• Korean Journal of Soil Science and Fertilizer
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• v.42 no.4
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• pp.280-288
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• 2009

To identify controlling factors for spatial variation of vegetation in reclaimed tidal flats, plant stands were investigated in a newly reclaimed as well as three matured tidal flats, and a natural tidal flat in the midwest coast of Korea. Electrical conductivity of saturated soil extract (ECe) was measured to assess soil salinity. Soil salinity differed significantly among plant stands. Depending on soil salinity, plant species showed different niches: glycophyte predominated low saline spots, halophyte predominated high saline spots. Soil salinity for each plant habitats was in order of as follow: bare soil or plant wilted > mixed pioneer halophyte > pioneer halophyte > mixed with pioneer halophyte and facultative halophyte > mixed facultative halophyte > facultative halophyte > mixed with facultative halophyte and glycophyte > glycophyte > mixed glycophyte stands. These results suggested that plant distribution might have been influenced by spatial edaphic gradient (soil salinity), and thus it could be utilized as an indicator for field soil salinity gradient. Relationship between soil salinity and plant distribution was not different among the aged reclaimed tidal flats, suggesting that the vegetative population might have changed into a similar direction since the reclamation.

• The Plant Pathology Journal
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• v.21 no.4
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• pp.391-394
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• 2005

Tomato seedlings (20- days old) were transplanted to infested soil with Orobanche cernua and non-infested soils. All plants were maintained under 0, 25, 50 and 75 mM NaCl soil salinity levels throughout their growing period under greenhouse conditions. Plants grown in O. cernua infested soil infIltrated with 0, 25, and 50 mM NaCl solution for salinity showed significant reduction in their growth as well as their total soluble carbohydrate and protein contents in compared with those grown in non-infested soil. However, under 75 mM NaCI salinity level all plants showed similar growth values whether they were grown in O. cernua infested or non-infested soil. Starting at the fifth and through out the eighth week after transplantation there was a significant increase in plant height in the 0, 25 and 50 mM NaCl irrigated plants over other treatments. Irrigation with 50 mM NaCl significantly reduced the emergence of O. cernua (2/plant) and the number of attachments (4.4 attachments) on roots of tomato. Furthermore, irrigation with 75 mM NaCl resulted in complete elimination of O. cernua emergence.

• Korean Journal of Soil Science and Fertilizer
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• v.41 no.2
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• pp.83-93
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• 2008

Assessing for flora distribution is necessary for land management and environmental research in reclaimed lands. This study was conducted to find out the relationship between vegetation distribution and soil salinity on three reclaimed tidal flats of Kyonggi-bay in the mid-west coast of Korea. We investigated the soil salinity and identified the vegetation at the continuum distribution spots, and describe the characteristics of continuum distribution. On the reclaimed tidal flats, spatial variation of vegetation formed partially, however as the result for connection of each spatial variation along with the soil salinity, continuum distribution formed and it was overlapped edaphic gradient with vegetation distribution, it means that the continuum distribution correspond with soil salinity gradient, as the evidence high salt tolerance species occurred at high saline spots, non salt tolerance species occurred at low saline spots. On the aged reclaimed tidal flats, continuum type was various and also clearly distinguished but it was not clear on the early stage of reclamation. The continuum distribution distinguished sequential and non-sequential type. Sequential type started from high saline zone and connected to low saline zone gradually, on this type, vegetation changed from pioneer halophyte to facultative halophyte and glycophyte along with the salinity gradient. Non-sequential type formed by non-sequential change of soil salinity, on this type, vegetation distribution was non-regular form because it has not changed gradually. In the aged reclaimed land, vegetation wilted zone existed with high salinity, and continuum distribution started from this zone with bare patch.

• Korean Journal of Soil Science and Fertilizer
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• v.49 no.4
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• pp.355-367
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• 2016

Soil salinization refers to the buildup of salts in soil to a level toxic to plants. The major factors that contribute to soil salinity are the quality, the amount and the type of irrigation water used. The presented review discusses the different sources and causes of soil salinity. The effect of soil salinity on biological processes of plants is also discussed in detail. This is followed by a debate on the influence of salt on the nutrient uptake and growth of plants. Salinity decreases the soil osmotic potential and hinders water uptake by the plants. Soil salinity affects the plants K uptake, which plays a critical role in plant metabolism due to the high concentration of soluble sodium ($Na^+$) ions. Visual symptoms that appear in the plants as a result of salinity include stunted plant growth, marginal leaf necrosis and fruit distortions. Different strategies to ameliorate salt stress globally include breeding of salt tolerant cultivars, irrigation to leach excessive salt to improve soil physical and chemical properties. As part of an ecofriendly means to alleviate salt stress and an increasing considerable attention on this area, the review then focuses on the different plant growth promoting bacteria (PGPB) mediated mechanisms with a special emphasis on ACC deaminase producing bacteria. The various strategies adopted by PGPB to alleviate various stresses in plants include the production of different osmolytes, stress related phytohormones and production of molecules related to stress signaling such as bacterial 1-aminocyclopropane-1-carboxylate (ACC) derivatives. The use of PGPB with ACC deaminase producing trait could be effective in promoting plant growth in agricultural areas affected by different stresses including salt stress. Finally, the review ends with a discussion on the various PGPB activities and the potentiality of facultative halophilic/halotolerant PGPB in alleviating salt stress.

• Journal of The Korean Society of Agricultural Engineers
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• v.63 no.6
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• pp.131-140
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• 2021

It is becoming more important to utilize reclaimed lands in South Korea, due to the increasing competition for its usage among different sectors. However, the high groundwater level and poor permeability are exposing them to deterioration by salinization. Salinization is difficult to predict because the pattern changes according to various characteristics of soil and groundwater. In this study, the capillary rising time was studied by the water content profile in the soil. The prediction equation of soil salinity was developed based on simulation result of the CHEMFLO model. to enable prediction considering various soil water content and groundwater level. The two terms constituting the equation showed the coefficients of determination of 0.9816 and 0.9824, respectively. Using the prediction equation of the study, the surface salinity can be easily predicted from the initial surface salinity and the salinity of the groundwater. In the future, more precise predictions will be possible with the results of studies on the hydraulic characteristics of various reclaimed soils, changes in water content profile by seasonal and climate events.

• Korean Journal of Soil Science and Fertilizer
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• v.42 no.3
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• pp.172-178
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• 2009

Relation between spatial variation of soil salinity and emergence of five upland crops such as sudan grass, sesbania, barnyard grass, corn and soybean was studied in the three reclaimed lands of Korea during two years from 2007 to 2008. Although soil salinity is vary high at seeding season, desalting treatment by three days-flooding before seeding, reach at favorable level lower than $6dS\;m^{-1}$ of soil salinity for emergence of soiling and forage crops and then plant number emerged(No. $m^{-2}$) was 55~149 for sudan grass, 118~266 for barnyard grass, 46~115 for sesbania, 3~11 for corn and 6~19 for soybean in 2007. However plant number emerged under no desalting treatment varies place by place because of soil salinity difference in 2008. Plant number emerged after seeding according to soil salinity was well expressed as logarithmic function, and sharply decrease with increase of soil salinity. It is accordingly concluded that desalting treatment of flooding before seeding of upland crops is essential for good emergence in the newly reclaimed land from tidal flat.

• Korean Journal of Soil Science and Fertilizer
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• v.44 no.5
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• pp.752-761
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• 2011

Recently, upland crops cultivation instead of paddy crops are more popular and highlighted by increase of social demand in agricultural land use. Especially, wheat cultivation for replacing of import food grain are more interested by government, and it is urgently needed that possibility of wheat cultivation is evaluated in the reclaimed tidal land. Crop cultivation is closely related with soil salinity and cultivation method in the reclaimed tidal land. In order to evaluate possibility of wheat cultivation, effect of different application level of compost and nitrogen additional fertilizer, also soil salinity on the grain yield and yield components of three wheat cultivars was studied at the newly reclaimed Saemangeum and Hwanong tidal lands in Korea. $270-300kg\;10a^{-1}$ of grain yield were obtained at the experimental site in the Saemangeum reclaimed tidal land where soil salinity was less than $4dS\;m^{-1}$ during growing periods from December, 2009 to June, 2010. However, almost no grain yield was obtained at the experimental site in the Hwaong reclaimed tidal land, where soil salinity was more than average $8dS\;m^{-1}$ ranged from 2.0 to $25.9dS\;m^{-1}$ during growing period and then salt demage was severe. Yield was significantly different among application level of compost and nitrogen additional fertilizer in the newly reclaimed Saemangeum tidal land. However, it is considered that three cultivars such as Chopum, Chogyung and Geumgang, have similar sensibility to soil salinity and fertilizer level, because there is statistically no difference among ciltivars in Hwaong and Saemangeum, and also among cultivars in the different levels of compost and fertilizer. Finally, it is concluded that wheat can be possibly produced by reasonable fertilizer application in the Saemangeum reclaimed tidal land, but wheat cultivation is impossible because of high soil salinity in the Hwaong reclaimed tidal land.

• Proceedings of the Korean Society for Agricultural Machinery Conference
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• 1993.10a
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• pp.556-564
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• 1993

The response of salt affected rice soils to salinity reclaimation by flushings and chemical amelioration by lime and gypsum were evaluated . Soils with good drainage system responded well to simple reclimation . The effects of seawater intrusion were reduced efficiently in a very short time. Yields of rice crops recovered to their potential level within one to two seasons of cropping. Soil profile strength was also improved under well drained areas. However, when drainage system was ineffective the problems of salinity and soil strength remained unsolved. Under both condition, water depth management played important role in the survival of rice crop under the sline soil conditions.

• Korean Journal of Environmental Agriculture
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• v.40 no.1
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• pp.49-59
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• 2021

BACKGROUND: Soil salinity causes reduction of crop productivity. Rhizosphere microbes have metabolic capabilities and ability to adaptation of plants to biotic and abiotic stresses. Plant growth-promoting bacteria (PGPB) could play a role as elicitors for inducing tolerance to stresses in plants by affecting resident microorganism in soil. This study was conducted to demonstrate the effect of selected strains on rhizosphere microbial community under salinity stress. METHODS AND RESULTS: The experiments were conducted in tomato plants in pots containing field soil. Bacterial suspension was inoculated into three-week-old tomato plants, one week after inoculation, and -1,000 kPa-balanced salinity stress was imposed. The physiological and biochemical attributes of plant under salt stress were monitored by evaluating pigment, malondialdehyde (MDA), proline, soil pH, electrical conductivity (EC) and ion concentrations. To demonstrate the effect of selected Bacillus strains on rhizosphere microbial community, soil microbial diversity and abundance were evaluated with Illumina MiSeq sequencing, and primer sets of 341F/805R and ITS3/ITS4 were used for bacterial and fungal communities, respectively. As a result, when the bacterial strains were inoculated and then salinity stress was imposed, the inoculation decreases the stress susceptibility including reduction in lipid peroxidation, enhanced pigmentation and proline accumulation which subsequently resulted in better plant growth. However, bacterial inoculations did not affect diversity (observed OTUs, ACE, Chao1 and Shannon) and structure (principle coordinate analysis) of microbial communities under salinity stress. Furthermore, relative abundance in microbial communities had no significant difference between bacterial treated- and untreated-soils under salinity stress. CONCLUSION: Inoculation of Bacillus strains could affect plant responses and soil pH of tomato plants under salinity stress, whereas microbial diversity and abundance had no significant difference by the bacterial treatments. These findings demonstrated that Bacillus strains could alleviate plant's salinity damages by regulating pigments, proline, and MDA contents without significant changes of microbial community in tomato plants, and can be used as effective biostimulators against salinity stress for sustainable agriculture.

• Korean Journal of Soil Science and Fertilizer
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• v.42 no.6
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• pp.454-459
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• 2009

In order to identify the effect of soil salinity on saturated hydraulic conductivity in reclaimed paddy soils, we established the soil columns uniformly packed with soils collected at every 20 cm up to 60 cm from the reclaimed paddy area with high and low salinity which has been cultivated rice plants for the last 30 years. The soil textures were sandy loam and loamy sand for high-salinity and low-salinity topsoils, respectively. For high-salinity and low-salinity soils the ECes were ranged from 25.2 to $37.8dS\;m^{-1}$ and 3.0 to $3.4dS\;m^{-1}$ while the ESPs were ranged from 7.70 to 20.84 % and from 5.12 to 11.33 %, respectively. The bulk densities of the soil columns were adjusted to $1.15{\pm}0.03g\;cm^{-3}$. The results of the soil column experiments shows that the stabilized saturated hydraulic conductivity of low-salinity soil was $0.62cm\;hr^{-1}$ at the topsoil while there were little water flow at the bottom of the soil columns packed with high-salinity soils. After removal of $Na^+$ ions with $1N\;NH_4OAc$ from the high-salinity soil, Ksat of the saline soil was drastically increased to $0.23cm\;hr^{-1}$. Soil columns of high-salinity topsoil treated with four different concentration of NaCl influent after removal of soluble and exchangeable cations with $1N\;NH_4OAc$ show Ksat in the range of $0.1{\sim}0.15cm\;hr^{-1}$ and the Ksat slightly decreased as the concentration of NaCl influent was increasing. Conclusively, we could assume that $Na^+$ can be significantly contributed to the saturated hydraulic conductivity in newly reclaimed sandy soil.