• 한국농공학회지
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• 제45권7호
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• pp.57-69
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• 2003

To evaluate nutrient dynamics with different fertilization in paddy field and develop water quality model, mass balance analysis was performed during growing season of 2001-2002 in field experimental plots irrigated with groundwater. As a result of water balance analysis, most of outflow was surface drainage as about half of total outflow and about 500mm was lost by evapotranspiration. The water budget was well balanced. The runoff from paddy field was influenced by rainfall and forced drain. Especially runoff during early cultural periods more depends on the forced drain. As a result of mass balance analysis, most of nutrient was input by fertilization and lost by plant uptake. Significant amount of nitrogen were supplied by precipitation and input from upper paddy field, comprising 12%∼28% of total inflow. Nutrient loading by surface drainage was occurred showing about 15%∼29% for T-N and 6%∼13% for T-P. The response of rice yield with different fertilization was not significant in this study. Water quality model for paddy field developed using Dirac delta function and continuous source was calibrated and validated to surface water quality monitoring data. It demonstrates good agreement between observed and simulated. The nutrient concentration of surface water at paddy field was significantly influenced by fertilization. During early cultural periods when significant amount of fertilizer was applied, surface drainage from paddy field can cause serious water quality problem. Therefore, reducing surface drainage during fertilization period can reduce nutrient loading from paddy fields. Shallow irrigation, raising the weir height in diked rice fields, and minimizing forced surface drainage are suggested to reduce surface drainage outflow.

• 한국농공학회지
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• 제44권4호
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• pp.39-50
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• 2002

Field experiment was performed to investigate water and nutrient mass balances in paddy field with groundwater irrigation from May to October, 2001. The total water inflow was about 1,183mm in which rainfall, overflow from upstream paddy, and groundwater irrigation accounted for 43, 30, and 27%, respectively. Notice that the precipitation of the study period was less than the average annual precipitation. The total drainage was almost balanced with the inflow and more than half of it was occurred by surface drainage. From the nutrient mass balance analysis, the T-P output (17.56kg/ha) was estimated slightly lower than the input (20.90kg/ha) and the T-N output (130.41kg/ha) was slightly greater than the input(129.24kg/ha). However, the difference was within the expectation and the nutrient mass was thought to be balanced considering uncertainties in field experiment and other activities not included in the study such as algae and soil microorganisms. The surface discharge of nutrient, which was about 10% of total nutrient output, was mainly affected by fertilization and rainfall runoff. Therefore, prudent surface drainage plan might be necessary particularly for the fertilization period to prevent degradation of receiving water quality. The study was performed under abnormally low rainfall compared to the average annual rainfall record, and further monitoring in diverse rainfalls and irrigation methods is recommended to estimate nutrient behavior in the paddy field more reasonably.

• 해양환경안전학회:학술대회논문집
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• 해양환경안전학회 2018년도 공동국제학술발표회
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• pp.2-2
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• 2018

• 한국농공학회논문집
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• 제55권6호
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• pp.167-175
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• 2013

The objective of this study was to investigate the nutrient load balance in the reservoir irrigated paddy block during growing seasons. Idong reservoir irrigation paddy block of 10.3 ha in size was selected to collect hydrologic and water quality data. Irrigation, canal flows, and paddy field drainage were measured using a water level gauge, while water samples were collected and analysed for water quality. The water balance analysis showed that 81 % and 75 % of total outflow were through paddy and irrigation canal drainage during 2011 and 2012, respectively. The water quality of paddy field drainage varied greatly depending on rice cultivation stage ranging from 0.05 to 24.55 mg/L and from 0.01 to 0.76 mg/L for T-N and T-P, correspondently. Paddy field drainage loads during May through June account for 64 % and 76 % in 2012 and 2013, while 82 % and 81 % for T-P in 2011 and 2012, respectively. The Pearson correlation analysis showed that rainfall was significantly correlated with nutrient loads during July through August due to runoff, and irrigation was related with nutrient loads of drainage during some period of July through September due to irrigation return flow. This study results showed characteristics of inflow and outflow nutrient loads from plentiful irrigated paddy block.

• 한국환경과학회지
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• 제20권7호
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• pp.919-927
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• 2011

A ecosystem model was applied for understanding of circulation process of state variables in marine ecosystem. A mass balance was conducted by calculating the physical process. The sensitivity analysis was conducted to know which coefficient is the most effective factor to the state variables in the model. The results of the mass balance indicate that the primary production was 58.6 ton C/day in the case of mass flux. DIN and DIP in nutrient ingestion of phytoplankton were each 7.9 ton N/day, 1.1 ton P/day. POC and DOC in mineralization of organic matter were each 10.8 ton C/day, 40.6 ton C/day. The results of sensitivity analysis showed that the maximum growth rate of phytoplankton was the most important factor for overall state variables. In the case of nutrients, Half saturation constant of DIN, and mineralization rate of DOM for COD were important factor.

• 한국습지학회지
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• 제10권3호
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• pp.1-7
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• 2008

본 연구에서는 논에서의 영양물질 제거능력에 대하여 평가하였다. 논을 인공습지라는 관점으로 보고 전라남도 함평군 엄다면 화양리의 논 지구(이하 학야지구)를 시험지구로 선정하여 2004년 5월부터 9월까지 영농기 기간동안 조사하였다. 학야지구를 대상으로 물수지 및 물질수지를 조사하여 논에서의 T-N, T-P의 제거능력을 조사한 결과 지표유출 부하로 T-N, T-P가 각각 20.82 kg/ha, 1.55 kg/ha로 나타났으며, 이는 연구대상 논에 총 투입된 T-N, T-P의 13.2%와 6.4%에 해당되는 양이다. 연구 결과는 투입된 대부분의 영양물질이 논에서 처리됨을 보여주었다.

• Journal of Nutrition and Health
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• 제29권9호
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• pp.1003-1012
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• 1996

We examined the relationship among riboflavin intake, work activity, erythrocyte glutathione reductase activity coefficient(EGR AC)and urinary riboflavin excretion. We also attempted to determine factors affecting seasonal riboflavin status of rural women. All information about nutrient intake, work activity and riboflavin biochemical status was repeatly collected in three seasons ; farming season(June), harvest season(October), nonfarming season(February). EGR AC was negatively correlated with riboflavin intake(P<0.005) and positively correlated with the duration(min) of farming activity(P<0.005) and the percentage of lean body mass(LBM) (%) representing long term physical activity(P<0.05) in harvestseason. Urinary riboflavin excretion was positively correlated with the ratio of riboflavin intake to 1,000kcal of energy expenditure (P<0.05) in farming season and negatively correlated with the duration(min) of farming activity (P<0.05) and crude nitrogen balance(P<0.005) in harvest season. It appeared that EGR AC seems to increase and urinary riboflavin excretion seems to decrease as work activity increase. Therefore work activity would be expected to deteriorate riboflavin status. Multiple regression analysis of variables showed that in general EGR AC was affected by riboflavin and energy intakes, energy expenditure, energy balance, the duration(min) of farming activity, LBM (%). Urinary riboflavin excretion was affected by riboflavin and protein intakes, LBM(kg) and crude nitrogen balance. Crude nitrogen balance affected urinary riboflavin excretion in all seasons. The result indicated that work activity as well as nutrient intake seemed to affect riboflavin status, especially EGR AC was affected preferentially be work activity in all seasons.

• 해양환경안전학회지
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• 제24권5호
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• pp.545-552
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• 2018

본 연구에서는 갈대군락의 영양염 물질수지 모델 구축을 위한 기초연구로서, 갈대군락 Mesocosm 실험을 통해 수층-갈대(뿌리, 잎, 줄기)-토양의 영양염(DIN, DIP) 농도의 춘계 및 하계 모니터링 결과를 이용하여 물질수지를 산정하였으며, 결과는 다음과 같다. 1) 갈대의 생체량은 춘계에는 지하경이 지상경에 비해 약 6.3~9.7 % 높으며, 하계에는 지상경이 지하경에 비해 약 19.2~21.2 % 높게 나타났으며, 갈대의 성장속도는 Mesocosm Tank A가 Mesocosm Tank D에 비해 지상경과 지하경 모두 2~3배 정도 빠르게 나타났다. 2) Mesocosm Tank에서의 갈대의 영양염(DIN, DIP) 농도는 춘계와 하계 모두 각각 2~3 %로 차이가 적었다. 3) Mesocosm Tank별 생체량의 차이는 최대 23 %로 나타나지만, 갈대가 흡수하는 영양염의 농도는 최대 3 % 정도로 차이가 적었다.

• 한국농공학회논문집
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• 제58권1호
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• pp.1-10
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• 2016

The objective of this study was to investigate the effects of farming methods on mass balance from paddy rice. The experiment fields were established at Chunpo-myeon, Iksan-si in the Saemangeum watershed. Experiment was performed during the growing season to assess water and mass balances of the study field in 2013. The three different farming practices were applied: conventional (TR-A), drainage outlet heighten (TR-B) and slow release fertilizer use (TR-C). Drainage amount from TR-B was reduced by 28.5 % compared to the TR-A, while the amount from TR-C was similar to that of TR-A. Overall, nutrient concentration of paddy water were similar among the treatments except for T-P. Mean T-P concentration from TR-C was lower than that from TR-A (p-value<0.05). As the results of mass balance, TR-B appeared to reduce nutrient surface loss, substantially by 30.9 % and 40.8 % for T-N and T-P an compared to TR-A. TR-C treatment also demonstrated nutrient load reduction by 38.2 % and 40.1 % for T-N and T-P. The study results showed that water and fertilizer treatments are effective in surface load reduction respectively from paddy fields, and, long-term monitoring and evaluation is needed to confirm the reduction.

• 한국농공학회지
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• 제43권6호
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• pp.154-162
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• 2001

This study was performed to examine the rice growth and nutrient change in paddy soil with reclaimed sewage irrigation. Total nitrogen and total phosphorus in the experimental system were analyzed before and after rice culture. The experiment lasted three consecutive years, and this paper presents results of the last year. Additional supply of nutrients to the rice culture by reclaimed sewage irrigation was significant and it increased the yield. Nutrient uptake by rice plant increased with more nutrient supplied, however. there was limit in plant uptake. Nutrient accumulation occurred in the soil and it was more apparent for the phosphorus where most of the remaining quantity was accumulated while substantial amount of nitrogen was lost during the growing season. This study suggested that additional nutrient supply by reclaimed sewage irrigation might be a supplemental benefit to the rice culture, and it can help the fertilization management. However, long term effects of continual reclaimed sewage irrigation should be assessed carefully including nutrient mass balance in the paddy rice culture system.