• Korean Journal of Soil Science and Fertilizer
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• v.9 no.3
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• pp.149-163
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• 1976

In Korea, the ever-increasing population has become a serious problem and the decreasing of cultivated lard area per person has become a major concern. Therefore, today we are implementing a green revolution using miracle varieties which require more fertilizer. The increased use of fertilizer along with development and adoption of high yielding varieties is the key to carrying out this green revolution. Fertilizer consumption in Korea is mainly influenced by agricultural techniques, fertilizer prices and government policies for increasing food production. If there are no special change, such as a cataclysm or an exhaustion of resources, it is quite clear that the fertilizer demand will increase to the near maximum ceiling point of optimum levels for crops in the year 2000. Fertilizer demand is not the amount of fertilizer that will be used by the farmer, but the actual optimum amount of plant nutrients required for maximum production. In this report, two alternative strategies are consideded in forecasting the future feitilizer demands. Alternative I is projected by reviewing consumption amounts over the last 10 years (1966~75) in Korea. The annual rate of increase in fertilizer consumption for the last 10 years was approximately 8.7% (table 1). Plant nutrient consumption rates in later years have been more balanced, and also fertilizer consumption per total acreage is considerably higher in Korea than in other countries (table 11), consequently the rate of increase in the future is expected to decline. Looking at the long term projections, the average annual rate of increase is expected to be 7% for 1976~80, 2.5% for 1981~90, 1.5% for 1991~2000. Thus, total projected fertilizer demands are estimated at 1,208,000M/T by 1980, 1,547,000M/T by 1990, 1,795,000M/T by 2000 (table 16). Alternative II is based on projected optimum fertilizer levels for crops and on increased crop acreage. The government recommended fertilizer rate has increased by a factor of 0.99 to 5.49 over the past twelve years depending on the specific crops (table 4). Levels of fertilizer demand recommended by government (table 7) in 1976 are still low compared with actual optimum fertilizer demands for crops (table 5). Therefore, future incaeases in fertilizer usage are anticipated. Thus, total projected fertilizer demands are estimated at 1,229,000M/T by 1980, 1,493,000M/T by 1990 and 1,898,000M/T by 2000(table 16).

• Korean Journal of Soil Science and Fertilizer
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• v.29 no.4
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• pp.378-384
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• 1996

This study was conducted to investigate the influence of root zone temperature on the growth of shoot and root and the mineral contents in leaf of 'Fuji/M26' apple tree. Shoot growth and enlargement of trunk girth increased linearly with increasing root zone temperature. Fresh and dry weight of root reached maximum at $35^{\circ}C$. Water content of root increased with rising root zone temperature. The chlorophyll content of leaves showed insignificant difference with root zone temperature. Leaf water potential was high at $35^{\circ}C$ at 15 day after treatment but 60 day after treatment this was decreased. The nitrogen content of the leaves was not different by root zone temperature whereas the phosphorus content of the leaves was increased at $30^{\circ}C$ in 1993 and at $25^{\circ}C$ in 1994. The potassium content of the leaves reached a maximum at $30^{\circ}C$ in 1993 and $25^{\circ}C$ in 1994. In 1994 the calcium content of the leaves was increased with rising root zone temperature and with lengthening duration of treatment but no such differences were found in 1993. The magnesium content of the leaves was highest at $25^{\circ}C$ in 1993 and at $20^{\circ}C$ in 1994. The nitrogen and potassium content of the roots were increased linearly with root zone temperature in 1993 and 1994 and the magnesium and phosphorus content of the roots were high at $35^{\circ}C$ in 1994 but no such differences were found in the calcium content of the roots.

• Journal of Korean Society of Forest Science
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• v.87 no.2
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• pp.276-285
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• 1998

The aboveground biomass and nutrient content (N, P, K, Ca and Mg) of Pinus koraiensis S. et Z., aged 9, 22, 34, 46, 66 years, were measured in the Experiment Forest of Kangwon National University of Kangwondo province. The site index of the stands ranged from 13.5 to 14.2. Allometric equations (logY=alogX+b, where Y, X is ovendry mass and DBH, respectively) relating dry weights of stem, branches and needles to diameter at breast height (DBH) were developed to estimate aboveground tree biomass. Total above ground tree biomass increased with stand age from $21.8t\;ha^{-1}$ in the 9-year-old stand to $130t\;ha^{-1}$ in the 66-Year-old stand. Aboveground biomass was allocated as follows : stem> branch > foliage, except for the 9-year-old stand which had a greater proportion of foliage biomass than branch biomass. As stand age increased, an increasing proportion of annual biomass increment was allocated to stems. The aboveground biomass of shrubs and herbs ranged from 0.4 to $3.9t\;ha^{-1}$ and from 0.05 to $0.6t\;ha^{-1}$, respectively. No relationship was found between aboveground understory biomass and stand age. The mass of woody debris and forest floor varied between 0.59 to $1.54t\;ha^{-1}$ and 6.0 to $21.63t\;ha^{-1}$, respectively. Nutrient accumulation in aboveground tree biomass increased with stand age and was in the order of N > Ca > K > P > Mg. Average rates of nutrients accumulation in biomass were greatest in the early stages of stand development, and less marked as stand aged. The nutrient concentrations in different tree components decreased in the order of needle > branch > stem. There were no detectable trends in nutrient content of the forest floor and mineral soils with stand age. Understory vegetation contributed little to the nutrient pool of these Korean pine ecosystems. Mineral soil contained the Breast proportion of nutrient capital of the various ecosystem compartments.

• Journal of Bio-Environment Control
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• v.20 no.4
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• pp.352-356
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• 2011

It is true that the industrial development has usually been accompanied with urbanization or centralization of population that has inevitably led to high-rise buildings and densely built-up living area in the cities. While it is badly needed to acquire as much green land within the city limits as possible to compensate for reduced space for recreational purpose in parallel with increasingly urbanized area, the living conditions of plants have become seriously devastated due to shortage of sun light walled-off by high-rise buildings and contaminated environment and air. The shade that is generated by high-rise and compact buildings hinders growth of plants, which makes it urgent to develop native ground cover plant that is strongly viable in the shade. For this purpose, Ligularia stenocephala, best known as greens for Ssam (rice and condiments wrapped in leaves) was cultivated under the 30%, 50%, and 80% shadings and observed to see if there would be any changes in soil conditions, growth of plants and chlorophyll contents depending on the shading rate. The leaf number was 10.8 pieces under the 50% shading and 8.4 under the 30%-shading, 7.7 pieces more than that cultivated under lighting. The leaf width turned out to be excellent from cultivation under the 50%- shading, an evidence indicating its possibility of being cultivated as native ground cover plant in the shade. The live weight of the plants cultivated under the shading increased to 31.63 g, 43.39 g and 19.40 g, respectively, compared to 90.43 g of those in the untreated control plot. The increase in growth of roots was particularly significant with 48.48 g in comparison to 12.33 g under 30% shading cultivation. The chlorophyll synthesis amounted to 46.2 under the 50% shading, showing an increase compared to 41.9 under lighting. The chlorophyll synthesis rather shrank under other shading conditions. The cultivation of Ligularia stenocephala under the 50% shading showed the best condition in growth as native ground cover plant.

• Korean Journal of Agricultural and Forest Meteorology
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• v.2 no.4
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• pp.183-189
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• 2000

This study was carried out to analyze ecophysiological responses for seedling of Quercus serrata, Quercus mongolica and Quercus variabilis that are the typical species of deciduous broadleaved forests in Korea. And executed experiments in the climatic control room to provide necessary information to ecological forest management and methods of natural regeneration through the analysis of seedling responses. The details of experimental analysis were growth processes of 4 months after seeding that vary with the condition of three light intensity[relative light intensity(RLI) 8%, 20%, 52%] and three soil moisture[water suction(WS) Ψ=100 hPa, Ψ=280 hPa, Ψ=330 hPa] gradient, growth factors after harvesting and the nutrition condition of leaves. The results of this study are followings: 1) Early growth was prosperous after germination for the species which have more weight of acorn. 2) The formation of lammas shoot was favourable with Q. variabilis and Q. mongolica. And the rate of the occurrence was the highest in the RLI 20%, and it was remarkably reduced in the RLI 8%. 3) As the height growth of seedling of all 3 species were greater in the RLI 20% and 8% than that of the RLI 52%, they showed strong shade tolerance. 4) The increase of light intensity promoted the diameter at root collar growth, and development of main and lateral roots with all 3 species. 5) It showed that the increase of light intensity in the experimental radiation condition raised special leaf area weight(mg/cm$^2$) and leaf area productivity(mg/cm$^2$). Consequently, these resulted in the increase of leaf thickness and total dry biomass per the unit area of leaf. 6) As the increase of light intensity, the minerals contents of leaves such as N, P and K were lowered, and the increase of soil moisture resulted in the increase of P, K, Ca and Mg.

• Korean Journal of Heritage: History & Science
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• v.50 no.4
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• pp.122-147
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• 2017

The Jungsandong sites are distributed across quartz and mica schist formations in Precambrian, and weathering layers include large amounts of non-plastic minerals such as mica, quartz, felspar, amphibole, chlorite and so on, which form the ground of the site. Neolithic pottery from Jungsandong exhibits various brown colors, and black core is developed along the inner part for some samples, and sharp comb-pattern and hand pressure marks can be observed. Their non-plastic particles have various composition, size distribution, sorting and roundness, so they are classified into four types by their characteristic mineral compositions. I-type (feldspar pottery) is including feldspar as the pain component or mica and quartz. II-type (mica pottery) is the combination of chloritized mica, talc, tremolite and diopside. III-type (talc pottery) is with a very small amount of quartz and mica. IV-type (asbestos pottery) is containing tremolite and a very small amount of talc. The inner and outer colors of Jungsandong pottery are somewhat heterogeneous. I-type pottery group shows differences in red and yellow degree, depending on the content of feldspar, and is similar to III-type pottery. II-type is similar to IV-type, because its red degree is somewhat high. The soil of the site is higher in red and yellow degree than pottery from it. The magnetic susceptibility has very wide range of 0.088 to 7.360(${\times}10^{-3}$ SI unit), but is differentiated according to minerals, main components in each type. The ranges of bulk density and absorption ratio of pottery seem to be 1.6 to 1.7 and 13.1 to 26.0%, respectively. Each type of pottery shows distinct section difference, as porosity and absorption ratio increase in the order as follows: I-type (organic matter fixed sample) < III-type and IV-type < I-type < II-type (including IV-type of IJP-15). The reason is that differences in physical property occur according to kind and size of non-plastic particles. Although Jungsandong pottery consists of mixtures of various materials, the site pottery has a geological condition on which all mineral composition of Jungsandong pottery can be provided. There, it is thought that raw materials can be supplied from weathered zone of quartz and mica schist, around the site. However, different constituent minerals, size and rock fragments are shown, suggesting the possibility that there can be more raw material pits. Thus, it is estimated that there may be difference in clay and weathering degree.

• Journal of the Korean association of regional geographers
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• v.5 no.1
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• pp.101-120
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• 1999

The purpose of this study is to analyze the impact of agricultural polices on the change of regional structure based on the specialization during the productivism period. Analysis are carried on through the comparison of distribution in 1950s and 1997. Since the 1950s, governmental policy has played a leading role in shaping the pattern of farming in Great Britain. The range of British measures have also been employed in an attempt to improve the efficiency of agriculture and raise farm income. Three fairly distinct phase can be identified in the developing relationship between government policies and British agriculture in the postwar period. In the 1st phase, The Agricultural Act of 1947 laid the foundations for agricultural productivism in Great Britain until membership of the EC. This was to be achieved through the system of price support and guaranteed prices and the means of a series of grants and subsidies. Guaranteed prices encouraged farmenrs to intensify production and specialize in either cereal farming or milk-beef enterprise. The former favoured eastern areas, whereas the latter favoured western areas. Various grants and subsidies were made available to farmers during this period, again as a way of increasing efficiency and farm incomes. Many policies, such as Calf Subsidy and the Ploughing Grant, Hill cow and Hill Sheep Schemes and the Hill Farming and Livestock Rearing Grant was provided. Some of these policies favoured western uplands, whilst the others was biased towards the Lake District. Concentration of farms occured especially in near the London Metropolitan Area and south part of Scotland. In the 2nd stage after the membership of EC, very high guaranteed price created a relatively risk-free environment, so farmers intensified production and levels of self-sufficiency for most agriculture risen considerably. As farmers were being paid high prices for as much as they could produce, the policy favoured areas of larger-scale farming in eastern Britain. As a result of increasing regional disparities in agriculture, the CAP became more geographically sensitive in 1975 with the setting up of the Less Favoured Areas(LFAs). But they are biased towards the larger farms, because such farms have more crops and/or livestock, but small farms with low incomes are in most need of support. Specialization of cereals such wheat and barely was occured, but these two cereal crops have experienced rather different trend since 1950s. Under the CAP, farmers have been paid higher guaranteed prices for wheat than for barely because of the relative shortage of wheat in the EC. And more barely were cultivated as feedstuffs for livestock by home-grown cereals. In the 1950s dairying was already declining in what was to become the arable areas of southern and eastern England. By the mid-1980s, the pastral core had maintained its dominance, but the pastoral periphery had easily surpassed arable England as the second most important dairying district. Pig farming had become increasingly concentrated in intensive units in the main cereal areas of eastern England. These results show that the measure of agricultural policy induced the concentration and specialization implicitly. Measures for increasing demand, reducing supply or raising farm incomes are favoured by large scale farming. And price support induced specialization of farming. And technology for specialization are diffused and induced geographical specialization. This is the process of change of regional structure through the specialization.

• Development and Reproduction
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• v.11 no.3
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• pp.245-251
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• 2007

Vinclozolin(VCZ), a systemic dicarboximide fungicide, has been used in the control of diseases caused by microorganism of some species in fruits, vegatables and ornamental plants. Although VCZ itself is a very weak antagonist for androgen receptor binding, both melabolites M1 and M2 are effective antagonists. The present study was undertaken to examine whether prepubertal exposure to VCZ affects on the onset of puberty and the associated reproductive parameters such as hormone receptor expressions in female rats. VCZ(10 mg/kg/day) was administered daily from postnatal day 21(PND 21) through the day when the first vaginal opening(V.O.) was observed. Gross anatomy and weight of reproductive tissues were compared to test the VCZ's effects on the cell proliferation. Furthermore, histological studies were performed to assess the structural alterations in the tissues. To determine the transcriptional changes in progesterone receptor(PR), total RNAs were extracted and applied to the semi-quantitative reverse transcription polymerase chain reaction(RT-PCR). As a result, delayed V.O. was shown in the VCZ group(PND $34.00{\pm}1.22$) compared to the control group(PND $38.20{\pm}1.92$; p<0.01). VCZ treatment significantly decreased the wet weight of ovaries and uteri compared to the control group(p<0.01). Graafian follicles and corpora lutea were observed only in the ovaries from the control animals, while numerous primary, secondary follicles and small atretic follicles were observed in the ovaries from VCZ group. Similarly, hypotrophy of luminal and glandular uterine epithelium was found in the VCZ group. In the semi-quantitative RT-PCR studies, the transcriptional activity of PR in ovary(p<0.01) from VCZ group were significantly lower than those from the control group while in uterus were similar compared with the control group. The present studies demonstrated that the acute exposure to VCZ during the critical period of prepubertal stage could inactivate the reproductive system resulting delayed puberty in female rats.

• Journal of the Korean association of regional geographers
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• v.5 no.2
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• pp.133-142
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• 1999

The wetland is very important ecologically as a habitat of diverse organisms. The purpose of this paper is to elucidate the morphogenetic environment of Jilmoe Bog found in the Odae Mountain National Park Jilmoe Bog is located in the high etchplain(1,060m) where Daebo Granite which had intruded in Jura epoch of Mesozoic era has weathered deeply and has uplifted in the Tertiary. The annual mean temperature of study area is $5.3^{\circ}C$, the annual precipitation is 2,888mm. The minimun temperature of the coldest month(january) is below $-30^{\circ}C$ and the depth of frozen soil is over 1.6m. Jilmoe bog consists of a large bog and a small bog. The length of the large bog is 63m and its width is 42m. The basal surface of Jilmoe bog is uneven. Jilmoe bog is a string bog fanned due to frost actions. In String bog, its surface is wavy with stepped dry hills and net-like troughs crossing hill slope. It seems that string bog is related to the permofrost or seasonal permofrost of cold conifer forest(taiga) zone(where the depth of frozen soil is very deep in the least in winters). String bog is a kind of thermokarst that frozen soil thaws differentially locally in declining permofrost and ground surface becomes irregular. There is turf-banked terracette of width $30{\sim}40cm$ in the headwall of small cirque-type nivation hollow formed at footslope of Maebong mountain around Jilmoe bog. This turf-banked terracette is formed by the frost growth of soil water below grass mat in periglacial climate environment. Where water is plentiful such as a nivation follow${\sim}$valley corridor and a headwall of valley, turf patterned grounds of width $30{\sim}50cm$ are found. This turf patterned ground is 'unclassified patterned ground', earth hummock. In conclusion, Jilmoe bog is a string bog of thermokarst that the relief of ground surface is irregular according to locally differentially thawing of permofrost(frozen soil). Jilmoe bog is high moor, its surroundings belongs to periglacial environment that turf-banked terracette and turf patterned ground are fanned actively.

• Journal of the Korean association of regional geographers
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• v.4 no.2
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• pp.49-64
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• 1998

Bing-gye valley(Kyongbuk Province, South Korea) is well known as a tourist attraction because of its meteorologic characteristics that show subzero temperature during midsummer. Also, there are some interesting geomorphic features in the valley area. Therefore, the valley is worth researching in geomorphology field. The aim of this paper is to achieve two purposes. These are to clarify geomorphic features on talus within Bing-gye valley area, and to infer the origin of Bing-gye valley. The main results are summarized as follows. 1) The formation of Bing-gye valley It would be possible to infer the following two ideas regarding the formation of Bing-gye valley. One is that the valley was formed by differential erosion of stream along fault line, and the other is that the rate of upheaval comparatively exceeded the rate of stream erosion. Especially, the latter may be associated with the fact that the width of the valley is much narrow. Judging that the fact the width of the valley is much narrow, compared with one of its upper or lower valley, it is inferred that Bing-gye valley is transverse valley. 2) The geomorphic features of talus (1) Pattern It seems to be true that the removal of matrix(finer materials) by the running water beneath the surface can result in partly collapse hollows. Taluses are tongue-shaped or cone-shaped in appearance. They are $120{\sim}200m$ in length, $30{\sim}40m$ in maximum width. and $32{\sim}33^{\circ}$ in mean slope gradient. The component blocks are mostly homogeneous in size and shape(angular), which reflect highly jointed free face produced by frost action under periglacial environment. (2) Origin On the basis of previous studies, the type of the talus is classified into rock fall talus. When considered in conjunction with the degrees of both weathering of blocks and hardness of blocks, it can be explained that the talus was formed under periglacial environment in pleistocene time. (3) The inner structure of block accumulation I recognize a three-layered structure in the talus as follows: (a) superficial layer; debris with openwork texture at the surface, 1.3m thick. (b) intermediate layer: small debris(about 5cm in diameter) with fine matrix(including humic soil), 70cm thick. (c) basal layer: over 2m beneath surface, almost pure soil horizon without debris (4) The stage of landform development Most of the blocks are now covered with lichen, and/or a mantle of weathering. It is believed that downslope movement by talus creep well explains the formation of concave slope of the talus. There is no evidence of present motion in the deposit. Judging from above-mentioned facts, the talus of this study area appears to be inactive and fossil landform.