• Journal of Biosystems Engineering
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• 제35권3호
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• pp.175-181
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• 2010

This study compared moisture content measured by moisture meter of microwave resistance type(MMMRT) and standard moisture content of paddy, and developed the correction equation using linear and curvilinear regression analysis, and to explore its significance test. The correction factor according to the range of moisture content was developed to improve the measurement precision of MMMRT. The results were as followings. The coefficients of determination of correction equation by linear and curvilinear regression analysis with comparing the MMMRT and standard moisture content were 0.946 and 0.968, respectively. The moisture content error of MMMRT and standard moisture content measured after the MMMRT were corrected by moisture content rate of every 5% using the correction equation by curvilinear regression analysis appeared with 0~0.5% and 0.9~1.8% respectively in the moisture content range of 15~20% and 20~25%.

• 한국농공학회논문집
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• 제52권5호
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• pp.77-86
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• 2010

Hydrologic Simulation Program-Fortran (HSPF) coupled with PEST which is optimization program was calibrated and validated at Bochung watershed by using monitoring data of water quantities and nutrient loading. Although the calibrated data were limited, model parameters of each land use type were optimized and coefficient of determinations were ranged from 0.94 to 0.99 for runoff, from 0.89 to 1.00 for TN loading, and from 0.92 to 1.00 for TP loading. The optimized hydrological parameters indicated that the forested land could retain rainfall within soil layer with high soil layer depth and infiltration rate compared with other land use type. Hydrological characteristics of paddy rice field are low infiltration rate and coefficient of roughness. The calibrated parameters related to nutrient loading indicated generation of nutrient pollution from agricultural area including upland and paddy rice field higher than other land use type resulting from fertilizer application. Overall PEST program is useful tool to calibrate HSPF automatically without consuming time and efforts.

• Ecology and Resilient Infrastructure
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• 제2권3호
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• pp.247-254
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• 2015

Changes in land-use type can affect soil and water properties in stream ecosystems. This study examined the effects of different land-use types on biogeochemical properties and microbial activities of a stream. We collected water and sediment samples in a stream at three different sites surrounded by varying land-use types; a forest, a radish field and a rice paddy. Nitrogen contents, such as nitrate, nitrite and total nitrogen in the stream water body, showed significant differences among the sampling sites. The highest nitrogen values were recorded at the site surrounded by cropland, as fertilizer runoff impacted the stream. Soil organic matter content in the sediment showed significant differences among sites, with the highest content exhibited at the forest mouth site. These differences might be due to the organic matter in surrounding terrestrial ecosystems. Microbial activities determined by extracellular enzyme activities showed similar values throughout all sites in the water body; however, the activities in the sediments exhibited the highest values near the forest site and mirrored the soil organic matter content values. From these results, we conclude that different land-use types are important factors affecting water and sediment properties in stream ecosystems.

• 한국토양비료학회지
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• 제46권5호
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• pp.333-342
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• 2013

Soil compaction is affected by soil texture, organic matter (OM), strength (ST) and soil moisture, which is difficult to understand the degree and effects of related factors. The purpose of the study is to assess the impact of them on the compaction with bulk density (BD). The analysis was conducted with data collected from national-wide monitoring sites including 105 upland soils, 246 orchard soils, and 408 paddy soils between 2009 and 2012. The distributions of soil physical properties were measured. The correlation and multi linear regression analysis were performed between soil physical properties using SAS. The regression equation of BD(y) includes ST, gravitational water contents (GWC), and OM as variables commonly, having additional factors, clay content and sand content in paddy soil and upland soil for only subsoil (p<0.001). Our results show that the BD could be explained about 40~50% by various physical properties. The regression was mainly determined by ST in orchard and upland soil and by the GWC in paddy soil. To mitigate soil compaction, it is important to maintain the proper level of OM in upland soil and to consider the moisture condition with soil texture in paddy soil when making work plan. Furthermore, it would be recommended the management criteria classified by soil texture for the paddy soils.

• 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.

• 한국농업기계학회:학술대회논문집
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• 한국농업기계학회 2000년도 THE THIRD INTERNATIONAL CONFERENCE ON AGRICULTURAL MACHINERY ENGINEERING. V.III
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• pp.819-826
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• 2000

This study was performed to develop a measurement system of tractor field performance for plow and rotary operations. Measurement system for tractor consisted of torque sensors to measure torque of drive axles and PTO axle, speed sensors to measure rotational speed of drive axles and engine, microcomputer to control data logger, and data logger as I/O interface system. The measurement system was installed on four-wheel-drive tractor. Four-element full-bridge type strain gages were used for torque measurement of drive axles and optical encoders were used to measure speeds of drive axles and engine. Slip rings were mounted on the rotational axles. Signals from sensors were inputted to data logger that was controlled by microcomputer with parallel communication. Sensors were calibrated before the field tests. Regression equations were found on completion of the calibrations. The field experiment was performed at paddy fields and uplands. Rotary and plow were used when the tractor was operated in the field. Travelling speeds of the tractor were 1.9 km/h, 2.7 km/h, 3.7 km/h, 5.5 km/h, 8.2 km/h, and 11.8 km/h. Operating depths of implements were maintained approximately 20cm during the tests. Torque data of drive axles were different at each location during plow and rotary operations. Results showed that torque of rear axles were greater than those of front axles. Total torque were 6860 - 11064 Nm at the upland and 7360 - 14190 Nm at the paddy field for plow operations. It was found that torque at the paddy field were about 20% greater than those at the upland for plow operations. Torque data showed that rotary operations required less power than plow operation at the paddy field and the upland. Torque measurements at each axle for rotary operations were only 8 - 16% of plow operations in the upland and 15 - 20% in the paddy field.

• 농촌계획
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• 제24권4호
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• pp.57-67
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• 2018

We examined the impact of paddy wetland's avian-diversity on the development of the protected horticulture complex. The results of this study were made to propose ecological protected horticulture complex and development direction suitable for avian habitat. The total number of species surveyed was analyzed as 1168 individuals in 11 orders 26 families and 36 generic 48 species. Type average was analyzed as paddy $17.25{\pm}4.83$ species and $74.50{\pm}38.08$ individuals, glass $10.00{\pm}0.82$ species and $46.75{\pm}2.06$ individuals, single $13.75{\pm}7.27$ species and $59.50{\pm}35.34$ individuals, multi $8.75{\pm}0.96$ species and $36.75{\pm}9.29$ individuals. Paddy showed higher species diversity than protected horticulture complex. The average number of species surveyed for one year was glass $14{\pm}2.83$, multi $12{\pm}1.41$, single $18{\pm}11.31$, and paddy $26{\pm}11.31$. The diversity difference was identified as paddy> single> glass and multi. Statistical analysis showed statistical difference of Ciconiiformes. Development of protected horticulture complex causes loss of avian habitat. The diversity index was glass $1.73{\pm}0.07$, multi $1.68{\pm}0.14$, single $1.91{\pm}0.47$, and paddy $2.29{\pm}0.17$. Paddy has a higher species diversity than the protected horticulture complex. For the purpose of ecological protected horticulture complex, detention ponds, artificial wetlands and habitats should be reflected in the design. This should be applied to reclamation areas or large-scale protected horticulture complexes.

• 한국잡초학회지
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• 제3권1호
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• pp.39-49
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• 1983

분벽경(分蘗莖)의 열개각도(裂開角度)가 상이(相異)한 수도초형(水稻草型)의 Near-isogenic line 3종(種)과 생육상(生育相)이 상이(相異)하연셔 문제(問題)가 되는 3종(種)의 다년생잡초(多年生雜草)(너도방동산이, 가래, 올미)를 작물(作物)에 대한 3 수준의 혼생밀도하(混生密度下)(0.25, 50%)에 공시(供試)하여 작물(作物)과 잡초(雜草)의 경시적(經時的)인 생육진전양상(生育進展樣相)과 건물생산(乾物生産) 및 수량(收量), 수량구성요소(收量構成要素)를 조사(調査)함으로써 작물(作物)-잡초(雜草)간(間)의 경합양상(競合樣相)을 조사(調査)하였다. 조사목적(調査目的)은 수도초형(水稻草型)에 의(依)한 잡초경합력(雜草競合力)의 차이(差異)를 측정(測定)하고 경합특성(競合特性)을 구명(究明)함으로서 잡초종(雜草種)에 따른 재배적(栽培的), 생태적(生態的) 방제(防除)의 가능성(可能性)과 육종방향(育種方向) 설정(設定)을 위한 기초자료(基礎資料)를 얻기 위함에 있다. 얻어 진 결과(結果)를 요약(要約)하면 다음과 같다. 1. 수도초형차이(水稻草型差異)가 잡초생육억제(雜草生育抑制)를 통(通)하여 간접적(間接的)으로 작물수량(作物收量)에 미치는 영향(影響)보다 잡초종별(雜草種別) 혼생밀도(混生密度)가 미치는 영향(影響)이 보다 높은 유의차(有意差)를 나타냈다. 2. Open type의 너도방동산이가 50% 혼생(混生)에서 Broom type은 모든 초형(草型)의 50%에서, 그리고 Spread type은 가래 외에 모든 초종(草種) 50%에서 감소(減少) 경향(傾向)이었다. 3. Broom 및 Spread type에서의 잡초경합해(雜草競合害)는 단위면적당수수(單位面積當穗數)와 수당영화수(穗當穎花數)가 모두 감소(減少)하고 반면 Open type에서는 단위면적당수수(單位面積當穗數)만 감소(減少)하는 경향이었다. 4. 잡초건물생산증가(雜草乾物生産增加)에 따른 수도생육(水稻生育) 및 수량감소(收量減少)는 Spread type에서 가장 현저(顯著)하였다. 5. 너도방동산이는 모든 초형(草型)의 수도(水稻)에서 단위면적당(單位面積當) 수수(穗數) 감소(減少)를, 올방개는 Broom 및 Spread type의 단위면적당(單位面積當) 수수(穗數)와 주당영화수(株當穎花數) 감소(減少) 및 Open type의 주당수수(株當穗數) 감소(減少)를 그리고 가래는 밀생조건하(密生條件下)에서 모든 초형(草型)의 수도(水稻)에 생육억제(生育抑制)시키는 경향(傾向)이었다. 6. Broom 및 Spread type은 가래에, Open type은 가래와 올방개에 보다 경합력(競合力)이 있었다. 7. 너도방동산이는 모든 초형(草型)의 수도(水稻)에 경합해(競合害)를 크게 미치는 경향(傾向)이었다. 8. 작물(作物)-잡초경합유형(雜草競合類型)은 잡초(雜草)-작물(作物)의 생육진전(生育進展) 및 수량형성(收量形成) 전반(全般)에 걸쳐셔 잡초종(雜草種)이나 혼생밀도(混生密度)보다 작물(作物)의 초형(草型)에 의(依)하여 그리고 생육진전(生育進展)은 잡초발생밀도(雜草發生密度)에 의(依)하여 부차적(副次的)으로 결정(決定)되는 경향(傾向)이었다. 9. 잡초종(雜草種)에 따른 이상적(理想的)인 생태적(生態的) 재배법(栽培法) 방제(防除)를 위하여 작물초형(作物草型)의 연구(硏究)는 지속(持續)될 필요(必要)가 있을 것으로 판단(判斷)되었다.

• 한국환경복원기술학회지
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• 제9권6호
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• pp.63-77
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• 2006

The research aim is to classify biotope types of rural eco-villages designed by ministry of environment and analyze landscape ecological characteristics of them. This information would provide information on eco-villages' potential and specific needs to improve landscape ecological structure of eco-villages. Two eco-villages, designated by ministry of environment, in Yoocheon-ri and Sanduk-ri were selected and the landscape ecological metrics used in this study were Area, Shannon diversity index, Shape index, Distance index. The results are as follows. 1) There were five biotope types in large-scale classification, 13 biotope types m Sanduk-ri and 9 biotope types in Yoocheon-ri in middle-scale classification, 31 biotope types in Sanduk-ri and 24 biotope types in Yoocheon-ri in small-scale classification. 2) In the case of area, artificial biotope types, such as artificial forest, agricultural irrigation canal, wet paddy, dry paddy and residential area, covered more than 80% of total area. However, natural biotope types, such as natural forest, river, reservoir, covered just more than 10% of total area. In details, an orchard (26.69%) was the dominant biotope type, followed by artificial forest (19.10%) in Sanduk-ri and the first most abundant biotope type was artificial forest (49.71%), followed by wet paddy (15.95%) in Yoocheon-ri. 3) The result of Shannon diversity index indicated that Sanduk-ri (2.158) had more heterogeneity landscape, rather than Yoocheon-ri (2.051). 4) In the case of shape index, road (13.09) had more complex and irregular shape than either agricultural irrigation canal (3.35) or artificial forest (2.46) in Sanduk-ri. Road (6.52) was also the most irregular biotope shape, followed by river (5.70) and agricultural irrigation canal (4.78) in Yoocheon-ri. 5) Mean Nearest-neighbour Distance (MND) was smallest in wet paddy and dry paddy biotope types in the two study area, suggesting that these biotope types were concentrated within these study areas. From the result, this research suggested information to protect and improve biotopes of eco-villages in the landscape ecological terms. To achieve this improvement plan, there should be strong support by ministry of environment and local governments.

• 한국토양비료학회지
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• 제44권6호
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• pp.1220-1225
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• 2011

논토양 종류가 메탄배출에 미치는 영향을 구명하기 위하여 적황색토인 화동통과 회색토인 신흥통을 공시하여 벼 재배기간중 메탄배출량, 산화환원전위 및 토양중 산화물 함량을 분석하였다. 적황색토에서 메탄배출이 회색토에 비해 유의하게 낮았으며, 산화환원전위는 상대적으로 높았다. 적황색토는 회색토에 비해 쉽게 환원될 수 있는 Active oxide 함량은 낮은 반면, 상대적으로 안정성이 높은 Free oxide의 함량이 높았다. 따라서 논토양 종류별 메탄배출은 벼 재배기간중 산화환원전위와 토양중 Geothite, Hematite 등과 같은 메탄산화제의 함량에 영향을 받는 것으로 나타났다.