• Journal of Soil and Groundwater Environment
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• v.23 no.5
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• pp.37-44
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• 2018

Soil trace elements and their bioaccumulation in agricultural products have attracted widespread concerns, yet the crop uptake characteristics of trace elements in different soil-plants systems have been rarely investigated. Experiments were carried out to investigate the effect of soil properties on trace element concentrations in cabbage and radish. Soil pH and total organic matter were major factors influencing trace elements transfer from soil to vegetables. Inclusion of other soil properties in the stepwise regression analysis improved the regression models for predicting trace element concentrations. Consideration of other soil properties should be taken into account for more precise prediction of trace element concentrations in the two vegetables, which could help quantitatively evaluate the ecologic risk of toxic trace elements accumulation in crops.

• Korean Journal of Soil Science and Fertilizer
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• v.47 no.1
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• pp.23-27
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• 2014

Nutrient accumulation in surface soil has become a serious problem for cucumber production in greenhouse. However, still in many cases, soil management practices are only focused on maintaining crop yield, regardless of sustainability related with soil chemical properties. This study was conducted to propose a sustainable soil management practice by investigating the impact of cover crop species and nitrogen rate of fertigated solution on cucumber yield and soil chemical properties in greenhouse condition. Rye and hairy vetch were tested as a fallow cover crop, and each amount of urea (1/2, 3/4, 1 times of N fertilizer recommendations), determined by soil testing result, was supplied in fertigation plots as an additional nitrogen source. The result showed that the yield of cucumber was higher in rye treatment than control and hairy vetch treatment. In addition, rye effectively reduced EC and accumulated nutrients from the soil. Meanwhile, N concentration of fertigated solution showed no significant effect on the growth and yield of cucumber. Consequently, these results suggest that it is desirable to choose rye as a fallow catch crop for sustainable cucumber production in greenhouse.

• The Korean Journal of Ecology
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• v.21 no.3
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• pp.313-320
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• 1998

Ameliorating effects of dolomite and sludge on the polluted soil sampled from Ulsan and yeocheon Industrial Complexes were investigated. Ameliorating effects were analysed by changes of soil properties and plant growth after treatment of dolomite and sludge. Soil properties were investigated by analysing organic matter, N, P, K, Ca and Mg contents and pH. Growth of sample plants was investigated by leaf area calculated from length and breadth of leaves and by biomass from diameter and height of sample plants. Quercus serrata and Celtis sinensis selected as tolerant plants in field survey were used as experimental plants. Treatment with dolomite showed ameliorating effects by increassing n, Ca, and Mg com\ntents, and pH of soil and by decreasing Al content. Treatment of sludge showed similar effects by increasing N, Ca, Mg and organic matter contents, and by decreasing A1 content. But treatment of sludge did not show any effect on pH. Both soil ameliorators showed accelerating effects on the growth of experimental plants in Ulsan soil. But those effects in Yeocheon soil were somewhat different. Treatment of sludge showed accelerating effects of the growth of both sample plants but dolomitic liming did not so. From those results, we confirmed availability of sludge, a kind of industrial waste, as one of ameliorators of the polluted soil. In addition, we recognized that soil properties had to be considered to select soil ameliorators suitable for restoration of degraded ecosystems.

• Geomechanics and Engineering
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• v.16 no.6
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• pp.627-634
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• 2018

Soil stabilization is an essential engineering process to enhance the geotechnical properties of soils that are not suitable for construction purposes. This study focuses on using coconut coir, a natural fibre to enhance the soil properties. Lime, an activator is added to the reinforced soil to augment its shear strength and durability. An experimental investigation was conducted to demonstrate the effect of coconut coir fibers and lime on the consistency limits, compaction characteristics, unconfined compressive strength, stress-strain behaviour, subgrade strength and durability of the treated soil. The results of the study illustrate that lime stabilization and coir reinforcement improves the unconfined compressive strength, post peak failure strength, controls crack propagation and boosts the tensile strength of the soil. Coir reinforcement provides addition contact surface, improving the soil-fibre interaction and increasing the interlocking between fibre and soil and thereby improve strength. Optimum performance of soil is observed at 1.25% coir fibre inclusion. Coir being a natural product is prone to degradation and to increase the durability of the coir reinforced soil, lime is used. Lime stabilization favourably amends the geotechnical properties of the coir fibre reinforced soil.

• Korean Journal of Organic Agriculture
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• v.21 no.4
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• pp.753-767
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• 2013

Soil contamination has continuously increased worldwide, thus the remediation for the contaminated soils has risen steadily. However, the consideration of ecological safety for the remediated soils and their agricultural uses has been very limited. Therefore, this study was to investigate the influences of selected environmentally-friendly agricultural materials, organic by-product fertilizer (OF), charcoal (CC), and biochar (BC), as soil conditioners for improving poor chemical properties of fuel-oil removed soil by land farming technique. Two different remediated soils, remediated soil A (RSA) and remediated soil B (RSB), were selected. Soil texture of both RSA and RSB was sandy loam. The chemical properties of RSA and RSB were as follows: soil pHs of 8.5 and 8.7, soil organic matter contents of 7.4 and 5.5g $kg^{-1}$, total nitrogen contents of 0.26 and 0.10g $kg^{-1}$, available phosphorus concentrations of 7.2 and 4.4mg $kg^{-1}$, and exchangeable calcium concentrations of 14.8 and $11.7cmol_c$ $kg^{-1}$, respectively. Results of the properties were not reached for the optimal values for cultivating crops that were recommended by National Academy of Agricultural Science at Rural Development Administration in Korea. However, after applying OF, CC, and BC, the chemical properties of soils were selectively improved, which were that soil organic matter content and available phosphorus concentration increased, whereas the soil pH were not changed. In particular, the chemical properties were positively changed more with the application of 5.0% biochar. Thus, continuous management of the remediated soils with applying the eco-friendly agricultural materials can improve the quality of reme-diated soils.

• Korean Journal of Soil Science and Fertilizer
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• v.46 no.6
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• pp.542-548
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• 2013

Soil properties and yields of liriopis platyphylla were investigated to establish soil suitability of Korean liriopis platyphylla at 116 farms in Korea. Morphological and physical properties of the soils were investigated along with the average yield of 2~3 years. The impact factors of soil properties to the yield of liriopis platyphylla were selected based on standard error of each factor. The yields of liriopis platyphylla showed the greatest values when the morphology was alluvial plains, when the drainage was well or moderately well, when the slope was 0-2%, the texture was coarse loamy, when the gravel content was less than 15% and when the available soil depth was more than 100 cm. Contribution factors of soil properties to the yields were 0.15 by morphology, 0.15 by drainage level, 0.13 by slope, 0.18 by texture, 0.16 by gravel content and 0.23 by available soil depth, respectively. Soil suitability classes were set as follows; the best suitable land if score was greater than 92, suitable land if score ranged from 91 to 86, the possible land if the score ranged from 85 to 83, and low productive land if score was less than 82. According to the criteria, 17.8% of the production area was the best suitable land, 43.1% was suitable land, 17.3% was possible land, and 21.8% was low productive land. The sum of both the best and suitable lands were 60.9% of the farm area of Miryang in Gyeongsangnam-do.

• Journal of Biosystems Engineering
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• v.33 no.4
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• pp.260-268
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• 2008

Optical diffuse reflectance sensing has potential for rapid and reliable on-site estimation of soil properties. For good results, proper calibration to measured soil properties is required. One issue is whether it is necessary to develop calibrations using samples from the specific area or areas (e.g., field, soil series) in which the sensor will be applied, or whether a general "factory" calibration is sufficient. A further question is if specific calibration is required, how many sample points are needed. In this study, these issues were addressed using data from 42 paddy fields representing 14 distinct soil series accounting for 74% of the total Korean paddy field area. Partial least squares (PLS) regression was used to develop calibrations between soil properties and reflectance spectra. Model evaluation was based on coefficient of determination ($R^2$) root mean square error of prediction (RMSEP), and RPD, the ratio of standard deviation to RMSEP. When sample data from a soil series were included in the calibration stage (full information calibration), RPD values of prediction models were increased by 0.03 to 3.32, compared with results from calibration models not including data from the test soil series (calibration without site-specific information). Higher $R^2$ values were also obtained in most cases. Including some samples from the test soil series (hybrid calibration) generally increased RPD rapidly up to a certain number of sample points. A large portion of the potential improvement could be obtained by adding about 8 to 22 points, depending on the soil properties to be estimated, where the numbers were 10 to 18 for pH, 18-22 for EC, and 8 to 22 for total C. These results provide guidance on sampling and calibration requirements for NIR soil property estimation.

• Korean Journal of Soil Science and Fertilizer
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• v.47 no.5
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• pp.340-344
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• 2014

Compost and gypsum can be used to ameliorate soil physicochemical properties in reclaimed tidal lands as an organic and inorganic amendment, respectively. To evaluate effects of compost and gypsum on soil water movement and retention as a soil physical property, we measured the soil's saturated hydraulic conductivity and field capacity after treating the soil collected in a reclaimed tidal land with compost and gypsum. Saturated hydraulic conductivity of soil increased when compost was applied at the conventional application rate of $30Mg\;ha^{-1}$. However, the further application of compost insignificantly (P > 0.05) increased saturated hydraulic conductivity. On the other hand, additional gypsum application significantly increased soil saturated hydraulic conductivity while it decreased soil field capacity, implying the possible effect of gypsum on flocculating soil colloidal particles. The results in this study suggested that compost and gypsum can be used to improve hydrological properties of reclaimed tidal lands through increasing soil water retention and movement, respectively.

• Magazine of the Korean Society of Agricultural Engineers
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• v.44 no.4
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• pp.123-128
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• 2002

This study was performed to use fiber mixed soil which has clayey soil or sandy soil with fibrillated fiber or monofilament fiber on purpose of construction materials, filling materials, and back filling materials. In addition, this study was conducted to analyze strength properties and fiber reinforcing effect with fiber mixed soil by direct-shear test. In case of fibrillated fiber mixed soil, the more quantity of fiber was in both cohesive soil and sandy soil, the larger shear stress was in respective step of normal load. The respective mixed soil at 0.5% and 0.1% mixing ratio of monofilament fiber mixed soil showed maximum shear stress. According to unconfined compression or direct-shear test, making specimen of the monofilament fiber mixed soil, it is required to be careful and stable mixing method, while it is expected that monofilament fiber mixed soil doesn't increase strength.

• Proceedings of the KSR Conference
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• 2011.05a
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• pp.1214-1221
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• 2011

It is an well-known fact that dynamic properties should be considered in design and maintenance of civil structures undergoing dynamic force such as rail track. For designing of the rail tack structures, dynamic properties of track bed soil such as shear modulus (G) and damping coefficients(D) obtained in small to medium range of shear strain must be known. In general, small size sample of D=5 cm and H=10cm has been used mostly for test convenience. However, ratio of largest particle diameter of the soil to sample diameter is very important and affects to the values of dynamic soil properties in track bed. In this study, an RC/TS test apparatus was built and was run for testing a medium size soil sample that can handle with compacted soil sample up to 10 cm diameter and 20 cm height.