• Korean Journal of Soil Science and Fertilizer
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• v.11 no.4
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• pp.247-262
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• 1979

Majority of reclaimable soils in hillside lands in Korea are red yellow soils, with exception in Jeju island, where most of reclaimable hillside lands are composed of volcanic ash soils. Songjeong, Yesan and Samgag series are the major soil series of red yellow soils which are available for the reclamation. When observed in the fields, they are distinguished as reddish brown clay loam, red yellow sand loam and yellowish brown sand loam. They have moderately good physical properties but their chemical properties are generally poor for crop cultivations. The chemical properties of red yellow soils, as compared to long time cultivated (matured) soils, are characterized by very low pH, high in exchangeable Al content and phosphorus fixation capacity. Also extraodinary low available phosphorus and organic matter contents are generally observed. On the other, the chemical properties of volcanic ash soils are characterized by high armophous Fe and Al hydroxides and organic matter contents, which are the causative factors for the extremely high phosphorus fixation capacity of the soils. The phosphorus fixation capacity of volcanic acid soils are as high as 5-10 times of that of red yellow soils. Poor growth of crops on newly reclaimed red yellow soils are mainly caused by very low available P and pH and high exchangeable Al. Relatively high P fixation capacity renders the failure of effective use of applied P when the amount of application is not sufficient. Applications of lime to remove the exchangeable Al and relatively large quantity of P to lower the P fixation capacity and to increase the available P are the major recommendations for the increased crop production on red yellow hillside soils. Generally recommendable amounts of lime and P to meet the aforementioned requirements, are 200-250kg/10a of lime and $30-35kg\;P_2O_5/10a$. Over doses of lime. frequently induces the K, B, arid Zn deficiencies and lowers the uptake of P. In volcanic ash soils, it is difficult to alter the exchangeable Al and the P fixation capacity by liming and P application. This may be due to the peculiarity of volcanic ash soil in chemical properties. Because of this feature, the amelioration of volcanic ash soils is not as easy as in the case of red yellow soils. Application of P as high as $100kg\;P_2O_5/10a$ is needed to bring forth the significant yield response in barley. Combined applications of appropriate levels of P, lime, and organic matter, accompanied by deep plowing, results in around doubling of the yields of various crops on newly reclaimed red yellow soils.

• Korean Journal of Soil Science and Fertilizer
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• v.49 no.4
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• pp.355-367
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• 2016

Soil salinization refers to the buildup of salts in soil to a level toxic to plants. The major factors that contribute to soil salinity are the quality, the amount and the type of irrigation water used. The presented review discusses the different sources and causes of soil salinity. The effect of soil salinity on biological processes of plants is also discussed in detail. This is followed by a debate on the influence of salt on the nutrient uptake and growth of plants. Salinity decreases the soil osmotic potential and hinders water uptake by the plants. Soil salinity affects the plants K uptake, which plays a critical role in plant metabolism due to the high concentration of soluble sodium ($Na^+$) ions. Visual symptoms that appear in the plants as a result of salinity include stunted plant growth, marginal leaf necrosis and fruit distortions. Different strategies to ameliorate salt stress globally include breeding of salt tolerant cultivars, irrigation to leach excessive salt to improve soil physical and chemical properties. As part of an ecofriendly means to alleviate salt stress and an increasing considerable attention on this area, the review then focuses on the different plant growth promoting bacteria (PGPB) mediated mechanisms with a special emphasis on ACC deaminase producing bacteria. The various strategies adopted by PGPB to alleviate various stresses in plants include the production of different osmolytes, stress related phytohormones and production of molecules related to stress signaling such as bacterial 1-aminocyclopropane-1-carboxylate (ACC) derivatives. The use of PGPB with ACC deaminase producing trait could be effective in promoting plant growth in agricultural areas affected by different stresses including salt stress. Finally, the review ends with a discussion on the various PGPB activities and the potentiality of facultative halophilic/halotolerant PGPB in alleviating salt stress.

• Korean journal of applied entomology
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• v.31 no.3
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• pp.205-240
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• 1992

In reality, it is a green revolution of the entire agricultural matrix in Korea that integrated pest control plays an important role in the possible breakthrough in rice self-sufficiency. In paddy agroecosystem as man-modified environment, rice is newly established every year by transplantation under diverse water regimes which affect a microclimate. Standing water benefits rice by regulating the microclimate, but it favors the multiplication of certain pets through the amelioration of the microclimate. Further, the introduction of high yielding varieties with the changing of cultural practices results in changing occurrence pattern of certain pests. In general, japonica type varieties lack genes resistant to most of the important pests and insect-borne virus diseases, whereas indica type possesses more genes conferring varietal resistance. Thus, this differences among indica type, form the background of different approaches to pest management. The changes in rice cultivation such as double cropping, growing high-yielding varieties requiring heavy fertilization, earlier transplanting, intensvie-spacing transplanting, and intensive pesticide use as a consequence of the adoption of improves rice production technology, have intensified the pest problems rather than reduced them. The cultivation of resistant varieties are highly effective to the pest, their long term stability is threathened because of the development of new biotypes which can detroy these varieties. So far, three biotypes of N. lugens are reported in Korea. Since each resistant variety is expected to maintain several years the sequential release of another new variety with a different gene at intervals is practised as a gene rotation program. Another approach, breeding multilines that have more than two genes for resistance in a variety are successfully demonstrated. The average annual rice losses during the last 15 years of 1977-’91 are 9.3% due to insect pests without chemical control undertaken, wehreas there is a average 2.4% despite farmers’insecticide application at the same period. In other words, the average annual losses are prvented by 6.9% when chemical control is properly employed. However, the continuous use of a same group of insecticides is followed by the development of pest resistance. Resistant development of C. suppressalis, L. striatellus and N. cincticeps is observed to organophosphorous insecticides by the mid-1960s, and to carbamates by the early 1970s in various parts of the country. Thus, it is apparent that a scheduled chemical control for rice production systems becomes uneconomical and that a reduction in energy input without impairing the rice yield, is necessarily improved through the implementation of integrated pest management systems. Nationwide pest forecasting system conducted by the government organization is a unique network of investigation for purpose of making pest control timely in terms of economic thresholds. A wise plant protection is expected to establish pest management systems in appropriate integration of resistant varieties, biological agents, cultural practices and other measures in harmony with minimizing use of chemical applications as a last weapon relying on economic thresholds.

• Journal of the Korean Electrochemical Society
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• v.10 no.3
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• pp.184-189
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• 2007

The importance of secondary battery industry is getting excited according to the development of battery industry as a high efficiency energy supplier of electronic machine of mobile information such as mobile phone, lap-top computer, PDA. It is rasing the interest about security of safety and high efficiency of cathode material for main part of secondary lithium battery. The cathode material which has been used like $LiCoO_2,\;LiMn_2O_4,\;LiNi_xCo_yMn_zO_2,\;LiNi_xCo_yM_zO_2$ (M=Al, Zr, Mg etc.,) the most typical material is $LiCoO_2$. But it is studying the development of substitute such as efficiency amelioration of $LiCoO_2$, thetiary element, olivine element because of the capacity of $LiCoO_2$, the matter of security; especially the betterment of efficiency, security research of safety has been actively processed in domestic and overseas about surface coating treatment of active cathode which is using oxide ($M_xO_3$). This study analyses side effect of battery according to increase of surface treatment, formation of precipitation for reagent condensation, non-reagent residue of oxide ($M_xO_3$) which is remains during the surface treatment of $LiCoO_2$; conducts study of new process, the consideration of the electrochemical property to improve oxide solution of mixing rate, mixture of surface treatment, dryness, calcinations conditionetc.

• Tuberculosis and Respiratory Diseases
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• v.60 no.4
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• pp.437-450
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• 2006

Background : Acute respiratory distress syndrome (ARDS) is characterized by severe inflammatory pulmonary edema of unknown pathogenesis. To investigate the pathogenesis of ARDS associated with neutrophilic oxidative stress, the role of phospholipase $A_2$ ($PLA_2$) was evaluated by the inhibition of calcium channel. Methods : In Sprague-Dawley rats, acute lung injury (ALI) was induced by the instillation of E.coli endotoxin (ETX) into the trachea. At the same time, diltiazem was given 60 min prior to tracheal instillation of ETX. Parameters of ALI such as lung and neutrophil $PLA_2$, lung myeloperoxidase (MPO), BAL neutrophils, protein, surfactant were measured. Production of free radicals from neutrophils was measured also. Morphological studies with light microscope and electron microscope were carried out and electron microscopic cytochemistry for detection of free radicals was performed also. Results : Diltiazem had decreased the ALI parameters effectively in ETX given rats and decreased the production of free radicals from neutrophils and lung tissues. Morphological studies denoted the protective effects of diltiazem. Conclusion : Diltiazem, a calcium channel blocker, was effective in amelioration of ALI by the suppression of neutrophilic oxidative stress mediated by $PLA_2$ activation.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.3 no.3
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• pp.81-99
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• 2000

The shelterbelts are very important to conserve and protect the sandy land, vegetation coverage, farmland, livestock and human life in the desertified land. The shelterbelts are constructed by the several row-plantings of high-adaptable species in the desertified land. The shelterbelts have various kind of type, and there are shelterbelts for conservation of farmland in dry the region, the protective shelterbelts (windbreaks for blowing-sand, artificial sanddune fixation by revegetation, and construction of farmland shelterbelts to protect farmland and pasture from wind erosion, etc.) in the semi-dry steppe, shelterbelts around the villages and oasis for sanddune fixation, shelterbelts for protection of railroads, and so on. The shelterbelts consist of main she1terbelts and minor shelterbelts. The main shelterbelts were constructed by being perpendicular to main wind direction, and the minor shelterbelts were constructed by being perpendicular to the main shelterbelts. Generally, the width of shelterbelts is 8~20m, and the number of row-planting is 4~10. The grid sizes of shelterbelts networks are $400{\times}400m$, $300{\times}500m$, $100{\times}200m$, and so on, and there are ventilation type and closing type in the type of shelterbelt. The width, number of row-planting, grid size and type of shelterbelt are selected by the local characteristics. The effects of shelterbelts are mainly the climate improvement and mitigation, such as prevention of occurrence of strong wind, cold wind and blowing-sand. And, the other effects of shelterbelts are effect of reforestation, increase of agricultural productions, establishment of greenbelts and green forests, construction of landscape-eco shelterbelts, improvement of life environment of local villages, supply of fuel wood and agricultural wood, land amelioration, effect of revegetation and restoration of desertified land, and so on. The kinds of the tree species mainly used for the construction of shelterbelts have differences between regions, but main species are Populus euphratica, Populus simonii, Populus bolleana, Populus tomentosa, Salix flavida, Salix mongolica, Tamarix chinensis, Hedysarum scoparium, and so on.

• Korean Journal of Soil Science and Fertilizer
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• v.36 no.2
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• pp.80-85
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• 2003

This study was conducted to find out the effect of a lime stabilized slaughterhouse waste(LSW) on the growth of chinese cabbage and soil pH. Two levels of the lime stabilized slaughterhouse waste treatment, 169 and $338kg\;10a^{-1}$, with N-P-K fertilization were tested, and treatments of N-P-K and N-P-K with slaked lime were included in the experiment as a control. Fresh weight of chinese cabbage at harvest was not significantly different among the treatments. However, in the LSW treatment of $169kg\;10a^{-1}$, fresh weight of chinese cabbage was 5% higher comparing to the N-P-K treatment. Contents of N, P, and K in chinese cabbage were higher in the LSW treatments in comparison to the control treatments. Competitive inhibition of Mg uptake by Ca in the treatments of LSW and lime was apparent. Soil pH was increased by the application of LSW, and the increase in the LSW treatment of $169kg\;10a^{-1}$ was nearly the same as the soil pH increase in the slaked lime treatment. The lime stabilized slaughterhouse waste can be considered as a potential soil amendment for amelioration of soil acidity and supply of organic matter as well.

• Journal of Environmental Health Sciences
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• v.16 no.1
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• pp.29-43
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• 1990

The purpose of this study is to investigate the vairous change in the toxicity of cadmium by the simultaneous administration of selenium and zinc, which have been reported to change -the toxicity of cadmium through the interaction with cadmium, to rat. For the experiment, 42 rats of Sprague-Dawley strain were used. The experimental groups were divided into 6 groups: a control group, a cadmium (100ppm) alone treatment group, a cadmium (100ppm) and zinc (100ppm) combined treatment group, and three cadmium (100ppm), zinc (100ppm) and selenium (1, 4, and 8ppm) combined treatment groups. The rats were allocated seven to each group and observed for seven weeks. The results of experiment are as follows: 1. The food consumptions of each group were reduced, compared with a control group, especially, in a cadmium and zinc combined treatment group and a cadmium $\cdot$ zinc and selenium(1ppm) combined treatment group to the significant level compared with a control group (p < 0.05). The water consumptions of each group were reduced to the very significant level compared with a control group (p < 0.01). The feed efficiencies of each group were lower than a control group, and among them the highest group was cadmium $\cdot$ zinc and selenium (8ppm) combined treatment group as 90% of a control group. 2. In all groups, the weight gains were highest in the second week and the total weight gains were reduced to the very significant level compared with a control group (p < 0.01). 3. In all groups, the relative weights of liver were reduced, compared with a control group, especially, a cadmium alone treatment group was reduced to the significant level (p < 0.05). The relative weight of kidney was high to the significant level in a cadmium alone treatment group (p < 0.05) compared with a control group. In all groups, the relative weights of testis were reduced, compared with a control group, but the levels were not significant. 4. The accumulation of cadmium was highest in the kidney and the order of height was in liver, testis and blood, respectively. In all groups, the amount of cadmium accumulation was high to the very significant level compared with a control group (p < 0.01). In liver, the amount of acdmium accumulation in. a cadmium alone treatment group was high to the significant level compared with a cadmium $\cdot$ zinc and selenium (8ppm) combined treatment group (p < 0.05), and in kidney, the amount of cadmium accumulation in a cadmium alone tretment group was high to the very significant level compared with the cadmium $\cdot$ zinc and selenium (4, 8ppm) combined treatment groups (p < 0.01). However, in testis, among the treatment groups the level was not significant and in blood, a cadmium alone treatment group was low to the significant level compared with the cadmium $\cdot$ zinc and selenium (4, 8ppm) combined treatment groups (p < 0.05). 5. According to the histopathological finding on the testis, some of the seminiferous tubules of a group treated with cadmium alone showed severe necrosis and atrophy. But the testis of cadmium $\cdot$ zinc and selenium (8ppm) combined treatment group was similar to that of a control group. From the results of this study, it can be concluded that the repeated simultaneous oral administration of large doses of selenium with the cadmium produces the partial amelioration of cadmium toxicity, whereas zinc does not.

• Journal of Ecology and Environment
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• v.31 no.1
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• pp.23-29
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• 2008

The effectiveness of rehabilitation programs for coal mining spoils in Samcheok, Jeongsun, and Mungyung were evaluated based on the physicochemical properties of soil in the rehabilitated areas. These spoils were reclaimed by introducing plants such as black locust (Robinia pseudoacacia), pitch pine (Pinus rigida), birch (Betula platyphylla var. japonica), alder (Alnus hirsuta), bush clover (Lespedeza cyrtobotrya), and grass (Lolium perenne) in planting beds covered with forest soil. In the surface soil, the pH, organic matter, total N, available P, and exchangeable Ca showed significant changes over the years after reclamation. The pH and exchangeable Ca content decreased exponentially over time, whereas organic matter increased linearly and total N and available P increased exponentially. Changes in the physicochemical properties of subsurface soils displayed a different pattern. There were significant changes over time in the organic matter, available P, and exchangeable Ca and Mg contents of the soil. Organic matter increased logarithmically with years since rehabilitation and available P increased exponentially. Meanwhile, exchangeable Ca decreased exponentially, and Mg decreased logarithmically. The changes in the subsurface soil were not as dramatic as those in the surface soil. This result suggests that the ameliorating effects of the establishment and growth of plants more pronounced on the surface soil layer. Stand ordination data showed different relationships with time since rehabilitation in the early and later stages of the rehabilitation process. In the early stages of rehabilitation, stands tended to be arranged in the order of reclamation age. However, in the later stages, there was not a clear relationship between reclamation age and vegetation characteristics. This result suggests that soil amelioration is required for the early stages, after which an autogenic effect becomes more prominent as the vegetation becomes better established.

• Journal of Animal Science and Technology
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• v.58 no.7
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• pp.24.1-24.7
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• 2016

Background: Clinoptilolite is a natural zeolite with high adsorption capacity for polar mycotoxins such as aflatoxins. The efficacy of clinoptilolite in ameliorating the toxic effects of aflatoxicosis has been proven in monogastric animals, but there is no such evidence for ruminants. The aim of this study was to evaluate, under field conditions, whether the dietary administration of clinoptilolite in dairy cows could reduce the concentration of aflatoxin M1 ($AFM_1$) in bulk-tank milk, in farms with higher than or close to $0.05{\mu}g/kg$ of milk (European maximum allowed residual level). An objective of the present study was also to investigate the effect of particle size of clinoptilolite on aflatoxin binding. Methods: Fifteen commercial Greek dairy herds with AFM1 concentrations in bulk tank milk ${\geq}0.05{\mu}g/kg$ were selected. Bulk tank milk AFM1 was determined prior to the onset and on day 7 of the experiment. Clinoptilolite was added in the total mixed rations of all farms at the rate of 200 g per animal per day, throughout this period. Two different particle sizes of clinoptilolite were used; less than 0.15 mm in 9 farms (LC group) and less than 0.8 mm in 6 farms (HC group). Results: Clinoptilolite administration significantly reduced $AFM_1$ concentrations in milk in all farms tested at an average rate of 56.2 % (SD: 15.11). The mean milk $AFM_1$ concentration recorded on Day 7 was significantly (P < 0.001) lower compared to that of Day 0 ($0.036{\pm}0.0061$ vs. $0.078{\pm}0.0074{\mu}g/kg$). In LC group farms the reduction of milk $AFM_1$ concentration was significantly higher than HC group farms ($0.046{\pm}0.0074$ vs. $0.036{\pm}0.0061{\mu}g/kg$, P = 0.002). As indicated by the Pearson correlation, there was a significant and strong linear correlation among the milk $AFM_1$ concentrations on Days 0 and 7 (R = 0.95, P < 0.001). Conclusions: Dietary administration of clinoptilolite, especially of smallest particle size, at the rate of 200 g per cow per day can effectively reduce milk $AFM_1$ concentration in dairy cattle and can be used as a preventive measure for the amelioration of the risks associated with the presence of aflatoxins in the milk of dairy cows.