• Journal of Biosystems Engineering
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• 제5권1호
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• pp.43-50
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• 1980

The milling plants in Korea have been generally used the paddy-separator that operated in accordance with the principle of sieving action. This type of paddy separator was considered as inefficient, especially in relation to the new high-yielding varieties which have different size characteristics within their varieties and also as compared to traditional varieties. With the installation of modern paddy separator it may be possible to increase the overall milling system efficiency and to reduce the grain loss. This study was intended to identify and define important parameters required for assessing the separation performance of a tray-type paddy separator and to determine the optimum conditions of the inclination of separator-table. The results of the study were summarized as follows : (1) Separation performance can be given by use of many parameters found from the measurement of separator outputs. such as upper-tail recovery $(\varepsilon)$, purity of upper-tail $(\gamma)$ , separation recovery of brown rice $(\alpha)$, separation recovery paddy $(\beta)$, and efficiency of separator $(\epsilon)$, Among these para-meters , $\varepsilon$, $\gamma$, $\alpha$ and $\beta$, were designated , respectively, their independent properties of the paddy separator. In addition, their modes of variation due to a varied inclination of the separation table did not indicated in the same direction . However, the efficiency of separator had an advantage to indicate the overall characteristics of the separator performance with a clear optimum inclination condition of the separator table. (2) The optimum feed rate and maximum efficiency of the separator did not occur at the identical inclination of the separator table. Thus, for its practical operation it is necessary to compromise between the qualitative and quantitative performances of the separator. (3) The optimum setting of the separator table tested in the study showed to occur at its inclination of approximately $26^\circ<$/TEX> for the front and $8^\circ<$/TEX> for lateral.

• Journal of Biosystems Engineering
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• 제24권5호
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• pp.399-406
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• 1999

This study was conducted to investigate the labor requirements and transportation cost of paddy for the different harvest and transportation systems for obtaining a basic reference to the improvement of present harvest-transportation systems. One hundred and eighty five farm households with sack type combine harvester and thirty farm households with bulk type combine harvester were surveyed for thirty counties from eight provinces except jeju and also eleven Rice Processing Complex were covered for this survey. This survey was carried from 8th. October 1997 to 5th. November 1997. For the labor requirements, bulk trailer system require 6.8th/ha, 10.3/ha for sack harvest-tractor trailer, and 8.8h/ha for bulk harvest-container bag. The machinery utilization cost for the different paddy harvest-transportation systems, combine sack harvest-tractor trailer system is 282 thousand won/ha, and most economical compared with other systems. Combine bulk harvest with tractor system was 416 thousands won/ha and combine bulk harvest with container bag system was 446 thousands won/ha. In order to propagate bulk harvest-transportation system, a proper bulk transportation means with considering road condition in the paddy field and paddy size should be developed, and considering cycle time it appeared that the proper capacity of bulk container was 3.5ton at the present.

• 한국작물학회지
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• 제47권6호
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• pp.422-426
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• 2002

비염해지인 육답에 대한 간척답의 염농도가 0.2%, 0.3%, 0.4%인 지역에서 수도 생육 및 수량반응을 비교 검토하여 수도의 내염성 및 품종육성의 기초자료를 얻고자 일반계 품종 6품종 통일형 5품종을 공시한 결과는 다음과 같다. 1. 출수지연 정도는 육답 대비 0.2%포장에서는 일반계 품종은 2일, 통일형품종은 3일이 지연되었고, 0.3%포장에서는 일반계품종이 5일, 통일형품종이 8일, 그리고 0.4%포장에서는 각각 10일과 13일이 지연되었다. 2. 간장은 일반계품종이 13-39%, 통일형품종이 12-35% 감소율을 보였고, 수수는 일반계품종이 16-40%, 통일형품종이 14-35% 감소율을 나타내어 간장 및 수수의 감소율은 일반계 품종이 더 심하였다. 3. 수당립수는 일반계품종과 통일형품종 공히 10-40%의 감수율을 보였으나, 등숙율은 일반계품종 20-48%와 통일형품종 19-52%의 감수율을 보여, 통일형품종이 더 심하였다. 4. 천립중은 23% 이내의 비교적 적은 감소율을 보인 반면, 수량은 일반계 품종은 20-62%, 통일형품종은 25-68%의 감소율을 보여 통일형품종이 더 컸다.

• 한국환경복원기술학회지
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• 제9권2호
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• pp.1-15
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• 2006

As the imports of foreign agricultural products are liberalized and the consumption of agricultural products declines, abandoned rice paddy fields continues to rise. However, such abandoned rice paddy fields has not been precisely surveyed yet. In this backdrop, a necessity to develop technology to utilize such abandoned rice paddy fields has emerged. Utilization of abandoned rice paddy fields as wetlands may be a good example. This study aimed to survey the current status and characteristics of wetlands created within abandoned rice paddy fields by selecting abandoned rice paddy fields throughout the nation and conducting field surveys on the sites that had transformed into wetlands. The abandoned rice paddy fields almost transformed into wetland and the types of wetlands transformed from abandoned rice paddy fields were mainly Inland/Moutain/Depression/Abandoned rice paddy fields/Marsh/Phragmites communis community and Inland/Moutain/Depression/Abandoned rice paddy fields/Swamp/Salix koreensis community. Abandoned rice paddy fields that had transformed into wetlands was depending heavily on waterways for water supply than other reservoirs and lakes do. Abandoned rice paddy fields transformed into wetlands was most observed in mountainous area. Abandoned rice paddy fields are because agricultural land is no longer profitable due to international and social changes and is not cultivated as government policy. Wetland period and dimension originated from abandoned rice paddy fields are very various and its surrounding land its mostly forest and the next largest follow roads and rural community. The abandoned rice paddy fields transformed into wetlands is mostly deserted currently. Despite their value as wetlands, no restoration and utilization efforts are made in Korea today. Therefore, it is imperative to conduct a precise current status survey on these areas and introduce management and restoration plans at the government level in the case of important habitats.

• 한국자원식물학회지
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• 제35권6호
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• pp.720-761
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• 2022

This study surveyed the vascular flora present in abandoned paddy field type of 237 forest wetlands in Korea to provide baseline data for conservation, management, and monitoring and to support preparation for damage and climate change. The study period was from April 2015 to November 2021. The vascular flora of 237 forest wetlands by abandoned paddy field type were identified to consist of 128 families, 510 genera, 1,022 species, 27 subspecies, 87 varieties, 10 forma, and 1,146 taxa. 4 taxa were identified as grade II endangered wild plants, 185 taxa were identified as northern lineage plants of the Korean Peninsula, 43 taxa were endemic to the Korean Peninsula, and 58 taxa were rare plants as designated by the Korea Forest Service. Further, 296 taxa were floristic target plants and there were 86 taxa of invasive alien plants. According to wetland preference, 79 taxa (6.9%) were obligate wetland plants, 103 taxa (9.0%) were facultative wetland plants, and 61 (5.3%) taxa were facultative plants. Additionally, 66 taxa (5.8%) were facultative upland plants, and 837 taxa (73.0%) were obligate upland plants.

• 한국균학회지
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• 제50권3호
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• pp.161-171
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• 2022

The edible paddy straw mushroom Volvariella volvacea (Bull. ex F.) Singer has high nutritional and medicinal values. They are grown on a wide variety of agricultural by-products using different several methods. The result of this present study showed that type of bed and cultivation condition (outdoor/indoor) had effects on the yield of paddy straw mushrooms grown on the spent oyster mushroom sawdust. The treatment of circular compact bed under indoor cultivation condition (CYIC) had the best yield and biological efficiency (B.E.) with 2,119.2 g/bed and 14.5%, respectively, followed by the treatment of conventional bed under outdoor cultivation condition (COOC) with the yield and B.E. of 1,935.5 g/bed and 13.2%, respectively, but the lowest yield and B.E. were observed in the treatment of conventional bed under indoor cultivation condition (COIC) with 1,226.1 g/bed and 8.4%, respectively. Paddy straw mushrooms cultivated on spent oyster mushroom sawdust should be proper in both outdoor and indoor conditions by conventional and circular compact methods as well. However, in indoor conditions, paddy straw mushrooms should be grown in a circular compact bed to ensure the temperature of the bed is suitable for the mushroom growth.

• 농업과학연구
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• 제44권3호
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• pp.325-331
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• 2017

This study was conducted to investigate the dominance and distribution of weed species in organic and conventional paddy fields. The organic paddy fields were maintained for organic farming for more than five years in Anseong, Gyeonggi province of Korea. According to the Braun-Blanquet method, 42 and 36 weed species were found in the organic paddy fields in 2015 and 2016, respectively, while 38 and 36 weed species were found in the conventional paddy fields in 2015 and 2016, respectively. As a result of two years' survey, 53 species from 24 families in the organic paddy fields were identified and classified as 32 annuals, 3 biennials and 18 perennials. In conventional paddy fields, 51 species from 24 families (30 annuals, 6 biennials, and 15 perennials) were identified. According to the classification by family, the most abundant weed species were Compositae (9 species), followed by Poaceae (8 species) and Polygonaceae (6 species) in organic paddy fields. In conventional paddy fields, Compositae (9 species) were the most abundant weed species, followed by Cruciferae (6 species), Poaceae, Polygonaceae, and Cyperaceae. This result indicates that the difference in diversity of weeds in paddy fields was influenced more by the agricultural environment than the type of cultivation. Our results could be used as a base data to control the occurrence of weed species in the paddy fields.

• Journal of Biosystems Engineering
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• 제38권4호
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• pp.240-247
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• 2013

Purpose: This study was conducted to develop a rubber-crawler type vehicle as a traveling device for harvesting water-dropwort cultivated in water contained paddy rice field in winter season. Methods: A commercial rubber-crawler type vehicle was used to investigate application of rubber crawler to the paddy rice field as preliminary test. As the result of the preliminary test, a both prototype traveling device with rubber crawlers for a water-dropwort harvest was designed with inclination of $45^{\circ}$ at the front-end and rear-end of crawler under the basic water depth of 0.6 m in the paddy rice field. The device was fabricated and attached to the experimental harvesting test devices on the front of the prototype vehicle. The size of the prototype crawler vehicle with a harvesting part is $2,800{\times}1,460{\times}1,040 $ (mm) ($L{\times}W{\times}H$) with weight of 9.21 kN (maximum). Sizes of the crawler of prototype vehicle are ground contact length of 900 mm, width of 180 mm, height of 1,070 mm and distance between center to center of crawlers of 720 mm. The side-overturn angle of the prototype was $26.4^{\circ}$. Results: Driving performance of the prototype vehicle in water contained paddy field were good at both forward and reverse (backward) directions as weights were applied. The drawbar pull and the maximum sinking depth of the prototype vehicle were 3.5 kN and 0.13 m respectively at water depth of 0.5 m, when the weight and bearing capacity of the prototype rubber crawler in the paddy field were 8.51 kN and 26.3 $kN/m^2$, respectively. Conclusions: Results of the driving test performance of the prototype crawler in paddy rice field at the water depth of 0.5 m were satisfactory. The prototype had enough drawbar pull and driving ability in the deep water contained paddy field.

• 한국토양비료학회지
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• 제44권6호
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• pp.1164-1168
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• 2011

경남지역 논 토양 미숙답 6개소, 보통답 9개소, 사질답 5개소를 대상으로 2011년에 미생물 세포벽 지방산 함량을 분석하여 미생물 군집과 토양 화학성을 주성분분석으로 해석하였다. 토양 미생물체량은 보통답이 $1,235mg\;kg^{-1}$으로 사질답 $441mg\;kg^{-1}$ 보다 유의적으로 많았으며 (p<0.05) 미숙답은 $854mg\;kg^{-1}$으로 유의적인 차이가 없었다. 토양 유기물 함량은 미숙답과 보통답이 $33g\;kg^{-1}$으로 사질답의 $18g\;kg^{-1}$ 보다 유의적으로 많았다 (p<0.05). 미생물 군집은 보통답이 총 세균 33.0%, 그람음성 세균 18.1%로서 사질답의 총 세균 29.4%, 그람음성 세균 14.8% 그리고 미숙답의 그람음성 세균 15.4%에 비해 유의적으로 많았다 (p<0.05). 주성분 분석결과 토양 유기물 함량과 총 세균 군집 비율이 경남지역 논 토양의 보통답과 사질답의 특성을 구분할 수 있었다.

• 한국작물학회지
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• 제30권2호
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• pp.117-125
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• 1985

수도이앙의 생력화를 위한 소식을 함으로써, 수도의 종내경합에 의한 수량감소를 막고, 시비로 증수가능성이 큰 초형을 탐색하기 위하여 본 연구는 수행되었다. 공시한 3개 초형의 동질유전자 계통은 Open-type, Spread-type 및 Broom-type 이었으며, 이들을 $m^2$당 47.62, 22.22, 15.15, 11.11, 8.33주로 이앙하고, 시비는 N-P$_2$O$_{5}$-K$_2$O=15.0-7.0-8.0kg/10a를 표준으로 한 0, 0.5, 1.0, 1.5 배비로 하였다. 시험결과, 1. 소식에 따른 출수지연은 종내경합정도에 비례하여서 다비할수록 약화되었으며, 작물초형별로는 Broom$\longrightarrow$ Spread$\longrightarrow$ Open-type의 순이었다. 2. 잡초와의 종간경합은 소식.다비로 증대되었으며, 작물초형별로는 Broom-type에서 특히 다연생잡초종에 의한 경합이 커지는 경향이었다. 3. 시비량증대에 따라 천립중을 제외한 면적당수수.수당영화수.등숙률은 3초형 모두 증대경향을 나타냈으나 재식밀도에 따른 반응은 면적당수수만 정의 상관을 나타냈다. 4. 수량성은 Open-type과 Spread-type의 경우, 이앙밀도와 정상관을 보인 반면에 Broom-type에서는 수량차이가 인정되지 않았다. 5. $m^2$당 이앙밀도를 15, 11, 8주로 낮추었을 때, Open-type은 각각 1.12, 1.21 및 1.28배비로써 그리고 Broom-type은 각각 1.22, 1.35, 1.4배비로써 Open-type 표준수량의 보상이 가능하였다.다.