• Journal of Environmental Science International
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• v.19 no.7
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• pp.843-848
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• 2010

This study focused on the characteristics of change soil water with respect to soil thickness and soil mixture ratio, in order to effectively carry out an afforestation system for a roof with a low level of management and a light weight. Soil hardness tended to increase as sand particle was increase regardless soil thickness and soil porosity had more higher artificial soil than natural soil mixture. In case of soil pH, natural soil mixture had between 6.7 and 7.4, and artificial soil mixture had 6.0~6.8. Organic matter, electrical conductance and exchangeable content were highest in $L_{10}$, which it had the highest leafmold ratio. Soil moisture tension(kPa) in 15cm soil thickness was observed natural soil mixture had a considerable change but artificial soil mixture had a gradual change when non-rainfall kept on. In the experimental $L_{10}$, $S_{10}$, $S_7L_3$ and $S_5L_5$ object, the amount of moisture tended to rapidly decrease. However, in the experimental $P_7P_1L_2$, $P_6P_2L_2$, $P_5P_3L_2$ and $P_4P_4L_2$ objects, which contained pearlite and peat moss, the amount of moisture tended to gradually decrease. As a result, the use of a artificial soil mixture soil seems to be required for the afforestation of a roof for a low level of management.

• Journal of Life Science
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• v.8 no.5
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• pp.557-562
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• 1998

This study was conducted to investigate the influence of soil moisture on the photosynthetic rate, transpiration rate, stomatal conductance, leaf water content and its any correlation in soybean. Followings were achieved as a conclusion. At the soil moisture was moved from drought condition to saturation condition, the photosynthetic rate, transpiration rate, stomatal conductance and leaf water content were gradually increased on the period of re-watering treatment. The recovery of photosynthetic rate was faster than others. There were positive correlation with the photosynthetic rate and leaf water content, the stomatal conductance and leaf water content, the photosynthetic rate and stomatal conductance respectively, but the correlation coefficient of photosynthetic rate and leaf water content was high.

• Journal of Biosystems Engineering
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• v.33 no.2
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• pp.115-123
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• 2008

This study was conducted to develop an automatic soil water content control system for greenhouse, which consisted of drip irrigation nozzles, soil water content sensors, an on/off valve, a servo-motor assembly and a control program. The control logic adopted in the system was Ziegler-Nichols algorithm and rising time, time constant and over/undershoot ratio as control variables in the system was selected and determined by various control experiments to maintain small delay time and low overshoot. Based on the experimental results, it was concluded that the control system developed in the study could replace the unreliable conventional greenhouse soil water management.

• The Korean Journal of Ecology
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• v.20 no.2
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• pp.145-151
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• 1997

A census of the forest vegetation of Mt. Kaya National Park was taken with respect to the medthods of ordination and classification. Eight groups were classified by cluster analysis : Quercus mongolica, Q. mongolica-Sasa borealis, Q. serrata, Q. variabilis, Carpinus laxiflora, Cornus controversa, Fraxinus mandshurica and Pinus densiflora. Among them, the Q. mongolica group and Q. mongolica-S. borealis group, the F. mandshurica group and C. controversa group showed similar floristic compositions to each other. The interrelationship between the floristic compositon of the vegetation and soil environment was analyzed by PCA, the Q. mongolica group and the Q. mongolica-S. borealis group were distributed in areas of high CEC and total nitrogen content, while the Q. serrata. Q. variabilis. C. laxiflora and Pinus densiflora groups formed their communities in the more moderate areas of pH, soil moisture and soil organic matter. F. mandshurica and C. controversa groups were distributed in the areas of high soil moisture, soil organic matter, pH and available phosphate.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.18 no.2
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• pp.45-52
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• 2015

Cool-season turfgrass is a rapidly increasing of usage for the revegetation of waterside slopes in dams, lakes and rivers. The purpose of this research is to identify the flooding tolerance of cool-season turfgrass with respect to the flooding periods of 0(control), 2, 4 and 6 days, respectively. The surface coverage ratio, turfgrass injury and soil moisture content were measured to assess the flooding tolerance of cool-season turfgrass. The increase in the flooding periods with 4 and 6 days resulted in the lower surface coverage ratio for cool-season turfgrass while no significant difference was found in the 2 days flooding when compared to 0 day (the control plot) flooding plot. In case of the turfgrass injury and the soil moisture content, however, the higher values were found with the increase of flooding periods in 2, 4 to 6 days. We observed that the higher the turfgrass injury and soil moisture content increased, the lower the surface covrage ratio decreased. In these regards, we also observed that the tolerance of cool season turfgrass were high in the 2 days flooding condition, medium in the 4 days flooding condition and low in the 6 days flooding condition. The flooding tolerance of cool-season turfgrass was gradually weakened in over 2 days flooding periods due to $O_2$ deficiency in the anaerobic soil condition. Therefore, we could suggest cool-season turfgrass within 2 days flooding periods for the revegetation of waterside slopes in dams, lakes and rivers.

• Asian Journal of Turfgrass Science
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• v.19 no.2
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• pp.95-102
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• 2005

USGA green specification is currently accepted in construction method of Korea. This study was carried out to find the factors influencing growth of turfgrass associated with soil physical properties of soil root-zone on golf green constructed with USGA method. Three putting greens in poor turfgrass and one in good turfgrass condition were selected for investigation on one golf course site at mid-South Korean peninsula. Soil hardness, moisture content, root length, and turf density were measured on-site greens, and soil physical properties and soil chemical properties also analyzed in laboratory. As a result of on-site surveys and soil physical tests in laboratory, soil physical properties were most important factors which influenced on turfgrass growth at tested greens. The results of soil particle analysis on green No. 2, in good turf condition, matched USGA sand particle recommendations. But those greens such as Nos. 1, 11 and 16, in poor putting greens, showed high soil compaction and improper soil particle distribution. Those factors created low leaf density, poor root depth, and higher moisture content compared with lower part of topsoil. Such phenomena caused inadequate turfgrass growth with soil hardening associated with poor drainage. Therefore, declines of soil physical properties associated with improper particle distribution caused a major factor influencing on turfgrass growth in golf green. Adequate test of soil particle analysis by USGA specification and proper construction method followed by adequate turf maintenance should be performed to obtain optimal turf quality on putting green.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.31 no.1
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• pp.56-61
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• 1986

Germination and seedling elongation of maize (Dekalb XL 72B), and soybeans (Williams) were measured at two temperatures (15 and 35$^{\circ}C$), three soil water potentials (-1.50, -0.5, and -0.05 MPa), and four polyethy-lene glycol 8000 (PEG) levels (0, 20, 30, and 50 percent). Twenty conditioned seeds of each cultivar were treated with 0.2% thiram and planted 2 cm deep in sterilized Mexico silt loam soil which was subsequently compacted to a bulk density of 1.20 g/㎤. Seedling moisture content, dry weight, and length were measured for each treatment combination. Osmoconditioning with PEG showed little effect at high temperature or low soil water potential conditions. Soybeans had higher seedling moisture content than corn and both crops in-creased moisture uptake as soil water potential and temperature increased. Seedling length of corn was longer than soybeans at 35$^{\circ}C$ but shorter at 15$^{\circ}C$. Seedling dry weight of corn decreased at 35$^{\circ}C$ and that of soybeans decreased as soil water potential increased.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.41 no.6
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• pp.685-691
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• 1996

This experiment was conducted to investigate the effect of some soil conditioners, such as polyvinylalcohol(PVA), zeolite and perlite, on the changes of soil physical properties and on tobacco growth in paddy-upland rotated field. Soil conditioners were treated at the rates of 120kg in PVA, 500kg in zeolite and perlite per l0a, respectively. Ratio of soil aggregates formed from the treated plots tended to. be higher than those from the control in the order of PVA > perlite > zeolite. The wet aggregate stability, mean weight diameter, moisture retention and air permeability from the treated plots tended to be higher than those from the control. Amounts of water-stable aggregates of PV A-treated soil increased with higher soil moisture showing a peak at 50% of moisture content. But with respect to particle of size aggregate formed for crop growth and workability in field, it was presumed that 40% of soil moisture content would be most desirable. Visual characters of soil surface throughout the experiment clearly showed that treated soils were maintaining better surface roughness and porosity than control, but difference in water stable aggregates among treated plots tended to be narrowed. The growths of tobacco, espacially its root zone were better in conditioner treated plots than in non-treated plot showing best in PVA-treated soil.

• Journal of Korean Society for Atmospheric Environment
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• v.24 no.E1
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• pp.12-23
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• 2008

Relationship between the optimum soil water content and clay content on soil samples from mid-latitude European forest was tested. Soil samples from 4 different experimental sites (two forest sites in the Netherlands and a Danish forest) were collected, and analyzed for the soil physical and chemical characteristics. Water retention curves for the soil samples were determined according to the standard procedure ISO 11274, and pF decreased with increase in soil water contents. NO is simultaneously produced and consumed by microbiological processes, which comprise of nitrification and denitrification. NO consumption and production rates were determined from the soil samples and compared to their corresponding water retention curves in order to find the optimum soil water content and matric potential for maximum NO release from mid-latitude soils. NO consumption rate coefficient (k) in Hollandse Hout was significantly lower than those in other soil sites. Maximum NO production was observed at an intermediate soil moisture ($0.2{\sim}0.3kg/kg$) in all the soil samples. Resulting from the NO consumption and production rates for the soils, the empirical NO fluxes of the different soils were calculated in the laboratory.

• Magazine of the Korean Society of Agricultural Engineers
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• v.27 no.1
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• pp.37-45
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• 1985

To define the amount of consumptive use of upland crops, the moisture consumption characters were investigated with different soil moisture content by soil properties(loam, sandy loam, sand) at the experimental farm of Kon-Kuk University from April 20 to July 20 1984. The results obtained are summarized as follows; 1. Total moisture consumption under bare soil condition had an order of loam> sandy loam> sand and showed an order of pF 1.5> pF2. 1> pF 2.7 by re-irrigation point and the average during the experimental period (92days) was 435. 9mm and the daily average moisture consumption was 4. 7mm. 2. The moisture consumption characters of bare soil plot obtained showed that the amount of irrigation water per one time and the days of intermission increased and, on the contrary, the times of irrigation and the total amount of irrigation water decreased by the increment of re-irrigation point in the same soil 3. Total moisture consumption of spring cabbage under open cultivation showed 528.6 rim in maximum and had an order of loam> sandy loam> sand. In the aspect of rc-irrigation point, it had an order of pFl. 5> pF 2.1> pF 2.7. In case the planning basic year was taken into account, the amount of irrigation water needed for open cultivation was 456. 3 mm and its average daily moisture consumption was 6. 2mm. 4. Total moisture consumption of summer cucumber under open cultivation showed 635. 8mm in maximum and had an order of loam> sandy loam> sand. In the aspect of re-irrigation point, it had an order of pF 1.5> pF2. 1> pF2. 7 In case the planning basic year was taken into consideration, the amount of irrigation water was 516. 9mm and its aversge daily moisture consumption was 6. 5mm. 5. The result of cabbage cultivation showed its maximum yield in loam soil when the pF values were maintained from 1,5 to 2.1 and then the evapotranspiration ratio was 1, 76 and also when the amount of irrigation water were similar, it showed effective to reduce the days of intermtission. 6. The result of cucumber cultivation showed its maximum yield in sandy loam soil when the pF value maintained from 1.5 to 1.7 and when the irrigation point maintained at pF 2,7 in sandy soil, its yield was severely decreased.