• 제목/요약/키워드: irrigated water

검색결과 287건 처리시간 0.146초

A COMPARISON OF THE IRRIGATION SYSTEMS IN CALCIUM HYDROXIDE REMOVAL (근관세정 방법에 따른 수산화칼슘 제재의 제거 효율 비교)

  • Eun, Jae-Seung;Park, Se-Hee;Cho, Kyung-Mo;Kim, Jin-Woo
    • Restorative Dentistry and Endodontics
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    • 제34권6호
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    • pp.508-514
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    • 2009
  • The purposes of this study were to compare the efficacy of irrigation systems by removing a calcium hydroxide $(Ca(OH)_2)$ paste from the apical third of the root canal and the effect of the patency file. Sixty single rooted human teeth were used in this study. The canals were instrumented by a crown-down manner with .04 taper ProFile to ISO #35. $Ca(OH)_2$ and distilled water were mixed and placed inside the root canals. The teeth were divided into 6 groups according to the root canal irrigation system and the use of patency file as follows: group 1 - conventional method: group 2 - $EndoActivator^{(R)}$: group 3 - $EndoVac^{(R)}$; group 4 - conventional method, patency: group 4 - $EndoActivator^{(R)}$, patency; group 6 - $EndoVac^{(R)}$, patency. All teeth were irrigated with sodium hypochlorite. After the root canal irrigation, the teeth were split in bucco-lingual aspect. Percentage of the root canal surface coverage with residual $Ca(OH)_2$ until 3 mm from working length was analyzed using Image Pro Plus ver. 4.0. Statistical analysis was performed using the One-way ANOVA, t-test and Scheffe's post-hoc test. Conventional groups had significantly more $Ca(OH)_2$ debris than $EndoActivator^{(R)}$, $EndoVac^{(R)}$ groups. There was no significant difference between $EndoActivator^{(R)}$ and $EndoVac^{(R)}$ groups. Groups with patency file showed more effective in removing $Ca(OH)_2$ paste than no patency groups. but. it was no significant difference. This study showed that $EndoActivator^{(R)}$ and $EndoVac^{(R)}$ systems were more effective in removing $Ca(OH)_2$ paste from the apical third of the root canal than conventional method.

Development of a Trial Product for Irrigation Management in Substrate Culture (고형배지경 급액관리 시작기 개발)

  • Kim, Sung-Eun;Sim, Sang-Youn;Lee, Sang-Don;Kim, Young-Shik
    • Journal of agriculture & life science
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    • 제44권5호
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    • pp.129-135
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    • 2010
  • This experiment was carried out to commercialize an irrigation control system by finding out problems and solving them in application of a nutrient supply system through this experiment. Its efficiency had been tested through hydroponic cultivation of tomato and cucumber using this system in the farmer's plastic house (1-2W, 20a : Yanggyo-ri, Oseong-myeon Gyeonggi-do) from November. 2006, too. In the first cultivation, tomato seeds (cultivar Coco, Takii Seed Co. Japan) were sowed on November 8, 2006, and transplanted on January 8, 2007. and then, in the second, cucumber (Chuichong, Nongwoo Seed Co.) were cultivated in the same plastic house (sowing date : June 27, transplanting date : July 13). In the third, another cucumber cultivar (Jo-woon, Dongbu-hannong Seed Co.) were cultivated (sowing date : September 5, transplanting date : September 23). All of seedlings were transplanted on perlite bag ($W340{\times}L1,200{\times}H150mm$, 40L). By using this system, 971 boxes (5 kg/box) of tomato were produced and sold, and then total income was 5,466 thousand won per 10a. On the second cultivation, total amount of cucumber production was 489 boxes (50 ea/box), and total income was 7,380 thousand won. On the third cultivation, total amount of production was 67 boxes (100 ea/box), and total income was 1,854 thousand won. On the other hand, this system saved irrigated water by 50% ($4,000{\rightarrow}2,000L/10a/day$) in tomato cultivation, and by 44%($4,500{\rightarrow}2,500L/10a/day$) in cucumber cultivation. It also saved cost of nutrients by 50% in tomato ($1,648{\rightarrow}824thousand\;won/10a$), and 44% in cucumber ($1,648{\rightarrow}725thousand\;won/10a$). Furthermore this irrigation system maintained moisture content in perlite bag stable during cultivation period. Therefore, this system was successfully applied on farmer's greenhouse without a problem and can be commercialized for farmers.

Growth of Creeping Bentgrass on Bottom Ash and Dredged up Sand with Four Organic Matter Amendment Rates Under Saline Irrigation Condition (염해 조건에서 유기물이 첨가된 준설모래와 석탄회 토양이 크리핑 벤트그래스의 생육에 미치는 영향)

  • Rahayu, Rahayu;Yang, Geun-Mo;Choi, Joon-Soo
    • Asian Journal of Turfgrass Science
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    • 제23권2호
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    • pp.241-252
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    • 2009
  • This study was carried out to check the possibility of substituting bottom ash from the Seosan power plant for sand as growing media for creeping bentgrass (Agrostis stolonifera L.) under saline irrigation condition. Characteristics of growing media were evaluated by using column and leaching method. Creeping bentgrass cv. Pen-A1 was grown in pots with dredged up sand (DS) and bottom ash (BA) media those were amended using 1%, 2%, and 3 % OM rates in a green house. The plants were irrigated with 1.5 $dSm^{-1}$ saline water. Results showed that visual quality, plant height and shoot dry weight from DS treatment were higher than those of BA treatment. Even though BA contained more salts, repeated leaching could decrease ECe efficiently. In case of no OM amendment, the visual quality, plant height and shoot dry weight were similar between in BA and DS. Amendment of 2% OM increased the height of creeping bentgrass in DS, while decreased the plant growth in BA.

Effect of Waste Nutrient Solution and Reclaimed Wastewater on Chinese Cabbage Growth and Soil Properties (폐양액과 하수처리수 재이용이 배추생육 및 토양에 미치는 영향)

  • Choi, Bong-Su;Lim, Jung-Eun;Shin, Yong-Keon;Yang, Jae-E.;Lee, Sang-Soo;Ok, Yong-Sik
    • Korean Journal of Soil Science and Fertilizer
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    • 제44권3호
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    • pp.394-399
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    • 2011
  • This study evaluated the effect of using waste nutrient solution (WNS) and reclaimed wastewater (WW) on the growth of Chinese cabbage and soil quality. The pH and electrical conductivity (EC) values of waste nutrient solution were 6.3 and $1.5dS\;m^{-1}$ and being 6.8 and $0.4dS\;m^{-1}$ in reclaimed WW, respectively. WNS found to be included more than $10g\;m^{-2}$ of $NO_3^-$, $K^+$, $SO_4^{2-}$ and $Ca^{2+}$, thereby enhancing Chinese cabbage growth. However, $Cl^-$ and $Na^+$ contents were higher than other nutrients in WW. Among the three irrigation resources, no significant differences were found for the growth of Chinese cabbage plants. On the other hand, pH was decreased in WNS-treated soil when compare to that in WW-treated soil which pH was increased. In spite of the uptake of nutrients by the growing plants, irrigation of the WNS led to an increase in available $P_2O_5$ and exchangeable cations such as $K^+$ and $Mg^{2+}$ in the soil when compared to soil that irrigated by groundwater or WW. Taken together, the use of WNS can remarkably reduce the amount of the chemical fertilizer for Chinese cabbage production; however, WNS can possibly cause a problem as nutrients accumulation in soil.

An Analysis of the Rice Situation in Nicaragua for Improving National Production.

  • Chang-Min Lee;Oporta Juan;Ho-Ki Park;Hyun-Su Park;Jeonghwan Seo;Man-Kee Baek;Jae-Ryoung Park;O-Young Jeong
    • Proceedings of the Korean Society of Crop Science Conference
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    • 한국작물학회 2022년도 추계학술대회
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    • pp.90-90
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    • 2022
  • Nicaragua is located in Central America, climatic conditions are considered tropical dry forest. Statistics reflex that in Nicaragua exits 24,000 rice farmers. National rice production only covers 73% of the national consumption. It exists two sowing system: irrigation and rainfed. Varieties used in both systems are mid-late maturity (120-135 days), there are 14 released varieties for irrigation, eight for rainfed, and eight landraces used in rainfed. The current breeding system (introduction of lines from Colombia) has increased the national production, however, has some limitation due to the lack of enough variability, reducing the proability of finding good genotypes and therefore the possibility of satisfying 100% of the demand. The purpose of this study was to analyze the problems that must be resolved in the short and long term to improve rice productivity in Nicaragua. In this paper we explain some proposal for an improvement plan. The selection of varieties with high adaptability to various cultivation environmental conditions it is necessary, also to thoroughly manage seed purity to supply certified seeds. In rice cultivation technology, it needs to improve seedling standing and weeding effect by improving soil leveling and water-saving cultivation technology. Also, proper fertilization and planting density must be established in irrigated and rain-fed areas. Furthermore, capacity must be strengthened by collecting and training with the most recent agricultural technology information, as well as by revitalizing the union rather than the individual farmer. It is necessary to develop varieties highly adaptable to the Nicaraguan cultivation environment, as well as to expand irrigation facilities and cultivation technology suitable for weather conditions in rain-fed areas. Last, it is necessary to maintain the consistency of agricultural policy for continuous and stable rice production in response to climate change events such as drought or intermittent heavy rain.

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Comparison of Soil Properties and Non-point Pollution Effects According to Puddling and Non-puddling before Rice Transplanting in Paddy Field: Preliminary Research Data (논 벼 이앙 전 써레질 유무에 따른 토양환경 및 비점오염원 효과 비교: 예비 연구자료)

  • HyunKi Kim;Yun-Ho Lee;Hyun-Jin Park;Heon-Joong Kim;Hee-woo Lee;Jong-Tak Yoon;Jaeki Chang
    • Korean Journal of Agricultural and Forest Meteorology
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    • 제26권3호
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    • pp.191-198
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    • 2024
  • Puddling before rice transplanting, which has been practiced traditionally, is no longer considered an essential process due to the overall development of agriculture. Non-puddling, a technique that omits rotary plow in a flooded condition after leveling and transplants immediately. In this study, we conducted the first case study in South Korea on the differences between puddling and non-puddling, and uploaded some of the data to Github. The effects of shortening and dispersing practices during the busy farming season, suppressing soil plow pan formation, and preventing non-point pollution emissions were confirmed in the early stages before and after transplanting. However, some limitations such as weed occurrence when lots of rain or water management practices fail, so it is recommended to implement non-puddling in irrigated paddy fields.

Studies on Controlling Mixed Annual and Perennial Weeds in Paddy Fields - On the Herbicidal Properties of Perfluidone - (수종(數種) 다년생잡초혼생답(多年生雜草混生沓)에 있어서 제초제(除草劑)에 의한 효과적(效果的)인 잡초방제(雜草防除) - Perfluidone의 작용특성구명(作用特性究明)을 중심(中心)으로 -)

  • Ryang, H.S.;Han, S.S.
    • Korean Journal of Weed Science
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    • 제3권1호
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    • pp.75-99
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    • 1983
  • The herbicidal properties of perfluidone [1,1,1-trifluoro-N-2-methyl-4-(phenylsulponyl) phenyl methanesulfonamide] were investigated in pots and paddy fields. At the rate of 2.0kg prod./10a, perfluidone did not cause any injury to the 4 leaf stage (LS) rice seedlings. Although the crop injury increased with increasing the application rate, the injury caused by 16kg prod. perfluidone/10a gave rise to only 30% yield reduction. The crop injury was greatest when perfluidone was applied 2 days before transplanting and decreased as the application time delayed. Perfluidone showed greater crop injury to the 3 LS seedlings, at more than 7cm water depth, and at high temperature than to the 4 LS seedlings, at 3-5cm water depth, and at low temperature. Indica and indica ${\times}$ japonica rice varieties were generally more sensitive to perfluidone than japonica rice variety. Perfluidone effectively controlled most of annual weeds and such perennial weeds as Sagittaria pygmaea MIQ., Potamogeton distinctus A. BENN, Cyperus serotinus ROTTB, Scirpus maritimus L., Eleocharis kuroguwai OHWL, and Scirpus hotarui OHWL, whereas Sagittaria trifolia L. and Polygonum hydropiper SPACH. were tolerent to perfluidone. The weeding effect decreased with increasing the leaching amount of water and the overflowing of irrigated water within 24 hours after the herbicide application. When the application time was done later than 8 days after transplanting, the perennial weeds were shown at deeper soil layers, and the standing water was deeper than 7cm, the effect tended to decrease. However, there was no difference in the weeding effect between soil types. Downward movement of perfluidone in flooded soil ranged from 2 to 8cm deep. The movement increased with increasing the leaching amount of water and the application rate and at a sandy loam soil which possessed less adsorptive capacity. Residual effect of perfluidone was found at 35 to 80 days after application, which varied such factors as Soil types. Increase in the leaching amount of water resulted in decrease in the period of the residual effect. The period was shorter at non-sterilized soil than at sterilized soil. The 0.75kg ai perfluidone + 1.5kg ai SL-49 (1,3-dimethyl-6-(2,4-dichlor-benzoyl)-5-phenacyloxy-pyrazole)/ha and 1.5kg ai perfluidone + 1.05kg ai bifenox (2,4-dichlorophenyl-3-methoxy carbonyl-4-nitro phenyl ether)/ha showed less crop injury than 1.5kg ai/ha perfluidone alone. However, the weeding effect of the former was similar to that of the later.

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Evaluation of Nutrient Discharges from Greenhouses with Flooding Soil Surface at Two Different Locations (입지조건이 다른 시설재배지에서 담수처리에 따른 양분 용탈량 평가)

  • Kim, Min-Kyeong;Roh, Kee-An;Ko, Byong-Gu;Park, Seong-Jin;Jung, Goo-Bok;Lee, Deog-Bae;Kim, Chul-Soo
    • Korean Journal of Soil Science and Fertilizer
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    • 제43권3호
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    • pp.315-321
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    • 2010
  • Greenhouse soil cultivated with excessive compost and chemical fertilizer has been an issue to deteriorate soil and water quality in the environment. The objective of this study was to evaluate the nutrient outflow by desalting method, flooding soil surface, after vegetable cropping in greenhouse soils. Field experiment from July to September 2008, was conducted to quantify greenhouse locations, i.e. alluvial plain and local valley. The changes of desalinization in both locations were higher as the amounts of irrigated and drained water were increased. Particularly, the ratio of desalinization in alluvial plain was much higher (66.7%) than the one in local valley (45.6%). However, $NH_4$-N contents of local valley soil during the flooding were higher than in those of alluvial plain. This was caused by high total nitrogen and organic matter in local valley soil than those in alluvial plain soil. With comparing to the input and output loads of T-N and T-P in greenhouses with local valley and alluvial plain soils, the output loads of nutrients were larger than the input loads of nutrients. This result showed that the flooding soil surface can be a good treatment to desalinize greenhouse soils. However, this conclusion remained that the flooding water containing high N and P concentrations might cause the secondary effect on the quality of streams and groundwater since excessive nutrient concentrations can be the main cause of eutrophication problem in aquatic environment.

Effects of Interruption Layer for Capillary Rise on Salt Accumulation and Kentucky Bluegrass Poa pratensis Growth in Sand Growing Media over the Reclaimed Saline Soil (임해 간척지에서 모래상토 층에 모세관수 차단 층의 도입이 염류 집적과 켄터 키블루그래스 생육에 미치는 영향)

  • Rahayu, Rahayu;Yang, Geun-Mo;Choi, Joon-Soo
    • Asian Journal of Turfgrass Science
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    • 제24권2호
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    • pp.106-116
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    • 2010
  • This research was conducted to determine the effect of interruption layer for capillary rise on the sand based growing media when growing Kentucky bluegrass (Poa pratensis L.) on soil reclamation and saline water irrigation. Growing media profile consists of three layers as top soil of 30 cm, 20 cm of the interruption layer for capillary rise and 10 cm of reclaimed paddy soil. Growing media profile was packed in 30 cm diameter column pots. The top soil was a mixture of sand dredged up from Lake Bhunam Tae Ahn, Korea and peat at the ratio of 95:5 by volume. Bottom part of column was covered with plastic net and the pots were soaked into 5 cm depth saline water reservoir with salinity $3-5\;dS\;m^{-1}$. Kentucky bluegrass was established by sod and irrigated using $2\;dS\;m^{-1}$ saline water ($5.7\;mm\;day^{-1}$) in 3 days interval. The results showed that the largest accumulation of salt in the spring with electrical conductivity in saturated extract (ECe) of $5.4\;dS\;m^{-1}$ and sodium absorption ratio (SAR) 34.0 in growing media without the interruption layer for capillary rise and ECe of $4.6\;dS\;m^{-1}$ and SAR 8.24 at growing media using gravel as the interruption layer for capillary rise material. The interruption layer for capillary rise of gravel and coarse sand reduced the accumulation of Na by 16% and 25%, ECe by 7% and 13% in the growing media. Visual quality of Kentucky bluegrass was higher in growing media with the interruption layer for capillary rise of gravel than no interruption layer by 8.3 compared to 7.9 in rates. The interruption layer for capillary rise of gravel and coarse sand enhanced the visual quality by 4.1 and 4.0%, root length by 50 and 38%, and root dry weight by 35 and 17% of Kentucky bluegrass, and reduced the accumulation of Na by 16% and 25%, ECe by 7% and 13% in the growing media.

Reduction of Nutrient Infiltration by Supplement of Organic Matter in Paddy Soil (유기물 시용에 의한 벼논에서의 양분 유출경감)

  • Roh, Kee-An;Kim, Pil-Joo;Kang, Kee-Kyung;Ahn, Yoon-Soo;Yun, Seong-Ho
    • Korean Journal of Environmental Agriculture
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    • 제18권3호
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    • pp.196-203
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    • 1999
  • To establish the best rice cultivating system in the aspects of environment-loving agriculture, the amounts and patterns of nitrogen leached in the paddy soil were investigated with 7 treatments; Recommendation(R), Farmer's usual practice(FUP), Straw compost+chemical fertilizers reduced(SCF), Fresh straw+recommendation(FSC), Fresh cow manure(FCM), Cow manure compost(CMC), and no fertilization as Control(C). And SCF, FCM and CMC were applied with same amounts of total nitrogen to R. The infiltrated water samples were collected in ceramic porous cups which were buried at 60cm depth from the top. Concentrations of nitrate-N in irrigated water were $1.3mg\;l^{-1}$ on rice transplanting season when nutrients began to elute from paddy soil, and $0.4mg\;l^{-1}$ after breaking off irrigation. But it was $4-6mg\;l^{-1}$ in rice growing period. The maximum concentration of nitrate-N in leachate was not more than $7mg\;l^{-1}$ during rice cultivation. The amounts of nitrogen leached in R, FUP, SCF, FSR, FCM, CMC and C were 59, 63, 25, 41, 24, 27, $17kg\;ha^{-1}y^{-1}$ respectively. Nitrogen leaching was decreased to about 30% by supplement of fresh rice straw(FSC) to R. Furthermore, it was possible to reduce to over 50% of nitrogen leaching by reducing chemical fertilizer application(CF), or by substituting of chemical fertilizers with fresh cow manure(FCM) or cow manure compost(CMC). In added organic fertilizer treatments, the amounts of infiltrated nitrogen were less $13-46kg\;ha^{-1}y^{-1}$ than that of input by irrigation. This experiment showed that nutrients leaching was minimized by substitution of chemical fertilizers with organic fertilizer or by application of straw with chemical fertilizers in rice paddy soil and rice cultivation with suitable fertilizer management can work as a purifier rather than contaminator of water.

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