• Korean Journal of Agricultural Science
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• v.27 no.2
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• pp.141-157
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• 2000

This study is aimed at identifying the socio-economic value of the total area of 23,500ha of paddy field which will be reclaimed in year 2003. In Korea, tidal land reclamation projects has been carried out not only for paddy field expansion to meet national food security but also for national land expansion to cope with the shortage of land supply in implementing urbanization and industrialization. As of end of 1999, 75,738ha of tidal land reclamation, 48.3%, out of 156,666ha has been carried out in Korea. In spite of continuous implementation of tidal land reclamation, 48.3%, out of 156,666ha has been carried out in Korea. In spite of continuous implementation of tidal land reclamation projects, the appraisal of the national land expansion value has not been made even though the severe competitiveness of land use in economic development. Agricultural land about 20,000 - 30,000ha per year has been converted to urban and industrial land and the converted areas have been produced higher added value than that of the farm land. Accordingly, farm land expansion equivalent to the converted area have to be reclaimed to cope with the food shortage and security in the future. In relation to the study, demand and supply of rice, the staple food of Korean, has been projected up to year 2025. The study results are as follows: 1. Under the assumption of continuing the present tendencies of rice consumption, population increase, farming practices and farm land conversion, paddy area requirement to meet self sufficiency of rice were forecasted as 136,950ha in 2015, 193,460ha in 2020 and 218,482ha in 2025 respectively. 2. The average converted price of paddy per pyeong in Kimje city, Puna Gun and Gunsan city was estimated at 241,150won and average farm land price was amounted to 63,760won. The differential rent was estimated at 177,400won per pyeong which was used as a criteria for valuation of national land expansion effect of the tidal land reclaimed by Saemangeum project. The total land rent of 23,250ha expanded by tidal land reclamation was amounted to 12,361 billion won. Annual expected value of the expanded national land was estimated at 988.9 billion won considering 8% of annual discount rate in Korea. 3. Tidal land resource for paddy area development is limited comparing with the future requirement of paddy area to cope with self sufficiency of rice consumption. Accordingly farm land conversion to urban and industrial land should be regulated and protected in the sense of sustainable development in the future.

• KCID journal
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• v.17 no.2
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• pp.105-114
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• 2010

Tidal land reclamation provided water resources and land for agriculture and contributed stable crop production. However, climate change by global warming disrupts the hydrologic circulatory system of the earth resulting in sea level rise and more frequent flood for reclaimed arable land. Recently, Suyu reclaimed paddy field in Jindo-gun experienced prolonged inundation after heavy rainfall and there is a growing risk of flood damage. Onsite survey and flood analysis using GATE_Pro model of Korea Rural Corporation were conducted to investigate causes of flooding. To perform the analysis, input data such as inflow hydrograph, the lowest elevation of paddy field, neap tide level, management level of Gunnae estuary lake at the time of the flood were collected. Flood analysis confirmed that current drainage facilities are not enough to prevent 20year return period flood. The result of analysis showed flooding more than 24hours. Therefore, flood mitigation alternatives such as sluice gate expansion, installation drainage pumping station, refill paddy land, and catch canal were studied. Replacing drainage culvert of Suyu dike to sluice gate and installing drainage pumping station at the Gunne lake were identified as an effective flood control measures. Furthermore, TM/TC (SCADA) system and expert for gate management are required for the better management of drainage for estuary dam and flood mitigation.

• Proceedings of the Korean Society of Agricultural Engineers Conference
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• 2000.10a
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• pp.637-642
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• 2000

In order to control the water quality of freshwater lake in tidal reclaimed land, it is needed to evaluate accurate amount of pollutant loadings from reclaimed paddy field. This study was carried out to investigate the pollutant loading from a reclaimed paddy field. Site of the study was a paddy field located in Taeho reclaimed land, with an areas of 38.5 hectares. The runoff loadings of Total-Nitrogen, Total-Phosphorus, and Chemical Oxygen Demand were 49.5 kg/㏊/yr, 3.2 kg/㏊/yr and 154.0 kg/㏊/yr, respectively. The runoff loadings in Total-Nitrogen and Total-Phosphorus from this study were much higher values than the pollutant load factor of Total-Nitrogen and Total-Phosphorus from the paddy field published by the Ministry of Environment.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.59 no.4
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• pp.526-531
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• 2014

This study was carried out to compare the growth characteristics and feed values of the whole crop silage rice from paddy field and reclaimed paddy field. The heading dates of tested varieties was August 8 to August 30 in the paddy field, 1~2 days later than the reclaimed paddy field's August 6 to August 29. Plant height was in the range of 105~135 cm in paddy field, and 97~126 cm in reclaimed paddy field, respectively. The plant height of Mokyang was tallest in the paddy field, but Suwon 544 was tallest in the reclaimed paddy field. The number of tiller per plant of Nokyang was largest in the paddy field. Dry matter (DM) yield of whole crop rice ranged from 15.26 to $23.24MT\;ha^{-1}$ in the paddy field and 11.94 to $18.89MT\;ha^{-1}$ in the reclaimed paddy field. The highest DM yield in both fields was attained by Mokwoo. Comparing with the paddy field, the reclaimed paddy field achieved 78~84% in the DM yield. The crude protein content of varieties was 8.5 to 11.6% in the reclaimed tidal land and 6.7~8.7% in the paddy field. Neutral detergent fiber (NDF) of varieties in both fields ranged from 31.2 to 55.5%. Suwon 544 recorded the highest NDF contents in both fields. All varieties did not show any significant difference in acidic detergent fiber (ADF) which had values ranging from 22.3 to 33.2%. Total digestion nutrient (TDN) was more than 60% overall in both fields. Regarding TDN yield, Mokwoo recorded $16.54MT\;ha^{-1}$ in reclaimed tidal land and $12.69MT\;ha^{-1}$ in the paddy field, which showed the highest figure among the varieties. These results suggest the feasibility for cultivation of the whole crop silage rice in reclaimed paddy field, which showed 80% of the yield compared to paddy field, and implied that Mokwoo would show the most excellent yield and feed value.

• Journal of the Korean Geographical Society
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• v.45 no.2
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• pp.275-292
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• 2010

This study investigated the land-cover changes in the tidal flat of the Taean peninsula due to man-made environmental changes between 1972 and 2008, through time-series analysis based on a modified post-classification comparison method and multi-temporal satellite images. The analysis revealed that the land-cover of the tidal flat has changed from tidal flat to wetland and from wetland to paddy field between 1972 and 2008. Also, the pattern of detailed land-cover changes is as follows: tidal flat to wetland; lake and saltpan to bare land and paddy field. The accurate classification of each image is needed for the application of the post-classification comparison method. The overall accuracy of the classified images was found to be 95.33% on average, and the Kappa value was 0.941 on average.

• KCID journal
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• v.18 no.1
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• pp.4-17
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• 2011

The standard design methodology was suggested to construct wetland system for reducing non-point source pollution from Saemangeum reclaimed paddy land. To set for the design flow and concentrations, runoff and water quality survey were conducted during the irrigation period in 2008 at Gyehwa reclaimed paddy land located at near Saemangeum lake. It is rational that 1ha is the optimum constructed wetland size. To meet this size, the moderate drainage area of reclaimed paddy field was 50ha under the conditions that rainfall is 30mm, average runoff coefficient is 0.83, and runoff capture ratio is 0.6. At these condition, the runoff volume from 50ha was 10,520 $m^3/d$ including base flow during irrigation period. To select the optimum wetland system, several case studies were conducted by focusing on the tidal reclaimed land areas having wetland systems in Seokmun. Pond-Wetland system was selected as the standard model because of showing the highest reduction efficiency. Single variable regression equation were delivered to estimate effluent water concentrations from the designed wetland by using long-term monitoring data from the Seokmun experiment site. The effluent concentration from the designed wetland using these equation were showed moderately range.

• Korean Journal of Soil Science and Fertilizer
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• v.29 no.3
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• pp.264-269
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• 1996

Four leavels of nitrogen and five split-application method were investigated in the puddled drill seeding of rice in tidal land paddy field of Munpo series in Gyehwado. Soil ammonium concentration increased of higer nitrogen level, and was higher in latex coated urea(LCU) than urea split-application, and stage of $NH_4-N$ was the higher in maximum tillering stage. Rice yield, nitrogen availability and yield increment rate according to nitrogen levels were the highest when nitrogen was applied 200kg/ha and also it were the highest in the LCU application by 30% decreased than urea application as affected by application method. Adequate application amount of nitrogen was estimated 222kg/ha in direct drill seeding of rice in tidal land paddy field.

• Korean Journal of Soil Science and Fertilizer
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• v.40 no.2
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• pp.109-113
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• 2007

In order to establish the fertilization and soil management method in Gyehwa reclaimed tidal land, we investigated soil property and actual farming condition. Soil properties of 100 field paddy soil and farming surveys of 177 farm households were conducted. Average of effective soil depth was 17.8 cm, which was very smaller than the optimum level 50 cm. The hardness and bulk density of subsoil were $12.40kg\;cm^{-2}$ and $1.59g\;cm^{-3}$, respectively. These results showed that soil physical condition of Gyehwa reclaimed tidal land was very poor. Soil salinity ranged from 0.03 to 0.12%, and average of pH was 6.0, which implied that desalinization of Gyehwa reclaimed tidal land was progressed. However, soil nutrients in Gyehwa reclaimed tidal land were very unbalanced conditions as following, available phosphate $58mg\;kg^{-1}$, available silicate $85mg\;kg^{-1}$, cation exchangeable capacity $7.4cmolc\;kg^{-1}$ and organic matter $8.6g\;kg^{-1}$. On the farm household in Gyehwa reclaimed tidal land, fertilization amounts were $200-54-61(N-P_2O_5-K_2O)kg\;ha^{-1}$ They mainly practiced spring tillage(84%) rather than autumn tillage(16%), and only 14% of them applied rice straw annually in the paddy soil.

• Korean Journal of Soil Science and Fertilizer
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• v.51 no.1
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• pp.50-60
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• 2018

This study was to evaluate the effect of organic amendments incorporation on soil properties and plant growth under two different soil salinity levels and various cultivated crops at Saemangeum reclaimed tidal land for three years from 2012 to 2014. The soil texture of the experimental site was sandy loam. Four different crops, sesbania (Sesbania grandiflora), sorghum-sudangrass hybrid (Sorghum bicolor-Sorghum sudanense), rice (Oryza sativa L.) and barley (Hordeum vulgare) were cultivated at low (< $1dS\;m^{-1}$) and high (> $4dS\;m^{-1}$) soil salinity levels. The soil salinity was significantly lowered at the rice cultivation site compared to continuous upland crops cultivation site in high soil salinity level. But the soil salinity was increased as cultivating sesbania coutinuously in low soil salinity level. The soil organic matter content was increased with the incorporation of straw at the continuous site of rice and barley, and the average of soil organic matter was increased by $0.9g\;kg^{-1}$ per year which was effective in soil aggregate formation. The highest biomass yield plot was found in barley (high salinity level) and sesbania (low salinity level) cultivation site, respectively. Our research indicates that rice cultivation in paddy field with high salinity level was effective in lowering soil salinity and sesbania cultivation was useful to biomass production at upland with low salinity. In conclusion, soil salinity and organic matter content should be considered for multiple land use in newly reclaimed tidal land.

• Proceedings of the Korean Society of Agricultural Engineers Conference
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• 2003.10a
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• pp.619-622
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• 2003

The concentrations of nutrients in precipitation increased slightly from May to June and did not change afterwards. Regarding irrigation water, the nutrient concentrations were high in the early stage of rice growth but decreased during the period of mid-June to mid-July. The concentration of Tot-N in runoff water increased significantly during the period of fertilizer application (basal, tillering, and panicle fertilization) and then decreased. The concentrations of Tot-N in runoff water ranged from 0.4 to 39.8mg/L (average of 5.9mg/L). The concentration of Tot-P in runoff water ranged from 0.0004 to 0.2084mg/L (average of 0.055mg/L). The Tot-P concentrations were high only at the early stage of rice growth after fertilizer application and did not change afterwards.