• 한국농공학회지
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• 제44권5호
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• pp.116-126
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• 2002

Discharge pattern and water quality were investigated in the drainage water from about 10 ha of groundwater-irrigated paddy field in the growing season of 2001. Total discharge quantity was about 1,117.2 mm in which about 75% was caused by management drainage due to cultural practice of paddy rice farming and the rest by rainfall runoff where total rainfall was about 515 mm. Dry-day sampling data showed wide variations in constituent concentrations with average of 26.14 mg/L, 0.37 mg/L, 3.54 mg/L at the inlet, and 43.60 mg/L, 0.34 mg/L, 3.58 mg/L at the outlet for CO $D_{cr}$ , T-P, and T-N, respectively. Wet-day sampling data demonstrated that generally CO $D_{cr}$ followed the discharge pattern and T-P was in opposite to the discharge pattern, but T-N did not show apparent pattern to the discharge. Discharge and load are in strong relationship. And based on regression equation, pollutant loads from groundwater irrigation area are estimated to be 288.34, 1.17, and 5.45 kg/ha for CO $D_{cr}$ , T-P, and T-N, respectively, which was relatively lower than the literature value from surface water irrigation area which implies that groundwater irrigation area might use less irrigation water and result in less drainage water, Therefore, total pollutant load from paddies irrigation with groundwater could be significantly lower than that with surface water. This study shows that agricultural drainage water management needs a good care of drainage outlet as well as rainfall runoff. This study was based on limited monitoring data of one year, and further monitoring and successive analysis are recommended for more generalized conclusion.

• 한국토양비료학회지
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• 제49권2호
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• pp.218-225
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• 2016

This experiment was conducted in Suwon and Iksan city from 2012 to 2014 to evaluate soil erosion and nutrient loss from irrigated paddy fields during cropping period. Rainfall amount and rainfall erosivity of $EI_{30}$ were, on average, 1,026 mm and $3,922mm\;ha^{-1}yr^{-1}hr^{-1}$ for the cropping period, respectively, and the rainfall event with maximum $EI_{30}$ occurred in July. Annual average of runoff was $2,508MT\;ha^{-1}yr^{-1}$ in Suwon and $3,375MT\;ha^{-1}yr^{-1}$ in Iksan, accounting for 36% of rainfall of the cropping period. Nutrient loss by runoff, on average, was $7.0kg\;N\;ha^{-1}yr^{-1}$, $1.3kg\;P\;ha^{-1}yr^{-1}$, and $16.6kg\;K\;ha^{-1}yr^{-1}$; N, P, and K loss were 5.0, 0.6, and $8.3kg\;ha^{-1}yr^{-1}$, respectively, in Suwon and 8.9, 1.9, and $16.7kg\;ha^{-1}yr^{-1}$ in Iksan. Soil loss in Korean paddy rice was evaluated as $0.33MT\;ha^{-1}yr^{-1}$ ranging from $0.05MT\;ha^{-1}yr^{-1}$ to $0.88MT\;ha^{-1}yr^{-1}$. Amount of soil loss, however, depended on areas and year influenced by variation of rainfall amount and intensity. Interestingly, soil erosion in Iksan in 2012 was remarkably greater than those in other periods due to heavy rainfall between late May and June with soil flake dispersion right after the rice-planting season.

• 한국식품과학회지
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• 제50권2호
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• pp.138-142
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• 2018

재배조건에 따른 차이를 보기 위해 논에서 재배되는 논쌀 두종과 제주밭쌀의 특성과 중금속 함량을 비교하였다. 두 논쌀 중 아밀로오스 함량이 높은 논쌀 2와 제주밭쌀은 높은 페이스팅 온도와 낮은 최고 점성, 그리고 상대적으로 높은 셋백(setback)을 보였으나, 재배조건에 따른 차이를 보이지는 않았다. 제주밭쌀은 짙은 노란색과 낮은 점성을 보여 외관과 기계적 식미치에서 논쌀보다 낮게 평가되었다. 중금속 중 카드뮴과 납은 논쌀과 밭쌀의 차이를 보이지 않았으나, 총 비소함량의 경우 제주밭쌀은 논쌀의 10.1-17.9%에 해당하는 양을 보였다. 또한 제주밭쌀의 무기비소함량도 논쌀 2의 무기비소함량의 15% 정도에 불과한 것으로 나타났다. 논쌀을 침수, 취반, 뜨거운 물로 씻어내리기 등의 처리에 의해 무기비소 함량을 각각 34.1, 23.8, 17.5% 줄일 수 있는 것으로 나타났으나, 제주밭쌀의 경우 무기비소함량이 매우 적어 처리에 의한 유의적 차이는 발견되지 않았다.

• 한국농공학회지
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• 제45권4호
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• pp.55-65
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• 2003

Pilot study was conducted to examine the effects of ponded-water depth and reclaimed wastewater irrigation on paddy rice culture. For the ponded-water depth effect, three treatments of shallow, traditional, and deep water depths were applied, and each treatment was triplicated. The irrigation water for the treatment pots was an effluent from constructed wetland system for sewage treatment, while the control pot was irrigated with tap water kept traditional ponded-water depth. Irrigation water quantity varied with ponded-water depth as expected and drainage water quantity also varied similarly, which implies that shallow irrigation might save irrigation water and also reduce environmental impacts on downstream water quality. Rice growth and production were not significantly affected by ponded-water depth within the experimental condition, instead there was an indication of increased production in shallow and deep ponded-water depths compared to the traditional practice. Raising drainage outlet to the adequate height in paddy dike might be beneficial to save water resources within the paddy field. There was no adverse effect observed in reclaimed wastewater irrigation on the rice production, and mean yield was even greater than the control pots with tap water irrigation although statistically not significant. Water-saving irrigation by shallow ponded-water depth, raising the outlet height in diked rice paddy fields, minimizing forced surface drainage by well-planned irrigation, and reclaimed wastewater irrigation are suggested to save water and protect water quality. However, deviation from traditional farming practices might affect rice growth in long term, and therefore, further investigations are recommended before full scale application.

• Agribusiness and Information Management
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• 제9권1호
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• pp.7-17
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• 2017

Agricultural water management has gained enormous attention in the developing world to alleviate poverty, reduce hunger and conserve ecosystems in small-scale production systems of resource-poor farmers. The story of food security in the $21^{st}$ century in India is likely t o be closely linked to the story of water security. Today, the water resource is under severe threat. The past experiences in India in general and in Andhra Pradesh in particular, indicated inappropriate management of irrigation has led to severe problems like excessive water depletion, reduction in water quality, water logging, salinization, marked reduction in the annual discharge of some of the rivers, lowering of ground water tables due to pumping at unsustainable rates, intrusion of salt water in some coastal areas etc. Considering the importance of irrigation water resource efficiency, Krishna Western Delta (KWD) of Andhra Pradesh was purposively selected for this in depth study, as the farming community in this area are severely affected due to severe soil salinity and water logging problems and hence, adoption of different water saving crop production technologies deserve special mention. It is quite disappointing that, canals, tube wells and filter points and other wells could not contribute much to the irrigated area in KWD. Due to less contribution from these sources, the net area irrigated also showed declining growth at a rate of -6.15 per cent. Regarding paddy production, both SRI and semi-dry cultivation technologies involves less irrigation cost (Rs. 2475.21/ha and Rs. 3248.15/ha respectively) when compared to transplanted technology (Rs. 4321.58/ha). The share of irrigation cost in Total Operational Cost (TOC) was highest for transplanted technology of paddy (11.06%) followed by semi-dry technology (10.85%) and SRI technology (6.21%). The increased yield and declined cost of cultivation of paddy in SRI and semi-dry production technologies respectively were mainly responsible for the low cost of production of paddy in SRI (Rs. 495.22/qtl) and semi-dry (Rs. 532.81/qtl) technologies over transplanted technology (Rs. 574.93/qtl). This clearly indicates that, by less water usage, paddy returns can be boosted by adopting SRI and semi-dry production technologies. Both the system-level and field-level interventions should be addressed to solve the issues/problems of water management. The enabling environment, institutional roles and functions and management instruments are posing favourable picture for executing the water management interventions in the State of Andhra Pradesh in general and in KWD in particular. This facilitates the farming community to harvest good crop per unit of water resource used in the production programme. To achieve better results, the Farmers' Organizations, Water Users Associations, Department of Irrigation etc., will have to aim at improving productivity per unit of water drop used and this must be supported through system-wide enhancement of water delivery systems and decision support tools to assist farmers in optimizing the allocation of limited water among crops, selection of crops based on farming situations, and adoption of appropriate alternative crops in drought years.

• 한국토양비료학회지
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• 제49권5호
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• pp.564-571
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• 2016

As the amount of rice straw collected increases, green manure crops are used to provide the needed organic matter. However, as green manure crops generate methane in the process of decomposition, we tested with different tillage depths in order to reduce the emission. The atmosphere temperature of the chamber was $25{\sim}40^{\circ}C$ during the examination of methane and soil temperature was $2{\sim}10^{\circ}C$ lower than air temperature. The redox potential (Eh) of the soil drastically fell right before irrigated transplanting and showed -300~-400 mV during the cultivating period of rice (7~106 days after transplant). When hairy vetch was incorporated to soil and the field was not irrigated, the generation of methane did not occur from 12 to 4 days before transplanting rice and started after irrigation. Regarding the pattern of methane generation during the cultivation of rice, methane was generated 7 days after transplanting, reached the pinnacle at by 63~74 days after transplanting, rapidly decreased after 86~94 days past transplanting and stopped after 106 days past transplanting. When tested by different soil types, methane emission gradually increased in loam and clay loam during early transplant, whereas it sharply increased in sandy loam. The total amount of methane emitted was highest in sandy loam, followed by loam and clay loam. In all three soil types, methane emission significantly reduced when tillage depth was 20 cm compared to 10 cm. The rice growths and yield were not affected by tillage depth. Therefore, reduction of methane emission could be achieved when application hairy vetch to the soil with tillage depth of 20 cm in paddy soil.

• 한국수자원학회논문집
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• 제36권1호
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• pp.117-128
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• 2003

본 연구에서는 소유역에서의 오염총량을 추정하기 위하여 위성영상 카테고리분류 인공신경망 모형과 지리정보시스템 기반의 오염총량모의시스템(Total maximum daily Loads simulation System, TOLOS)을 개발하였으며, 발안유역의 HP#6 소유역을 시험유역으로 선정하여 유역 수문·수질 모니터링을 수행하였고, 시험유역의 도형 자료를 구축하여 TOLOS의 적용성을 평가하였다. TOLOS의 오염총량추정 모듈인 SWAT 모형은 논에서의 지표배수량을 고려하여 구성하였다. TOLOS을 이용하여 일별 측정 자료인 유출량, 유사량, 그리고 영양물질에 대하여 SWAT 모형의 보정과 검정을 실시하였으며, 그 결과 적용 가능성이 있는 것으로 나타났다.

• 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.

• 한국작물학회지
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• 제45권3호
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• pp.195-198
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• 2000

무경운 담수표면산파재배시 잡초성벼의 발생양상과 비선택성 및 토양처리제를 이용한 잡초성벼 방제 결과는 아래와 같다. 1. 무경운에 의해 토양표면에서 월동한 잡초성벼의 생존율은 92.7%였고 재배벼는 4.3%였다. 2.토양내의 잡초성벼 발생심도는 건답에서 6.8cm, 무논에서 3.0cm, 그리고 무경운답에서 1.5cm로, 무경운답의 잡초성벼 발생은 건답과 무논에 비하여 토양 표층부위에서 주로 발생하였다. 3. 4월 하순의 우리나라 중부지역 평균기온인 13$^{\circ}C$에서 잡초성벼 발아에 소요되는 일수는 14-15일이었다. 4. 무경운상태에서 포장 표면위에 떨어져 있는 잡초성벼의 발아를 유도한 후 비선택성 제초제인 paraquat 처리한 결과 92.2%의 잡초성벼를 방제할 수 있었으며, 토양처리제 중 가장 높은 출아억제를 보인 제초제는 oxadiazon으로 53.3%의 방제 효과가 있었다. 5. Paraquat과 oxadiazon의 체계처리에 의해 96.4%의 잡초성벼를 방제할 수 있었다.

• 한국약용작물학회지
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• 제20권2호
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• pp.124-128
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• 2012

When ginseng seedlings are cultured in paddy fields, quality degradation and yield reduction are induced by severe plant loss with chlorosis on leaves occurred physiological disorder by excessive salt and poor drainage, rusty-root occurrence, and root rot etc. Accordingly, in order to solve these problems, this study was performed to investigate the treatment method, concentrations and time of activated ion calcium as environment-friendly agricultural materials. Activated ion calcium is an enriched and purified water-soluble mineral calcium component for absorbing quickly into plant as a highly functional calcium and it is an alkaline calcium of 37% (370 $m{\ell}$/1 ${\ell}$) concentration with pH 13. Treatment method was that ginseng seeds were sown after removing water in the shade after seed immersion for 1 minute with active ion calcium of 20-fold diluted solution, and then irrigated $4{\ell}$ per 3.3 $m^2$ with 200-fold, 400-fold, and 600-fold diluted solution before emergence on late March, and supplied 1 time on leaves with 500-fold diluted solution in June and July respectively. The disease rate by treatment of activated ion calcium was that on the treatment of soil irrigated with 200-fold diluted solution compared to non-treated soil, damping-off was 33%, anthracnose was 100% reduced and the occurrence rate of rusty-root was 30% reduced. In addition, when active ion calcium of 200-fold diluted solution were soil irrigated, first and second grade ginseng were respectively 26% and 22% produced more, compared with control.