• Korean Journal of Soil Science and Fertilizer
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• v.42 no.6
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• pp.472-477
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• 2009

This study was conducted to reclassify Bugog series based on the second edition of Soil Taxonomy : A Basic System of Soil Classification for Making and Interpreting Soil Surveys. Morphological properties of typifying pedon of Bugog series were investigated and physico-chemical properties were analyzed according to Soil Survey Laboratory Methods Manual. The typifying pedon of Bugog series has strong brown (7.5YR 4/6) loam Ap horizon (0~22 cm), brown (7.5YR 4/4) clay loam BAt horizon (22~41 cm), strong brown (7.5YR 4/6) silty clay loam Bt1 horizon (41~59 cm), strong brown (7.5YR 4/6) silty clay loam Bt2 horizon (59~78 cm), brown (7.5YR 4/4) silty clay loam Btx1 horizon(78~90 cm), and brown (7.5YR 4/4) Btx2 horizon(90~160 cm). That occurs on swale foot slope in area of mainly granite gneiss, granite, and schist rock materials. The typifying pedon has an argillic horizon from a depth of 22 to more than 160 cm and a base saturation (sum of cations) of less than 35% at 75 cm below the upper boundary of the fragipan. That can be classified as Ultisol, not as Alfisol. The pedon has udic soil moisture regime, and can be classified as Udult. That has a fragipan with an upper boundary within 100 cm of the mineral soil surface, and keys out as Fragiudult. Also that meets the requirements of Typic Fragiudult. That has 18% to 35% clay at the particle-size control section, and has mesic soil temperature regime. Bugog series can be classified as fine silty, mixed, mesic family of Typic Fragiudults, not as fine loamy, mixed, mesic family of Typic Fragiudalfs.

• Korean Journal of Soil Science and Fertilizer
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• v.43 no.3
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• pp.315-321
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• 2010

Greenhouse soil cultivated with excessive compost and chemical fertilizer has been an issue to deteriorate soil and water quality in the environment. The objective of this study was to evaluate the nutrient outflow by desalting method, flooding soil surface, after vegetable cropping in greenhouse soils. Field experiment from July to September 2008, was conducted to quantify greenhouse locations, i.e. alluvial plain and local valley. The changes of desalinization in both locations were higher as the amounts of irrigated and drained water were increased. Particularly, the ratio of desalinization in alluvial plain was much higher (66.7%) than the one in local valley (45.6%). However, $NH_4$-N contents of local valley soil during the flooding were higher than in those of alluvial plain. This was caused by high total nitrogen and organic matter in local valley soil than those in alluvial plain soil. With comparing to the input and output loads of T-N and T-P in greenhouses with local valley and alluvial plain soils, the output loads of nutrients were larger than the input loads of nutrients. This result showed that the flooding soil surface can be a good treatment to desalinize greenhouse soils. However, this conclusion remained that the flooding water containing high N and P concentrations might cause the secondary effect on the quality of streams and groundwater since excessive nutrient concentrations can be the main cause of eutrophication problem in aquatic environment.

• Korean Journal of Soil Science and Fertilizer
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• v.45 no.3
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• pp.444-450
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• 2012

The physical and chemical properties of soil in the Mangyeong and Dongjin river basin had been investigated in order to establish the most optimum soil improvement plan on the reclaimed land. The total soil area by reclamation in Saemangeum basin is 113,971 ha. The classification by the distribution of soil series and soil texture is as following. 13 soil series including Chonnam, Buyong and Chonbuk series are period-unknown areas. Regarding the soil texture, they are fine silty ~ clayey very fine. From 1920s to 1960s, Mangyeong, Gwanghwal and Chonbuk series had coarse silty textured soil. After the 1970s, Mangyeong, Gwanghwal, Munpo, Yeompo, Poseung, Gapo and Hasa series have more sandy soil ~ moderately coarse loamy textured soil. Regarding the chemical properties, the concentrations of EC, Exch. $K^+$, $Mg^{2+}$, $Na^+$ and pH are high regardless of the time of reclamation. On the other hand, organic matter (OM) of top soil were 3.3~16.1 g $kg^{-1}$. The organic matter contents were very low though the soil had been farmed for a long time. Furthermore, the deep soil had almost no organic matter with 5.6~1.1 g $kg^{-1}$. The reason is believed that there had not been any movement of OM and clay because pressure or induced pans had been formed by large agricultural machineries and poor vertical drain. Regarding the forming of illuvial horizon (B layer) which tells the development extent of soil, only in the Hwapo reclaimed area where rice had been cultivated for past 90 years, Fe and Mn from top soil are deposited at underground 20~30 cm with 7~8 cm thickness by the movement of clay. It is believed that it had been possible because the earthiness is silty clay loam soil with relatively high content of clay. The soils are soil with concern of damage from sea water, soil on flimsy ground and sandy soil. Therefore, soil improvement for stable crop production can be expected; if the water table would be lowered by subsurface drainage, the water permeability would be enhanced by gypsum and organic matter, and the sandy soil would be replaced by red soil with high content of clay.

• Journal of Korean Society of Forest Science
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• v.86 no.2
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• pp.186-199
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• 1997

The soils derived from granite gneiss occupy almost one third of the land area in Korea. The soils under forest vegetation, formed on granite gneiss, in Sun chon-shi, Chollanam-do in southern part of Korea, were studied to evaluate the weathering and the transformation of primary minerals into secondary minerals, clay minerals. The studied soils contained large amounts of ferromagnesian minerals, weathered biotites and were well weathered, strongly acid and low in organic matters and in ration exchange capacity. The clay contents in the Bt horizon were almost two times higher than those in the C horizon. The O horizon had a thin layer which consisted of a little decomposed plant components with a granic fabric and high porosity, and showed the micromorphological characteristics of moder humus. The related distribution pattern of the E horizon were enaulic and large amounts of silts and small amounts of sand grains were another characteristics of the E horizon. The most striking micromorphological features were multilaminated clay coating and infillings in the voids in the Bt and C horizons, and generally limpid ferriargillans ejected from the biotites and imparted red color to the soils in the Bt horizon. High clay contents in the Bt horizon was not only due to clay translocation, but also due to intensive in situ mineral weathering in this horizon. The most significant pedogenic process, revealed by the petrographic microscope and SEM, was the formation of iron oxides from biotites, the formation of tubular halloysites and the weathering models of biotites; wedge weathering and layer weathering. The thick coating on the weathering biotites showed the characteristics of the weathering process and the synthetic hematites were revealed in clays by TEM. Total chemical analysis of clays revealed extensive loss of Ca, and Na and the concentration of Fe and Al. Mineralogical studies of clays by XRD showed that micas were almost completely weathered to kaolinite, vermiculite-kaolinite intergrade, hematite, gibbsite, while halloysites from other primary minerals. Some dioctahedral mica appeared to be resistant in the soils. Parent rock of the soils contained a considerable amounts of biotites and this forest soils showed especially a dominant characteristics of biotite weathering.

• Progress in Medical Physics
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• v.25 no.3
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• pp.151-156
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• 2014

The purpose of this study was to confirm the feasibility of imaging of therapy region from the boron neutron capture therapy (BNCT) using the measurement of the prompt gamma ray depending on the neutron flux. Through the Monte Carlo simulation, we performed the verification of physical phenomena from the BNCT; (1) the effects of neutron according to the existence of boron uptake region (BUR), (2) the internal and external measurement of prompt gamma ray dose, (3) the energy spectrum by the prompt gamma ray. All simulation results were deducted using the Monte Carlo n-particle extended (MCNPX, Ver.2.6.0, Los Alamos National Laboratory, Los Alamos, NM, USA) simulation tool. The virtual water phantom, thermal neutron source, and BURs were simulated using the MCNPX. The energy of the thermal neutron source was defined as below 1 eV with 2,000,000 n/sec flux. The prompt gamma ray was measured with the direction of beam path in the water phantom. The detector material was defined as the lutetium-yttrium oxyorthosilicate (Lu0,6Y1,4Si0,5:Ce; LYSO) scintillator with lead shielding for the collimation. The BUR's height was 5 cm with the 28 frames (bin: 0.18 cm) for the dose calculation. The neutron flux was decreased dramatically at the shallow region of BUR. In addition, the dose of prompt gamma ray was confirmed at the 9 cm depth from water surface, which is the start point of the BUR. In the energy spectrum, the prompt gamma ray peak of the 478 keV was appeared clearly with full width at half maximum (FWHM) of the 41 keV (energy resolution: 8.5%). In conclusion, the therapy region can be monitored by the gamma camera and single photon emission computed tomography (SPECT) using the measurement of the prompt gamma ray during the BNCT.

• Korean Journal of Soil Science and Fertilizer
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• v.27 no.2
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• pp.98-104
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• 1994

Effects of paddy-upland rotation system on nutrients distribution in soil profile and nutrient balance were studied in paddy fields from 1989 to 1993. The obtained results are summarized as follows. 1. $NO_3{^-}-N$, Av.$P_2O_5$, Ex.-K, and EC were high by small extent in surface layer of 0~20cm soil depth without the sign of salt movement to deeper layers. On the contrary Ex.-ca, Ex.-Mg, and pH became high with increase of soil depths. 2. $NO_3{^-}-N$, Av.$P_2O_5$, Ex.-K, and EC in surface soil were high in the order of Converted, Paddy-Upland Rotation, Potato-Chinese Cabbage>2 Year, Rotation, Potato-Chinese Cabbage>Converted, Paddy-Upland Rotation, Soybean>Continous Paddy, which responded well to fertilizer application rates. On the other hand Ex.-Ca, Ex.-Mg, and pH in whole layers were high in the order of Converted, Paddy-Upland Rotation, Soybean>Converted, Paddy-Upland Rptation, Potato-Chinese Cabbage>2 Year, Rotation, Potato-Chinese Cabbage>Continuous Paddy, which largely depended on plant absorption. 3. Nutrient balance in upland cropping system cultivating potato and Chinese cabbage showed that the input of chemical fertilizer of nitrogen and potassium was less than the plant uptake, while it was reverse for phosphorus with much gap between fertilizer input and plant uptake. Therefore, phosporous was expected to be accumulated by 27kg/10a every year. 4. Nutrient balance in upland cropping system cultivating soybean showed that nitrogen was not deficient to soybean crops even the chemical fertilizer input was less than plant uptake because of nitrogen fixation by rhizobia. However, there was about 1kg/10a deficit of potassium, which resulted dificiency symptom in the middle stage of soybean growth. For phosphorous there was excess of 4kg/10a, which was expected to be short for maintaining phosphorous fertility of upland soils.

• Korean Journal of Soil Science and Fertilizer
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• v.8 no.2
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• pp.45-51
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• 1975

The morphological, physical, chemical, and mineralogical characteristics of planosols in Korea were studied in an effort to establish the suitabilition of the planosols for agricultural development. The Yeongog series which are planosols were established in Korea. Results from the Yeongog series are briefly as follows : 1. Morphologically, the surface soils are brown to dark brown friable loam and subsoils are of varied colors but mainly are dark brown, black and pale brown mottles. The texture of these horizons are silty clay loam with moderate to strong platy structure and clay cutans are on the ped faces. The consistences of these horizons are extremely compact and hard when moist and sticky, plastic when wet. The substrata show varied soil colors and loam to clay loam. 2. Physically, the clay content of the Yeongog soils is highest in the subsoils and gradually decreases below the subsoils. Water holding capacity and bulk desity is higher than in other mineral soils. 3. Chemically, the organic matter content is low and soil reaction ranges from very strongly to strongly acid. The cation exchange capacity is medium and base saturation a high. Active iron, easily reducible manganese and available silicate are high compared with normal soils. 4. In chemical composition of clay fraction of the Yeongog series, sesquioxide ratio, $Fe_2O_3$, $K_2O$ and MgO are high. The cation exchange capacity of the clay fraction is also very high. 5. The clay minerals in Yeongog series are mainly kaoline, vermiculite with Al interlayers and illite. The quarts, primary minerals are in the Yeongog soils. 6. These soils are formed in a warm, humid climate under native grasses on the terraces and rolling or hilly footslopes. In soil classification, the Yeongog soils are classified planosols with claypan. According to 7th approximation system in U.S.A., the Yeongog series are classified as Fragiudalfs because they have an argillic horizon, a hard pan and a high base saturation which is more than 35 percent and classified as Eutric Planosols by FAO/UNESCO classification system.

• Korean Journal of Soil Science and Fertilizer
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• v.8 no.2
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• pp.53-60
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• 1975

Vegetables are often cultivated continuously year round in a vinyl house with heavy application of fertlilizers, which leads to accumulation of salts in the soil. A field experiment was conducted to investigate the effect of watering on salt eluviation from the soil, and on the yield of tomatoes in the vinyl house. The results were summarized as the followings: The salt eluviation increased with the amount of water applied. The efficiency of the salt eluviation was greater for the silty clay loam soil than the sandy loam soil. With a given amount of water, the efficiency increased with frequency of watering. The yield of tomatoes was increased by watering. However, the yield was not necessarily correlated to the amount of salt leached. Increase in yield of tomatoes by watering was in order of the treatment, 100mm (50-50), 150mm (50-50-50 or 100-50), and 200mm (100-100) of water for both soils. Relationship between the yield of tomatoes and electrical conductibity of the soil (1 : 5 extract) was described by the following regression equation : $Y=1,739.0+437.5X-290.5X^2$ $(R=0.632^{**})$ for sandy loam soil, and $Y=1.542.2+454.1X-275.0X^2$ $(R=0.622^{**})$ for silty clay loam soil. The yield of tomatoes in salt accumulated soil was inversely correlated to extractable sodium and potassium, and to the ratio of extractable sodium to calcium (Na/Ca), while the yield was not correlated to extractable calcium and magnesium.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.60 no.3
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• pp.374-380
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• 2015

This study firstly provides basic data for selection of cultivatable bioenergy grass in barren reclaimed lands applied with solidified sewage sludge. The experimental plots consisted of a plot containing reclaimed land mixed with solidified sewage sludge (MSS 50), a plot covered by solidified sewage sludge (CSS 100), and an original reclaimed soil plot (ORS). The growth, biomass production of bioenergy grasses and soil chemical properties were investigated in each experimental plot for 5 years. The organic matter (OM) and total nitrogen (T-N) content in both MSS 50 and CSS 100 were considerably higher than those in ORS. In bioenergy grasses, M. sacchariflorus cv. Geodae 1 showed an excellent growth and adaptability on reclaimed land applied with solidified sewage sludge. The application of solidified sewage sludge may provided soil nutrition in the reclaimed land due to the fact that bioenergy crops grew better in soils applied with solidified sewage sludge than in untreated soils, and treated soils had higher OM and T-N content than untreated soils. This study suggests that M. sacchariflorus cv. Geodae 1 is the most suitable biomass feedstock crop for biomass production and that solidified sewage sludge may be used as a soil material for cultivation of bioenergy grass on reclaimed lands.

• Journal of Animal Environmental Science
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• v.11 no.3
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• pp.153-160
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• 2005

This study was conducted to determine the effect of floor type of finishing building and increasing market weight of finishing Pigs on Performance, carcass traits and pork quality. Four hundred and forty-four finishing pigs were confined and administered with different floor type(concrete slat and bedded with sawdust) and increasing market weight(110kg to 130kg) of finishing building. The result obtained from this study were summarized as follows; 1. There was no significant difference between the floor type of finishing building in the body weight gain, feed intake and gain per feed. And also increasing market weight of finishing pigs was not affected the performance of finishing pigs. 2. Increasing market weight of finishing pigs affect the carcass yield. The market weight at 130kg showed more amount of each cut of carcass, especially the belly portion was higher, but backfat thickness was not different. 3. Carcass traits did not show any significant difference due to the difference of market weight of finishing pig and floor type of finishing building. 4. There was no significant difference in the chemical compositions and meat color of pork loin between the floor type of finishing building and increasing market weight of finishing pigs.