• Magazine of the Korean Society of Agricultural Engineers
• /
• v.11 no.4
• /
• pp.1803-1809
• /
• 1969

The newly designed mole drainage plower which is attached to tractor is tested for work capacity comparing with the pulling by man animal and winch. Besides. the effect of desalinization by the mole drainage in reclaimed tideland was observed. The results as obtained in this experiment are as follows: 1. The mole drainage plower of tractor attachment has higher work capacity by 3 to 5 times than that of winch 2. The suitable soil moisture content to carry out the layout of mole drains is from 21 to 25 percent. 3. The new design mole drainage plower requires th lowest cost as comparing with the other methods. 4. Carrying out the mole drainage in reclaimed tideland it is effective in desalinization from 2 to 3 times than the only use of irrigation water. 5. The reasonable depth and interval of mole drains may be 60cm and 3m respectively. 6. The desalinization by the mole drainage increases the yield of rice from 40 to 45 percent in reclaimed tideland.

• Korean Journal of Soil Science and Fertilizer
• /
• v.24 no.1
• /
• pp.35-40
• /
• 1991

A laboratory column experiment was conducted to learn the desalinization effect of rice straw, fresh or predecayed in limed marine soil, compared with gypsum. One third of Ca equivalent to indigenous Na plus Mg of the soil was applied to the top 10g out of 80g of total column soil, mixing one half of it to the top soil and the rest spreading on the surface. 1. Pre-decaying of rice straw in limed marine soil promoted the permeability of column soil. but showed a less effectiveness in desalinization of sodium than lime alone or lime plus fresh rice straw treatemenents. 2. Gypsum and calcium carbonate treatments without rice straw fixed Mg in the limed top soil and washed it down disolving more from the layer immediatly be low the treated top soil But the treatment of calcium carbonate and rice straw both together washed out Mg more from lower layers than the upper's, showing only physical desalinization. 3. The desalinization of Na was also severe in the layer immediately below the $CaSO_4$ treated top soil, leauing more Na ilo the top soil, which seemed to be attributed to the peptisation of the top soil and retard peptisation of desalinization when washed the soil applying not enough amount or non of gypsum.

• Magazine of the Korean Society of Agricultural Engineers
• /
• v.30 no.4
• /
• pp.85-93
• /
• 1988

This laboratory study was carried out in order to produce fundamental data for analyzing salt movement and desalinization effects, using samples of silt loam soil collected in Gyehwado and Daeho reclaimed tidelans, and samples of silty clay loam soil collected in Kimie tideland. Desalinization experiments with gypsum treatment were performed to analyze changes of the hydraulicc conductivity with changes of the soil property and the salt concentration during the desalinization of reclaimed tideland soils by leaching through the subsufface drainage, and correlations between factors infl uencing the reclamation of salt affected soils were analyzed by the statistical method. The results were summarized as follows: 1. The reclaimed tideland soils used in this study were saline-sodic soils with the high exchangeable sodium percentage and the high electrical conductivity. 2. Changes of the hydraulic conductivity with the amount of leaching water and the leaching time elapsed were affected by the amount of gypsum except exchangeable sodium and clay contents. The regression equation between the depth of water leached per unit depth of soil (Dw / Ds : X) or the square root of the leaching time elapsed (T $^1$ $^2$ : X) and the relative hydraulic conductivity (HCr:Y) could be expressed in Y=a . bx. 3. The more exchangeable sodium and clay contents regardless of the amount of gypsum, the more the leaching time was required until a given volume of water was leached through the soil profile. The regression analysis showed that the relationship between the depth of water leached per unit depth of soil(Dw /Ds:X) and the square root of the leaching time elapsed(T$^1$$^2$ :Y) could be described by Y=a . Xb. 4. The hydraulic conductivity was influenced to a major degree by the salt concentration provided that the electrical conductivity was below 10 mmhos / cm during the desalinization of reclaimed tideland soils. The regression equation between the relative electrical conductivity ( ECr : X) and the relative hydraulic conductivity (HCr:Y) could be expressed in Y=a + b . X-$^1$. 5. In conclusion, the hydraulic conductivity, leaching requirements and the leaching time elapsed can be estimated when the salt concentration decreases to a certain level during the desalinization of reclaimed tidelands, and the results may be applied to the analysis of salt movement and desalinization effects.

• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.42 no.1
• /
• pp.112-118
• /
• 1997

This study was conducted to obtain basic information on the desalinization in newly reclaimed tideland. A desalinization experiment with leaching method was carried out using the soil samples collected in Haenam tideland, and the early growth response of winter barley to salt stress during the desalinization was investigated by measuring emergence rate, plant height, leaf area and fresh weight. The soil in Haenam tideland was saline-sodic with 59mS / cm of electrical conductivity and pH 8.0, and the soil texture was silty loam with 16％ clay and 75％ silt. Depth of water for desalinization(DWD) to decrease the electrical conductivity below 4mS /cm was 140mm in 5cm depth soil and 240mm in 20cm depth soil. The value of pH of soil and leaching water increased from 8.0 to 8.3 until the electrical conductivity decreased to about 6mS / cm during the desalinization. .The emergence rate of winter barley was over 75％ in the DWD above 80mm and showed no significant difference with the DWD. The DWD for the normal growth of winter barley seedling was above 120mm at 1 and 2 weeks after sowing(WAS), and above 160mm at 3 and 4 WAS. The leaf area and fresh weight showed no response for salt stress with the DWD above 12mm at 2 WAS, and above 16mm at 3 WAS. It was estimated that the electrical conductivity of soil saturation extract for the normal growth of winter barley during early seedling growth stage in new reclaimed tideland would be below 9mS / cm in 20cm depth soil.

• Magazine of the Korean Society of Agricultural Engineers
• /
• v.34 no.4
• /
• pp.80-96
• /
• 1992

This study was carried out in order to determin optimum irrigation requirements and water management practices for normal growth of dry field crops in reclaimed tidelands, and apply m planning of the irrigation projects. Desalinization experiments were performed by water management practices in the experimental field with high salt concentration, and growth experiments were conducted by irrigation point treatments using tomato and beet with relatively high salt tolerance. The results obtained from this study were summarized as follows : 1. Leaching or rinsing-leaching method was found to be effective in desalinizing the reclaimed tideland with rather high permeability. In this case, the water requirement for desalinizing the root zone layer of 40cm in depth, was estimated to be 1,200mm in depth. 2.The gypsum treatment in the desalinization of reclaimed tidelands, was ineffective in water requirements ; however, it could produce the desired effect in the facility of desalinization and the shortening of desalinization period with the sustaining permeability, in case of the desalinization by leaching method. 3.The optimum irrigation point which maintains the salt concentration within salt tolerance and maximizes the crop yield in reclaimed tidelands of silt loam soil, was found to be pF 1.6 in tomato and pF 1.8 in beet. The interval of irrigation date within 2 days was proved to he effective in both cases. 4.The optimum irrigation requirement and the water reguirement for the prevention of salt rise during the growing period after transplanting, were estimated to be 602mm(6.7mm/day) and 232mm for tomato, respectively. 5.The optimum irrigation requirement and the water requirement for the prevention of salt rise during the growing period after transplanting, were estimated to be 261mm(3.7mm/day) and 66mm for beet, respectively.

• Magazine of the Korean Society of Agricultural Engineers
• /
• v.43 no.5
• /
• pp.63-69
• /
• 2001

The main purpose of this study is to seek desalinization effect of subsurface drainage system with rice hull packing in Dae-Ho Reclaimed Land. After 4 years installed sub-surface drainage system, distribution of drained water electric conductivity (ECw) was 4.43~12.78 ds/m. The soil profile showed partial development of the soil structure and compaction of subsoils with increased bulk density. The bulk density of the subsoil was 1.42~1.66 g/cm$^3$, which might limit root growth. The soil color changed near the drainage pipe line. Distribution of soil extract solution ECe and SAR as subsurface drainage pipe position and drainage canal distance showed desalinization effect of subsurface drainage system with rice hull packing as widening effective zone of subsurface drainage pipe.

• Journal of the Korean Society of Tobacco Science
• /
• v.19 no.1
• /
• pp.24-28
• /
• 1997

The field experiment for field desalinization by precultivation of orchard crops were carried out to evaluate relationship between the varieation of chlorine contents of soil and crop uptake in the upland diverted from paddy field. After harvest of grass crops, soil samples were taken for analysis of chlorine contents of soil layers. Regardless of kinds of grass crops cutivated, contents of soil chlorine were decreased comparing to non-crop plot. Chlorine content in plant harvested at just before the flowering stage was much higher than that of after flowering. Chlorine uptake and dry matter were increased in order of Italian ryegrass, Perennial ryegrass, and Sudan grass. Positive correlations were showed between chlorine uptake and dry matter. The content of soil chlorine decreased by higher yield of dry matter.

• Korean Journal of Soil Science and Fertilizer
• /
• v.21 no.1
• /
• pp.3-10
• /
• 1988

A laboratory study was carried out to investigate the effects of application level of soil amendments, mixing method of soil amendments, and compost treatment on desalinization by examining the changes in hydraulic conductivity and chemical properties of effluent of the soil during desalinization. 1. The treatment of soil amendments brought about the increase in hydraulic conductivity. 2. The higher the application level of a soil amendment, the higher the hydraulic conductivity and the shorter the time elapsed to complete the desalinization. 3. Complete mixing of calcium compounds was more effective for desalinization than surface mixing. 4. The compost treatment induced the rise in pH and therefore brought about the remarkable drop in hydraulic conductivity. 5. During the desalinization, the changes in physical and chemical properties of the soil were influenced by the kind and application level of soil amendments, mixing method of soil amendment, and compost treatment.

• KCID journal
• /
• v.11 no.2
• /
• pp.64-71
• /
• 2004

This study was carried out to obtain the desalinization effect of saline-sodic soils as water pending condition. Three soils with different salinity were collected and packed at 115000a pot. With artificial 1,000 mg/L water made of sea salt, three cases w

• Proceedings of the Korean Society of Agricultural Engineers Conference
• /
• 1999.10c
• /
• pp.162-168
• /
• 1999

This study was performed to analyze dealinization effects on gypsum treatments in reclaimed tidelands and to obtain the basci data for developing prediction techniques f desalinization to be applicable in the begining of tideland reclamation. In this study , the reclamation experiments with 4 treatments were conducted through the leachig method, using the samples of silt soil and silt loam soil collected in 5 units of tideland reclamation projects. The electrical conductivity , exchangeable sodium percentage and hydraulic conductivity were analyzed in order to investigate the effects of desalinizatino for reclaiming the tidelands with high salt concentration.