• Korean Journal of Medicinal Crop Science
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• v.2 no.3
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• pp.193-197
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• 1994

Bupleurum falcatum was cultivated in plots of different soil textures, which were sandy loam(SL), loam(L), and clay loam(CL). The growth charafters of shoot and root parts in SL and L plots were better than CL one, and root yield was the most excellent in SL one. But the contents of total saikosaponins and methanol extract in its roots were the highest in CL plot. In any soil textures, one and two year old plants showed almost the same results in growth characters and saikosaponins contents. The growth and root yield of two year old plants were higher than those of one year old ones, but the contents of methanol extract and saikosaponins were lower. Flant characters were highly negative-correlated with the contents of saikosaponins and methanol extract.

• Korean Journal of Medicinal Crop Science
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• v.8 no.2
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• pp.89-93
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• 2000

This experiment was conducted to investigate the effects of soil texture on agronomic characteristics and tuber yield in chinese yam (Dioscorea opposita Thunb). Tuber length and weight was greater and tuber shape was much better in sandy loam and loam soil than in sandy or clay loam soil. In loam and sandy loam soil, fresh tuber yield was increased by $21{\sim}27%$ in short-tuber type and 6% in long-tuber type, and large tubers yield (above 260g) was increased by $45{\sim}55%$ in short-tuber type and $20{\sim}22%$ in long-tuber type compared to those in sandy soil. There was no differences in large tuber yield at the 5% level of significance between loam and sandy loam soil. Malformation of tuber with bifurcation was extremely increased in sandy soil, and tuber diameter of long-tuber type was decreased in clay loam soil compared to those of the other soil texture.

• Korean Journal of Soil Science and Fertilizer
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• v.17 no.4
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• pp.319-324
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• 1984

Spatial variability of sand, silt, and clay contents on Hwadong SiCL and Jungdong SL was studied by using geostatistical concept. The measurements were made within a $33{\times}14m^2$ area at the nodes of 2 by 2m grids. The validity of all assumptions (stationarity, variogram models, etc.) was proved by Jack-knifing procedure and frequency distribution performed on the original data grids. The variogram of sand content on Hwadong SiCL was different from the linear model and that of clay content of Jungdong SL the linear and the spherical model in calculation of both kriged values and kriged variances in identification of its choice for simplicity.

• Korean Journal of Soil Science and Fertilizer
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• v.13 no.1
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• pp.1-6
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• 1980

The infiltration rates of the upland soils on hill side slope were investigated in situ using rainulator of which rainfall intensity was 100mm/hr. The soil moisture profile after the water infiltration was compared with that calculated from Youngs' equation. The results obtained are as follows: 1. Time required for infiltration rate to reach constant during rainfall was 15 to 25 min. The infiltration rate measured after 30 min was considered to be final infiltration rate. 2. The final infiltration rates of clay soils were lower than 10mm/hr., loamy soils 10 to 20., coarse loamy soils 20 to 30, and sandy soils higher than 30mm/hr., respectively. 3. The saturated hydraulic conductivity of the surface soil of Samgag sandy loam was 0.47mm/min., Songjeong clay loam0.16 mm/min., and Jeonnam silty clay loam 0.14mn/min., respectively. 4. The soil moisture profile calculated from Young's equation was in close agreement with measured in situ.

• Korean Journal of Environmental Agriculture
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• v.18 no.1
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• pp.1-5
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• 1999

This study was conducted to investigate methane emission among rice ecotypes in paddy soil (Jeonbug series). The varieties of rice involved early maturing short-grain variety, Samcheonbyeo, middle maturing variety, Hawsungbyeo and late maturing variety, Dongjinbyeo. The seasonal change of methane flux was high from ear formation stage to heading stage. It was found that the methane flux was tended to be lower in early maturing variety than in the mid-to-late maturing variety. The plots without rice straw reduced methane emission as much as 46% relative to rice straw application. The methane emission rate through rice stem was highly correlated with temperature fluctuation. Methane emission on ecotypes by rice straw application was 0.394 g $m^{-2}day^{-1}$ in early maturing variety (Samcheonbyeo), 0.407 g $m^{-2}day^{-1}$ in mid maturing variety(Hawsungbyeo), 0.411 g $m^{-2}day^{-1}$ in late maturing variety(Dongjinbyeo).

• Korean Journal of Soil Science and Fertilizer
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• v.43 no.2
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• pp.194-199
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• 2010

Compost as a soil amendment is of importance in enhancing the soil chemical and microbial qualities; however, soil microbial community can vary depending on the composition, and the amount of compost applied to plant in the soil. Responses of soil microbial properties to compost applications with 0, 30, and 60 Mg $ha^{-1}$ were investigated in silt loam soils where red pepper(Capsicum annuum L.) was mainly cultivated in Yeongyang, Gyeongbuk, Korea. The analysis of phospholipid fatty acids (PLFAs) extracted from soil showed that compost amounts significantly increased PLFAs representing as bacteria, fungi, and VAM-fungi as well as the ratio of fungi/bacteria, and monounsaturated/saturated PLFAs. Increasing the amount of compost significantly increased Gram-/Gram+ PLFAs' ratio, but significantly decreased monounsaturated/saturated PLFAs' ratio. Therefore, this result shows that compost would vary to a limited extent the microbial community in red pepper field. However, increase in compost application would change the subgroup structure of microbial community only.

• Economic and Environmental Geology
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• v.31 no.4
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• pp.291-296
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• 1998

Pedogenic hematite is a well known agent for sink of pollutants and nutrients and for aggregation of particles in soils. Changes in physical and chemical properties of two sandy loam soils (Anahuac and Crowley soils) from the Southern Coastal Plain, the United States of America, were tested after adding finely ground crystalline hematite prepared for drilling fluid weighting material. There was an increase in hydraulic conductivity (HC) of the soils with addition of up to 3% by weight of hematite but a decrease in HC with addition of more hematite. The aggregate stability (AS) of the soils was not affected by adding hematite. Anahuac soil with higher content of organic matter and lower sodium adsorption ratio (SAR) had higher values of HC and AS than Crowley soil. Adding hematite also resulted in a slight increase in zinc (Zn) adsorption by the soils, but had no influence on the adsorption of phosphate.

• Analytical Science and Technology
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• v.12 no.1
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• pp.53-60
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• 1999

Dissolution properties for the 6 inorganic pollutants (As, Cd, Cu, Pb, Zn, Cr) in soils have been studied. These 6 inorganic pollutants were spiked to 3 kinds of fresh soils which were sand, clay, and loam. The dissolution properties of the prepared samples were investigated under the various extracting conditions such as extracting time, acid concentration, particle size, etc. in order to obtain basic information about the process of extraction test and improvement of related analytical methods. As the results, dissolution properties were affected mainly by acid concentration in extracting procedure and mineral composition of soils. On the other hand, extracting time, sort of acids and particle size of soils had a little influence on the dissolution properties. Cd revealed very high dissolving efficiency and As was very low in whole extracting test.

• Current Research on Agriculture and Life Sciences
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• v.23
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• pp.53-60
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• 2005

This study was carried out in order to produce useful material for the forest multiple use and forest protection management by soil physio-chemical analysis of studied area in Mt. Namsan. The result of soil physio-chemical analysis and statical analysis represented as following. In side of physical properties of forest soil in Mt. Namsan, Soil depth was average 31.4cm and available soil depth was average 20.0cm. Soil type was Brown forest soil that representative soil type in Korea. Soil texture was sandy loom(SL) except valley area. In side of chemical properties, the range of soil acidity was 4.29 ~ 5.19 (average 4.76), organic matter content was 3.17% that compared the lowest value to organic matter content of Korea forest soil. Available phosphorus was 3.64ppm that was lower than others forest soil. Exchangeable cation content was similar to the Korea brown forest soil. Cation exchange capacity(CEC) was $8.22cmol_c/kg$ in Mt. Narnsan.

• Asian Journal of Turfgrass Science
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• v.25 no.1
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• pp.69-72
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• 2011

Soil aggregate is a vigorous procedure including soil physical, chemical, and biological processes. Pore space created by binding these particles together improves retention and exchange of air and water. Various researches have reported that the benefits of organic polymers that may increase aggregate stability. The purpose of the study was to determine if a liquid organic polymer mixture has any influence on perennial ryegrass quality or soil aggregation. $Turf2Max^{(R)}$ was applied to two soils as a source of liquid organic polymer. Fine-loamy soil from local Iowa topsoil with 4.0% organic matter was screened and dried. Commercial baseball infield clay, $QuickDry^{(R)}$, was used as the second soil There were three rates of liquid organic polymer (0, 2, and 4%). there was no visual improvement in turf grass color, quality, or growth by using organic polymer. It is possible that aggregate stability increases with use of organic polymer. The aggregate stability study needs to be repeated in the greenhouse and then substantiated under field conditions for these preliminary observations.