• KOREAN JOURNAL OF CROP SCIENCE
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• v.65 no.3
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• pp.214-221
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• 2020

Salinity is one of the major abiotic stressors that inhibits the growth, yield, and productivity of crop plants. Therefore, it is necessary to develop crops with increased salt tolerance for cultivation in saline soils such as is found in reclaimed land. The objective of this study was to develop a salt-tolerant silage rice line that grows on reclaimed land. In order to develop this salt-tolerant silage rice, we transferred Saltol, a major QTL associated with salt tolerance, from IR64-Saltol, a salt-tolerant indica variety, into Mogyang, a susceptible elite japonica variety. To determine the effect of salt stress, Mogyang and IR64-Saltol cultivars were grown on a medium containing various concentrations of NaCl in in vitro conditions. Shoot length was found to decrease with increasing salt concentrations, and root growth was almost arrested at NaCl concentrations over 50 mM in the Mogyang cultivar. Based on these preliminary results, we screened five salt-tolerant lines showing superior growth under salt stress conditions. Polymerase chain reaction and sequencing results showed that the introgression types of Saltol QTL were derived from the IR64-Saltol cultivar in almost all selected lines. Based on the observed growth and physiological characteristics, the new Saltol introgression lines showed higher salt tolerance compared to the Mogyang parental cultivar. The salt-tolerant lines identified in this study could be used as a genetic resource to improve rice salt tolerance.

• Korean Journal of Weed Science
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• v.32 no.1
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• pp.1-9
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• 2012

This study was conducted to survey vegetation changes and soil characteristics in Saemangeum new reclaimed tidal land. Soil salinity in border area to tidal land was 22.3 dS $m^{-1}$ but showed 1.1~3.44 dS $m^{-1}$ over the distance of 2 km from border line. The vascular plants in survey sites were recorded as total 26 taxa in 6 families. The frequency of species appearance of Aster tripolium, A. subulatus var. sandwicensis were highest by 61.5 and that of Phragmites communis, Puccinellia nipponica were 53.8. The almost vegetations occurred in the patch which range of soil salinity 14 dS $m^{-1}$ were halophytes as Salicornia europaea, Suaeda asparagoides, S. japonica. As lowed soil salinity as 6.7 dS $m^{-1}$, mixed vegetation of halophytes with P. communis, P. nipponica, Carex pumila were occurred. Dominant species in the range of 3.0 dS $m^{-1}$ area were A. subulatus var. sandwicensis, P. communis, Echinochloa spp., Zoysia sinica and Conyza canadensis. Biomass production was the highest in the area of dominant vegetation with P. communis, and mixed zone with P. communis and Aeschynomene indica are followed. The correlation between vegetation biomass and soil salinity, soil pH and dominance index of vegetation were negative. But that of vegetation biomass and soil organic content were positive.

• Journal of Bio-Environment Control
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• v.24 no.4
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• pp.275-280
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• 2015

The objective of this study was to investigate the effect of drip irrigation level on soil salinity and growth of broccoli (Brassica oleracea L. var. italica) at the 'Saemangeum Reclaimed Tidal Land' from April to June, 2015. Drip irrigation was conducted at 1.5, 3.0 and $6.0mm{\cdot}day^{-1}$ level for reduction of resalinization in the plastic vinyl house using 10cm spacing drip irrigation tape. At harvesting stage, the average EC of surface soil was $10.9dS{\cdot}m^{-1}$ for $1.5mm{\cdot}day^{-1}$, $11.5dS{\cdot}m^{-1}$ for $3.0mm{\cdot}day^{-1}$ and $5.1dS{\cdot}m^{-1}$ for $6.0mm{\cdot}day^{-1}$ and was significantly reduced by 52~56% in $6.0mm{\cdot}day^{-1}$ treated plot compared to those in 1.5 and $3.0mm{\cdot}day^{-1}$ plots. The fresh bud weights of 1.5, 3.0 and $6.0mm{\cdot}day^{-1}$ treatment plots were 60.9, 129.1 and $371.3g{\cdot}plant^{-1}$, respectively. The estimated soil EC for 50% yield reduction was $7.6dS{\cdot}m^{-1}$ and the desalinization depth by drip irrigation was 30~40cm in soil profile. The total amount of drip irrigation water was estimated to be 422mm and the daily drip irrigation level was $6.0mm{\cdot}day^{-1}$ for the prevention of resalinization during the broccoli growing period at the 'Saemangeum Reclaimed Tidal Land'. Our results suggested that drip irrigation shows effectiveness on the lowering the soil salinity according to the drip irrigation quantity but it needs more research on this study because dynamics of salts in soil can vary with many factors such as soil physico-chemical properties and seasonal climate.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.60 no.1
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• pp.63-69
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• 2015

This study was conducted to measure the effect of PE film mulching and irrigation methods on the growth, yield and antioxidant activity of potatoes tubers, in order to examine the possibility of cultivating potatoes in winter season in vinyl greenhouse on the reclaimed tidal land with weak ground inside the sea wall currently completed. The test was conducted on the sandy loam soil (Munpo series), and its salt concentration was 0.42% at the time of planting. The emergence speed per kind of PE film mulching was in the order of black > coloration > transparent > green color, with the black color showing the fastest speed. The temperature change during a day per kind of PE film mulching was in the order of transparent > coloration > green > black color. As for the salt concentration in the soil for each different way of water management, the salt concentration in the treatment of drip irrigation with 1 week interval was lower than that drip irrigation with 2 weeks interval. As for the growth of above-aerial part, plant length was higher, number of tiller and leaves were more and dry weight of above-aerial part was larger in the treatment of drip irrigaton with 1 week interval than drip irrigation with 2 weeks interval. As for the yield of potatoes depending on each way of water management, the yield in the treatment of drip irrigation with 1 week interval was more than drip irrigation with 2 weeks interval. The yield for each different kind of PE film mulching in the weekly drip-irrigation management section was in the order of transparent ${\geq}$ black ${\geq}$ coloration ${\geq}$ green color. In both of total phenol content and DPPH free radical activity experiments, the content and activity were higher with pear color vinyl treatment.

• Korean Journal of Soil Science and Fertilizer
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• v.45 no.2
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• pp.135-142
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• 2012

Exchangeable cations are often overestimated especially in salt-affected soils due to the presence of high levels of soluble ions in soil solution. Thus, quantitative analysis of the soil exchangeable cation based on ammonium acetate extraction method {(Exch. Cation)$_{total}$} requires additional process to remove the free ions (pre-washing) in soil with distilled water or alcohol {(Exch. Cation)$_{pw}$} or subtraction of the soluble ion contents from the total exchangeable cations {(Exch. Cation)$_{ref}$}. In this research, we compared the three different methods for the determination of exchangeable cations in soils affected by different types of salt accumulation such as the soils from upland, plastic film house, and reclaimed tidal land. In upland soils, non-saline and non-sodic soils, the regular ammonium acetate extraction method did not have any problem to determine the content of exchangeable cations without any additional process such as the pre-washing method or the subtraction method. However, the contents of exchangeable cations in the salt-affected soils might be determined better with the pre-washing method for the plastic film house soils and with the subtraction method for the reclaimed tidal land soils containing high Na.

• Journal of Environmental Science International
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• v.14 no.9
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• pp.817-825
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• 2005

The purpose of this study was to research about salt marsh flora and vegetation in the Dongjin-river estuary area where has a project for Sea Man Geum Reclaimed Land so that we can foster foundation on restoration of an ecological habitat, development of applicable plant and establishment of a conservation policy after deceloping the reclaimed land for salt marsh vegetation which has great value ecologically. In conclusion, we was distributed that there are 7 families 21 genera, 25 species, 2 varieties of vascular plant at the Dongjin-river estuary area which have 27 taxa in total and are $0.64\%$ among 4,191 of korean vascular plant. There are also 2 family, 2 genus, 2 species of a naturalized plant which are $1.1\%$ of indicator of a naturalized plant salt marsh vegetation of the downstream are very much affected by the time of inundation, tidal water so that a low degree of salt marsh has frequent flooding by sea water and has a pure group of Suaeda japonica. A Phragmites communis, Carex scabrifolia are distributed mainly around a waterway of salt marsh and Zoysia sinica, Atriplex subcordata, Phragmites communis are living in stock as forming into patch around medium salt marsh. Suaeda asparagoides, Phacelurus latifolius are living around a little high ground and a Phragmites communis is a behind vegetation of Phacelurus latifolius and a part of the Phragmites communis are living along with waterway in a salt marsh as a community. By the 2-M method twelve plant communities were recognized ; Suaeda japonica. Carex scabrifolia, Zoysia sinica, Artemisia scoparia, Phacelurus latifolius, Phragmites communis, Suaeda maritima, Suaeda japonica-Atriplex gmelini, Phragmites communis-Suaeda japonica, Suaeda japonica-Salicornia herbacea, Salicornia herbacea-Suaeda aspar-agoides and Scirpus planiculmis community. The actual vegetation map was constructed on the grounds of the communities classified and other data.

• Journal of Wetlands Research
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• v.11 no.3
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• pp.37-47
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• 2009

This research was conducted at the constructed wetland in Goheung reclaimed land, and water quality components were measured at the 12 points in 15 March 2008 and 10 January 2009, respectively. Temperature, pH, DO, EC and salinity components were measured at the field, and TOC, Cl-, COD, TSS, T-P and TN components were analyzed laboratory. Concentrations of field measured components at inflow points were higher than in constructed wetland. TOC concentration ratio of inflow water to constructed wetland water was higher in January, and Cl concentration ratio of it was higher in March. And, COD concentration ratio of it were 1.37 for March and 1.49 for January, respectively. T-P and T-N concentration ratios of it at inflow points were higher 3 times than in constructed wetland. Constructed wetland attenuated concentration of contaminated components inflow to it. Removal efficiencies of Cl-, T-P and T-N components in inflow water were high at the constructed wetland. removal efficiencies of Cl component were 83% for 1st monitoring and 76% for 2nd monitoring, this removal efficiency be caused by dilution effect of constructed wetland. removal efficiencies of T-P component were 67% for 1st monitoring and 69% for 2nd monitoring, and they of T-N component were 100% for 1st monitoring and 95% for 2nd monitoring. Abnormal removal efficiency of T-N component is caused that nitrogen in inflow water was a little. Removal efficiency of T-P component was higher in January, and T-N component was higher in March. This is caused by environmental difference between growing season and winter.

• Korean Journal of Soil Science and Fertilizer
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• v.24 no.1
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• pp.28-34
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• 1991

This study was carried out to investigate the salt movement in upland soils in reclaimed region (Kye-Hwa Do). The results obtained were summarized as follows : 1. The cation content in ground water increased during time course. but in the case of land-surface water the content was variable, and $K^+$ was lower than that of $Na^+$ and $M^{+2}$. At the L. S. P(Low salinity plot) under rainproof condition, the salinity was directly proportional to soil water content, but at the H. S. P (High salinity plot) the tendency was no reversed. 3. In condition of rainproof, the amount of available phosphorous was higher at the H. S. P than at the L. S. P. 4. Positive correlation was obtained between the soil water content and available phosphorous content at the rainfall plot, but there was no significance at the surface soil of the rainproof plot. 5. SAR (Sodium adsorption ratio) and anion ($Cl^-$, $SO_4{^{2-}}$) contents in soil were repressed in the order of black vinyl>white vinyl>rice straw>control.

• Korean Journal of Soil Science and Fertilizer
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• v.15 no.3
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• pp.172-177
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• 1982

This experiment was conducted to evaluate the broadcast and band applications of phosphate fertilizer and the application amounts of fertilizer during the soybean-barley cropping periods from 1976 to 1979 on the Sam-gag sand loam of a newly reclaimed hilly land. 1. The broadcast application was superior to band in view of yields for both soybean and barley. The yield was the highest in the broadcast application with the amount 38 kg $P_2O_5$ per 10a of fused phosphate which was calculated from soil testing at the first crop period and thereafter additional 6 kg at every crop period. 2. According to the quadratic relationship between yield and the available phosphate in soil, the maximum soybean Yield, 322 kg per 10a obtained at 220 ppm of available phosphate under broadcast and 259 kg per 10a at 200ppm under band. 3. By broadcast application of phosphorus, root weight was higher and horizontal root expansion was much better than by band application.

• Korean Journal of Soil Science and Fertilizer
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• v.14 no.4
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• pp.190-194
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• 1982

The differences in soil productivity between the cut site and the fill site in a newly reclaimed land were compared with the experimental results conducted during 1978 to 1980 under soybean-barley and sweet potato-barley cropping systems. The results were summerized as follows; The bulk density of the cut site was near $1.5g/cm^3$ with the hardness above 23mm by Yamanaka method and that of the fill site was $1.3g/cm^3$ with the hardness of 14mm at the first year of reclaiming. The bulk densities and soil hardnesses asymptotically approched to $1.4g/cm^3$ and 19mm, respectively. The chemical productivity of the fill site was also significantly higher than that of the cut site. Differently from the bulk density and hardness, chemical compositions of the fill site maintained high untill the third year of cropping. The yields of soybean, sweet potato and barley from the cut site at the first year were very poor and, thereafter, were remarkably increased by 2 to 9 times at the third year of cropping while those from the fill site maintained high from the first year to the third year of cropping.