• 환경생물
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• 제36권4호
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• pp.488-497
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• 2018

형질전환 벼와 일반 벼의 환경위해성 평가 기초자료를 위해 경상남도 사천시에서 2013~2017년, 경상북도 군위군에서 2015~2016년 7월 말부터 10월 초까지 벼에 발생하는 곤충상을 조사하고 군집특성을 분석하여 비교하였다. 사천시에서 형질전환 벼는 경상대학교 LMO (Living genetically Modified Organism) 격리포장 내에서 재배되었고, 일반 벼는 경상남도 사천시 사천읍 두량리에서 재배되었다. 군위군에서 형질전환 벼는 경북대학교 LMO 격리포장 내에서 재배되었고, 일반 벼는 경상북도 군위군 효령면 화계리에서 재배되었다. 채집방법으로 육안 조사, 포충망 조사, 유아등 트랩, 끈끈이 트랩을 이용하였다. 5년 동안 사천시에서 총 15목 123과 464종 37,941개체가 채집되었고, 2년 동안 군위군에서 총 13목 111과 366종 10,030개체가 채집되었다. 다년간 LMO포장과 일반포장을 비교해본 결과 매년 상위 주요 목은 우점 순서를 제외하면 거의 같은 목이 나타나는 것을 보아 아직까지는 LMO포장과 일반포장의 차이가 뚜렷하게 나타나지 않았다고 사료된다. 그리고 LMO포장과 일반포장 사이의 유사도 지수와 일반포장 사이의 유사도 지수가 차이가 없는 것으로 보아 LMO로 인한 차이가 아닌 환경에 의한 차이로 사료된다.

• 한국토양비료학회지
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• 제49권1호
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• pp.30-35
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• 2016

Rice cultivation in paddy field affects the global balance of methane ($CH_4$) as a key greenhouse gas. To evaluate a potential use of by-product gypsum fertilizer (BGF) in reducing $CH_4$ emission from paddy soil, $CH_4$ fluxes from a paddy soil applied with BGF different levels (0, 2, 4 and $8Mg\;ha^{-1}$) were investigated by closed-chamber method during rice cultivation period. $CH_4$ flux significantly decreased (p<0.05) with increasing level of BGF application. $8Mg\;ha^{-1}$ of BGF addition in soil reduced $CH_4$ flux by 60.6% compared to control. Decreased soil redox potential (Eh) resulted in increasing $CH_4$ emission through a $CO_2$ reduction reaction. The concentrations of dissolved calcium (Ca) and sulfate ion (${SO_4}^{2-}$) in soil pore water were significantly increased as the application rate of BGF increased and showed negatively correlations with $CH_4$ flux. Decreased $CH_4$ flux with BGF application implied that ${SO_4}^{2-}$ ion led to decreases in electron availability for methanogen and precipitation reaction of Ca ion with inorganic carbon including carbonate and bicarbonate as a source of $CH_4$ formation under anoxic condition. BGF application also increased rice grain yield by 16% at $8Mg\;ha^{-1}$ of BGF addition. Therefore, our results suggest that BGF application can be a good soil management practice to reduce $CH_4$ emission from paddy soil and to increase rice yield.

• Journal of Biosystems Engineering
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• 제33권2호
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• pp.83-93
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• 2008

In order to save labor and cost, direct seeding has been considered as an important alternative to the machine transplanting in rice cultivation. Current direct seeding machines for rice in Korea drill irregularly under various operating conditions. This study was conducted to develope a precision seeder which enables the accurate, even-spaced in row placement of rice seeds at uniform depths of 3-4 cm on dry paddy. Design, construction and performance evaluation of the precision seeder were carried out. The tractor rear-mounted type 8-rows precision seeder which performs seeding in addition to fertilizing, ditching, and rotary tilling works on dry paddy was developed. Main components of the seeder were ditcher and leveller, rotary tiller, powered roller type furrow opener, seeding device, powered roller type furrow covering and firming device, hydraulic unit, seeding speed control system, power transmission system, hitch and frame. Ditching, furrow opening, and seed covering and firming performances were good and seeding depths of 2-4 cm could be maintained. Planting accuracies and planting precisions were within 13.6%, and 31.2%, respectively, for planting space of 15 cm, and seeding velocity of 0.5 m/s. These mean variations of average planting space were within 2.1 cm, and 90% of seeds in a hill were seeded within 4.7 cm of hill length, respectively. Error ratios between setting planting space and measured average planting space were shown within 6.7%. Therefore the seeder showed good planting performance up to seeding velocity of 0.5 m/s in field tests. And field capacity of the seeder was about 0.28 ha/hour.

• Journal of Biosystems Engineering
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• 제5권1호
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• pp.33-42
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• 1980

This study was carried out to investigate the actual environmental paddy storage conditions in conventional Korean farm warehouses. The paddy storage conditions by the locations and sizes of warehouses were figured out. The effectiveness of the small insulated box for storing paddy was also examined. Observations were made at sixteen different warehouses located in Moonsan-Myeon, Jinyandg-gun, Gyungnam Province from July lst to September 28 th, the period which was considered to be the worst for storing grains. The results are as follows ; 1. the average temperatures of rough rice and air inside the warehouse were 0.9 and 0.7$^\circ$ higher than the outside air temperature. 2. The average relative humidity in warehouses was 1.5percent higher than that of the atomosphere. This fact resulted in the increased moisture content of grains. Therefore, the ventilation for equalizing the relative humidity of inside and outside of warehouses was required. 3. The dry matter of stored rough rice was decreased by 1.1 percent in average druing the observation period. In order to reduce the dry matter loss, application of new grain storing method ;hermetic storage or filling inert gas storage, was highly recommended. 4. Environmental conditions for storing rough rice in a warehouse located in a sloping site are, in general , better than those of a warehouse located in a flat site. But as far as the dry matter of rough rice was concerned, above situation is not always satisfactory. Because it is fairly frequent to observe the higher rate of moisture absorption by grains stored in a warehouse located in a sloping site. 5. Environmental conditions for storing rough rice in a large-scale warehouse were better than those in a small size warehouse. Therefore, it is advisible for farmers to store their grins in the large-scale warehouses commonly used by villagers. 6. It was undesirable to store rough in a insulated box.

• 한국토양비료학회지
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• 제41권5호
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• pp.342-347
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• 2008

미생물에 의해 분비되는 유기산에 의해 난용성 인산염이 가용화되어 토양 용액 중으로 확산되면 식물 혹은 다른 미생물이 이용할 수 있게 된다. 본 연구는 논 토양을 대상으로 볏짚 퇴비, 석회, 규산 등의 개량제가 토양 인산 가용화균의 생태에 미치는 영향을 조사하였다. 인산가용화 균의 비율이 증가할 수록 토양의 유효인산 함량이 높아지는 경향을 보였다. 논 토양 호기성 세균에 대한 인산가용화 세균의 비율은 석회, 규산 및 퇴비를 함께 시용한 처리구에서 크게 증가하였다. 논 토양에서 분리된 인산가용화 세균은 Aquaspirillum, Arthrobacter, Bacillus, Flavobacterium, Micrococcus, Micromonospora, Pseudomonas속 등이었으나 가장 많이 분리된 균은 Bacillus속이 그 다음으로는 Pseudomonas속이 우점하였다.

• 한국토양비료학회지
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• 제46권4호
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• pp.270-275
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• 2013

Hairy vetch can fix nitrogen from the atmosphere as a leguminous cover crop. This research was carried out to determine optimum seeding method of hairy vetch and application effect in paddy. Field experiment was conducted at Sinheung series (fine loamy, mixed, nonacid, mesic family of Fluvaquentic Endoaquepts) from Sep. 2011 to Oct. 2012 at the National Institute of Crop Science (NICS), RDA, Suwon, Gyeonggi province, Korea. Hairy vetch used in the study was 'Cheongpyungbora', developed by National Institute of Crop Science. Seeding methods of hairy vetch consisted of Broadcasting Before Rice Harvesting (BBRH), Partial Tillage Seeding (PTS), Minimum Tillage Seeding (MTS), No Tillage Seeding (NTS), and Drill Seeding (DS). Both MTS and NTS showed the highest biomass among the seeding methods. The rice yield of MTS and NTS significantly increased compared to conventional fertilization (CF). Also soil properties including organic matter and bulk density were improved by incorporation of hairy vetch. Therefore, we suggested that MTS and NTS could be used to produce hairy vetch and rice in paddy.

• 한국농공학회논문집
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• 제53권4호
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• pp.67-74
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• 2011

The objectives of this study were to assess the rice yields and evaluate fertilizer reduction effect of reclaimed wastewater irrigation in paddy fields using the Decision Support System for Agrotechnology Transfer (DSSAT) v4.5 model. The experimental plots were designed, which was located near the Suwon wastewater treatment plant in Gyeonggi-do, Korea. The rice yield, irrigation amount, irrigation water quality and soil data were monitored and collected between 2006 and 2009. The DSSAT model was calibrated and validated with observed data. The methods that were used to evaluate this model were the root mean square error (RMSE), normalized root mean square error (nRMSE), and index of agreement (d). The values of RMSE, nRMSE, and d ranged from 145 to $789\;kg\;ha^{-1}$, 3.0 to 13.3 %, and 0.90 to 0.95 for the calibration period, respectively and represented from 91 to $538\;kg\;ha^{-1}$, 2.0 to 10.4 %, 0.94 to 0.98 for the validation period, respectively. Overall, this model showed good agreement with observed data of rice yields irrigated with reclaimed wastewater. The fertilizer reduction effect in paddy field of reclaimed wastewater irrigation was assessed about 60 % in 2008 and 40 % in 2009.

• 한국농공학회논문집
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• 제55권4호
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• pp.55-63
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• 2013

This study investigates the trends and uncertainty of the impacts of climate change on paddy rice production in the Geumho river basin. The Long Ashton Research Station stochastic Weather Generator (LARS-WG) was used to derive future climate data for the Geumho river basin from 15 General Circulation models (GCMs) for 3 Special Report on Emissions Scenarios (SRES) (A2, A1B and B1) included in the Intergovernmental Panel on Climate Change (IPCC) 4th assessment report. The Food and Agricultural Organization (FAO) AquaCrop, a water-driven crop model, was statistically calibrated for the 1982 to 2010 climate. The index of agreement (IoA), prediction efficiency ($R^2$), percent bias (PBIAS), root mean square error (RMSE) and a visual technique were used to evaluate the adjusted AquaCrop simulated yield values. The adjusted simulated yields showed RMSE, NSE, IoA and PBIAS of 0.40, 0.26, 0.76 and 0.59 respectively. The 5, 9 and 15 year central moving averages showed $R^2$ of 0.78, 0.90 and 0.96 respectively after adjustment. AquaCrop was run for the 2020s (2011-2030), 2050s (2046-2065) and 2090s (2080-2099). Climate change projections for Geumho river basin generally indicate a hotter and wetter future climate with maximum increase in the annual temperature of $4.5^{\circ}C$ in the 2090s A1B, as well as maximum increase in the rainfall of 45 % in the 2090s A2. The means (and ranges) of paddy rice yields are projected to increase by 21 % (17-25 %), 34 % (27-42 %) and 43 % (31-54 %) for the 2020s, 2050s and 2090s, respectively. The A1B shows the largest rice yield uncertainty in all time slices with standard deviation of 0.148, 0.189 and $0.173t{\cdot}ha^{-1}$ for the 2020s, 2050s and 2090s, respectively.

• 한국토양비료학회지
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• 제30권1호
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• pp.35-40
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• 1997

담수된 논 토양에서는 산소공급의 차단으로 환원상태가 조장되어 메탄가스가 생성되는데, 생성된 메탄은 확산이나 벼 식물체를 통하여 대기로 배출되어 지구온난화 가스로 작용된다. 본 연구는 메탄가스 저감방법을 구명하고자 벼 재배양식별 메탄가스 배출특성을 조사한 결과를 요약하면 다음과 같다. 1. 벼 재배양식에 따른 메탄 배출량은 이앙재배, 담수직파, 건답직파순으로 많았으며 볏짚을 시용한 건답직파의 평균메탄 배출량($mg{\cdot}m^2{\cdot}h^{-1}$)은 10.27, 담수직파는 21.94, 그리고 이앙재배는 24.05였다. 2. 출수기의 시간별 메탄발생 양상은 오전 9시에서 오후7시까지 메탄배출량이 많았으며 밤에는 낮보다 메탄 배출량이 낮았다. 3. 메탄 배출량은 기온과 Eh와 높은 상관을 보였다. 4. 시기별 메탄 배출정점은 유수형성기와 출수기 무렵에 두번 보였다.

• 한국토양비료학회지
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• 제43권6호
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• pp.917-922
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• 2010

To assess the bioavailability of As in soils and to provide a basic information for adequate management of As contaminated fields, paddy soils and rice grains near 5 closed mines were collected and analyzed for As using sequential extraction procedure. The As contents extracted with 1M HCl against total As content in soils were ranged from 5.4 to 41.9% ($r=0.90^{**}$). However, these two contents of As in soils were not positively correlated with As concentration in rice grains. Major As fractionation of paddy soils was residual form ranging 38.1 to 84.1% except NS mine. Also, specially adsorbed fraction and fraction associated with amorphous Fe and Al oxyhydroxides, which are partially bioavailable As fractionation to the rice plant, were positively correlated with As in rice grains while fraction associated with crystalline Fe and Al oxyhydroxides and residual form were not correlated.