enlarged for domestic supply of forages in Korea. Several studies were carried out to select the promising forage crops and barley cultivars for whole crop silage production, to determine productivity, nutritive value and production cost of forages produced in paddy field, and feeding effect of forages with Hanuwoo and milking cow for whole crop silage with forages produced in paddy field, 1999 to 2001, and also discussed restraint factors and activation plans for enlargement of forage production in paddy land. The promising forage crops in paddy field were rye and barley for Middle region, and rye, barley, early maturing Italian ryegrass and wheat for Southern region. The promising barley cultivars for whole crop silage in paddy field were Albori in Suwon, Keunalbori, Milyang 92, Saessalbori, and Naehanssalbori in Iksan, and Keunalbori, Albori, Naehanssalbori, and Saegangbori in Milyang, respectively. Silage production, quality and animal palatability of silage by trench and round bale were also compared. The production yields of whole crop barley silage(WBS) were 17,135kg as a fresh matter, and 6,011kg as a dry matter per ha, and the quality of WBS was 2∼3 grade, while that of rice straw silage was 4 grade as a farm basis. The production cost of WBS per kg was 83won as a fresh matter, and 238won as a dry matter. Feeding of WBS as forages on Hanwoo was very desirable for the improvement of live-weight gain, beef quality and farm income, particularly in growing stage of Hanwoo. Milk production and income were also increased, and feed cost was decreased by feeding of WBS. The daily voluntary intake of WBS in milking cow was 26.3kg as a fresh matter(DM 7.7kg) per head. Milk production when WBS was fed, was very similar to that of imported hay feeding such as Kentucky bluegrass or domestic corn silage. The issues to be solved in near future f3r stable forage production and supply in paddy land are sustainable livestock-forages policy, development & seed production of new varieties of barley, rye, Italian ryegrass and other promising forages, efficient demand & supply system of forages, solidification for mass production and utilization of forages, efficient application management of animal slurry on paddy field considering environmental agriculture/livestock industry, and break k development of bottleneck technique in production field. Domestic production & supply of high cost agricultural machine (round baler, wrapper, handler and so on), plastic wrapping film, and silage additives are also important.