• KCID journal
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• v.18 no.1
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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.

• Magazine of the Korean Society of Agricultural Engineers
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• v.38 no.5
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• pp.55-63
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• 1996

The situation and cause of bund collapse in steep sloping paddy area by a heavy rainfall of Chungbuk Province were investigated by field surveys. Shapes of paddy plots are irregular and average size of them is 12.6a. Surface, groundwater and plot-to-plot irrigations are being carried out in the study plots. The type of bund collapse can be divided as follows: overflow type and inundation type. The overflow type generally occurs at the bund with slope lacking the design standard. The inundation type damages paddy plots more seriously than the overflow type. It induces continuous bund collapse from a inflow-plot to a outflow-plot and includes lots of type (inside paddy) collapse, which results in much subsoil erosion. The installation of mountain stream weir and maintenance of mountain stream are proposed to prevent the inundation type collapse.

• Proceedings of the Korean Society of Agricultural Engineers Conference
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• 2001.10a
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• pp.80-83
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• 2001

In this study, we investigated irrigation effect for the paddy plot irrigated by pipeline with two types of hydrants: automatic and manual. The automatic hydrant have been introduced to the paddy field to save water and reduce the labor for water management. The automatic hydrant is automatically opened and closed according to the water depth of a paddy plot. The water management labor to close manual hydrant in the afternoon of every three days can be eliminated when we use the automatic hydrant. The water requirements for the automatic hydrant plot 3.26mm/d are much less than those for manual hydrant plot 9.99mm/d.

• Proceedings of the Korean Society of Agricultural Engineers Conference
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• 2000.10a
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• pp.629-636
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• 2000

In this study, we investigated the characteristics of labor of water management and maintenance, water requirement, water quality(T-N, T-P, COD) in the paddy plot irrigated by pipeline with two types of hydrants: automatic and manual. The automatic hydrant have been introduced to the paddy field to save water and reduce the labor for water management. The automatic hydrant is automatically opened and closed according to the water depth of a paddy plot. The automatic hydrant generally developed more troubles than the manual hydrant. The water requirements are 2.7mm/d for the automatic hydrant plot and 17.6mm/d for the manual hydrant plot. The concentrations of pollutants in the two plots are higher in the ponded water than in the irrigation water and are highest after fertilizer application.

• Proceedings of the Korean Society of Agricultural Engineers Conference
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• 2001.10a
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• pp.451-455
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• 2001

This study was performed to examine water and nutrient balance during rice cropping period using difference fertilization paddy plot in ground water irrigation region. The experimental rice paddy consist of three plot, Treatment of Excess fertilization(TEF) and Treatment of Standard Fertilization(TSF) and Treatment of Reduce Fertilization(TRF). As result, input amount to rice paddy was almost rainfall and output was direct runoff through drainage. nutrient input amount was upper paddy in case COD and fertilization in case Total nitrogen and total phosphorus, and output was drainage in all nutrient.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.43 no.4
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• pp.264-268
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• 1998

The experiment was conducted to clarify irrigation requirement and percolation rate in rice paddy. The four rice cultural system of no-tin, till, transplanting, and direct seeding condition were treated in the lysimeter filled with sandy loam soil. The amounts of irrigation and soil percolation were measured daily, and irrigation requirement was estimated. The daily percolation was 19.5 l/$\textrm{m}^2$ in no-till direct seeding on flooded paddy surface, 17.4 l/$\textrm{m}^2$ in both of till-direct seeding on flooded surface and no-till transplanting, and 15.2 l/$\textrm{m}^2$ in transplanting plot. This is equivalent to 19.5, 17.4, and 15.2 mm per day, respectively. Highest irrigation requirement was 3,770 l/$\textrm{m}^2$ in no-till direct seeding plots. Others were 3,249, 2,577, and 2,321 l/$\textrm{m}^2$ in till-direct seeding, no-till transplanting and transplanting plot, respectively. The estimated irrigation requirement of no-till transplanting, till-direct seeding and no-till direct seeding was increased by 11, 37, and 59% compared to till-transplanting plot. Percolation rate of no-till transplanting, till direct seeding and no-till direct seeding was increased by 12%, 40%, and 66%, respectively compared to the till-transplanting plot. The percolation rate in paddy soil was increased greatly after reproductive stage of rice.

• Korean Journal of Organic Agriculture
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• v.8 no.2
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• pp.79-87
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• 2000

This experiments was carried out to find the effect of different organic farming types, the Duck-pasture plot, the Pond-snail pasture plot andd control of the conventionalculture plot farming on the yield and its components of paddy rice. The results obtained are summarized as follows. Plant height an Tillering were significantly increase in the Duck-pasture plot. Panicle number pr hill, NO. of grain per spike and 1,000grain weight were significantly increase in the conventional culture plot. Yield pre 10a were 574.13kg at pond-snail pasture plot, 576.81kg at Duck-pasture plot and 579.04kg at conventional culture plot. From these results, it seems that the organic farming are useful and pasture of the Duck, Pond-snail for depression of the weed occurrence or increase of yield per 10a is effective as the environmental perservation farming.

• Magazine of the Korean Society of Agricultural Engineers
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• v.44 no.7
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• pp.53-63
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• 2002

Runoff, sediments and nutrient losses were studied under different patterns of paddy field management: (1) fall and spring plowing (Plowing)i (2) fall plowing for half of plot and spring plowing (Semi-plowing); (3) no-till for fall and spring plowing (Un-plowing) during the non-cropping period in the southern Korea for two years. The runoff amount and initial abstract were significantly affected by plowing practices. Un-plowing plot showed the highest runoff amount among treatments. The concentrations of sediment from Plowing plot were much higher than those from Un-plowing plot, especially after (all plowing. Sediment losses from Plowing plot were 25% more than those from Un-plowing plot. There was significant difference in nutrient losses via runoff water and sediment according to plowing practice. Two-year average of losses of N from paddy field during non-cropping period were 9.42 kg ha$\^$-1/, 8.17kg ha$\^$-1/, and 7.76 kg ha$\^$-l/ for Un-plowing, Semi-plowing, and Plowing plot, respectively, while losses of P were 0.64 kg ha$\^$-1/, 0.58 kg ha$\^$-1/, and 0.58 kg ha$\^$-1/ for each tillage system. Losses of total-N, ammonia-N, nitrate-N, Total-P from Un-plowing plot was larger than those from Plowing and Semi-plowing plots during study period.

• Plant Resources
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• v.8 no.1
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• pp.32-35
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• 2005

This study was conducted to investigate the influence of $K_{2}O$ fertilizer application on growth, yield and lodging resistance of rice. Culm length and panicle length were lowest at the treatment of fertilizer level, $N-P_{2}O_{5}-K_{2}O=16-8-8$ plot but number of panicle, percentage of fruitful culm, $1{\ell}$ grain weights of paddy rice and brown rice, 1,000 grains weight of brown rice, brown rice ratio, yields of paddy rice and brown rice were highest at the treatment of fertilizer level, $N-P_{2}O_{5}-K_{2}O=16-8-8$ kg/10a plot. Bending moment, breaking strength and lodging index were lowest at the treatment of fertilizer level, $N-P_{2}O_{5}-K_{2}O=16-8-8$ kg/10a plot. Judging from the results reported above, an optimum fertilizer level of rice for lodging resistance is most likely be $N-P_{2}O_{5}-K_{2}O=16-8-8$ kg/10a treatment.

• Journal of The Korean Society of Agricultural Engineers
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• v.46 no.4
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• pp.13-21
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• 2004

The purpose of this study was to investigate tile effects of pending depth treatment on water balance in paddy fields. Field experiment was performed in an experimental farm in Taegu, southern part of Korea during the rice growing season In 2001, 2002 and 2003. Experimental plots were three 8m ${\times}$ 80m rectangular plots. Three pending depth treatments, very shallow, shallow, and deep were used. Daily values of water balance components were measured in the field. The irrigation amounts measured at the experimental plots showed that the very shallow and the shallow ponded plots required smaller amount than the deep ponded plot. The shallow ponded plot saved irrigation water about 17.7% compared with the traditional deep ponded plot in 2001 The very shallow ponded plot saved irrigation water about 25.7% compared with the traditional deep ponded Plot in 2002, The shallow ponded plot saved irrigation water about 18% compared with the deep ponded plot in 2003.