• 한국농공학회:학술대회논문집
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• 한국농공학회 2002년도 학술발표회 발표논문집
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• pp.385-388
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• 2002

We investigated net outflow load and unit load of pollutants from a paddy fields area in dry year 2001. Amount of irrigation water in 2001 was about 61-63% of that in previous years 1999 and 2000 due to drought. The net outflow load and unit load of pollutants in 2001 were negative, showing that paddy fields acts as sink of pollutants due to function of water quality purification. The relationship between unit load of pollutants and net surface outflow (= surface outflow - irrigation water) showed positive correlation. The results showed that abatement of surface outflow by appropriate water management contribute to reduce surface outflow load from paddy fields.

• 한국관개배수논문집
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• 제18권1호
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• pp.94-102
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• 2011

The aim of this study was to evaluate the load of non-point sources pollutant at a paddy plot located at the valley watershed during irrigation period. Irrigation, runoff and water quality data in the paddy plot were analyzed periodically from June 1 to October 31 in 2005. The observed amount of precipitation, irrigation, runoff for the experimental paddy plot during the irrigation period was 1,297.8, 223.2, and 825.4mm, respectively. Total-N concentrations ranged from 3.73 to 18.10mg/L, which was generally higher than the quality standard of agricultural water (1.0mg/L). Total-P concentrations ranged from 0.111 to 0.243mg/L and the average was 0.139mg/L. The observed runoff pollutants loadings from the paddy plot were measured as 34.4 kg/ha for T-N, 1.0 kg/ha for T-P and 213.8 kg/ha for SS. The non-point sources pollutant load in drainage water depends on rainfall and surface drainage water amount from the paddy plot. We are considering that these results were affected by rainfall as well as hydrological condition, soil management, whether or not fertilizer application, cropping, rice straw and plowing.

• Journal of Applied Biological Chemistry
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• 제59권1호
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• pp.83-90
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• 2016

The aim of the present study was to evaluate the degree of metal contamination of the Turag River water and its suitability for irrigation. Twenty water samples were analyzed for physicochemical parameters and metals viz., calcium, magnesium, potassium (K), sodium, copper (Cu), zinc (Zn), iron (Fe), manganese (Mn), lead (Pb), cadmium (Cd), chromium (Cr), and nickel (Ni). All water samples were slightly alkaline to alkaline. Regarding electrical conductivity (EC), all samples were suitable for crop in soils with moderate permeability and leaching. Water samples were medium salinity and low alkalinity hazard classes. In terms of total dissolved solids (TDS), all samples were classified as freshwater. As per sodium adsorption ratio (SAR) and soluble sodium percentage (SSP), all samples were classified as excellent. No residual sodium carbonate (RSC) was detected in any of the samples, indicating suitability for irrigation; and all samples were considered very hard. Cr and Mn contents in all samples were above FAO guideline values and, therefore, these metals were considered toxic. Zn, Cu, Pb, Cd, and Ni concentrations were below acceptable limit for irrigation and do not pose a threat to soil environment. Significant relationships were found between EC and TDS, SAR and SSP, SAR and RSC, and SSP and RSC. The combinations of ions such as K-Zn, K-Fe, K-Cu, K-Mn, K-Pb, Zn-Fe, Zn-Cu, Zn-Mn, Fe-Mn, Cu-Mn, Cu-Pb and Mn-Pb exhibited significant correlation. This study revealed that Turag River water samples are contaminated with Cr and Mn. This fact should not be ignored because water contamination by metals may pose a threat to human health through food chain.

• 한국농공학회지
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• 제32권3호
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• pp.56-66
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• 1990

To investigate the status of irrigation water use and the degree of repeated use of irrigation water, observations for water balance analysis were made during the irrigation periods in 1986 and 1987 crop year. The total area of studied site is 1,441 ha. The site is a major portion of Jedaecheon basin which is located in Bubuk-myeon, Miryang-gun, Gyeongnam Province. The studied area was subdivided into six small blocks. The water balance analysis for these subdivided blocks were carried out considering characteristics of each block. Obtained results are as follow: 1.In mountainous sloppy paddy area(less than 7% slope), the surface inflow was 5A mm/day in average that is one third of the surface inflow into plain paddy area ; 16.7 mm/day. 2.The surface inflows at the vegetative stage and the ripening stage were 15.5 mm/day and 10.4 mm/day, respectively. Those figures were larger than the actual consumptive use at respective same stages ; 13.3 mm/day and 9.2 mm/day, respectively. Whereas, the surface inflow at generative stage was 12.5 mm/day which was less than 14.0 mm/day ; the actual consumptive use. 3.The range of the variation of water storage term was 1 mm/day. This means that there were no change in depth of ponded water on paddy fields. The relationship between the variation of water storage(AS) and the variation of ground water table(H) could be expressed as follow: : AS=0.14H+0.26 4.The ground water inflow: into the transition region ; paddy fields which are located continuously from the mountainous area to the plain area, was larger than the out flow from this region, in general. Rowever, in the plain region where the ground water utilization was predominant, the ground water outflow from this region was larger than inflow: to this region. The relationship between the ground water flow(G2- G1) and the consumptive use in large paddy area(D1-D2) could be expressed as follow: (G2-G1) =0.95(D1-D2) -3.79

• 한국농공학회지
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• 제44권2호
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• pp.136-147
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• 2002

Characteristics of unit loads of pollutants were investigated at a paddy fields area(Soro-ri) with large-scaled plots on loam soil during irrigation seasons of 1999 ∼2000. The average irrigation requirement of experimental paddy area are estimated at over 3,000 mm. The unit loads of pollutants in paddy fields area are determined by subtracting irrigation water load from outflow load (percolated and surface outflow loads). Surface outflow load in rainy days was calculated using the relationships of discharge and load, which are grouped into fertilizing and non-fertilizing periods. The ratios of the surface outflow load in rainy days to the total surface outflow load are 16.4% for T-N, 26.8% for T-P, and 23.3% far CODc,. The unit loads of pollutants show month-to-month and year-to-year variations, and monthly unit load of pollutants can show negative values, indicating that the paddy area acts as the pollutants sink. The average unit loads of the pollutants during irrigation seasons were estimated at 18.2 kg/ha fur T-N, 0.31 kg/ha for T-P, and 43.3 kg/ha for CODc,, which are smaller than the reported values for Kosei area in Japan.

• 한국농공학회:학술대회논문집
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• 한국농공학회 2001년도 학술발표회 발표논문집
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• pp.390-393
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• 2001

Mass balance and unit load of pollutants were investigated at paddy field area during irrigation periods in 1999 and 2000. The amounts of irrigation water during irrigation periods were 3,690mm in 1999 and 3,160mm in 2000. The concentration of surface outflow is not so high as that of irrigation because 44% of irrigation water discharge without entering the paddy plots. The unit loads of pollutants during irrigation periods were estimated 19.2kg/ha for T-N, 0.29kg/ha for T-P and 47.5kg/ha for COD.

• 한국농공학회지
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• 제13권3호
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• pp.2322-2341
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• 1971

관개용수(灌漑用水)의 부족(不足)과 한해(旱害)의 적응책(適應策)로서 절수(節水)를 피함과 동시(同時)에 수도수야(水稻收野) 증가(增加)시킬 수 있는 관개조절방법(灌漑調節方法)을 구명(究明)하기 위하여 $1968{\sim}1969$ 의 양년도(兩年度)에 걸처서 만생종(晩生種)인 농림(農林) 6호(號)를 공시(供試)하여 서울대학교(大學校) 농과대학(農科大學) 실험포장(實驗圃場)의 누수형답(漏水形畓)에서 밑다짐 간단관수(間斷灌水) 및 작토(作土)밑에 비닐깔기 등의 세가지 3방향(方向)으로 19처리(處理)를 하여 3반복(反覆)의 완전임의배치법(完全任意配置法)으로 시험(試驗)하였던 바 그 결과(結果)를 요약(要約)하면 다음과 같다. 1. 경토(耕土) 15cm 밑에 점토(粘土)를 $3{\sim}9cm$ 두께로 밑다짐한 것은 양년도(兩年度)에 각각(各各) $36{\sim}45%$ 및 $78{\sim}88%$ 의 관개용수(灌漑用水)가 절약(節約)되었다. 특히 밑다짐 9cm 구(區)는 양년도(兩年度)에 45% 및 88% 의 관개용수절약(灌漑用水節約)과 20% 및 12%의 수도증수(水稻增收)를 보였다. 2. 분얼기(分蘖期)와 등숙기(登熟期)에 $5{\sim}8$ 일(日) 간격(間隔)으로 40mm 식 간단관수(間斷灌水)한 것은 양년도(兩年度)에 각각(各各) $52{\sim}65%$ 및 $41{\sim}55%$ 의 관개용수절약(灌漑用水節約)과 $10{\sim}16%$ 의 수도증수(水稻增收)를 보였다. 3. 경토(耕土) 15cm 밑에 비닐을 깐 것은 비닐의 공극량(孔隙量)에 따라서 $75{\sim}88%$의 관개용수절약(灌漑用水節約)을 보였다. 비닐의 공극량(孔隙量) $3cm/m^2$의 경우에는 수도수량(水稻收量)이 표준구(標準區)와 비등(比等)하였으나 그 보다 공극(孔隙) 작으면 수도수량(水稻收量)은 저하(低下)하였다. 4. 처리구(處理區) 주위(周圍)에 깊이 57cm, 높이 6cm로 비닐을 삽입(揷入)하여 지수벽(止水壁)을 만들면 수분침투량(水分浸透量) $25{\sim}33%$ 정도 감소(減少)되었다. 5. 경토(耕土) 15cm 밑에 밑짚을 6cm 두께로 다저 넣은 것은 표준구(標準區)에 비(比)하여 1963, 년도(年度)에는 약(約) 30% 의 증수(增收)를 보였으나 1969년도(年度)에는 약(約) 7%의 감수(減收)를 보여 양년도(兩年度)의 성적(成績)이 극(極)히 대조적(對照的)이었다. 6. 전체적(全體的)으로 1969년도(年度)에는 전년도(前年度)보다 수량(收量)이나 주당수수(株當穗數) 및 수립수(穗粒數)가 적은데 이것은 1969도(度)의 기상(氣象)이 분얼성기(分蘖盛期)에 저온다우(低溫多雨)이고 등숙기(登熟期)에 일조(日照)가 적었기 때문일 것이다. 7. 생육상태(生育狀態)의 처리간(處理間) 변이(變異)는 다음과 같다. (1) 밑다짐과 간단관수(間斷灌水)에 의하여 초장신장(草長伸長)이 조장(助長)되었다. (2) 밑다짐 9cm 구(區)와 일간격(日間隔)의 간단관수구(間斷灌水區)는 고(高) 수량(收量)이며 간장(稈長)도 컸다. (3) 간단관수(間斷灌水)의 경우에 고수량(高收量)이며 주당수수(株當穗數)가 많은 경향(傾向)이 있었다. (4) 밑다짐 9cm 구(區)나 $5{\sim}8$ 일(日)의 간단관수구(間斷灌水區)에서 수립수(穗粒數)가 많었고 수량(數量)도 많었다. (5) 1000립중(粒重)에서도 1수립수(穗粒數)와 비슷한 경향(傾向)이 인정(認定)되었다. (6) 실임율(實稔率)은 밑다짐과 간단관수(間斷灌水)의 경우에 증대(增大)되었다.

• 한국농공학회논문집
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• 제59권2호
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• pp.37-47
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• 2017

In this study, we analyzed the variability of irrigation water amounts based on the combination of various crops and soil textures using the Irrigation Water Management Model (IWMM). IWMM evaluates the degree of agricultural drought using the Soil Moisture Deficit Index (SMDI). When crops are damaged by the water scarcity under the drought condition indicating that the SMDI values are in negative (SMDI<0), IWMM irrigates appropriate water amounts that can shift the negative SMDI values to "0" to crop fields. To test the IWMM model, we selected the Bandong-ri (BDR) and Jucheon (JC) sites in Gangwon-do and Jeollabuk-do provinces. We derived the soil hydraulic properties using the near-surface data assimilation scheme form the Time Domain Reflectrometry (TDR)-based soil moisture measurements. The daily root zone soil moisture dynamics (R: 0.792/0.588 and RMSE: 0.013/0.018 for BDR/JC) estimated by the derived soil parameters were matched well with the TDR-based measurements for validation. During the long-term (2001~2015) period, IWMM irrigated the minimum water amounts to crop fields, while there were no irrigation events during the rainy days. Also, Sandy Loam (SL) and Silt (Si) soils require more irrigation water amounts than others, while the irrigation water were higher in the order of radish, wheat, soybean, and potato, respectively. Thus, the IWMM model can provide efficient irrigation water amounts to crop fields and be useful for regions at where limited water resources are available.

• Journal of Biosystems Engineering
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• 제14권2호
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• pp.128-136
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• 1989

The purpose of this study was to develop a computer operated automatic drip irrigation system for application in vinyl-house cultivation. The results can be summarized as follows: 1) The T-type ice compensation wire was used to measure the temperature. The voltage level measured up to 0.02 volt was used as input to an 8-bit A/D converter. 2) A specially devised tensiometer was used to content the watering system. When the needle of the pressure gauge reaches the lower threshold position it turns on the pumping system and turns off when it reaches higher threshold position. 3) In order to use the multiple gypsum blocks for one transducer, reed relays and a D/O board were used to make the sequential switching possible. 4) It was possible to automate the trickle irrigation system for the whole growth period of vinyl-house crops with the help of microcomputer. 5) In terms of furrow irrigation, the irrigation water consumption was the smallest, 2.8 times less than conventional method of surface trickle irrigation, 3.4 times less than subsurface trickle irrigation method. 6) In terms of productivity of cucumber, there was a drop in productivity when compared to furrow irrigation method, 7.2% for surface trickle irrigation, 27.4% for subsurface irrigation method.

• 한국토양비료학회지
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• 제43권1호
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• pp.68-74
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• 2010

담수상태의 토양이나 습지생태계에서 ${NO_3}^-$는 환원상태의 발달을 지연시키는 완충역할을 할 수 있다. 논토양에서 관개용수를 통하여 공급되는 ${NO_3}^-$가 Fe의 환원과 그에 따른 P의 가용화에 미치는 영향을 조사하였다. 관개용수중의 ${NO_3}^-$ 함량이 5 mg N $L^{-1}$ 수준일 경우 5 cm 깊이 토양에 도달하기 전에 대부분 탈질작용에 의해 제거되었으며, 5 cm 깊이 토양에서 일어나는 Fe의 환원과 P의 용출이 저해되었고 10 cm 깊이 토양의 환원현상에는 영향을 미치지 못하였다. ${NO_3}^-$ 함량이 10 mg N $L^{-1}$ 수준인 관개용수를 공급하였을 경우에는 10 cm 깊이 토양층까지 ${NO_3}^-$가 잔류 유입되었으며, Fe의 환원과 P의 용출을 현저히 억제하는 것으로 나타났다. 이상의 결과를 보면 관개용수를 통하여 ${NO_3}^-$를 포함한 질소가 과도하게 논토양으로 유입되면 질소과다현상을 유발할 뿐만 아니라 P의 가용화를 억제함으로써 인 결핍을 초래할 수도 있을 것이다.