• Geomechanics and Engineering
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• v.10 no.6
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• pp.727-736
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• 2016

Excessive rainfall can cause runoff flows over the soil surface and as a consequence some amount of water will infiltrate into the soil. From a hydrologic modeling perspective it is necessary to estimate infiltration rate in order to calculate the actual runoff discharge. There are many parameters that can affect the infiltration rate such as soil texture, moisture and compaction. However, the most common equations used in hydrological calculations for estimating the infiltration rate do not consider the soil properties directly and estimate infiltration rate without any soil properties expressions. The purpose of this research was to investigate the relations between infiltration rate and soil texture, moisture and compaction. To achieve this purpose an experimental study was performed to show the effect of soil properties and their relations on infiltration rate by using non-linear regression.

• Journal of Forest and Environmental Science
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• v.37 no.1
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• pp.25-34
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• 2021

This study was conducted at Sitakunda coastal afforestation range, comprised of four beats- Bansbaria, Bakkhali, Baterkhil and Bogachattar, in Chittagong. Afforestation effects on soil physicochemical properties in comparison to adjacent barren land were analysed. In the study area, an area of 3277.33 ha was planted with Sonneratia apetala, Avecinnia officinalis, Excoecaria agallocha, Bruguiera sexangula, Ceriops decandra from 1968 to 2011. We found positive soil physicochemical changes in plantations in comparison to adjacent barren land. Soil bulk density of plantation was lower than the adjacent barren land. Soil pH and soil salinity were significantly higher in barren land whereas soil organic matter, organic carbon, nitrogen, phosphorus, potassium of plantations were higher in afforested land. Soil texture ranged from clay loam to sandy loam in different depth of these two types of land. However, this study concludes that there is clear evidence that afforestation has positive impacts on all soil properties in different location and soil depths in the study area.

• Journal of Industrial Technology
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• v.18
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• pp.77-86
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• 1998

This study is to provide the useful data for the design and construction of the geotechnical engineering works by collecting and analyzing the soil properties of granite soil in the Kangwon Province. Data base was obtained from 92 field sites in the Kangwon province divided into 15 areas based on administration district. Total numbers of data were 478. Correlations between soil constants, especially compaction properties, were obtained by performing statistical analysis. Analyzed results were as follows. 1. Most of granite soil consists of SM and GM based on United Soil Classification System. 2. Mean gravity of granite soil is 2.65 3. High correlations between optimum moisture content and the maximum dry density, plasticity index and liquid limit are obtained. 4. Analyzed results between other soil constants show relatively low correlation. However, they show consistent trends matchable to geotechnical engineering senses.

• Korean Journal of Environmental Agriculture
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• v.29 no.4
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• pp.354-361
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• 2010

Soil physico-chemical properties and microbial densities are affected by organic sources and soil amendment applied to improve soil environments or quality. Generally organic fertilizer effects on forage crops yield and soil properties are partly due to changes of soil composition. We investigated the effects of swine slurry (SS), swine slurry composting-biofilteration(SCB) and chemical fertilizer(F) with gypsum(G) combinations on soil physico-chemical properties and yields of summer forage crop in the Sukmoon reclaimed tidal land in Korea. The forage crops used in this experiment were corn and sorghum$\times$sudangrass hybrid(hereafter sorghum). Our results showed that the soil physico-chemical properties in the combined (F+G, SS+G, SCB+G) treatments increased contents of organic matter and exchangeable $Ca^{2+}$, but exchangeable $Na^+$, $K^+$ and $Mg^{2+}$ reduced to 1-10% for two forage crops, compared to non-combined (F, SS, SCB) treatment. The density of soil microorganism such as bacteria, actinomycetes and fungi, increased significantly by SS+G and SCB+G treatments. This means that treatment of combined organic fertilizer with G lowered salinity levels and improved with microbial growth. The combined treatments also increased the total yields 2.3-6.2% for corn and 2.0-8.7% for sorghum, compared with non-combined treatment. This experiment suggests the combined treatments could increase the total yields of summer forage crops and change of soil physico-chemical properties in the Sukmoon reclaimed tidal land in Korea.

• Journal of the Society of Naval Architects of Korea
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• v.55 no.5
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• pp.438-447
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• 2018

For a fixed jacket type offshore structure directly supported by the seabed, the structural behavior of offshore structure depends on the soil properties. Soil properties affect on the stiffness of the piles and the boundary condition in the structural analysis. The structural analysis is performed using PSI (Pile-Soil Interaction) suggested in the code and design rule. PSI analysis of the jacket structure is carried out after various soil types are selected according to the soil properties like internal friction angle, undrained shear strength, unit weight and so on. Three types of soil are selected by varying strength for a clay and sand, respectively. The structural analysis of the jacket structure is performed using these soils. The results about axial and lateral reaction force and the stress and displacement on the structure are compared. As a results, the structural response is smaller as the soil becomes more stiff. In conclusion, it is confirmed that the structural response of fixed jacket type offshore platform supported by seabed is sensitive to the change of soil properties.

• Korean Journal of Environmental Agriculture
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• v.38 no.3
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• pp.213-218
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• 2019

BACKGROUND: Monitoring of the dynamic changes of chemical properties in agricultural land is very important for agricultural sustainability. Chemical properties of agricultural soils in Korea have been investigated at four-year interval in the order of paddy, plastic film house, upland, and orchard soils since 1999. METHODS AND RESULTS: Total 8,160 topsoil samples were taken from the upland in 2001, 2005, 2009, 2013, and 2017, respectively. Soil chemical properties such as pH, electrical conductivity (EC), organic matter (OM), available phosphate (Avail. $P_2O_5$), and exchangeable (Exch.) cations (K, Ca, and Mg) were analyzed. Soil pH and Exch. Ca contents have increased since 2001. Average concentration of Avail. $P_2O_5$ increased from $547mg\;kg^{-1}$ in 2001 to $657mg\;kg^{-1}$ in 2017. Average concentration of Exch. Ca in 2017 was higher than the upper limit of its optimal range for upland cultivation. Excess and deficiency of chemical properties of upland soils comply with soil analysis and fertilizer prescription. CONCLUSION: We concluded that excessive nutrient in upland needed to be properly managed with soil test.

• Korean Journal of Soil Science and Fertilizer
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• v.46 no.5
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• pp.333-342
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• 2013

Soil compaction is affected by soil texture, organic matter (OM), strength (ST) and soil moisture, which is difficult to understand the degree and effects of related factors. The purpose of the study is to assess the impact of them on the compaction with bulk density (BD). The analysis was conducted with data collected from national-wide monitoring sites including 105 upland soils, 246 orchard soils, and 408 paddy soils between 2009 and 2012. The distributions of soil physical properties were measured. The correlation and multi linear regression analysis were performed between soil physical properties using SAS. The regression equation of BD(y) includes ST, gravitational water contents (GWC), and OM as variables commonly, having additional factors, clay content and sand content in paddy soil and upland soil for only subsoil (p<0.001). Our results show that the BD could be explained about 40~50% by various physical properties. The regression was mainly determined by ST in orchard and upland soil and by the GWC in paddy soil. To mitigate soil compaction, it is important to maintain the proper level of OM in upland soil and to consider the moisture condition with soil texture in paddy soil when making work plan. Furthermore, it would be recommended the management criteria classified by soil texture for the paddy soils.

• Journal of the Korean Institute of Landscape Architecture
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• v.33 no.2 s.109
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• pp.60-70
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• 2005

This study was carried out to elucidate the vertical characteristics of soil properties at six planted sites of land reclaimed from the sea, in Gwangyang Bay, Jeollanam-do Province, Korea. Based on the types of planting site, the chemical properties of the vertical soil layers varied. The vertical variation was great in the planting sites $Z_1\;and\;Z_2$, but less varied in the mounded planting sites $Z_3,\;Z_5,\;and\;Z_6$. Major reasons for the vertical variation in soil chemical properties included differences in the accumulation of organic matter, soil disturbance by heavy construction equipment, and heterogeneity of soil properties between soil horizons. As soil depths increased, soil salts varied. The electrical conductivity (ECe) increased in the lower areas of planting sites $Z_1\;and\;Z_2$, and the disturbed, saline planting site $Z_3$, but decreased in the lower areas of $Z_3,\;Z_5,\;and\;Z_6$. These tendencies did not coincided with exchange cation concentrations $(Na^+,\;K^+,\;Mg^{++},\;Ca^{++})$. Both total carbon (T-C) and total nitrogen (T-N) accumulated more in the lower areas of planting sites than in the higher areas, and levels were higher closer to the surface than in the soil depths. It is supposed that these tendencies are related to the accumulation of fallen leaves or other organic matter at the soil surface, and the soil chemicals then slowly move downward from the surface. Impediments to tree growth included soil hardiness, high soil salinity and exchangeable cation concentration, low soil moisture content, acidic or alkaline soil, low organic matter, heterogeneity of soil texture and establishment of soil stratification.

• Korean Journal of Soil Science and Fertilizer
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• v.48 no.5
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• pp.522-527
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• 2015

Decision of available soil depth based on soil physical and hydraulic properties for the $3^{rd}$ Landscape Vegetation Project in the Incheon International Airport was attempted. The soil samples were collected from the 8 sites at different depths, 0-20 and 20-60cm, for the three project fields, A, B, and C area. Physical and chemical properties including particle size distribution, organic matter content and electrical conductivity were analyzed. Hydrological properties including bulk density and water holding capacity at different water potential, -6 kPa, -10 kPa, -33 kPa, and -1500 kPa were calculated by SPAW model of Saxton and Rawls (2006), and air entry value was calculated by Campbell model (1985). Based on physical and hydrological limitation, feasibility and design criteria of soil depth for vegetation and landfill were recommended. Since the soil salinity of the soil in area A area was $19.18dS\;m^{-1}$ in top soil and $22.27dS\;m^{-1}$ in deep soil, respectively, landscape vegetation without amendment would not be possible on this area. Available soil depth required for vegetation was 2.51 m that would secure root zone water holding capacity, capillary fringe, and porosity. Available soil depth required for landscape vegetation of the B area soil was 1.51 m including capillary fringe 0.14 m and available depth for 10% porosity 1.35 m. The soils in this area were feasible for landscape vegetation. The soil in area C was feasible for bottom fill purpose only due to low water holding capacity.

• Korean Journal of Soil Science and Fertilizer
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• v.36 no.6
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• pp.367-375
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• 2003

The aim of this study was to investigate the soil physical properties and the traction characteristics of paddy field before tillage by a computer simulation. Soil physical properties, such as soil moisture content, bulk density, soil hardness, and soil texture were measured in the twelve rice production area. Mathematical model based on dimensional analysis which include soil physical properties and vehicle factors was used for the computer simulation. Most of the soil texture of the investigated area was silty loam, loam and silty clay loam. Soil moisture content ranged between 20 and 40% mostly. Soil bulk density was in the range of 1,500 to $1,700kg\;m^{-3}$. Soil hardness ranged between 2 to $12kg\;cm^{-2}$ mostly. Soil hardness incorporates the effects of many soil physical properties such as moisture content, texture and bulk density, and so the range of soil hardness was greater than that of any other physical properties. The predicted net traction was in the range of 70 to 1,500 kgf depending on the area, but it was above 1,000 kgf for most of the investigated area. Thus it was concluded that 50 HP tractor can pull the four row moldboard plow considering the conventional tillage depth and width. But for the soft soil area such as Andong and Namyang, tractor itself may have mobility problem and show high slip during plowing operation.