• Korean Journal of Soil Science and Fertilizer
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• v.43 no.6
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• pp.844-847
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• 2010

Water is the most important factor in crop cultivation. Water requirement of red pepper can be calculated based on the lysimeter experiments carried out by the RDA for 11 years about potential evapotranspiration, crop coefficient with climate data. The mean water requirement and total water requirement of red pepper in different growth stages are evaluated for two kinds of cultivation method.

• Journal of The Korean Society of Agricultural Engineers
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• v.46 no.1
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• pp.3-13
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• 2004

For optimal irrigation reservoir operation during flood and normal period, a general and systematic policy is suggested to make balance of the conflicting purposes between water conservation and flood control. We developed Open Water Management Program (OWMP) with an open architecture to deal with newly arising upgrade problems for optimal management of irrigation reservoir. And we evaluated the applicability of OWMP to estimate daily runoff from an agricultural watershed including irrigation reservoirs, and analyzed behaviour of irrigation reservoirs as irrigation water requirements considering frequency analysis of reservoir storage and frequency analysis water requirements for effective management of reservoir. When we executed OWMP with data produced from an experimental field, IHP basins, the mean relative errors of application of daily runoff and irrigation water requirement were less than 5％. We also applied OWMP to a Seongju irrigation reservoir to simulate daily runoff, storage and water requirement from 1998 to 2002, and the mean model efficiency between measured and simulated value was 0.76. Our results based on the magnitude of relative errors and model efficiency of the model simulation indicate that the OWMP can be a tool nicely adapted to the effective water management of irrigation reservoir for beneficial water use and flood disaster management.

• Korean Journal of Soil Science and Fertilizer
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• v.45 no.6
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• pp.861-866
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• 2012

Water is the most important resource for the potato cultivation, especially to get the maximum water use efficiency and yield of potato, Water has to be applied moderately based on the water requirement of the potato. Crop water requirement (WR) is a function of the Potential evapo-transpiration(PET) and Crop coefficient (Kc). PET can be estimated by the climate data measured at the weather station in the production region. Kc was measured by the NIAST (RDA) through Lysimeter experiments. In this study, the growth stage of potato was divided as four (G-1 : Apr. 1~Apr. 15, G-2 : Apr. 16~May. 10, G-3 : May. 11~May. 31, G4 : Jun. 1~Jun. 15). The average PET during potato growing season of the 45 areas was $2.95mm\;day^{-1}$. The most water requirement was the G-3 stage among the potato growth stage. The MWR (Mean water requirement) according to growth stage was 1.0~1.2 (average 1.1), 1.5~1.8 (average 1.6), 1.9~2.2 (average 2.0) and 1.7~2.1 (average 1.8) mm $day^{-1}$, in the G-1, G-2, G-3 and G-4 stage, respectively. The TWR (Total water requirement) according to growth stage was 18.0~22.1 (average 19.3), 50.6~66.6 (average 56.3), 63.5~88.2 (average 72.4) and 38.3~54.5 (average 44) mm, in the G-1, G-2, G-3 and G-4 stage, respectively.

• Korean Journal of Soil Science and Fertilizer
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• v.46 no.1
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• pp.16-22
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• 2013

Water is the most important resource for the maximum water use efficiency and yield of maize. Water has to be applied moderately based on the water requirement of maize. Crop water requirement (WR) is a function of the potential evapo-transpiration (PET) and crop coefficient (Kc). PET can be estimated by the climate data measured at the weather station in the production region. Kc was measured by the NIAST (RDA) through lysimeter experiments. In this study, the growth stage of maize was divided into five ones (G-1: Apr. 25 ~ May 20, G-2: May 21 ~ Jun. 20, G-3: Jun. 21 ~ Jul. 20, G4: Jul. 11 ~ Jul. 25, G5: Jul. 26 ~ Aug. 20). The average PET during maize growing season of the 45 areas was 2.85 mm $day^{-1}$. The highest water requirement was at the G-3 stage among the maize growth stages. The mean water requirement (MWR) according to growth stage was 1.74 ~ 2.42 (average 2.02), 2.99 ~ 4.21 (average 3.41), 3.82 ~ 5.25 (average 4.41), 3.05 ~ 4.31 (average 3.48), and 2.62 ~ 3.49 (average 3.01) mm $day^{-1}$ in the G-1, G-2, G-3, G-4 and G-5 stage, respectively. The total water requirement (TWR) according to growth stage was 45.37 ~ 63.04 (average 52.56), 92.54 ~ 130.59 (average 105.77), 76.46 ~ 105.09 (average 88.14), 45.73 ~ 64.67 (average 52.20), and 68.25 ~ 90.75 (average 78.33) mm in the G-1, G-2, G-3, G-4 and G-5 stage, respectively.

• Korean Journal of Soil Science and Fertilizer
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• v.43 no.6
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• pp.848-851
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• 2010

The essential factor for house cultivation is water management. Water requirement of crop is the most important for the water management. The water requirement of crop is different according to the area as well as climate condition and growth stage. However, the measurement of PET (Potential Evapo-Transpiration) and crop coefficient (Kc) is very difficult especially in house cultivation. Therefore, the PET and Kc of red pepper are estimated based on the lysimeter experiments carried out by the RDA for 11 years about the ratio of house cultivation to wild cultivation. Periodic PET, mean water requirement (MWR) and accumulated water requirement (AWR) of red pepper cultivated in house are evaluated.

• Journal of The Korean Society of Agricultural Engineers
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• v.61 no.2
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• pp.97-104
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• 2019

The purpose of this study was to establish the estimation method of irrigation water amount for sewage treated water reuse for agricultural purpose. To calculate the irrigation water amount, we adopted Penman-Monteith for potential evapotranspiration estimation and applied crop coefficient and irrigation efficiency factor. We developed the irrigation water amount calculation program using C language in Xcode environment. The target district for calculation is having 259 ha of agricultural land located near the Jinyeong Clear Water Circulation Center in Hanrim-myeon, Gimhae city. The meteorological data of the study area were obtained from Changwon weather station from 1986 to 2017. Calculated average and maximum of annual mean potential evapotranspiration were 2.72 mm/day and 6.22 mm/day, respectively. We used K-S (Kolmogorov-Smirnov) for goodness-of-fit test to find optimal probability distribution of annual mean and maximum evapotranspiration. As a result, the normal distribution was selected for the appropriate distribution. The annual mean and maximum potential evapotranspiration for 10-year return period by applying normal distribution were 2.88 mm/day and 6.76 mm/day, respectively. Assuming that the irrigation efficiency is 80%, the irrigation water requirement was calculated as $36.05m^3/day/ha$ and $84.45m^3/day/ha$, respectively, when annual mean and maximum potential evapotranspiration were applied. The actual irrigation water amount can be calculated by applying the crop coefficient and cropping days for the study area based on the developed irrigation water amount estimation program in this study.

• Korean Journal of Soil Science and Fertilizer
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• v.48 no.4
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• pp.246-254
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• 2015

This study explored the effect of rainfall pattern and soil characteristics on water management in rice paddy fields, using a soil water balance model, BUDGET. In two sites with different soil textural group, coarse loamy soil (Gangseo series) and fine soil (Hwadong series), respectively, we have monitored daily decrease of water depth, percolation rate, and groundwater table. The observed evapotranspiration (ET) was obtained from differences between water depth decrease and percolation rate. The root mean square difference values between observed and BUDGET-estimated ET ranged between 10% and 20% of the average observed ET. This is comparable to the measurement uncertainty, suggesting that the BUDGET model can provide reliable ET estimation for rice fields. In BUDGET model of this study, irrigation requirement was determined as minimum water need for maintaining water-saturated soil surface, assuming 100 mm of bund height and no lateral loss of water. The model results showed different water balance and irrigation requirement with the different soil profile and indicated that minimum percolation rate by plow pan could determine the irrigation requirement of rice paddy field. For the condition of different rainfall distribution, the results presented different irrigation period and amounts, representing the importance of securing water for irrigation against different rainfall pattern.

• Korean Journal of Exercise Nutrition
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• v.23 no.4
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• pp.1-5
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• 2019

[Purpose] The goal of this study was to review data on physical activity level (PAL), a crucial index for determining estimated energy requirement (EER), calculated as total energy expenditure (TEE, assessed with doubly labeled water [DLW]) divided by resting metabolic rate (RMR, PAL = TEE/RMR) in female athletes and to understand the methods of assessing athletes' EERs in the field. [Methods] For the PAL data review among female athletes, we conducted a PubMed search of the available literature related to the DLW method. DLW studies measuring TEE and RMR were included for the present review. [Results] Briefly, the mean PAL was 1.71 for collegiate swimmers with moderate training, which was relatively low, but the mean PAL was 3.0 for elite swimmers during summer training camp. This shows that PAL can largely vary even within the same sport depending on the amount of training, and the differences in PAL were remarkable depending on the sport. Aside from the DLW method, there is currently no research tool related to athletes' EERs that can be used in the field. [Conclusion] Briefly, the mean PAL was 1.71 for collegiate swimmers with moderate training, which was relatively low, but the mean PAL was 3.0 for elite swimmers during summer training camp. This shows that PAL can largely vary even within the same sport depending on the amount of training, and the differences in PAL were remarkable depending on the sport. Aside from the DLW method, there is currently no research tool related to athletes' EERs that can be used in the field.

• Magazine of the Korean Society of Agricultural Engineers
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• v.31 no.2
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• pp.82-91
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• 1989

This study was carried out to get the basic information of irrigation plans for the red pepper, such as optimum irrigation level and irrigation requirement in Taegu and Kyungpook province. In this study, red peppers were cultivated in 6 PVC pot lysimeters filled with 60cm deep clay loam soil. Four tensiometers were installed in each plot to measure the soil water pressure head. Field measurements were made during the period June 6 to October 31, 1988 at the experimental farm of Kvungpook National University. Six levels of irrigation were used. They were PF 1.8-2.0, PF 2.2-2.4, PF 2.8-3.0, FC-PF.1.7, FC-PF 2.2, and FC-PF 2.7. The results obtained from this study are summarized as follows : 1. In case of irrigation levels of narrow ranges of water contents, the higher the soil water content was, the larger the ET was. Hut in case of the irrigation levels returning to the field capacity, the lager the PF value of irrigation point was, the larger the ET was. Considering ET, yield and weight per fruit, the latter is much better than the former irrigation method. 2. The mean daily ET and mean ET ratio for each 10-day period showed that the maximum value occured in the last of August. The ranges of those were 3.74-14.64 mm/day and 0.87-3.40, respectively. These values showed that small during the early stage of growth, large during the middle stage and getting smaller in the last stage. 3. In case of irrigation levels of narrow ranges of water contents, the increase of irrigation water supplied increased the ET. The relationship between the two showed nearly straight line. Most of irrigated water was consumed as ET and the rest as percolation. But, in case of irrigation levels returning to the field capacity, the higher the PF value of irrigation point was, the larger the ET ratio was. However, their relationship didn't show straight line. 4. The irrigation level of PC - PP 2.7 was found to be the optimum irrigation level with respect to the yield, the weight per fruit, stem length, irrigation requirement and percolation quantity. In this case, mean daily ET and mean ET ratio were 6.79 mm/day (total 10052 mm) and 1.67, respectively. The maximum mean daily ET and mean ET ratio for 10-day period were 14.64 mm/day and 3.40, respectively, in the last of August, and the maximum daily ET was 2126 mm/day on August 24. 5. In case of PC - PP 2.7 which is found the optimum irrigation level, mean irrigation water required, mean ET and mean percolation water quantity were 7.44 mm/day, 6.79 mm/day(91.3% of irrigation water), and 0.38 mm/day (5.5% of it), respectively.

• Magazine of the Korean Society of Agricultural Engineers
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• v.33 no.4
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• pp.52-60
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• 1991

This study was conducted to investigate the appropriate operation method minimizing the deviation between irrigation water demand and release from the reservoirs, and the simulation technique was used in the operation model. This model was applied to the grouped reservoirs system consisted of Dongsang, Daia and Keungchun reservoirs and Eowoo-weir in Chonbuk FLIA district. The results obtained in this study are summarized as follows; 1.The area above the Eowoo weir point was divided into 6 small watersheds, and daily inflows from each watershed were calculated by Tank model. It showed that the average annual runoff ratio was 40-60% respectively. 2.Based on the Blaney-Criddle formula daily water requirement of Chonbuk FLIA irrigation area was estimated, mean water requirement for paddy field during the irrigation period was 818.lmm. 3.Using the basic data such as inflow and water demand, four different release types were selected. Through the simulated operation the difference between intake water required at Eowoo-weir point and release from the 3 reservoirs was estimated. The best result was obtained when Daia and Keungchun reservoirs are operated parallelly at fixed release ratio and the release of Dongsang reservoir was determined according to the storage of Daia reservoir.