• Proceedings of the Korean Association of Geographic Inforamtion Studies Conference
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• 2008.10a
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• pp.153-161
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• 2008

Agriculture and forest are basis for livelihood in Nepal while both sectors constitute around 40 percent of the national product and over two-thirds of the economically active population is dependent on agriculture. However, radical changes in land use, depletion in crops production and food availability are major threats due to loss of soil fertilityand severe environmental degradation. In this study, we used time series data from 1986/87 to 2005/06 about food crop production and population published by Government of Nepal, Ministry of Agriculture and Cooperatives and Central Bureau of Statistics. Descriptive statistics and ArcGIS were used to assess and map the food security status of Nepalese Terai based on the local food demand and supply system. Food supply to demand ratio(FSDR) was the main idea of assessment. Our results showed that out of 20 districts, only 8 districts were categorised under secured food districts whereas 5 districts were still under food unsecured situation. The analysis further revealed that 7 districts had faced food deficit more than 8-16 times during the last 20 year periods. Data further showed that there was surplus food supply relative to the requirements dictated by FSDR. However, the average FSDR was less than 1.2(less than 20% surplus) exploring fact that most of the districts were not producing sufficient food to cope up the food shock and after 1995 it was relatively stagnant. Our prediction reveals that food supply in Terai even in the future would remain at almost the same level as now, and there will not more than 16-17% surplus by 2021 considering medium vibrant population growth. The findings thus, indicate that Terai may not be a food secure region in the future, even though the region is considered as a food storage house of Nepal. In addition, this paper suggests ways to make future comprehensive case studies more widely comparable in Terai, Nepal.

• Korean Journal of Soil Science and Fertilizer
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• v.33 no.2
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• pp.79-84
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• 2000

The aim of this study was to evaluate the chemical properties of orchard soils through which their soil fertilities were discriminated. Total 877 soil samples in major orchard area, i.e. from 239 apple, 369 pear, 168 grape, 101 peach orchards, were examed on the basis of temporary optimal range for each component. The levels of fertility were ranged from 3.0 to 65.2% compared to optimum fertility, suggesting that almost orchard soils contained inadequately soil components. The contents of chemical component have a tendency to decrease with soil depth gradually from surface to subsoil. This meaned that the contents of various components in subsoil could be estimated on the basis of analysis of surface soil, using the linearly fitted equations of the relationship between component in subsoil and in surface at least to which fertility were samely managed. Furthermore, even when only the content of components in 20cm depth surface soil was analyzed, it could be determined whether the amount of each component in the surface soil is surplus or deficient.

• Journal of the Korean GEO-environmental Society
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• v.10 no.7
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• pp.33-41
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• 2009

In the case of underground power utilities pipe such as circular pipe, the most difficult problem is low compaction efficiency of the bottom of pipe inducing the failure of utilities. To overcome this problem, various studies have been performed and one of these is CLSM (controlled low strength materials) accelerated flow ability. CLSM has already been stage of commercial use in the foreign countries led by power company. In this study, we estimated the behavior of flexible pipe with flowable backfill materials and sand to compare on the DB24 load. The results showed that the deformation of flexible pipe is affected by types of backfill materials. CLSM shows better behavior characteristics than compacting sand. But numerical and analytical results that peformed to compare to the field test results showed big gap with the field results.

• Proceedings of the Korean Geotechical Society Conference
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• 2005.10a
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• pp.395-404
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• 2005

This study is to evaluate the physical and mechanical characteristics of flowable backfill and search for the optimal mixture contents of it used for constructing underground power utilities. flowable backfill is known as soil-cement slurry, void fill, and controlled low-strength material(CLSM). The benefits of CLSM include reduced equipment costs, faster construction, re-excavation in the future, and the ability to place material in confined spaces such as narrow parts nearly impossible for compaction or perimeter of underground power cables. The flowable slurry mixture made with 9 types of soil and 6 types of accelerated mixtures in the laboratory were evaluated for bleeding, flowability, heat resistance, and unconfined compressive strength to meet the aim values of this study.

• Geomechanics and Engineering
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• v.10 no.5
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• pp.677-687
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• 2016

Industrialization and urbanization are the two phenomena that are going relentless all over the world. The consequence of this economic success has been a massive increase in waste on one hand and increasing demand for suitable sites for construction on the other. Owing to the surplus raw materials and energy requirement needed for manufacturing synthetic fibers, applications of waste fibers for reinforcing soils evidenced to offer economic and environmental benefits. The main objective of the proposed work is to explore the possibilities of improving the strength of soil using fly ash waste as an admixture and Human Hair Fiber (HHF) as reinforcement such that they can be used for construction of embankments and land reclamation projects. The effect of fiber content on soil - fly ash mixture was observed through a series of laboratory tests such as compaction tests, CBR and unconfined compression tests. From the stress - strain curves, it was observed that the UCC strength for the optimised soil - flyash mixture reinforced with 0.75% human hair fibers is nearly 2.85 times higher than that of the untreated soil. Further, it has been noticed that there is about 7.73 times increase in CBR for the reinforced soil compared to untreated soil. This drastic increase in strength may be due to the fact that HHF offer more pull-out resistance which makes the fibers act like a bridge to prevent further cracking and thereby it improves the toughness which in turn prevent the brittle failure of soil-flyash specimen. Hence, the test results reveal that the inclusion of randomly distributed HHF in soil significantly improves the engineering properties of soil and can be effectively utilized in pavements. SEM analysis explained the change of microstructures and the formation of hydration products that offered increase in strength and it was found to be in accordance with strength tests.

• Korean Journal of Soil Science and Fertilizer
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• v.46 no.5
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• pp.351-358
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• 2013

A suitable supply of mineral elements into shoot via a root system from growth media makes plants favorable growth and yield. The shortage or surplus of minerals directly affects overall physiological reactions to plants and, especially, strongly influences carbohydrate metabolism as a primary response. We have studied mineral uptake and synthesis and translocation of soluble carbohydrates in N, P or K-deficient tomato plants, and examined the interaction between soluble carbohydrates and mineral elements. Four-weeks-old tomato plants were grown in a hydroponic growth container adjusted with suboptimal N ($0.5mmol\;L^{-1}\;Ca(NO_3)2{\cdot}4H_2O$ and $0.5mmol\;L^{-1}\;KNO_3$), P ($0.05mmol\;L^{-1}\;KH_2PO_4$), and K ($0.5mmol\;L^{-1}\;KNO_3$) for 30 days. The deficiency of specific mineral element led to a significant decrease in its concentration and affected the concentration of other elements with increasing treatment period. The appearance of the reduction, however, differed slightly between elements. The ratios of N uptake of each treatment to that in NPK sufficient tomato shoots were 4 (N deficient), 50 (P deficient), and 50% (K deficient). The P uptake ratios were 21 (N deficient), 19 (P deficient), and 28% (K deficient) and K uptake ratios were 11 (N deficient), 46 (P deficient), and 7% (K deficient). The deficiency of mineral elements also influenced on carbohydrate metabolism; soluble sugar and starch was substantially enhanced, especially in N or K deficiency. In conclusion, mineral deficiency leads to an adverse carbohydrate metabolism such as immoderate accumulation and restricted translocation as well as reduced mineral uptake and thus results in the reduced plant growth.

• Korean Journal of Soil Science and Fertilizer
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• v.45 no.6
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• pp.910-919
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• 2012

The role of inorganic nitrogen assimilation in the production of amino acids, organic acids and soluble sugars is one of the most important biochemical processes in plants, and, in order to achieve normally, nitrate uptake and assimilation is essential. For this reason, the characterization of nitrate assimilation and metabolite composition from leaves, roots and xylem sap of tomato (Solanum lycopersicum) was investigated under different nitrate levels in media. Tomato plants were grown hydroponically in liquid culture under five different nitrate regimes: deficient (0.25 and 0.75 mM $NO_3{^-}$), normal (2.5 mM $NO_3{^-}$) and excessive (5.0 and 10.0 mM $NO_3{^-}$). All samples, leaves, roots and xylem sap, were collected after 7 and 14 days after treatment. The levels of amino acids, soluble sugars and organic acids were significantly decreased by N-deficiency whereas, interestingly, they remained higher in xylem sap as compared with N-normal and -surplus. The N-excessive condition did not exert any significant changes in metabolites composition, and thus their levels were similar with N-normal. The gene expression and enzyme activity of nitrate reductase (NR), nitrite reductase (NIR) and glutamine synthetase (GS) were greatly influenced by nitrate. The data presented here suggest that metabolites, as a signal messenger, existed in xylem sap seem to play a crucial role to acquire nitrate, and, in addition, an increase in ${\alpha}$-ketoglutarate pathway-derived amino acids under N-deficiency may help to better understand plant C/N metabolism.

• Korean Journal of Plant Resources
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• v.12 no.4
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• pp.282-288
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• 1999

The experiment was carried out to determine the effects of soil condition on the agronomic characters and aromatic substances in cultivated Codonopsis Lanceolata. An increase of planting densities of Codonopsis Lanceolata. from 1 to 5 plant per pot resulted in the smaller root width, but root yield increased from 109.8g to 286.9g per 1/200pot. The width growth as soil water contents were higher in surplus soil water than that of cultivated deficit soil water. The contents of water, reducing sugar, crude protein and malic acid were higher in cultivated wild than in cultivated upland soil. The higher contents of volatile essential oils as 3-rnethylpentanoic acid and squalene was obtained at the normal soil moisture.

• Journal of the Korean Geotechnical Society
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• v.19 no.5
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• pp.189-197
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• 2003

The treatment and hauling of surplus soils which occur from construction activity are costly and have been demanding a reasonable recycling method. This study presents laboratory test results regarding the mechanistic properties of asphalt stabilized soils. The foamed asphalt equipment which generates the asphalt bubble was used to mix the soil. The marshall stability, indirect tensile test, resilient modulus, creep test and triaxial test(UU) were conducted to find out the performance of the asphalt stabilized soil. The test results were compared with the samples that fabricated in different conditions(the samples without asphalt and the reinforced samples using 2% cement). The inclusion of the asphalt in the soil has improved the marshall stability, resilient modulus and moisture susceptibility, and the addition of the 2% cement has even more increased these properties. The amount of the fines and the optimum moisture contents for mixing affects the mechanistic properties and important parameters for mix design.

• Korean Journal of Soil Science and Fertilizer
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• v.9 no.3
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• pp.133-147
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• 1976

1. The purpose of this study is to provide a series of statistical "bench marks" from which one can begin to think systematically about the required development of the Korean food and fertilizer needs over the next quarter-century. 2. The Korean population has been estimated by the characteristics of the population and its social and political situations today. Because fertility and mortality rates are relatively stable and are under control of politics concerned, the estimation rates were established with 1.6% over 1975-1980, 1.3% over 1981-1990, and 1.0% over 1991-2000. 3. Annual per capita absorption of milled rice has fluctuated rather closely around 140kg, since 1968, with no evidence of declining trend. Per capita absorption of barley and wheat around 120 kg, and legumes around 10.6kg, However because the case of wheat and corn productions are rather difficult the self-sufficiency in the future, the rice is considered to be accelerate its yield growth surplus the level of self-sufficiency to export. 4. The fertilizer demand in each element has been calculated by mechanical multiplication of "the recommend index of fetilizer application" to yield a unit production over the need of national food supply by crop year. 5. As a results refer to Table (8), the estimated quantities of total fertilizer demand to meet the national food supply of the years of 1974, 1980, 1985, 1.990, 1995, and 2000 are reached around 871500, 1138150, 1375480, 1515030, 1652090 and 1799850 metric tons in each year.