• Journal of Korean Society of Forest Science
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• v.50 no.1
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• pp.56-71
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• 1980

To study the changes of vegetational composition of each plant successional stage of Pinus densiflora forest caused by pine gall midge damage, Thecodiplosis japonensis, located in Kyonggi-do area, the middle part of Korea, four districts, Anseong, Yongin, Gwangju, and Gapyeong, were selected according to the length of insect damage duration. The forest in the Anseong district was the noninfested one selected as the check. And forests in Yongin, Gwangju, and Gapyeong were the recent]y damaged, severely damaged, and damage prolonged ones in sequence. It was considered that this order could be in concord with the gradual transition of plant successional stage. In view of temperature, precipitation and soil factors, these four districts were sited within the same environment. Four survey plots were selected from each district and the distance between them was 3~4 km. Then again four subplots were set within a plot. Through needle accumulation after insect infestation, light intensity, soil moisture content, and the amount of soil organic matter were increased and these conditions could create a favorable environment enabling the new species invasion and their growth. These were naturally closely related with the increase in quantity of Pinus densiflora defoliation. After considerable time lapse, the quantities of above mentioned factors decreased with the development of the new substitute tree species. It was found that Quercus mongolica was an excellently substitute tree species come first in this studied area. Species diversity increased to a degree at the early stage of the duration of pine gall midge damage and decreased thereafter. As the same manner, similarity index value between plots in the same district decreased to a degree and increased thereafter. This was linked admittedly with the increase and decrease of tree species and evenness. Synthesizing above mentioned results, the process of plant succession studied quantitatively by changes of relative density and relative importance value, it can be concluded that Pinus densiflora forest gives way to Genus Quercus forest in which Genus Lespedeza and Genus Rhododendron species become as subdominance species after removal of the Pinus densiflora trees damaged by pine gall midge.

• Korean Journal of Soil Science and Fertilizer
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• v.44 no.6
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• pp.1195-1206
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• 2011

This study was conducted to apply LCA (Life cycle assessment) methodology to lettuce (Lactuca sativa L.) production systems in Namyang-ju as a case study. Five lettuce growing farms with three different farming systems (two farms with organic farming system, one farm with a system without agricultural chemicals and two farms with conventional farming system) were selected at Namyangju city of Gyeonggi-province in Korea. The input data for LCA were collected by interviewing with the farmers. The system boundary was set at a cropping season without heating and cooling system for reducing uncertainties in data collection and calculation. Sensitivity analysis was carried out to find out the effect of type and amount of fertilizer and energy use on GHG (Greenhouse Gas) emission. The results of establishing GTG (Gate-to-Gate) inventory revealed that the quantity of fertilizer and energy input had the largest value in producing 1 kg lettuce, the amount of pesticide input the smallest. The amount of electricity input was the largest in all farms except farm 1 which purchased seedlings from outside. The quantity of direct field emission of $CO_2$, $CH_4$ and $N_2O$ from farm 1 to farm 5 were 6.79E-03 (farm 1), 8.10E-03 (farm 2), 1.82E-02 (farm 3), 7.51E-02 (farm 4) and 1.61E-02 (farm 5) kg $kg^{-1}$ lettuce, respectively. According to the result of LCI analysis focused on GHG, it was observed that $CO_2$ emission was 2.92E-01 (farm 1), 3.76E-01 (farm 2), 4.11E-01 (farm 3), 9.40E-01 (farm 4) and $5.37E-01kg\;CO_2\;kg^{-1}\;lettuce$ (farm 5), respectively. Carbon dioxide contribute to the most GHG emission. Carbon dioxide was mainly emitted in the process of energy production, which occupied 67~91% of $CO_2$ emission from every production process from 5 farms. Due to higher proportion of $CO_2$ emission from production of compound fertilizer in conventional crop system, conventional crop system had lower proportion of $CO_2$ emission from energy production than organic crop system did. With increasing inorganic fertilizer input, the process of lettuce cultivation covered higher proportion in $N_2O$ emission. Therefore, farms 1 and 2 covered 87% of total $N_2O$ emission; and farm 3 covered 64%. The carbon footprints from farm 1 to farm 5 were 3.40E-01 (farm 1), 4.31E-01 (farm 2), 5.32E-01 (farm 3), 1.08E+00 (farm 4) and 6.14E-01 (farm 5) kg $CO_2$-eq. $kg^{-1}$ lettuce, respectively. Results of sensitivity analysis revealed the soybean meal was the most sensitive among 4 types of fertilizer. The value of compound fertilizer was the least sensitive among every fertilizer imput. Electricity showed the largest sensitivity on $CO_2$ emission. However, the value of $N_2O$ variation was almost zero.

• Journal of Korean Society of Forest Science
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• v.11 no.1
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• pp.1-24
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• 1970

This experiment was carried out to elucidate the behavior of nutrition absorption and the acid tolerance, on varying soil pH levels, of Pinus thunbergii, Pinus densiflora, Pinus rigida, PInus koraiensis, Larix leptolepis and Abies holophylla which are 6 month old seedlings through examinations of the absorption behavior, the acid and alkali tolerance of N,P,K, Ca and Fe in the sand culture media with artificially controlled pH. 1. The increase rate of dry matter conditioned by the behavior of nutrition absorption in a strong acidic condition (pH3) was found in the following decreasing order of Pinus rigida, Pinus thunbergii. This order, therefore, can also be said to apply to the case of acid tolerance. 2. The increase rate of dry matter in a strong alkaline condition (pH9) was found in the following decreasing order of Pinus thunbergii, Pinus rigida, Pinus densiflora, Pinus koraiensis, Abies hoplohylla, Larix leptolepis. This order, therefore can be said to apply to the case of alkali tolerance. 3. Considering the absorption behavior of K and Ca, it is possible to decide the tolerance of acid from the absorption behavior and it can be said that if the absorption quantity is K>Ca the acid tolerance is strong and vice versa. 4. Considering the ratio of K:Fe and Ca:Fe in this experiment, a strong acid tolerance shows a higher ratio of K/Fe and vice versa. And also a strong acid tolerance shows a lower ratio of Ca/Fe and vice versa. It is therefore possible to decide the acid tolerance from the absorption behavior of K, Ca and Fe. 5. Of the tree species subjected to this experiment, Pinus thunbergii was the strongest in both acid and alkali tolerance. 6. In spite of that in all species the dry weight in the root is smailer than that in the top, the quantity of Fe contained in the root was larger than that in the top.

• Journal of the Korea institute for structural maintenance and inspection
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• v.17 no.3
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• pp.136-144
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• 2013

In this study, in order to establish a plan that will enable safe use of renewable resources such as diverse industrial by-products and urban recycled materials, we conducted experiments that focused on flow, bleeding, compressive strength and environmental pollution evaluation to evaluate the material properties of low strength concrete using BFS and SS. In the case of low strength concrete using BFS and SS, blending of at least BFS 6000 within a 30% range regardless of the type of sand used was found to be the most effective approach for improving the workability by securing the minimum unit quantity of water, restraining the bleeding ratio and establishing compressive strength by taking account of the applicability at the work site. In particular, in view of the efficient use of SS, the optimal mixing condition was found to be the mixing of BFS 8000 with in the 30% range, not only for improving the workability restraining the bleeding ratio and establishing the compressive strength but also for application to the work site. Further, the results of tests on hazardous substance content and those of elution tests conducted on soil cement using SS indicated that all values satisfied the environmental standards without any harmful effects on the surrounding environment.

• Journal of Animal Environmental Science
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• v.10 no.2
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• pp.75-80
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• 2004

Field experiments were conducted in 2002 on sandy loam soil under variable fertilizer management; swine slurry and chemical fertilizer. The effect of different fertilizer management and application method on the growth characteristics and yield of rice were determined. The rice was planted to examine the effect of swine slurry on the crop growth. As slurry manure was fertilized, yield of each group of rice was decreased from 3 to $5\%$. In conclusion, basal application of slurry was maintained productivity of rice, but to improve of productivity of rice, the rice should be fertilized with the basal application of animal slurry and supplementary application of chemical fertilizer. The results indicates that application of animal slurry improves quality of rice rather quantity, which means grain yield. Rice quality of the slurry+chemical and the slurry were significantly better than that of the chemical fertilizer. That indicates application of animal slurry could improve rice quality. Application of animal slurry seemingly has potentials for reducing pollution of animal slurry and improving environment of rural area as well as producing high-quality rice.

• Journal of The Korean Society of Grassland and Forage Science
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• v.18 no.4
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• pp.351-354
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• 1998

Centipedegrass (Eremochloa ophiuroides) is a popular lawn grass in the southeastern USA. It has a naturally light green color and grows well on a wide range of soil types. Studies show limited morphological variation present in centipedegrass germplasm. To obtain the high morphological variation, plants were established from the irradiated seed at 10 Kr, allowed to interpollinate and harvested bulk seed, and then irradiated again for the next cycles. Morphological characteristics were measured in the 5 genetic varition lines (TC201 : cv. Common and non irradiated, TC202 : 4th cycles, TC241 : 6th cycles, TC306 : 8th cycles, and TC318 : 5th cycles) induced by recurrent gamma radiation. The ranges of variation of recurrently radiated centipedegrass lines < TC202, TC241 and TC306 except TC318(TifBlair) > for the stolons per plant, total stolon length per plant, longest stolon length, leaf length and width at top-most exposed internode were wider than those of non-irradiated line (TC201). Recurrent gamma radiation was very effective to enlarge the ranges of variation of morphological characteristics in reproductive organ like stolons of centipedegrass. The effect of quantity of gamma ray irradiation cycles on the means and ranges of variation in the morphological characteristics of centipedegrass was not regularly tended.

• Proceedings of the Korean Society of Near Infrared Spectroscopy Conference
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• 2001.06a
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• pp.1262-1262
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• 2001

The rice plant is one of the important staple crops in Korea. The high yield with low cost in rice is required the soil fertility and the development of new precise method of fertilizer application by nutritional diagnosis. Now, in Korea, the nitrogen application system for the rice plant is composed of the basal fertilization, fertilization at tillering stage and fertilization at panicle stage, which the nitrogen fertilization at panicle stage amount to about 30 percent in the total amount. Thus, this experiment carried out to the development of the system that can measure the nitrogen content in the rice plant at panicle stage rapidly with the near infrared spectroscopy, and to predict the appropriate quantity of the nitrogen fertilization at panicle stage based on calibration model for test of nitrogen content in rice plant. The samples were collected from 48 varieties in 4 regions which are mainly cultivated in the southern part of Korea. And then, it collected by classifying into the leaf, the whole plant and the stem since 7 days before the nitrogen fertilization at panicle stage. The ranges of the nitrogen contents were 1.6∼4.0%, 1.7∼3.0% and 1.4∼2.7% in the leaf, the whole plant and the stem, respectively. In the calibration models created by each part of the plant under the Multiple Linear Regression(MLR) method, the calibration model for the leaf recorded the relatively high accuracy. The mutual crossing test on unknown samples were carried out using Partial Least Square(PLS) calibration model. That is, the nitrogen content in the stem was tested by calibration model made by the leaf model and that of stem was tested by calibration model made by whole plant sample. When unknown leaf sample was tested by calibration model made by all sample that collected from each part in rice plant such as leaf, stem and whole plant, it recorded the highest accuracy. As a result, to test the nitrogen content in the rice plant at panicle stage, the nitrogen content in the leaf shall be tested by the calibration model composed of the leaf, the stem and the whole plant. In future, to estimated the amount of nitrogen fertilization at panicle stage for rice plant , it will be calculated based on regression model between rice yield and nitrogen content of leaf measured by calibration model made by mixed sample including leaf, stem and whole plant.

• Journal of Conservation Science
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• v.26 no.3
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• pp.229-245
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• 2010

The pupose of this study was to identify the material characteristics, firing environments and making techniques for the jar coffins from the Oryangdong kiln site and the Ungokdong tomb site in Naju. All jar coffins had very similar physical, mineralogical and geochemical characteristics, although it was excavated from the different sites. The wall thickness of the jar coffins was about 2.3 to 5.3 cm. Under the microscopy, the jar coffins include a large quantity of various quartz with some microcrystalline and showed partly orthoclase and biotite. It is presumed that the mineral sherds added to maintain the thick wall and to control the percentage of contraction during drying and firing of jar coffins and it has contained about 11.4 to 19.8 %. Firing temperature of the jar coffins is estimated as 1,000 to $1,150^{\circ}C$. Also, all jar coffins and soils show similar geochemical behavior of elements and clay-mineralization degree within the site. This indicates making that the soil is probable to be a raw material of the jar coffins. But it shows different characteristics in major elements of soils which is collected at the kiln floor and the trench region of the Oryangdong kiln site because of the lack of quartz and feldspar in the soils. Therefore, it can use of the jar coffins making clay, if it goes through a simple special process such as mixing temper.

• Journal of Korea Water Resources Association
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• v.38 no.7 s.156
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• pp.517-526
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• 2005

In Korea, the methods of estimating groundwater recharge can categorized into two groups. One is baseflow separation method by means of groundurater recession curve, the other is water level fluctuation method by using the data from groundwater monitoring wells. Baseflow separation method is based on annual recharge and lumped concept, and water-table fluctuation method is largely dependent on monitoring wells rather than water budget in watershed. However, groundwater recharge rate shows the spatial-temporal variability due to climatic condition, land use and hydrogeological heterogeneity, these methods have various limits to deal with these characteristics. For this purpose, the method of estimating daily recharge rate with spatial variability based on distributed rainfall-runoff model is suggested in this study. Instead of representative recharge rate of large watershed, the subdivided recharge rate with heterogeneous characteristics can be computed in daily base. The estimated daily recharge rate is an advanced quantity reflecting the heterogeneity of hydrogeology, climatic condition, land use as well as physical behaviour of water in soil layers. Therefore, the newly suggested method could be expected to enhance existing methods.

• Journal of the Korean Society for Marine Environment & Energy
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• v.7 no.1
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• pp.42-46
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• 2004

Deep Ocean Water (DOW) is formed within restricted area including polar sea (high latitude) by cooling of surface seawater and globally circulating in the state of isolation from surface seawater. Although it is not as obvious as estuaries mixing, brine ground water is mixture of recirculated seawater and ground water. Seawater having high osmotic pressure infiltrates into an aquifer which is connected to the sea. In order to clarify the characteristics of deep ocean water and brine ground water, we investigated their origins, chemical compositions, water qualities and resources stabilities. While concentrations of stable isotopes (/sup 18/O and ²H) in seawater is 0‰, those in brine ground water is on meteoric water line or shifted toward oxygen line. It means that origin of brine ground water is different than that of deep ocean water. The ions dissolved in seawater (Na, Ca, Mg, K) are present in constant proportions to each other and to the total salt content of seawater. However deviations in ion proportions have been observed in some brine ground water. Some causes of these exception to the rule of constant proportions are due to many chemical reactions between periphery soil and ground water. While DOW has a large quantity of functional trace metals and biological affinity relative to brine ground water, DOW has relatively small amount of harmful bacteria and artificial pollutants.