• Korean Journal of Environmental Agriculture
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• v.40 no.4
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• pp.345-352
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• 2021

BACKGROUND: Salinity is one of the major limiting factors in agriculture that affect the growth and productivity of crops. It is economically difficult to artificially purify the soil affected by salt. Therefore, the use of plant growth-promoting bacteria (PGPB) in an effort to reduce stress caused by salt is emerging as a cost-effective and environment-friendly method. In this study, the purpose was to isolate the salt-tolerant bacteria from the rhizosphere soil and identify their ability to promote plant growth under salt stress condition. METHODS AND RESULTS: The isolates KST-1, KST-2, AST-3, and AST-4 that showed plant growth-promoting activity for barley in salt conditions were close to Bacillus cereus (KST-1, KST-2, and AST-4) and Bacillus thuringiensis (AST-3) and showed high salt tolerance up to 7% of additional NaCl to the media. When inoculated to barley, the strains had only minor effect on the length of the barley. However, the concentrations of chlorophyll in the barley leaves were found to be higher from the bacteria-inoculated pots than those from the uninoculated control. In particular, the chlorophyll concentration in Bacillus cereus AST-4 experiment was 5.45 times higher than that of the uninoculated control under the same experimental condition. CONCLUSION(S): The isolated salt-tolerant bacteria were found to influence on chlorophyll concentration of the barley. As represented by the strain AST-4, microbes may suggest a cost-effective and environmentally benign method to alleviate salt stress of crops cultivated in salt-accumulated soils such as reclaimed lands.

• Korean Journal of Agricultural Science
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• v.42 no.3
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• pp.177-181
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• 2015

Food waste has been widely considered as a recycling resource to be applied to agricultural lands due to the effects of organic matter and nutrient for plant productivity. but the maturity and salt concentration in the compost produced from food waste processing facilities should be considered firstly, which was little information on compost quality produced from food waste treatment facility. In this study, we examined actual situation of food waste processing facility on the composting of food waste and evaluated the characteristics of composts produced from food waste processing facilities. The quality of composts was analyzed on the basis of the criteria of fertilizer processing manual. The 46% of food waste treatment facility registered composting produced actually the compost mixed with food waste or animal waste. The compost maturity and salt concentration as indicators of the quality of compost were not met 46.8% of composts collected from food waste processing facilities to the criteria of fertilizer processing manual. Also, 15.6%(moisture) were not satisfied with the criteria. In conclusion, the compost produced from food waste processing facilities is firstly required with better compost maturity and reduced salt concentration in order to use to agricultural lands as an amendment.

• Journal of Microbiology and Biotechnology
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• v.20 no.9
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• pp.1288-1294
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• 2010

Rhizobium phaseoli strains were isolated from the mung bean (Vigna radiata L.) nodules, and the most salt tolerant and high auxin producing rhizobial isolate N20 was evaluated in the presence and absence of L-tryptophan (L-TRP) for improving the growth and yield of mung bean under saline conditions in a pot experiment. Mung bean seeds were inoculated with peat-based inoculum and NP fertilizers were applied at 30-60 kg/ha, respectively. Results revealed that imposition of salinity reduced the growth and yield of mung bean. On the contrary, the separate application of L-TRP and Rhizobium appeared to mitigate the adverse effects of salt stress. However, their combined application produced more pronounced effects and increased the plant height (28.2%), number of nodules per plant (71.4%), plant biomass (61.2%), grain yield (65.3%), and grain nitrogen concentration (22.4%) compared with untreated control. The growth promotion effect might be due to higher auxin production in the rhizosphere and improved mineral uptake that reduced the adverse effects of salinity. The results imply that supplementing Rhizobium inoculation with L-TRP could be a useful approach for improving the growth and yield of mung bean under salt stress conditions.

• Proceedings of the Korean Geotechical Society Conference
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• 2010.03a
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• pp.448-456
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• 2010

The mechanical behavior of granular soils is affected by particle bonding including natural cementation. This study addresses a simple model of small strain stiffness and salt concentration based on wave measurements of salt-cemented particulate media. Published models of artificially cemented soils with different curing methods and several types of cementation agents are reviewed. Glass beads with the median diameter of D50 = 0.5mm are prepared in rectangular cells using the water-pluviated method in salt water with different concentrations. Piezo disk elements and bender elements embedded in the cell are used for the measurements of compressional and shear waves. The relationships between elastic wave velocities and salt concentration show an exponential function. The measured small strain stiffness matches well the predicted small strain stiffness based on micromechanics for simple cubic monosized sphere particles. This study demonstrates that the salt concentration in salt-cemented specimen may be evaluated by using elastic wave velocities.

• Asian Journal of Turfgrass Science
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• v.23 no.1
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• pp.143-150
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• 2009

High salt concentration is one of the most important limit factor on plant growth at a disused saltpan for golf course construction site. The control of salt in soil is definitely required and the monitoring of salt concentration in soil and ground water also required to amend soil physiochemical properties. This research was carried out to monitor the pH and salt concentration changes by the height of ground water. By the physiochemical analysis test, the soil contains a high salt concentration and classified as a slight alkaline clay soil. The height of ground water table changed to 1.3m, 3.3m and 2.8m at dry season(mid-late June, 2005), monsoon season(early-mid July) and after monsoon(late July), respectively. Compare to the average ground level of 2.9m, the ground water was over flooded about OAm at monsoon season. The electrical conductivity(ECe) was measured above $4.0dS{\cdot}m^{-1}$ over all areas and however, some areas showed over $20dS{\cdot}m^{-1}$. During a monsoon season, ECe was lowered to $1.2{\sim}15.0dS{\cdot}m^{-1}$, compared with those of the dry season. Therefore, the interception of the capillary connection between planting layer and ground water which contains high salt concentration should be adapted when golf courses are constructed on disused saltpan. The phytotoxicity caused by salt damage may be controled by the interception of capillary fringe of salt flow to the topsoil profile at the upper layer of the ground water table.

• Journal of People, Plants, and Environment
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• v.23 no.4
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• pp.445-453
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• 2020

Background and objective: Calcium chloride (CaCl₂) and sodium chloride (NaCl) are commonly used as a deicing agent in South Korea and penetrate the soil on the roadside, causing damage to plants. This study was conducted to investigate the salinity reduction effect of Pennisetum alopecuroides and the chemical characteristics of soil leachate. Methods: The plants were treated with five different concentrations of CaCl₂ (0, 1, 2, 5, and 10g·L^-1) and were grouped into the Cont., C1, C2, C5, and C10 groups. CaCl₂ of 200 m·L^-1 was sprayed to each plant once every two weeks. The growth of P. alopecuroides (plant height, leaf length, leaf width and the number of leaves) was measured. The level of EC and pH, and exchangeable cations (K⁺, Ca²⁺, Na⁺, and Mg²⁺) in the leachate of soil was monitored. Results: The pH of soil leachate decreased as the CaCl₂ concentration increased, and the EC increased significantly. The content of K⁺ did not change significantly until the concentration of CaCl₂ reached 5 g·L^-1, but the content of Ca²⁺, Na⁺, and Mg²⁺ significantly increased. The plant height, leaf length, and leaf width of P. alopecuroides showed the highest value in CaCl₂ 1 g·L^-1 followed by CaCl₂ 2 g·L^-1 and the control group. Root fresh weight was the highest in CaCl₂ 2 g·L^-1. On the other hand, there was no change in the shoot fresh weight, dry weight and root dry weight, and P. alopecuroides growth inhibition at the concentration of 5 g·L^-1 or higher in the plant height and leaf length. Conclusion: P. alopecuroides is relatively highly salt-tolerant and can improve the salt damaged soil by lowering the content of the salt-based exchangeable K⁺ ions.

• Journal of the Korean Institute of Landscape Architecture
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• v.47 no.4
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• pp.61-67
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• 2019

The purpose of this research is to evaluate the salt tolerance of the Miscanthus sinensis and to characterize the content of pigments in the leachate in relation to calcium chloride ($CaCl_2$) deicing salt. Miscanthus sinensis were cultured at five different concentrations of calcium chloride deicing salt, 0, 1, 2, 5, and $10g{\cdot}L^{-1}$ (referred to Cont. C1, C2, C5, and C10) for four months. The salt tolerance and leachate while growing Miscanthus sinensis on soil which was artificially contaminated by calcium chloride deicing salt. Soil chemical properties (pH, E.C., $Ca^{2+}$, $Na^+$, $K^+$, and $Mg^{2+}$) and plant growth parameters (plant height, leaf length, leaf width, number of leaves, shoot fresh weight, root fresh weight, shoot dry weight, an root dry weight) were evaluated. Soil pH decreased, while electrical conductivity significantly decreased ($p{\leq}0.05$) with a higher concentration of deicing salt $0g{\cdot}L^{-1}$ (Cont.). The increase in the concentration of chloride-based exchangeable cations, along with the increase in the deicing salt treatments, were observed in $Ca^{2+}$ > $Na^+$ > $K^+$ > $Mg^{2+}$. Notably the $Ca^{2+}$ exchangeable cations were 83~90% higher than the others. The growth of Miscanthus sinensis significantly increased ($p{\leq}0.05$) with the concentration of deicing salt higher than $1g{\cdot}L^{-1}$ (C1) when compared to 0 g/L (Cont.), except for the $10g{\cdot}L^{-1}$ (C10) treatment. The results determined that the contamination of soil by deicing salt could negatively impact the soil and Miscanthus sinensis was a tolerant species for the deicing salts. Further research will be focused on soil improvement additives and the stable stimulated plant growth of Miscanthus sinensis and a formulation on that basis for the soil-plant continuum.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.13 no.5
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• pp.172-179
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• 2010

This study was conducted to establish a management plan for the Songrim woodland restoration by analyzing the site characteristics of the Songrim Woodland Natural Monument (Natural Monument 445) in Hadong-Gun, Gyeongsangnam-Do, Korea. The Songrim woodland was a pure pine forest. To stimulate the growth of sub-trees or mid- story vegetation in both a non-rest year forest and a rest year forest, it is recommended to take a silvicultural practices such as pruning because canopy of over-story trees was closely covered. The Songrim woodland in the non-rest year forest severely competed among individual trees of DBH classes of 60 cm and height of 18 m, while the woodland in the rest-year forest competed with DBH classes of 62 cm and height of 10 m, respectively. Soil physical property such as soil hardness, soil pore space rates, and pF 2.7 was restored following the rest-year forest designation. Mean salt concentration in the Songrim woodland soils was 0.006%. The result suggests that it is needed to take a study to prevent the salt inputs to conserve the Songrim woodland.

• Journal of Plant Biology
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• v.14 no.3
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• pp.60-65
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• 1971

In order to observe the factors affecting light utilization efficiency in the canopy of a rice crop grown in reclaimed saline areas in Korea, 22 varieties of rice were cultured at the average salt concentration of 6.05mmhos/cm $25^{\circ}C$, (0.39%) in saline soils and non-saline silty loam soils. The inhibition of tillering ability by salt damage at the maximum tillering stage was greater than to growth in height. A significant direct correlation was observed between both ratios and salt concentration with each variety. In the salty areas the length of the flag leaf of the maturing stage showed a positive correlation with the production of rough rice while other living leaf showed a negative correlation. LAI of maturing stage was less in the salty area than in the non-salty area, while the former showed higher ratio in net assimilation and translocation to head with greater RGR before and after the heading stage.

• Journal of Environmental Science International
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• v.29 no.4
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• pp.395-402
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• 2020

This study was conducted to analyze seasonal variations of de-icing salt ions harvested from soils and plants according to salt damage of Pinus densiflora f. multicaulis, a evergreen conifer, on roadsides. Pinus densiflora f. multicaulis was divided into three groups referred to SD, ND, and WD (serious salt damage (SD) = 71-100%, normal salt damage (ND) = 31-70%, and weak salt damage (WD) = 0-30%) based on the degree of visible foliage damage, and measured acidity (pH), electrical conductivity(EC), and de-icing salt ions (K⁺, Ca²⁺, Na⁺, and Mg²⁺) harvested from soils and plants. The results indicated that acidity, electrical conductivity, and de-icing salt ions of soils and plants were significantly affected by seasonal variation and salt damage. In addition, a strong positive liner relationship was observed in plants between the concentration of de-icing salts and salt damage in spring, while the relationship among seasonal variation and salt damage in soil were not significant. The results from this study has important implications for the management of conifer species in relation to salinity and roadsides maintenance.