• Proceedings of the Korean Society of Agricultural Engineers Conference
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• 2002.10a
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• pp.449-452
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• 2002

Characteristics of pollutant load during irrigation and non-irrigation periods was investigated for streamwater from a rural watershed. Water was sampled and discharge was measured at 5-days intervals at outlet of study area. The mean concentrations of TN and TP in an irrigation period are higher than in an non-irrigation period, while mean COD concentration in an irrigation period is lower than in a non-irrigation period. For increasing discharge during an irrigation period, TN concentration increase, TP concentration is nearly unchanged, and COD concentrations decreases.

• Journal of Bio-Environment Control
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• v.8 no.1
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• pp.1-8
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• 1999

This study was carried out to estimate the warmed water irrigation and the warmed soil efficiency on protected cultivation of cucumber in winter season. The water of 28$^{\circ}C$ was continuously supplied for soil warming and that is $25^{\circ}C$ for warmed water irrigation. Cucumber growth was analyzed when tile soil kept up the optimum temperature in the root zone. The cucumber growth are compared with the warmed soil plots. isolated warmed soil plots and non-warmed soil plots. The cucumber growth in warmed soil plots and isolated warmed soil plots were 20~50% higher than non-warmed soil plots compare to that by the warmed irrigation. In the non-warmed soil plots, the stem diameter and the number of leaves in the warmed water irrigation plots are 10% higher than those in the normal water irrigation plots. The yields in isolated warmed soil plots were 37~38% higher than non-warmed soil plots and those in warmed soil plots were 85~96% higher than non-warmed soil plots. The fruit length, weight and diameter in warmed soil plots were 15% higher than those in the non-warmed plots.

• Journal of The Korean Society of Agricultural Engineers
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• v.60 no.4
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• pp.63-72
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• 2018

The main function of an agricultural reservoir is to supply irrigation water to paddy rice fields in South Korea. Therefore, the operation of a reservoir is significantly affected by the phenology of paddy rice. For example, the early stage of irrigation season, a lot of irrigation water is required for transplanting rice. Therefore, water storage in the reservoir before irrigation season can be a key factor for sustainable irrigation, and it becomes more important under climate change situation. In this study, we analyzed the climate change impacts on reservoir storage rate at the beginning of irrigation period and simulated the reservoir storage, runoff, and irrigation water requirement under RCP scenarios. Frequency analysis was conducted with simulation results to analyze water supply probabilities of reservoirs. Water supply probability was lower in RCP 8.5 scenario than in RCP 4.5 scenario because of low precipitation in the non-irrigation period. Study reservoirs are classified into 5 groups by water supply probability. Reservoirs in group 5 showed more than 85 percentage probabilities to be filled up from half-filled condition during the non-irrigation period, whereas group 1 showed less than 5 percentages. In conclusion, reservoir capacity to catchment area ratio mainly affected water supply probability. If the ratio was high, reservoirs tended to have a low possibility to supply enough irrigation water amount.

• Magazine of the Korean Society of Agricultural Engineers
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• v.12 no.1
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• pp.1861-1871
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• 1970

This experiment was carried out to compare soil moisture contents and the amounts of irrigation water by varying irrigating methods for chinese cabbages. The irrigating methods were non-irrigation (Plot A), furrow irrigation(Plot B). fixed nozzle pipe irrigation(Plot C), subsoil pipeline irrigation at the depths of 15cm. and 30cm., laying out in the middle of the rows of chinese cabbages(Plot D) and subsoil pipeline irrigation at the depths of 15cm, and 30cm., laying out beneath the rows of the roots of chinese cabbages(Plot E). In this experiment soil moisture contents were measured by using a simple electric device. As a result, the fallowing items are derived; 1) A significionce of 5% was observed between the yields produced at the furrow irrigation plot and fixed nozzle pipe irrigation plot, and those at the non-irrigation plot and subsoil pipe-line irrigation plot. 2) In the subsoil pipe-line irrgatiion, the Plot D type was observed to be slightly better than the Plot E type in the effect of the growth of cabbages. 3) The ratio of the amounts of irrigation water applied in the furrow irrigation plot, fixed nozzle pipe irrigation plot and subsoil pipe-line irrigation plot is approximately 3.2:2.1.

• Applied Biological Chemistry
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• v.43 no.4
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• pp.285-290
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• 2000

This research was carried out to investigate the runoff pattern of nutrients by rainfall from the paddy field located at the southwest of Korea. Effective rainfalls were 17.0 and 21.2 mm for irrigation and non-irrigation period, respectively. The first runoff in paddy field was 6.3-33.7 mm (average=12.9 mm) and 5.9-12.5 mm (9.2 mm) for irrigation and non-irrigation period, respectively. And runoff ratio was 0.59-1.36 and 0.57-0.86 for irrigation and non-irrigation period, respectively. During irrigation and non-irrigation period, the outflow increased significantly with the precipitation. Pattern of precipitation-runoff differed between irrigation and non-irrigation period, as affected by precipitation intensity, hydrological condition, and cropping. There existed a linear relationship between the runoff loading of N and P and precipitation. During the irrigation and non-irrigation period, runoff loadings of N and P were not significantly different. However, there was significant difference in case of total suspended solids.

• Journal of Ginseng Research
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• v.32 no.4
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• pp.279-282
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• 2008

This study was conducted to compare the aerial parts growth, yield of fresh ginseng roots, quality of red ginseng roots, and photosynthesis (Fv/Fm, PSII) in leaves between non-irrigation plot and furrow irrigation plot during the ginseng growing seasons. The aerial part growth in furrow irrigation plot was higher than non-irrigation plot in all including the emergency rate, leafing rate and relatively growth rate. Root yield per 10a in irrigation plot was increased about 50% as compared with that of non-irrigation, also heaven and earth grade of red ginseng roots yield in irrigation plot was higher (40.3%) compared with that (30.6%) of non-irrigation plot in 6-years-old ginseng plant. Furrow irrigation markedly improved the ginseng quality and yield in comparison to non irrigation condition. Therefore it needs to control the soil moisture during the growing season for high yield and good qualities of ginseng roots.

• Korean Journal of Agricultural Science
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• v.15 no.1
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• pp.36-46
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• 1988

Twelve soybean cultivars were cultivated in the 1/2,000a. Wagner pots with irrigation and without irrigation for 30 days after flowering, and the differences of plant growth and bean yield among cultivars were compared. And to investigate the varietal differences in the rate of photosynthesis under different relative humidity, 6soybean cultivars were cultivated in 1/2,000a. Wagner pot and the rate of photosynthesis of each soybean cultivar at flowering time was measured under the relative humidity of 80, 70, 60, 50 and 40%. The results obtained are summarized as follows; 1. The days to maturity of the soybean cultivars were shortened by non-irrigation treatment. The response of the maturing dates to non-irrigation was significantly different among the soybean cultivars. The days for maturing of Paldal, Danyeob and Eundaedu were delayed 2 days but those of Jangbaek and Tamahomare were delayed about 7 to 8 days under non-irrigation treatment. 2. The stem length, stem diameter, number of nodes of the mainstem, number of branches and number of branch nodes of all soybean cultivars were decreased by non-irrigation treatment. The number of branches and the number of branch nodes were especially severely influenced by non-irrigation treatment. 3. The number of pods per plant and the number of perfect pods was significantly reduced by non-irrigation treatment but the number of imperfect pods was increased. The non-irrigation treatment reduced the number of pods per plant by 58.0% and the ratio of the number of the perfect pods per plant by 46.6% relative to the ordinary cultivation with irrigation. 4. The grain yield of all cultivars was significantly reduced by the non-irrigation treatment, and average grain yield of soybean cultivars cultivated under non-irrigation treatment was 35.9% of that of soybean cultivars cultivated with irrigation. The influence of non-irrigation treatment was lowest in Paldal and significantly high in Tamahomare and Jangbaek. 5. The rate of photosynthesis of soybean leaves was significantly different among cultivars and was also influenced by relative humidity. Ratio of the photosynthetic amount of soybean leaves at 40% RH to the maximum photosynthesis at optimal humidity was 97.2% in Paldal, 96.4% in Danyeob and 88.8% in Baekun. 6. At 40% relative air humidity, highly significant correlations were found among the photosynthesis rate, the amount of transpiration and the respiration rate.

• 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.

• Journal of The Korean Society of Agricultural Engineers
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• v.59 no.1
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• pp.31-43
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• 2017

Recent studies about irrigation water use have focused on agricultural reservoir operation in irrigation period. At the same time, it is significant to store water resource in reservoir during non-irrigation period in order to secure sufficient water in early growing season. In this study, Representative Concentration Pathways (RCP) 4.5, 8.5 scenarios with the Global Climate Model (GCM) of The Second Generation Earth System Model (CanESM2) were downscaled with bias correlation method. Cumulative precipitation during non-irrigation season, October to March, was analyzed. Interaction between cumulative precipitation and carry-over storage was analyzed with linear regression model for ten study reservoirs. Using the regression model, reservoir drought response ability was evaluated with expression of excess and deficiency. The results showed that future droughts will be more severe than past droughts. Especially in case of non-exceedance probability of 10%, drought in southern region seemed to be serious. Nine study reservoirs showed deficiency range from 10% to 55%, which turned out to be vulnerable for future drought. Only Jang-Chan reservoir was secure for early growing season in spite of drought with deficiency of 8% and -2%. The results of this study represents current agricultural reservoirs have vulnerability for the upcoming drought.

• KCID journal
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• v.12 no.1
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• pp.69-77
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• 2005

In order to investigate effect of irrigation on soil moisture and garlic growth, a experimental plot, which was shielded from precipitation was established. The irrigation levels during the experimental period were 30, 20, 10 mm and non-irrigation with th