자동점적관수에 의한 토성별 수분함량 및 장력 변화특성 비교 연구

김학진,안성욱,한경화,최진용,정선옥,노미영,허승오 (사) 한국생물환경조절학회 2013 생물환경조절학회지 Vol.22 No.4

Maintenance of adequate soil tension or content during the period of crop growth is necessary to support optimum plant growth and yields. A better understanding of soil tension and content for precision irrigation would allow optimal soil water condition to crops and minimize the adverse effects of water stress on crop growth and development. This research reports on a comparison of soil water tension and content variations in differently textured soils over time under drip irrigation using two different water management methods, i.e. pulse time and required water irrigation methods. The pulse time-based irrigation was performed by turning the solenoid valve on and off for preset times to allow the wetting front to disperse in root zone before additional water was applied. The required water estimation method was a new water control logic designed by Rural Development Administration that applies the amount of water required based on a conversion of the measured water tension into water content. The use of the pulse time irrigation method under drip irrigation at a high tension of −20 kPa and high temperatures over 30oC was not successful at maintaining moisture tensions within an appropriate range of 5 kPa because the preset irrigation times used for water control could not compensate for the change in evapotranspiration during day and night. The response time and pattern of water contents for all of the tested soils measured with capacitance-based sensor probes were faster and more direct than those of water tensions measured with porous and ceramic cup-based tensiometers when water was applied, indicating water content would be a better control variable for automatic irrigation. The required water estimation-based irrigation method provided relatively stable control of moisture tension,even though somewhat lower tension values were obtained as compared to the target tension of −20 kPa, indicating that growers could expect to be effective in controlling low tensions ranging from −10 to −20 kPa with the required water estimation system. 본 연구에서는 토성에 따른 물의 이용효율을 높이면서재배 작물의 생산성을 최대화하기 위한 효율적인 자동관개 로직을 개발하고자, 수분장력값을 관수 개시점으로하여 물 공급 유지와 멈춤을 간헐적으로 수행하는 펄스형 관개방식과 측정한 수분장력값을 이용하여 토양수분량을 예측해 재배작물에 적합한 물량을 추가 투입하는필요물량계산 관수방식을 적용하여 토성이 다른 실험베드에서 2년간 토마토 작물을 재배하면서 토양수분 함량과 장력의 변화를 측정비교하였다. 물공급 30초와 멈춤30분 및 15분 조건을 이용한 펄스형 관수방식과 필요물량계산 방식에서 얻어진 수분장력값은 목표한 −20kPa 조건에 비해 각각 −42~−8kPa, −20~−10kPa로 나타나 필요물량 계산방식이 균일한 수분장력을 유지하는 측면에서는 유리하였으나 토양수분상태는 상대적으로 습하였다. 공시 토성 모두에서 수분함량은 수분장력에 비해 시간반응이 빠르면서 물공급에 따라 비례적으로 증가하는 경향이 뚜렷하였다. 수분변화 값은 펄스형 관수와 필요물량계산 관수방식의 경우 사양토 기준으로 각각 17~24%, 19~31%로서 펄스형 관수방식이 수분변화 값이 작으면서 시간에 따라 안정적인 값을 유지한 것으로 나타났는데 이는 물공급에 따른 수분함량의 시간변화가 수분장력에 비해 뚜렷하게 빠름과 관계가 있는 것으로 판단하였다. 이러한 결과로부터 펄스형 관수방식은 수분함량값을 이용하여 수분을 조절하는 것이 유리함을 의미한다.

A narrative review on the application of doubly labeled water method for estimating energy requirement for Koreans

Oh Yoen Kim,Jonghoon Park,Eun-Kyung Kim 한국영양학회 2022 Nutrition Research and Practice Vol.16 No.no.sup1

Research articles were reviewed to validate the estimated energy requirements (EERs) equations developed by the Institute of Medicine of the National Academies (IOM). These equations are based on total energy expenditure (TEE) measured by the doubly labeled water (DLW) method. We subsequently aimed to provide the basis for the suitability to apply the IOM equations as EER equations for Koreans, and develop relevant equations for EER in the Dietary Reference Intake for Koreans (KDRI). Additionally, besides the EER(IOM) equations, other equations were examined for EER estimation. Research papers demonstrating the validation of the EER(IOM) equations based on TEE(DLW) were searched through PubMed (up to September 2019). Of the 637 potentially relevant articles identified, duplicates and unsuitable titles and abstracts were excluded. Furthermore, papers with irrelevant subject and inappropriate study design were also excluded. Finally, 11 papers were included in the review. Among the reviewed papers, 8 papers validated the application of the EER(IOM) equations for EER based on TEE(DLW). These included 3 studies for children (USA 1, Korea 2), 1 for adolescents (Portugal), 2 for adults (Korean), and 2 for the elderly (Korea, USA). EER(IOM) equations were found to be generally acceptable for determining EER by using the DLW method, except for Korean boys at 9-11 yrs (overestimated) and female athletes at 19-24 yrs (underestimated). Additionally, 5 papers include the validation of other EER equations, beside EER(IOM) for EER based on TEE(DLW). In Japanese dietary reference intake and recommended dietary allowance, EER equations are acceptable for determining EER based on TEE(DLW). The EER(IOM) equations is generally acceptable for determining EER using the DLW method in Koreans as well as several populations, although certain defined groups were found to be unfit for the estimation. Additionally, the concept of healthy body mass index of Koreans and physical activity levels need to be considered, thereby providing the basis for developing relevant equations of EER in KDRI.

A narrative review on the application of doubly labeled water method for estimating energy requirement for Koreans

김오연,박종훈,김은경 한국영양학회 2022 Nutrition Research and Practice Vol.16 No.3

Research articles were reviewed to validate the estimated energy requirements (EERs) equations developed by the Institute of Medicine of the National Academies (IOM). These equations are based on total energy expenditure (TEE) measured by the doubly labeled water (DLW) method. We subsequently aimed to provide the basis for the suitability to apply the IOM equations as EER equations for Koreans, and develop relevant equations for EER in the Dietary Reference Intake for Koreans (KDRI). Additionally, besides the EER(IOM) equations, other equations were examined for EER estimation. Research papers demonstrating the validation of the EER(IOM) equations based on TEE(DLW) were searched through PubMed (up to September 2019). Of the 637 potentially relevant articles identified, duplicates and unsuitable titles and abstracts were excluded. Furthermore, papers with irrelevant subject and inappropriate study design were also excluded. Finally, 11 papers were included in the review. Among the reviewed papers, 8 papers validated the application of the EER(IOM) equations for EER based on TEE(DLW). These included 3 studies for children (USA 1, Korea 2), 1 for adolescents (Portugal), 2 for adults (Korean), and 2 for the elderly (Korea, USA). EER(IOM) equations were found to be generally acceptable for determining EER by using the DLW method, except for Korean boys at 9–11 yrs (overestimated) and female athletes at 19–24 yrs (underestimated). Additionally, 5 papers include the validation of other EER equations, beside EER(IOM) for EER based on TEE(DLW). In Japanese dietary reference intake and recommended dietary allowance, EER equations are acceptable for determining EER based on TEE(DLW). The EER(IOM) equations is generally acceptable for determining EER using the DLW method in Koreans as well as several populations, although certain defined groups were found to be unfit for the estimation. Additionally, the concept of healthy body mass index of Koreans and physical activity levels need to be considered, thereby providing the basis for developing relevant equations of EER in KDRI.

50mm 깊이 증발(蒸發) 팬을 이용한 한발 평가 모델 설정

오영택,오동식,송관철,엄기철,신제성,임정남,Oh, Yong Taeg,Oh, Dong Shig,Song, Kwan Cheol,Um, Ki Cheol,Shin, Jae Sung,Im, Jung Nam 한국토양비료학회 1996 한국토양비료학회지 Vol.29 No.2

한발 간이 평가에 가상의 초지가 적합하다는 전제하에, 관여 인자를 작물 계수, 토양의 저수능, 토양 수분 상태로 정의되는 한발 개시점으로 제한하여, 토양 수분 회계장부 법으로 한발 전산 모델을 개발하였다. 최대 유효 강우는 토양 저수능 중에 잔여량과 같다고 전제 하였는데, 이 모델은 일정 깊이 개방통에 강우 최대 수용력이 수면 위 여유 공간 만큼인 것과 유사하며 이 통에 저장된 물이 증발하여 미리 규정한 수위 이하로 되면 한발로 취급함과 같다. 이 모델은 한발 평가를 위하여 전제한 가상 초지의 수분 부족을 추적하는데, 물 요구량, 한발 강도, 한발에 의한 수량 감소 지수를 계산할 수 있다. 선정된 인자의 영향 강도 비율을 이 모델에 의한 년간 필요 개량을 고려하여 계산하면, 작물계수 100, 토양 저수능 21, 한발개시점 16이었다. 이 모델에서 선발된 인자의 최적값은 작물 계수는 대형 증발계 증발량의 0.85배였고, 토양 저수능은 사양토 양토 식양토와 식토에서 실측 결과의 평균은 50mm 였으며, 한발 개시점은 저수능의 65% 였다. Imaginary grass field was assumed suitable as the representative one for simplified estimation of local drought, and a moisture balance booking model computing drought was developed with the limited numbers of its determining factors, such as crop coefficient of the field, reservoir capacity of the soil, and the beginning point of drought as defined by soil moisture status. The maximum effective rainfall was assumed to be the same as the available free space of soil reservoir capacity. The model is similar to a definite depth evaporation pan, which stores rainfall as much as the available free space on the water in it and consumes the water by evaporation. When the pan keeps water less than a certain defined level, it is droughty. The model simulates soil moisture deficit on the assumed grass field for the drought estimation. The model can assess the water requirement, drought intensity, and the index of yield decrement due to drought. The influencing intensity indices of the selected factors were 100, 21, and 16 respectively for crop coefficient, reservoir capacity, and drought beginning point, determined by the annual water requirements as influenced by them in the model. The optimum values of the selected factors for the model were respectively 58% for crop coefficient defined on the energy indicator scale of the small copper pan evaporation, 50 mm for reservoir capacity on the basis of the average of experimentally determined values for sandy loam, loam, clay loam, and clay soils, and 65% of the reservoir capacity for the beginning point of drought.

Using physical activity levels to estimate energy requirements of female athletes

박종훈 한국운동영양학회 2019 Physical Activity and Nutrition (Phys Act Nutr) Vol.23 No.4

[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.

Using physical activity levels to estimate energy requirements of female athletes

( Jonghoon Park ) 한국운동영양학회 2019 Physical Activity and Nutrition (Phys Act Nutr) Vol.23 No.4

[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.