• Korean Journal of Soil Science and Fertilizer
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• v.47 no.2
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• pp.120-126
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• 2014

An accurate analysis of nutrient balance in different cropping systems is necessary for improving soil fertilities, causing higher crop yields and quality. This study was carried out to investigate the nutrient balance, changes in soil properties, and their effects on crop yield in long-term field cultivation under mono- and rotation-cropping systems (MCS and RCS, respectively). The analytical results of the soil properties showed that the application of mineral fertilizers alone in the MCS leads the reduction of soil CEC, exchangeable Ca, and microbial biomass C and N. Compared with the MCS of soybean, the RCS of soybean and barley significantly improved the soil properties, which increased crop yield. It might be due to the barley residue added to the RCS soil. Mean nutrient balances for 4 years were -55.9 kg N, +34.7 kg $P_2O_5$, and -0.3 kg $K_2O$ $ha^{-1}$ for the MCS and +19.7 kg N, +107.4 kg $P_2O_5$, and -48.6 kg $K_2O$ $ha^{-1}$ for the RCS, respectively. These nutrient imbalances mean that conventional fertilizer recommendations were inadequate for maintaining soil nutrient balance. From these results, we can conclude that the crop rotation may change comprehensive physical, chemical, and biological soil properties. These changes could affect the nutrient balance and then the crop yield.

• Journal of Biosystems Engineering
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• v.36 no.1
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• pp.33-39
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• 2011

An optical sensing approach based on diffuse reflectance has shown potential for rapid and reliable on-site estimation of soil properties. Important sensing ranges and the resulting regression models useful for soil property estimation have been reported. In this study, a similar approach was applied to investigate the potential of reflectance sensing in estimating soil properties for Korean paddy fields. Soil cores up to a 65-cm depth were collected from 42 paddy fields representing 14 distinct soil series that account for 74% of the total Korean paddy field area. These were analyzed in the laboratory for several important physical and chemical properties. Using air-dried, sieved soil samples, reflectance data were obtained from 350 to 2500 nm on a 3 nm sampling interval with a laboratory spectrometer. Calibrations were developed using partial least squares (PLS) regression, and wavelength bands important for estimating the measured soil properties were identified. PLS regression provided good estimations of Mg ($R^2$ = 0.80), Ca ($R^2$ = 0.77), and total C ($R^2$ = 0.92); fair estimations of pH, EC, $P_2O_5$, K, Na, sand, silt, and clay ($R^2$ = 0.59 to 0.72); and poor estimation of total N. Many wavelengths selected for estimation of the soil properties were identical or similar for multiple soil properties. More important wavelengths were selected in the visible-short NIR range (350-1000 nm) and the long NIR range (1800-2500 nm) than in the intermediate NIR range (1000-1800 nm). These results will be useful for design and application of in-situ close range sensors for paddy field soil properties.

• Proceedings of the Korean Geotechical Society Conference
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• 2010.09a
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• pp.1122-1129
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• 2010

Various soil tests were performed in the laboratory after soil samples were obtained from natural terrains distributed on the granitic rocks where are located in Mt. Bukhan, Mt. Surak and Mt. Gwanak around Seoul. Through the comparison of soil properties in each mountain, the difference of soil properties in a similar geological condition was investigated. According to the result of soil test, the soils were generally classified into calyey and silty sands with a well grade. Soil densities are ranged from $2.62kg/cm^3$ to $2.67kg/cm^3$, and water contents of soils are ranged from 3.77% to 31.12%. These values are not sorted locally. The wet unit weights of soils are ranged from $1.092kg/cm^3$ to $1.814kg/cm^3$. It has a big difference between the average values because that of Mt. Bukhan is $1.604kg/cm^3$ and those of Mt. Surak and Mt. Gwanak are $1.500kg/cm^3$ and $1.331kg/cm^3$, respectively. The internal friction angles are ranged from $31^{\circ}$ to $39^{\circ}$ and the cohesions are ranged from 1.57kPa to 8.63kPa. The shear strengths are too high and similar in all regions. The coefficients of permeability are ranged from $3.07{\times}10^{-3}cm/sec$ to $4.61{\times}10^{-2}cm/sec$. So, these soils are evaluated as a middle to high permeable ground. On average, the value of Mt. Bukhan is $1.47{\times}10^{-2}cm/sec$ and the values of Mt. Surak and Mt. Kwanak are $1.29{\times}10^{-2}cm/sec$ and $1.66{\times}10^{-2}cm/sec$, respectively.

• Journal of the Korean Institute of Landscape Architecture
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• v.31 no.6
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• pp.85-94
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• 2004

This study was carried out to analyze physicochemical properties according to the soil height and to the six types of sites that were used as planting ground in the reclaimed land from the sea, Gwangyang Bay. The physicochemical properties of the soil types were tested by t-test(p<0.01, 0.05), at each of the 6 planting ground sites(p<0.01, 0.05), and at each height(p<0.01) of the planting grounds. These areas were tested by ANOVA and were significantly different. Improved soil was better than reclaimed soil from the sea for Zelkova growth because the improved soil contained lower amounts of pH, ECe, N $a^{+}$, $Ca^{++}$, $Mg^{++}$ SAR. Due to freedom from variables such as salt content in the underground as well as the physical and chemical disturbance of the soil, favorable planting ground for tree growth was recorded at the higher grounds than at the lower ones. Soil detriment to the tree growth in the studied sites included elements such as soil hardness, and the distribution of sodium in the tree root systems. The planting grounds for the favorable growth of landscape trees were determined in the following order: the grounds of mounding> the coved ground of improved soil, and the filled ground of improved soil.l.l.l.

• Journal of The Korean Society of Grassland and Forage Science
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• v.20 no.2
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• pp.139-146
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• 2000

A trial was carried out to investigate the effect of fermented saw-dust pig manure (FSP) and N fertilizer application on physical, chemical properties and microbial population of soil on Cheju brown volcanic ash pasture during the period from September, 1997 to January, 1999. Average soil N contents during 3 different periods, August and October, 1998, and January, 1999 were 0.39, 0.41 and 0.39% for fertilizer N level 0, 150 and 300kg/ha, respectively. Soil N contents determined in January, 1999, was significantly increased by an increase of fertilizer N. Nitrogen contents in the soil applied with 0, 3, 6 and 12 tons 1 ha of FSP were 0.43, 0.40, 0.38 and 0.38%, respectively, showing decreasing tendency of soil with increasing levels of FSP application. Soil N contents determined in August, 1998 and January, 1999, were significantly decreased by increasing levels of FSP application. Organic matter contents of the soil applied with N 0, 150 and 300 kg/ha was 8.04, 8.37, and 9.08%. Soil organic matters determined on the 1st and 2nd period trended to increase with increasing level of fertilizer N. FSP application significantly decreased organic matter contents of pasture soil, (9.14, 8.79, 8.28 and 7.78% OM in soil applied with FSP 0, 3, 6 and 12 tonlha of FSP), respectively. Soil OM determined in October, 1998, also showed a significant decrease with increasing level of FSP. Soil pH, available phosphorus, exchangeable K, Ca, Mg and Na in soil studied were not influenced by fertilizer N or FSP application during all three periods. N application tended to increase soil bacteria count, ($27.0\;{\times}\;10^4\;cfu/g,\;29.4\;{\times}\;1-^4\;cfu/g$ and $53.6\;10^4\;cfu/g$ in the soil applied with 0, 150 and 300 kg N/ha, respectively). The number of colonies of soil bacteria and fungi determined in June and October, 1998 was not increased remarkably by FSP application, but the number of colonies of bacteria determined in March, 1998 showed a significant increase with increasing level of FSP application. In conclusion, N contents and OM of soil increased with increasing level of N application, but decreased with increasing level of FSP application.

• Magazine of the Korean Society of Agricultural Engineers
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• v.35 no.3
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• pp.36-46
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• 1993

The purposes of this study are to develop three-layered Green-Ampt infiltration model considering temporal variation of physical properties of soil and to evaluate the model with field experiment on bare-tilled and soybean-growing soil plots under natural rainfalls. Infiltration tests were conducted on a sandy loam soil. The model has three-layered soil profile including a surface crust, a tilled layer, a subsoil and considers temporal variation of porosity, hydraulic conductivity, capillary pressure head on a tilled layer by natural rainfalls and canopy density variation of crop. Field measurement of porosity, average hydraulic conductivity and average capillary presure head on a tilled layer were conducted by soil sampler and air-entry permeameter at regular intervals-after tillage. It was found that temporal variation of porosity and average hydraulic conductivity might be expressed as a function of cumulative rainfall energy and average capillary pressure head might be expressed as a function of porosity of a tilled soil. The model was calibrated by an optimization technique, Hooke and Jeeves method using hourly surface runoff data. With the calibrated parameters, the model was verified satisfactorily.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.10 no.2
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• pp.61-70
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• 2007

This study aims to clarify the effect of forest management practices(thinning and pruning) on soil physical properties and water quality to get the fundamental information on the facility of purifying water quality after forestry practices. Rainfall, throughfall, stemflow, soil and stream water were sampled at the study site which consists of Pinus rigida in Jinju National University Experimental Forest for 4 years from Mar. 1, 2002 to Nov. 30, 2006. Averaged tree height of the management site increased by 1.6m, compared to the value of the non-management site in Pinus rigida. Increment of averaged D. B. H. at the management site showed 4.2cm more in Pinus rigida compared with that at non-management sites. Mesopore ratios (pF2.7) and total porosities of A layer soil at the management site increased more than those at the non-management sites in both stands. Otherwise, soil bulk density resulted in being reversely. Water qualities of throughfall, stemflow and buffered soil water were influenced more positively by the management practice. The average electrical conductivity of stream water was $32.9{\mu}S/cm$ within the range of non-polluted stream water.

• Korean Journal of Soil Science and Fertilizer
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• v.20 no.3
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• pp.205-208
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• 1987

This study was conducted to find out the optimum ranges of soil physical properties for red pepper growth by characterizing the relationship of soil physical properties and plant growth. Various environmental factors and soil physico-chemical properties and red pepper growth were investigated at 94 farmers fields in red pepper-growing area. Soil texture of the red pepper fields were mainly coarse loamy covering 72% of surveyed fields. Available soil depth, plowing layer and root zone were deeper, but bulk density and hardness of soils were lower in the area where red pepper grew well. The optimum ranges of soil three phases were identified as the solid phase below 50%, liquid phase above 10% and sir phase above 20%. The various soil physical properties were closely related with plant growth of red pepper which were highly influenced in order of available depth>bulk density>plowing layer>hardness>slope.

• 한국환경농학회:학술대회논문집
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• 2011.07a
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• pp.177-187
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• 2011

This study was conducted to determine some physical and chemical properties of the soil and their relationship to spectroscopic-based (visible range) analytical methods while evaluating soil organic matter fractions and soil quality in degraded and non-degraded soils in a wide range of environments. Soil samples were collected from the different landscape positions of cultivated and noncultivated soils, and the latter from the same landscape positions but with different vegetation, at Songco, Lantapan, Bukidnon. The physical and chemical properties of the soils were determined at the SPAL, CMU, Musuan, Bukidnon while the metagenomic properties were determined at the Laboratory of the University of Missourri, Missourri, USA. Bulk density and air dry soil strength values of the soils from the cultivated areas were generally higher than those of the uncultivated areas. Also, soils at the summit generally had lower bulk density and soil strength values than the other landscape positions. Moreover, soils planted to camote (Ipomoea batatas) had higher bulk density and soil strength values compared to soils grown to pepper under the trees. Exchangeable calcium (Ca), magnesium (Mg), and potassium (K) and cation exchange capacity (CEC) of the soils were generally higher in uncultivated areas than those of the cultivated areas. A similar trend was observed for the potassium permanganate ($KMnO_4$)-oxidizable organic C contents determined by spectroscopic method and the total C contents determined by the Walkley-Black method. The $KMnO_4$-oxidizable organic C contents determined by spectroscopic method and the total C contents determined by the Walkley-Black method were closely related ($r=0.631^{**}$). Hence, the former method shows promise in assessing soil quality as it is a rapid test, relatively low cost and can be distributed as a field kit either with a portable spectrometer or with a color chart.

• Conservation Science in Museum
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• v.25
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• pp.35-50
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• 2021

This study analyzed the basic properties of soil material gathered around Maegok-dong in Gwangju, Gyeonggi-do Province (hereafter, "Maegok soil") and the physicochemical changes in the Maegok soil resulting from the addition of other clay materials in order to present scientific information about the properties of clay available for pottery production. Gravel, coarse sand, and fine sand account for 73% of the total mass of the Maegok soil. Therefore, it required refinement through sifting in order to serve in pottery clay. After sifting, the amount of silt and clay in the soil increased to 95% of the total mass. However, since it lacked plasticity and viscosity, buncheong soil was added. When it was mixed with bungcheong soil at a ratio of 7:3, Maegok soil improved as pottery clay as its viscosity increased, demonstrating compositional properties appropriate for ceramic clay even after firing. Further, its water-absorption rate was decreased to 0.40. This means that soil gathered from anywhere can be used for pottery-making by refining its original properties and through mixture with clay with specific components which help the pottery maintain its shape even after firing.