• Korean Journal of Soil Science and Fertilizer
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• v.14 no.2
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• pp.70-75
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• 1981

The ammonia volatilization from two different soils, an acidic normal soil and a neutral tidal soil applied with different nitrogen sources was investigated through a laboratory incubation experiment conducted at about $30^{\circ}C$ for 18 days. Results obtained were summerized as follows; 1. The ammonia volatilizat ion was increased by the urea application that increased soil pH. 2. Ammonium sulfate and ammonium chloride did not raise reduced soil pH over 7.30 and showed little ammonia volatilization keeping the $pK_b$ value of 4.72-3 3. An organic fertilizer (Miweon Co. made) raised pH of the tidal land soil little more than ammonium sulfate or ammonium chloride ; however, it did not increase the ammonia volatilization as much as from other fertilizer treatment plots of the same pH, which may mean that the organic fertilizer is effective in reducing ammonia volatilization. 4. It seemed that easier volatilization of ammonia from urea may occor in ordinary soil low in original pH than from tidal soil by the application of urea which may mean that if the pH of soils are the same, greater volatilization would result from the former than the latter. 5. Application of raw straw to tidal soil lowed pH and reduced ammonia volatilization.

• Korean Journal of Soil Science and Fertilizer
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• v.31 no.2
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• pp.120-127
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• 1998

This study was performed to produce basic data for developing prediction techniques of desalinization through analyzing soil properties of reclaimed tidal lands, using soil samples collected in 11 units of tidal land reclamation projects. The average apparent specific gravity (bulk density), real specific gravity (particle density), porosity, and saturation percentage were measured to be 1.33, 2.64, 49.6%, and 56.3%, respectively. It was estimated that the soil texture class of reclaimed tidal lands would be silt or silt loam. The electrical conductivity and exchangeable sodium percentage were estimated to be $20{\sim}40dS\;m^{-1}$ and 30~50% in the beginning of tidal land reclamation, and the value of pH was measured to be 6.5~7.9. In conclusion, the soil properties of reclaimed tidal lands could be descrived to be saline-sodic soils with the high electrical conductivity and exchangeable sodium percentage.

• Korean Journal of Soil Science and Fertilizer
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• v.42 no.3
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• pp.201-206
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• 2009

It is generally accepted that organic materials are a significant factor on the soil aggregation formation but little information exists on how the formation and stabilization of aggregates in reclaimed tidelands. In this work, the effects of organic materials on the soil aggregate formation in reclaimed tidelands were determined. The soil was treated with 5 cm-size chopped fresh italian ryegrass residues (fresh organic material), commercial livestock compost with swine manure and sawdust (by product fertilizer), and fresh organic material + by product fertilizer (1 : 1 w/w) after ploughing at 20 cm soil depth. The three organic materials applied $2,000kg\;10a^{-1}$ every year. Water stable aggregate was estimated by wet-sieving method. Three years after the beginning of the experiment, water stable aggregate rate and MWD (mean weight diameter) were higher fresh organic material treatment than two other treatments. For improvement of physical property and structure of soil in reclaimed tidelands, fresh organic material treatment was more suitable than two other treatments.

• Korean Journal of Soil Science and Fertilizer
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• v.42 no.6
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• pp.492-499
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• 2009

Effect of drip irrigation on soil salinity control and growth of vegetable crops was studied in the three reclaimed lands of Korea in 2007. Drip irrigation was done one or two times per month for reduction of salt stress by using vinyl hose with tiny holes laid on ridge surface under black plastic film mulch during growing season of cabbage and chinese cabbage. It was observed that drip irrigation was generally effective to soil salinity control, but soil salinity variation of some place was not fully solved to lower down under level of free salt stress. It is also considered that high salinity of runoff water spilled out from cultivation ridge plays another key role for soil salinity management. Consequentially, this soil salinity variation might be one of factors brought low average yield and low commercial ratio of agricultural products. Relation between soil salinity and head growth of cabbage and chinese cabbage was well expressed as logarithmic function. Surface soil EC to reach at 50% of growth reduction to the heaviest head can be estimated was $6.1dS^{\circ}{\S}m^{-1}$ for cabbage and $5.7dS\;m^{-1}$ for chinese cabbage transplanted at optimum season.

• Proceedings of the Plant Resources Society of Korea Conference
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• 2003.04a
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• pp.79-82
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• 2003

대부분의 신 간척지 논은 점토 함량이 적은 반면 미사 함량이 많고 토양 콜로이드의 분산제 역할을 하는 Na함량이 높기 때문에 이러한 토양은 입단화가 저해되고 투수성이 불량해 진다. 이러한 투수와 더불어 다량의 SiO$_2$, F$_2$, MR, MgO 등이 하층으로 용출되어 투수성과 통기성을 저하시키고 간척지 토양의 토양 물리화학적 불량에 의한 저수확답의 원인의 되어 벼의 재배가 어렵고 생산성이 낮아 경제성을 기대하기 어렵다. (김, 1992 : 고건, 1988 ;단야, 1983 ; 전중등, 1974). 따라서 본 실험에서는 토양의 염분농도차이가 토양화학성과 수량에 미치는 영향을 검토하여 간척지 토양의 경제성을 높이는데 기초자료로 활용코자 시험한 결과는 다음과 같다. 1. 출수기는 0.1%의 염분농도 토양은 8월15일, 0.4%의 염분농도 토양은 8월 20일, 0.8%의 염분 농도 토양은 8월 25일로서 0.1%의 염분농도 토양이 가장 빨랐다. 2. 쌀수량은 토양의 염분농도가 0.1%로 낮은 토양이 599kg/10a로 가장 많았고, 다음으로는 0,4%의 염분농도 토양이 568kg/10a이었고 0.8%의 염분농도 토양은 446kg/10a로 가장 낮았으며 쌀수량 구성요소 역시 같은 경향으로 0.1%의 염분농도 토양에서 가장 우수하였고 다음으로는 0.4%, 0.8%순으로 나타났었다. 3. 쌀수량과 토양의 이화학적 특성간의 상관에서는 pH와는 부의 상관, 유기물, 인산, 질소, 가리, 칼슘, 마그네슘의 함량간에는 정의상관이있다. 4. 전남광양만 간척지에서 쌀수량과 수량 구성요소면에서 볼때에 적합한 토양의 염분농도는 0.1%이라고 사료된다.

• Applied Biological Chemistry
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• v.44 no.3
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• pp.206-207
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• 2001

• Korean Journal of Soil Science and Fertilizer
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• v.42 no.6
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• pp.447-453
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• 2009

Vegetation distribution and soil salinity were surveyed on the conservation plot in the Daeho reclaimed tidal land, in where the plants species distribution was more various than a periodically inundated tidal flat and the early stage of reclamation. According to the soil salinity where the vegetation patches were occurred, the mono patches of Salicornia europaea, Suaeda maritima, and Suaeda glauca were distributed in the average range of 31.05 dS/m in soil salinity, the mixed patches of them were distributed in the average range of 42.75 dS/m. Therefore, Salicornia europaea, Suaeda maritima, and Suaeda glauca showed strong salt tolerance. The mono patches of Aster tripolium, Sonchus brachyotus, and Scirpus planiculm were distributed in the range of 11.73 dS/m in soil salinity, and the mixed patches were distributed in the average range of 9.43 dS/m. Therefore Aster tripolium, Sonchus brachyotus, and Scirpus planiculmis showed moderate salt tolerance. The mono patches of Imperata cylindrica, Trifolium pratense, Miscanthus sinensis, Setaria viridis, and Trisetum bifidum were distributed in the range of 2.42 dS/m in soil salinity. These species showed characteristics of glycophytes with weak salt tolerance. The distribution of vegetation patches was influenced by the soil salinity as pioneer halophytes patches occurred at higher soil salinity zone than facultative halophytes patches, glycophytes patches occurred at lower soil salinity zone than facultative halophytes. These results suggested that occurrence of plant species and plant distribution type might be useful index to evaluate the soil salinity and desalinization in the reclaimed land of the midwest coastal area of Korea.

• Korean Journal of Soil Science and Fertilizer
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• v.45 no.6
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• pp.1222-1229
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• 2012

The total area of a reclaimed tidal soil distributed on the south-west coast is approximately 156,600 ha, and the soil contains high contents of sand and silt as well as highly saline. Most of the reclaimed tidal soils are used as a paddy due to bad permeability and high groundwater table, resulting in easy accumulation of salts on the soil surface by capillary rise. Therefore, resalinization may occur because of rise of groundwater table after desalinization. The researches related to the reclaimed tidal soil mainly focused on desalinazation while most of the researches completed were limited to yields of crop based on desalinazation. pH of old reclaimed tidal soil is neutral or less than 7 while that of newly developed reclaimed tidal soils is greater than 7, that cause N-fertilizer to be volatile as ammonia. Thus, the physical and chemical properties should be investigated to be used as an arable upland instead of a paddy soil due to change in government policy. We need to develop measures to make soils grow crops normally by identifying problems related to reclaimed tidal soils.

• Korean Journal of Plant Resources
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• v.16 no.3
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• pp.181-186
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• 2003

In order to evaluate the effect of salinity content in soil on chemical composition and productivity of rice which is suitable for the reclaimed saline paddy field, yield components and yield were investigated in 2,000 at reclaimed paddy field of Kwangyang bay in Korea. Heading date was early with Aug. 15 in soft salinification of 0.1 percent and late with from Aug. 20 to Aug. 25 in heavy salinification of 0.4 and 0.8 percent. Brown rice yield was highest in soft saliniflcation of 0.1 percent with 599kg/10a and was decreased with from 568kg/10a to 446kg/10a in heavy salinification of 0.4 and 0.8 percent. The correlation coefficient between brown rice yield and content of soil chemical composition, on organic matter, phosphate, nitrogen, potassium, calcium, and magnesium showed highly positive correlation and was shown negative correlation with pH meter. Judging from the results reported above, optimum salinification of saline paddy field seemed to be 0.1 percent.

• Korean Journal of Soil Science and Fertilizer
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• v.43 no.5
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• pp.529-539
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• 2010

In order to evaluate the effect of soil salinity and culturing conditions including compost application and vinyl mulching on the maintenance of ridge and the growth of upland crops, three crops such as corn, soybean and sweet potato were experimented by using three or four cultivars of crops in the Saemangeum reclaimed tidal land. Average soil salinity before seeding was 2 dS $m^{-1}$, which was low enough for general upland crops to grow. However, high soil EC more than 16 dS $m^{-1}$ was observed in some parts of the experimented field. In the experiment, it was concluded that growth retardation and yield reduction of summer upland crops might be from severe erosion of ridge, soil compaction, flooding or wet soil condition and high salinity of some parts, and then these deteriorations were possibly improved for good crop growth and yield increase by compost application and vinyl mulching cultivation in the Saemangeum reclaimed tidal land.