• Korean Journal of Environment and Ecology
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• v.20 no.1
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• pp.70-74
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• 2006

To study for proper growing conditions of Hydrangea macrophylla var. acuminata, used as ornamental trees or sources of natural sweetenings and biological active compounds, two-year-old cuttings of the plant were subjected to different conditions, light intensity, watering, and fertilizing levels. Photosynthetic rates measured on October 2 differed significantly between two light intensity regimes, but the values measured on September 3 were not significantly different. Mean photosynthetic rates on the plot watered three times a week were higher than the cuttings on the plot watered once a week. Mean photosynthetic rates on the plot fertilized 200grams/cuttings were slightly higher than those of the cuttings on the control plot. Chlorophyll contents measured on August 2 and on September 3 were significantly different between the light intensity regimes. Chlorophyll contents measured on August 2 were significantly different between the moisture regimes, but not significantly different between the fertilizing levels. Means of leaf growth(length and width) measured the highest values on the plot watered three times a week, and on the plot in full-sun lighted.

• Journal of Bio-Environment Control
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• v.18 no.2
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• pp.132-136
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• 2009

To investigate the effect of mycorrhiza on drought resistance and plant growth, Ardisia pusilla were colonized with arbuscular mycorrhiza (AM), Glomus spp. Host plants were cultured in a growth chamber for 30 days after colonization with AM. Water stress treatment was carried out by repeating five days off-watering and re-watering for 60 days. The growth of A. pusilla was enhanced by AM colonization compared to that of control, while the proline contents was significantly reduced in AM colonized plants compared to that of non-mycorrhizal plants. The inorganic nutrient contents i.e. Fe, Mn, Zn, and Cu in arbuscular mycorrhizal plants were higher than those of control.

• Korean Journal of Agricultural Science
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• v.2 no.1
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• pp.101-110
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• 1975

This study was carried out to determine the effect of water control on Rice plan in warmer season(July~August). The results are summarized as follows; 1. Compared to ordinary watering methods, a constant irrigation method indicated a decrease in water temperature of $1.5^{\circ}C$. 2. In the plot of constant irrigation, there was an increase in the root system in general and an increase of root distribution near the surface in particular. The near surface root distribution under ordinary watering method shows about forty percent distribution. The constant irrigation method shows a near-surface root distribution of sixty-percent within a perimeter of five centimeters. 3. Under the contants irrigation method, there was an increase in length and area of the flag leaf. 4. The total nitrogen and silica content of leaf-bodies at maturing stage was greater when using the constant irrigation method. 5. There was an increase in the number of panicles and the number of spikelets when using the constant irrigation method. 6. The yield was remarkably increased with constant irrigation.

• Journal of Biosystems Engineering
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• v.20 no.1
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• pp.73-86
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• 1995

The automatic control system in the greenhouse have to be developed to the direction of considering various factors the variables such as condition of the cultivation and greenhouse, the properties and types of products. Therefore, it is more important to set up variables appropriately than the problems of automatic control system itself, and the automatic control system which satisfy these problems should be simplified in the aspect of operation. In addition, even the individual automations are not perfect yet, so more studies are required for the development of comprehensive automatic system in korea. This study was carried out to automatize environment control systems for greenhouse, especially from most intensive labor requiring parts such as watering, irrigating liquefied fertilizer, spraying chemicals, mixing and ventilation system, etc. The results are summarized as follows. 1. Control type tensiometer was expected to be desirable in the automation of watering system, therefore, a new tensiometer was designed and developed through this study. 2. The chemical spraying system developed through this study was found to be excellent in the aspect of operation. 3. When pulse type water discharge meter was used in the mixing of liquefied fertilizer and chemical solution, the error of mixing were range $\pm$0.1~0.15%. 4. The water level switch of electrod type used for controlling water level was found to be affective in both control performance and operation cost. 5. The water and level control system can be omitted if each tank size are standardized in accordance with greenhouse size, therefore, the installation cost might be significantly reduced. 6. The developed general controller was excellent in hardware parts, but still remained to be improved in software parts.

• Korean Journal of Medicinal Crop Science
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• v.28 no.6
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• pp.412-420
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• 2020

Background: Measurement of chlorophyll fluorescence (CF) is useful for detection the ability of plants to tolerate environmental stresses such as drought, and excessive sunlight. Cnidium officinale Makino is highly sensitive to water stress and excessive sunlight. In this study, we evaluated the effect of soil water and shade treatment on the photosynthesis and leaf temperature change of C. officinale. Methods and Results: C. officinale was cultivated under uniform irrigation for 1 week drought stress (no watering) for 6 days. A significant decrease in CF was observed on the 5th day of withholding water (approximately 6% of soil water content) regardless of shading. Notably, the Rfd_lss parameter (CF decrease rates) with and without shade treatment was reduced by 73.1% and 56.5% respectively, at 6 days compared with those at the initial stage (0 day). The patterns of the degree of CF parameters corresponded to those of the soil water content and difference between leaf temperature (Ts) and air temperature (Ta). Meanwhile, CF parameters recovered to the 3 - 4 days levels after re-watering, while the soil water potential was completely restored. The suitable soil water content for C. officinale optimal growth was between -5 kPa and -10 kPa in this experiment. Conclusions: Lack of soil water in the cultivation of C. officinale, even with shading, decreased latent heat cooling through transpiration. As a result, heat dissipation declined, and the plant was subjected to drought stress. Soil water content plays a major role in photosynthesis and leaf temperature in C. officinale.

• Journal of the Korean Society of Food Culture
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• v.37 no.6
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• pp.555-563
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• 2022

The purpose of this study was to confirm the quality characteristics of distilled soju with different rice pretreatment processes. The non-steamed fermentation method is a technology that uses starch to produce saccharification and alcohol without going through the steaming of raw materials. It has advantages such as reduction of manpower and cost, prevention of nutrient loss, and minimization of waste water. In this study, rice used were non-steamed and pulverized 'Baromi2', nonsteamed and steamed 'Samgwang', and puffed rice. As the fermenting agent, koji, modified nuruk, N9 yeast, and purified enzyme were used, and lactic acid was added to prevent contamination during fermentation. The amount of water was 300% in total, and after the first watering, 5 days after fermentation, the second watering was carried out. As a result of the study, it was confirmed that the non-steamed fermentation method using 'Baromi' was superior to the existing fermentation method in terms of temperature during fermentation, final alcohol content, soluble solids, and pH. By expanding the stability of the production technology of non-steamed fermentation technology, product quality improvement can be expected.

• Journal of People, Plants, and Environment
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• v.23 no.5
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• pp.507-519
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• 2020

Background and objective: This study analyzed the growth characteristics, in relation to the soil moisture content, of trees planted in an environment with limited soil depth to provide the baseline data for effective irrigation management. Methods: The experimental treatment was divided into soil moisture contents (SMC) of 20%, 15%, 10%, 5%, and 1%, and the respective watering times were set accordingly. As for plant materials, Nandina domestica, Euonymus alatus, Thuja occidentalis, Hibiscus syriacus, Pinus densiflora, and Pyracantha angustifolia, were chosen for this study, because they are highly likely to be used in urban street environments. Results: The minimum irrigation point suitable for each species was determined by considering various aspects of visual quality and water efficiency in terms of plant growth, including characteristics such as height, root diameter, rootlet development, and weight. Our results indicate that N. domestica should be watered so that the moisture content of the soil is of at least 5%, based on the balance between the stem and roots, as well as on visual quality. E. alatus and P. angustifolia are suitable for watering that results in at least 10% SMC, considering the height, root growth, weight, and visual quality of plants. As for T. occidentalis, it showcases moderate growth with a soil moisture content of at least 5%. Finally, the minimum irrigation time required to obtain 15% SMC is appropriate, in terms of plant growth, fresh weight, and visual quality, for H. syriacus and P. densiflora. Conclusion: This study suggested a basic irrigation guideline for container gardens where trees planted in environments with limited soil depth can be managed so that they are visually appropriate and in good condition of growth.

• Asian Journal of Turfgrass Science
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• v.14 no.1
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• pp.257-262
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• 2000

This study was conducted on ten golf courses in the vicinity of Yongin city to find out the kinds of algae and factors affecting algae development on creeping bentgrass greens. 1. Serious algae contamination was observed on almost of creeping bentgrass greens after and before rainy season. 2. There were ten kinds of algae occurred on creeping bentgrass greens, most of which were Oscillatoria spp. (bluegreen algae) 3. The fact that the same kind of algae inhabiting in the pond was observed on greens indicated that greens were easily contaminated by algae in case of greens watered with the pond. 4. This study showed that the main factor affecting algae contamination on greens was not high total nitrogen and phosphorus contents in the green soil, but pond watering.

• The Korean Journal of Ecology
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• v.27 no.4
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• pp.211-216
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• 2004

The complex ecological researches were made in the broad-leaved forest zone of Central Europe in nature reserves and national parks located on the banks of the river (hydrology, vegetation, soils, unconfined ground waters). The natural conditions of terrestrial ecosystems and natural sites were compared along the course of the rivers. The significant negative influence of low-dammed (low-confined hydrotechnic) construction and small reservoirs on vegetation and soils of floodplain was revealed. On the basis of analysis of mean annual water level and flow trends on the multi-years series (60-100 years) of the hydrometric stations on the rivers under consideration the significant influence of natural long-term variability of watering on vegetation dynamics in the floodplains was revealed.

• International Journal of Concrete Structures and Materials
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• v.5 no.2
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• pp.133-137
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• 2011

In this study, a physical and chemical properties analysis was conducted for PCSP to evaluate properties of its materials and, for comparison purpose, was also conducted for CSP. The result of experiment confirmed improvement of iron recovery rate due to introduction of rapid water-cooling equipment and greater density of exterior and interior structure through SEM observation and porosity measurement. Also, SEM, XRD and DSC-TGA analysis showed that content of f-CaO in PCSP was minuscule so it was decided that problems of material stability including f-CaO-caused bulging failure, which has been problematic, can be solved.