• KOREAN JOURNAL OF CROP SCIENCE
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• v.44 no.4
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• pp.321-329
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• 1999

The effect of water deficits on soybean [Glycine max (L.) Merr.] could appear on seed quality through changes of morphological plant characteristics. Two Korean genotypes, Hwangkeum (determinate growth habit) and Muhan (indeterminate growth habit), were used to examine the influences of treatment stage and method of water deficit during reproductive growth period on yield and seed quality of soybean. Water deficit at R5 or R6 stages was as damaging to seed quality as double water-deficit treatments at R2+R5 or R2+R6. However, seed from double water-deficit treatment tended to have lower oxidation-reduction potential compare to the corresponding single water-deficit treatment. In comparison with Muhan, Hwangkeum had significantly greater oxidation-reduction potential value. Seed yield per plant in both genotypes depended greatly on seed yield of branches. However, the proportion of number of branch seed to total seed umber in Hwangkeum was increased as the water deficit was applied during later reproductive stage, whereas, in Muhan the proportion was lower. Water-deficit treatments including the single and double water-deficit treatments and non-stressed treatment were able to be classified into five groups for Hwangkeum and four groups for Muhan based on the influences on yield components, number of pod, number of seed, and single seed weight, using principal component analysis. In both genotypes, R2+R5 water-deficit treatment decreased number of pod and seed, but increased single seed weight. On the contrary, R6 or R2+R6 stress increased the pod and seed number, but decreased single seed weight.

• Magazine of the Korean Society of Agricultural Engineers
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• v.42
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• pp.31-37
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• 2000

Regulated Deficit Irrigation (RDI) is one of the most important measures for the water-saving and high yield of crops. RDI is based on the crop and water relations. The theories of RDI were analyzed using the experiment data in Shaanxi and Gansu Province. There are several problems of RDI in practical use, which include; the uncertainty of crop-water relations, the proper growth stages and water deficit degree of RDI applied, and the requirements of RDI to irrigation system and irrigation techniques.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.45 no.1
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• pp.6-13
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• 2000

Water deficit is the primary constraint of soybean [Glycine max (L.) Merr.] yield, and a physiological understanding of processes affected by water deficit is a key step in identifying and improving drought tolerance in soybean. The objectives of this research were to evaluate biomass and nitrogen accumulation patterns and water use efficiency (WUE) as possible mechanisms associated with the drought tolerance of Jackson. Biomass accumulation of Jackson was contrasted with the PI416937, which also has demonstrated tolerance to drought. For water-deficit treatment, total biomass accumulation was negligible for PI416937, but biomass accumulation continued at approximately 64 % of the well-watered treatment of Jackson. Transpirational losses for Jackson and PI416937 were approximately the same for the water-deficit treatment, indicating that Jackson had superior WUE. Isotopic discrimination of $^{13}$ C relative to $^{12}$ C also indicated that Jackson had higher WUE. Results indicated that increased WUE for Jackson under water deficit showed it was tolerant to drought rather than had an avoidance mechanism.

• Journal of the Korean Professional Engineers Association
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• v.35 no.4
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• pp.19-23
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• 2002

Recently, deficit of water for daily We, industrial, agricultural use and Increasing water demand of river maintenance has increased gradually by the improvement of living condition of the Republic of Korea. Comprehensive measures for water deficit In the future are studied, based on the Investigated result of the actual condition of water use.

• Journal of Oriental Neuropsychiatry
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• v.20 no.1
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• pp.43-57
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• 2009

Objectives : This experiment was designed to investigate the effect of the Hwanso-dan hot water extract & ultra-fine powder on microglia and memory deficit model Methods : The effects of the Hwanso-dan hot water extract on expression of IL-l${\beta}$, IL-6, TNF-${\alpha}$ mRNA and production of IL-l${\beta}$, IL-6, TNF-${\alpha}$ in BV2 microglial cell line treated by lipopolysacchaide were investigated. The effects of the Hwanso-dan hot water extract & ultra-fine powder on the behavior of the memory deficit mice induced by scopolamine and uric acid & AChE in serum of the memory deficit mice induced by scopolamine were investigated. Results : 1. The Hwanso-dan hot water extract suppressed the expression of IL-l${\beta}$, IL-6, TNF-${\alpha}$ mRNA in BV2 microglial cell line treated by lipopolysacchaide. 2. The Hwanso-dan hot water extract suppressed the production of IL-l${\beta}$, IL-6, TNF-${\alpha}$ in BV2 microglial cell line. 3. The Hwanso-dan hot water extract & ultra-fine powder decreased uric acid and AChE significantly in the serum of the memory deficit mice induced by scopolamine. 4. The Hwanso-dan hot water extract & ultra-fine powder groups showed significantly inhibitory effect on the scopolamine${\sim}$induced impairment of memory in the experiment of Morris water maze. Conclusions : This experiment shows that the Hwanso-dan hot water extract & ultra-fine powder might be effective for the prevention and treatment of Memory deficit disease. Investigation into the clinical use of the Hwanso-dan hot water extract & ultra-fine powder for Alzheimer's disease is suggested for future research.

• Journal of Korea Water Resources Association
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• v.55 no.12
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• pp.1021-1030
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• 2022

Currently, South Korea implements water resources management policies focusing on integrated water quantity, quality and hydro-ecology management. In particular, rehabilitation of natural rivers has become a major issue. As for reservoir operation during non-flood season, efforts have been made continuously to apply the Deficit Supply Method that can maximize water supply to address droughts and increase in water demand. When Deficit Supply Method is applied, the water supply capacity of reservoir can be maximized. However, downstream water flow would remain constant. In consideration that a natural stream, a long-time-created hydro-ecology, can be significantly influenced by flow variability, the Deficit Supply Method-based reservoir operation can generate effective water supply. Still, it may trigger adverse effects from the aspects of natural rehabilitation and hydro-ecology recovery. The main objective of this study is to analyze impacts on downstream flow duration through reservoir simulation by comparing the Firm Supply Method, the Deficit Supply Method and the Selective Deficit Supply Method, and examining each method's effects on reservoir operation. This study found that the Firm Supply Method could maintain water flow variability, but could not maximize water supply capacity. When the Deficit Supply Method was applied, water supply capacity could be increased while remaining vulnerable regarding water flow variability, as a difference between average flow and low flow was negligible at downstream. In comparison, the Selective Deficit Supply Method was found to sustain time-based reliability at 95% or higher, whereas downstream flow duration could be maintained at a level similar to the level generated by the Firm Supply Method.

• Water for future
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• v.16 no.2
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• pp.111-122
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• 1983

The water demand has been rapidly increased by the growth of population, industrialization, unbanization, water pollution and so on. This study carried out the seasonal pre-reserved planning for the five zones, comparing the water demand with the available water resources up to the goal year, 2001. The results of this study are as follows; 1) It is principle that the monthly water demand is supplied by the surface and ground water as the increasing tendency of it, and the deficit of water is supplemented by the water supplying capacity of dam. And water demand should be completely reserved before supplying the deficit of water. 2) The monthly and seasonal maximum deficit of water demand take place in June and summer. 3) The periods when the deficit of water demand exceeds the water supplying capacity of dam are 1984-1990, 1994-2001 in zone III. 4) To reserve the deficit of water demand in zone III, we would like to pre-construct Masan-Keumbo estuary barrage from 2001 to 1991 in Seomjin river basin, the deficit of water demand is supplied by the diversion of water from Yeongsan river basin with the developments of the ground water and small reservoirs until 1986.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.45 no.1
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• pp.1-5
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• 2000

Leaf area is critical for crop light interception, and thereby has a substantial influence on crop yield. This experiment was conducted to characterize the development of soybean [Glycine max (L.) Merr.] leaf area. Plastochron index and leaf relative growth rate of Jackson was contrasted with the PI416937, which also has demonstrated tolerance to drought. First, plastochron ratio (PR) and plastochron index (PI) were evaluated in greenhouse to compare the leaf growth rate between two genotypes under well-watered condition. There was reasonable constancy of PR between two genotypes. The PR means of Jackson and PI416937 were 0.41 and 0.44, respectively. A fairly smooth increase of PI during vegetative stage was observed. Second, the relative growth rates were graphed against leaf area, normalized with respect to final leaf area, under well-watered and water-deficit conditions. Leaf growth was sustained longer in well-watered condition than water-deficit condition and there was a sizable proportion of leaves which was ceased earlier their growth in water-deficit condition compared to well-watered condition. The leaf relative growth rate of Jackson until leaves had completed at 45% of their growth during water deficit period was higher than that of PI416937.

• Water for future
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• v.19 no.4
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• pp.329-338
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• 1986

the purpose of this study is to estimate the storage deficit by Run's Characteristics of (-)Run-length and (-)Run-sum. Runoff data are obtained from the guaging stations of Y대-Ju in Hanriver Basin, Wae-Gwan in Nak Dong River Basin and Gyo Am in Geum River Basin. In order to estimate the storage deficit, runhydrographs are established with each return period of 10, 30, ......, 200 years and regression equation is derived from relationship between (-) run-length and storage deficit. From the comparison of estimated reservoir storage with observed values., it was proved that this suggested method can be used for the estimation of the storage deficit.

• Journal of The Korean Society of Grassland and Forage Science
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• v.34 no.1
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• pp.15-20
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• 2014

To investigate lignification process and its physiological significance under water-deficit condition, the responses of peroxidases, polyphenol oxidase (PPO) and phenylalanine ammonia-lyase (PAL) in relation to leaf water status to the short term of water deficit treatment in the leaves with different maturities in forage rape were measured. The significant decrease in relative water content (RWC) and leaf osmotic potential (${\Psi}{\pi}$) were apparent after 5 d of water-deficit treatment. The activity of guaiacol peroxidase (GPOD), ascorbate peroxidase (APOD), coniferyl alcohol peroxidase (CPOD), and syringaldazine peroxidase (SPOD) was depressed especially in middle and old leaves when compared with that of control leaves. On the other hand, in young leaves, a significant increase in CPOD (+34%) and SPOD (+24%) activity as affected by water-deficit treatment was apparent. The activation of PAL and PPO was observed in middle and old leaves for PAL and in young and middle leaves for PPO. These results suggest that peroxidases in middle and old leaves did not involve in lignification under mild water-deficit stress, whereas CPOD and SPOD in young leaves participate in lignification by a coordination with PAL and PPO to incorporate phenol and lignin into the cell walls.