• KOREAN JOURNAL OF CROP SCIENCE
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• v.48 no.3
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• pp.238-242
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• 2003

Reclaimed tidal areas for rice cultivation are irrigated with salt mixed water when there is severe drought. Therefore, we identified the critical concentration of saline water for rice growth on a reclaimed saline soil in Korea. The experiment was conducted at the Kyehwado substation of the National Honam Agricultural Experiment Station (NHAES) during 2001-2002. Two experimental fields with 0.1-0.2% for low soil salinity and 0.3-0.4% for medium soil salinity levels were used. The experiment involved four levels of salt solution mixed with sea water (at 0.1, 0.3, 0.5, 0.7%) compared with a control using tap water in a split-plot design with three replicates. Saline solution was applied only two times at seedling stage (10 DAT and 25 DAT) for 5 days. Gyehwabyeo and dongjinbyeo, japonica rice varieties, were used in this experiment. Plant height and number of tillers sharply decreased in the 0.5% saline water in low soil salinity level and 0.1% in medium soil salinity level. For yield components, panicle number per unit area and percentage of ripened grain dramatically decreased in the 0.5% saline water in low soil salinity and 0.1% in medium soil salinity level. But 1,000-grain weight of brown rice decreased sharply in the 0.5% saline water in low soil salinity and 0.3% in medium soil salinity, indicating that this component was not much affected unlike other yield components. Milled rice yield decreased significantly with saline water level in both low and medium soil salinity. In the 0.7% low saline soil, the yield index was only 36% compared with the control. In medium soil salinity, even the control plot showed only 62% yield index compared with the control in the low soil salinity treatment. Results indicated that the critical concentration of saline water for rice growth in terms of economical income of rice production was 0.5% in low soil salinity and tap water in medium soil salinity.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.52 no.2
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• pp.204-207
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• 2007

This study was conducted to suggest proper water management practices after and before broadcasting of rice seed on flooded paddy surface at reclaimed saline soil with two different saline levels in Gyehwado Substation of Honam Agricultural Research Institute (HARI) NICS, RDA for two years from 2004 to 2005. The stable seedling stand in low saline soil of 0.1% salinity was obtained by one time of water exchange after soil rotary Whereas in medium saline soilof 0.3% salinity, three times of water exchange was required for the stable seedling stand. Milled rice yield was not affected by frequency of water exchange in low saline soil, while it decreased sharply in one and two times of water exchange compared with three times of water exchange in medium saline soil. Irrigation water immediately after direct seeding increased the number of seeding stand in low saline soil. With the increase in the interval of water exchange after direct seeding, the milled rice yield decreased. Although the continuous water flowing showed the most number of seedling stand and was increased milled rice yield compared with the others interval of water exchange in medium saline soil, the number of seedling stand and milled rice wasn't significantly different up to exchange of two days interval compared with the continuous water flowing.

• Journal of Environmental Science International
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• v.17 no.2
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• pp.141-148
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• 2008

In order to investigate the effect of inflow of Yangze river on the distribution of chlorophyll-${\alpha}$, the results of serial oceanographic observation during 2000-2005 were used. The oceanographic conditions in the northern East China Sea is influenced by the Tsushima Warm Current and low saline water derived from the Yangze river. The distributions of these water masses vary significantly by the season in the northern East China Sea. The sea surface temperature and salinity were stable and concentrations of chlorophyll-${\alpha}$ were low in the eastern part of $126^{\circ}E$. On the contrary, the salinity was significantly influenced by the low saline water derived from Yangze river with the high concentrations of chlorophyll-${\alpha}$. It is suggested that the low saline water inflowed from the Yangze river affects high concentrations of chlorophyll-${\alpha}$ in the northern East China Sea in summer.

• Journal of the Korean Society of Marine Environment & Safety
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• v.18 no.5
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• pp.379-387
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• 2012

In order to see the oceanographic conditions, the observations of aquaculture farm of ascidian in Youngdeuk, the east coast of Korea were conducted through 6 times-23 February, 6 April, 8 June, 19 August, 6 October and 20 December-in 2010. Surveys were conducted in 20 stations bimonthly using SBE 19 CTD instrument. The mixed layer depth (MLD) was deep in winter and shallow in summer. The cold water below $5^{\circ}C$ in temperature was occupied below thermocline through all season. The temperature was high in the southeastern area. The salinity was increased from the coast to the open sea. The halocline was distinct at 20 m depth in August and at 40 m depth in October. The lowest value of salinity was appeared at the depth of 10 m in October. In addition the value of precipitation minus evaporation denoted negative in October. These low saline water seemed to inflow to the coast from the open sea. Therefore the low saline water moved to the east coast of Korea. The EKWC may play an important role to convey the low saline water. It may affect the aquaculture farm along the coast as the mass mortality of ascidian. It needs to clarify the role and pathway of EKWC to transfer the low saline water along the east coast of Korea.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.3 no.2
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• pp.72-80
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• 1991

This study presents the behavior of unsteady saline wedge in which it is examined velocity profile variations at the lower layer (inner wedge) and wedge tip responses to a tidal action in a rectangular open channel. Unsteady saline wedge has just tidal excursions corresponding to tidal amplitudes at the river mouth, although two wedge tips in flood and ebb tide remarkably have different shapes. Maximum velocities at the lower layer appear immediately from high water to low water level (or low to high water). Numerical computation results obtained by only just interfacial friction factor at the steady state show satisfactory agreements with experimental data. However, the numerical model on one-demensional two-layer flor still has some problems to date.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.13 no.1
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• pp.27-41
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• 2008

Distribution characteristics of phytoplankton community were investigated by HPLC and flow cytometry in Jeju Strait and the Northern East China Sea (NECS) in May 2004, in order to understand the relationship between physical environmental factors and distribution pattern of phytoplankton communities. Based on temperature and salinity data, three distinct water masses were identified; warm and saline Tsushima Warm Current (TWC), which is flowing from northwest of Jeju Island, warm and low saline water at the center of Jeju Strait, which is originated from China Coastal Water (CCW) and relatively cold and high saline water originated from Yellow Sea at the bottom of the Jeju Strait. At Jeju Strait, less saline water (<33 psu) of 15 km width occupied surface layer up to 20 m which located at 20 km offshore and strong thermal front between warm and saline water and cold and less saline water was found in the middle of the Jeju Strait. Vertical transect of temperature and salinity at the NECS also showed that low saline (<33 psu) water occupied the upper 20 m layer and cold and saline water was present at the eastern part. Chl a was measured as $0.06{\sim}3.07\;{\mu}g/L$. Spring bloom of phytoplankton was recognized by the high concentrations of Chl a at the low saline water masses influenced by the CCW and subsurface chlorophyll maximum layer appeared between $20{\sim}30\;m$ depth, which was at thermocline depth or below. Abundances of Synechococcus and picoeukaryote were $0.2{\sim}9.5{\times}10^4\;cells/mL$ and $0.43{\sim}4.3{\times}10^4\;cells/mL$, respectively. Dinoflagellate, diatom and prymnesiophyte were major groups and minor groups were chlorophyte+prasinophyte, chrysophyte, cryptophyte and cyanophyte. Especially high abundance of dinoflagellate was identified by high concentration (>1\;{\mu}g/L$) of peridinin at the bottom of the thermocline, which showed an outbreak of red tide by high density of dinoflagellates. Abundances of picoeukaryote in Jeju Strait were about $5{\sim}10$ times higher than abundance measured in Kuroshio water and showed a good correlation with Chl b (Pras+Viola), which implies the most of population of picoeukaryote was composed of prasinophytes. Prochlorococcus was not detected at all, which suggests that Kuroshio Current did not directly influenced on the study area. Based on the strong negative correlations between biomass of phytoplankton (Chl a) and temperature+salinity, the primary production and biomass of phytoplankton in the study area were controlled by the nutrients supply from CCW.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.35 no.4
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• pp.362-369
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• 1990

In order to determine the mechanism of saline stress, forage plants were irrigated with sea water. Saline stress was investigated on photosynthesis, root respiration, evapotranspiration and visual symptoms. All crops showed increased relative evapotranspiration and relative photosynthesis under low temperature (11-16$^{\circ}C$) rather than high temperature (22-24$^{\circ}C$). The correlation coefficients calculated for each crop between relative evapotranspiration and root respiration were 0.996$\^$**/ for orchard grass, 0.828$\^$*/ for alfalfa and 0.963$\^$**/ for white clover. No significant correlation coefficient between relative evapotranspiration and root repiration was found for the tall fescue. The effects of OED spray on the evapotranspiration and root respiration of crops in the sea watered pots were low compared with those in the fresh watered pots. When OED was sprayed and zeolite was used, the evapotranspiration and root respiration were low compared with check pots and sand pots. The root damage due to sea water treatment was characterized by brown colored root cortex in orchard grass and tall fescue, and water penetration of root cortex in alfalfa and white clover.

• Journal of Environmental Science International
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• v.14 no.2
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• pp.167-175
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• 2005

Based on the observation on 20, 23 and 26 July 2004, the distributions of temperature, salinity and stratification was investigated in relation to ebb, turn of tide and flood. The results are as follows: I) The high temperature and low saline water with $23.5\~24.0^{\circ}C\;and\;32.4\~33.0psu$ existed at Naro Island. 2) The cold surface water below $21.0^{\circ}C\;and\;33.0\~33.4psu$ appeared in the area near Gae Island and Geumo Island. 3) The cold and saline water, below $24.0^{\circ}C$ at the surface and $17.0^{\circ}C$ near the bottom, $32.8\~33.8psu$ at the surface and $33.8\~34.0psu$ near the bottom, existed in Sori Island. These waters were more saline compared to the South Sea Coastal Water with about 31.8psu. This suggests that the oceanic saline water intruded into the Bottol Bada through the area near Sori Island. The stratification appeared during all the observation periods due to a high solar radiation of $22MJ/m^2$, and a weak wind speed of 2.9m/s on the average while the mean speed of wind in July is around 3.9 m/s. It qualitatively suggested that the stratification was maintained during the observation periods because of a high solar radiation, a weak wind speed and intrusion of saline oceanic water.

• Journal of Electrochemical Science and Technology
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• v.14 no.3
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• pp.205-214
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• 2023

Soil salinity is becoming one of the most devastating environmental hazards over the years. Soil investigation involves fast, low cost and non disturbing methods to measure soil characteristics for both construction projects as well as for agricultural use. The electrical resistivity of saline soils is greatly governed by salt concentration and the presence of moisture in soil matrix. Experimental results of this investigation highlight that there is a significant relationship between the electrical resistivity of soil samples mixed with chloride solutions (NaCl, KCl, and MgCl₂) at various concentrations, and soil physical properties. Correlations represented by quadratic functions were obtained between electrical resistivity and soil characteristics, namely, water content, degree of saturation and salt concentration. This research reveals that the obtained correlations between electrical resistivity, salt concentration, water content and degree of saturation are effective for predicting the characteristics of salt affected soils in practice, which constitute a governing element in the assessment of saline lands sustaining infrastructure.

• Asian-Australasian Journal of Animal Sciences
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• v.18 no.2
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• pp.296-300
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• 2005

Human-induced soil salinity is becoming a major threat to agriculture across the world. This salinisation occurs in both irrigated and rain-fed agricultural zones with the highest proportions in the arid and semi-arid environments. Livestock can play an important role in the management and rehabilitation of this land. There are a range of plants that grow in saline soils and these have been used as animal feed. In many situations, animal production has been poor as a result of low edible biomass production, low nutritive value, depressed appetite, or a reduction in efficiency of energy use. Feeding systems are proposed that maximise the feeding value of plants growing on saline land and integrate their use with other feed resources available within mixed livestock and crop farming systems. Salt-tolerant pastures, particularly the chenopod shrubs, have moderate digestible energy and high crude protein. For this reason they represent a good supplement for poor quality pastures and crop residues. The use of salt-tolerant pasture systems not only provides feed for livestock but also may act as a bio-drain to lower saline water tables and improve the soil for growth of alternative less salt tolerant plants. In the longer term there are opportunities to identify and select more appropriate plants and animals for saline agriculture.