밭 작물(作物)의 최적관개수준(最適灌漑水準)과 계획용수량(計劃用水量) 산정(算定)

윤학기 ( Yoon Hak Ki ),정상옥 ( Chung Sang Ok ),서승덕 ( Suh Seung Duk ) 한국농공학회 1990 韓國農工學會誌 : 전원과 자원 Vol.32 No.1

This study was carried out to get the basic information of irrigation plans for upland crops such as the optimum irrigation level and the project water requirement. Red peppers and cucumbers were cultivated in PVC pot lysimeters filled with 60cm deep clay loam soil. Four tensiometers were installed in each pot to measure the soil water pressure head. Six levels of irrigation were used. The results obtained from this study are summarized as follows: 1. The optimum irrigation level. The irrigation level of FC-PF2.7 was found to be the optimum level for both red pepper and cucumber with respect to the yield and the weight per fruit. In case of FC-PF2.7, total ET during the irrigation period were 1005.2mm for red pepper, and 429.6mm for cucumber, respectively. 2. soil moisture extraction patterns. Average soil moisture extraction patterns (SMEP)during the irrigation period were from 1st soil layer 43% : 32% : 16% : 9% for red pepper and 39% : 34% : 15% : 12% for cucumber, respectively. The extraction ratio of the upper soils showed very large values during the early stage of growth and decreased largely during the middle stage, and became larger in the last stage. 3. The project water requirement. Among the reference crop evapotranspiration(ETo) computation methods presented by FAO, the Penman method was found to be the best. The effective rainfall was computed by a modified USDA-SCS curve number equation. Availability ratios of the total rainfall during irrigation season were 59.2% for red pepper and 48.9% for cucumber, respectively. Net project water requirement of design year are 837.3mm for red pepper, and 502.5mm for cucumber, respectively. 4. Design irrigation interval and maximum water quantity per irrigation. It was found that design irrigation intervals are 2 days for red pepper and 3 days for cucumber, respectively. Maximum water quantity per irrigation were 37.4mm for red pepper and 36.3mm for cucumber, respectively.

삼각도형에 의한 단위도의 유도에 관한 연구

윤학기,김시원,서승덕,Yun, Hak-Gi,Kim, Si-Won,Seo, Seung-Deok 한국농공학회 1977 한국농공학회논문집 Vol.19 No.2

The curvilinear hydrograph can be replaced by an equivalent triangular hydrograph which is more easily constructed and, for routing through reservoirs or stream channels, gives results about as accurate as those obtained using the curvilinear hydrograph. A synthetic hydrograph is prepared using the data from a number of watersheds to develop a dimensionless unit hydrograph applicable to ungauged watersheds. The dimensionless unit hydrograph for the NakDong River Basin was prepared from the unit hydrographs of a variety of nine subwatersheds. The equation for the peak rate of flow (unit volume of runoff in 1.0mm) was derived as {{{{ { q}_{p } = { 0.21AR} over { {T }_{p } } }}}} The results summarized in this study are as follows: 1) It found that the watershed lag time (Lg, hrs) could be expressed by Lg=0.253(L.Lca)0.4171 The product L.Lca is a measure of the size and shape of the watershed. Correlation coefficient for Lg was 0.97 which defined with high significance. 2) The base length of the unitgraph, in hours, was adopted as Tb=17.51+2.073Lg with high significant correlation coefficient, 0.92. 3) Time in hour from start of rise to peak rate (TP) generally occured at the position of 0.289 Tb with some indication of higher values for larger watershed. 4) Triangular hydrograph is a dimensionless unitgraph prepared from the 40 unitgraphs. The equation is shown as {{{{ { q}_{p } = { K.A.R} over { { T}_{p } } }}}}. The constant K=0.21 is defined to NakDong River basin. 5) In the light of the results analyzed in this study, average errors in the peak discharge of the Trjangular unitgraph was estimated as 5.34 percent to the peak of observed average unitgraph. Each ordinate of the Triangular unitgraph was approached closely to the observed one.

관개수준이 고추의 수확량 및 소비수량에 미치는 영향

윤학기,정상옥,서승덕 한국농공학회 1989 한국농공학회논문집 Vol.31 No.2

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.

밭 작물의 최적관개수준과 계획용수량 산정

윤학기,정상옥,서승덕 한국농공학회 1990 한국농공학회논문집 Vol.32 No.1

This study was carried out to get the basic information of irrigation plans for upland crops such as the optimum irrigation level and the project water requirement. Red peppers and cucumbers were cultivated in PVC pot lysimeters filled with 60cm deep clay loam soil. Four tensiometers were installed in each pot to measure the soil water pressure head. Six levels of irrigation were used. The results obtained from this study are summarized as follows: 1.The optimum irrigation level. The irrigation level of FC-PF2.7 was found to be the optimum level for both red pepper and cucumber with respect to the yield and the weight per fruit. In case of FC-PF2.7, total ET during the irrigation period were 1005.2mm for red pepper, and 429.6mm for cucumber, respectively. 2.soil moisture extraction patterns. Average soil moisture extraction patterns (SMEP)during the irrigation period were from 1st soil layer 43% : 32% : 16% : 9% for red pepper and 39% : 34% : 15% : 12% for cucumber, respectively. The extraction ratio of the upper soils showed very large values during the early stage of growth and decreased largely during the middle stage, and became larger in the last stage. 3.The project water requirement. Among the reference crop evapotranspiration(ETo) computation methods presented by FAO, the Penman method was found to be the best. The effective rainfall was computed by a modified USDA-SCS curve number equation. Availability ratios of the total rainfall during irrigation season were 59.2% for red pepper and 48.9% for cucumber, respectively. Net project water requirement of design year are 837.3mm for red pepper. and 502.Smm for cucumber, respectively.

삼각도형(三角圖形)에 의(依)한 단위도(單位圖)의 유도(誘導)에 관(關)한 연구(硏究)

윤학기 ( Hak Ki Yoon ),김시원 ( Si Whon Kim ),서승덕 ( Seung Duk Suh ) 한국농공학회 1977 韓國農工學會誌 : 전원과 자원 Vol.19 No.2

The curvilinear hydrograph can be replaced by an equivalent triangular hydrograph which is more easily constructed and, for routing through reservoirs or stream channels, gives results about as accurate as those obtained using the curvilinear hydrograph. A synthetic hydrograph is prepared using the data from a number of watersheds to develop a dimensionless unit hydrograph applicable to ungauged watersheds. The dimensionless unit hydrograph for the NakDong River Basin was prepared from the unit hydrographs of a variety of nine subwatersheds. The equation for the peak rate of flow (unit volume of runoff in 1.0mm) was derived as q_p=0.21AR/T_p The results summarized in this study are as follows: 1) It found that the watershed lag time (L_g, hrs) could be expressed by L_g=0.253 (L.L_ca).^0.4171 The product L.L_ca is a measure of the size and shape of the watershed. Correlation coefficient for L_g was 0.97 which defined with high significance. 2) The base length of the unitgraph, in hours, was adopted as T_b=17.51+2.073L_g with high significant correlation coefficient, 0.92. 3) Time in hour from start of rise to peak rate (T_P) generally occured at the position of 0.289 Tb with some indication of higher values for larger watershed. 4) Triangular hydrograph is a dimensionless unitgraph prepared from the 40 unitgraphs. The equation is shown as q_p=K.A.R/T_p. The constant K=0.21 is defined to NakDong River basin. 5) In the light of the results analyzed in this study, average errors in the peak discharge of the Trjangular unitgraph was estimated as 5.34 percent to the peak of observed average unitgraph. Each ordinate of the Triangular unitgraph was approached closely to the observed one.

관개수준(灌漑水準)이 고추의 수확량(收穫量) 및 소비수량(消費水量)에 미치는 영향(影響)

윤학기 ( Yoon Hak Ki ),정상옥 ( Chung Sang Ok ),서승덕 ( Suh Seung Duk ) 한국농공학회 1989 韓國農工學會誌 : 전원과 자원 Vol.31 No.2

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 FC-PF 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 1005.2 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 FC-PF 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.

施設園藝에 있어서 栽培管理의 自動化 시스템에 關한 硏究 : Dilution and Spray System of Agricultural Chemicals 農藥의 稀釋 및 撒布 自動化

李基明,尹學基,具健孝 慶北大學校 1987 農業科學技術硏究所報 Vol.4 No.-

This study was carried out to develop an automatic diluting and spraying system of agricultural chemicals in a vinylhouse controlled by a micro-computer. Salt was used in this experiment as a tracer to measure the concentration of agricultural chemicals. Two methods measured by an electrical conductivity and a constant flow rate were introduced to control the agricultural chemicals. The results obtained from this study were summarized as follows: 1. In order to control the quantity of dilute solution, water level detecting sensor was used. This sensor was consist of two enamel wire which were installed perpendicular to the water surface and designed to convert from condensor capacity to voltage output. 2. Also, in order to measure the dilute ratio, electrical conductivity sensor was used. This sensor was designed with an aluminum plate as an electrode and to measure the DC voltage which was proportional to electrical conductivity. 3. Two methods, measured by an electrical conductivity and a constant flow rate, were studied to control the dilute ratio. Also, a software was developed for this purpose. According to the result of this study, both methods were turned out to be a good way to control the agricultural chemicals in vinylhouse by a micro-computer.

排水系統이 蒸發散量과 排水量에 미치는 影響

鄭相玉,尹學基 慶北大學校 1992 論文集 Vol.52 No.-

The effects of drainage system on evapotranspiration and drainage flows are studied. Data from drainage field experiment at Castalia in North Central Branch, Ohio Agricultural Research and Development Center were used in this study. A water table management model, ADAPT(Agricultural Drainage and Pesticide Transport), which was developed by combining the GLEAMS and the subsurface drainage part of the DRAINMOD model with several modifications, was used to predict hydrologic components. The ET is very much affected by the presence of subsurface drainage system but not significantly affected by the surface drainage system. The combined surface and subsurface drainage system gives the largest total outflow values while the surface drainage system gives the smallest. Comparisons of model predicted and measured drainage values are in satisfactory agreements. The model predicted values are within the range of the variations of the observed replications in general. Based on this study, the ADAPT model can be used in designing water table management systems.

경북지역 농촌공업화 단지조성사업이 지역개발에 기여하는 영향평가

서승덕,천만복,윤학기,윤경식 한국농공학회 1990 한국농공학회논문집 Vol.32 No.4

Government has propelled strongly the Agricultural - cum - Industrial region development project in the nation wide. This project will not only provide employment opportunity for rural inhabitants, but also be designed to activate the rural economy. In addition, it will lead to a balanced development between the urban and rural areas. Under this project, building sites of 3 to 30 hactres will be established in the rural area in order to settle factories which are suitable to the rural condition. In this report, the researches which relating to the achievement conditions of planning, design and constructions of the building sites and the contribution conditions of Agri. - cum - Industrial Region development projects, activated to the rural economy and regional development in the Kyungpook regional areas, were surveyed and studied. On the average evaluation studies the results are as follows : 1. The achievement conditions of the planning, design and construction of the building sites. Very good 27.0 % Good 47.0 % Fair 24.0 % Poor 2.0 % 2. The contribution conditions of the Agri - cum - Industrial factories managements. Very good 17.0 % Good 41.0 % Fair 32.0 % Poor 10.0 %

양액재배에 의한 국화 '백마'의 줄기동공 경감과 절화품질 향상

황인택,조경철,김희곤,기광연,윤봉기,김정근,임진희,최성렬,신학기 한국화훼산업육성협회 2009 화훼연구 Vol.17 No.4