• Korean Journal of Soil Science and Fertilizer
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• v.27 no.3
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• pp.149-157
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• 1994

The conditions for formation of allophane in volcanic ash soils in Cheju Island were investigated. Soils of toposequence distributed along the sourthern slope of Mt. Halla, and the major soil groups such as dark brown soils, very dark brown soils, black soils, and brown forest soils were colleted and analyzed for Al, Fe and Si extracted with solutions of pyrophosphate and oxalate. Mean annual temperature decreased $0.8^{\circ}C$ and mean annual precipitation increased 110mm with increase elevation of 100m. Organic carbon content increased and soil pH decreased with elevation, and the formation of allophane in soils formed a climosequence. Dark brown soils widely distributed in the northern and western coastal areas, where the mean annual precipitation ranged 1,240~1,420mm and the evaporation ranged 1,290~1,320mm, contained only small amounts of allophane and Al-humus complexes. For other soils, organic carbon content, pyrophosphate extractable Al, and $Al_p/Al_o$ were inversely correlated with $pH(CaCl_2)$. Allophane content showed close relationships wlth $pH(CaCl_2)$, and inverse relationships with organic carbon content and $Al_p/Al_o$.

• The Korean Journal of Malacology
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• v.32 no.2
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• pp.95-102
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• 2016

This study investigated the growth characteristics of juvenile abalone when has been rearing as other different feed rates by the commercial abalone formulated feed on indoor tank, during the winter period that was maintaining on the low water temperature. Experimental abalones were use to 1 year old (shell length $29.14{\pm}2.56mm$, wet weight $2.9{\pm}0.6g$), and it has cultured at six feeding rate groups (0.75 DFW, 1.50 DFW, 2.25 DFW, 3.00 DFW, 3.75 DFW, 4.5 DFW) that were set up the daily feeding rate about total weight (DFW), and two replicated. The average water temperature in the experiment period was $9.7{\pm}3.27^{\circ}C$. In the monthly change absolute growth rate (AGRSL) and specific growth (SGRSL) of shell length, at January, 3.00 DFW was significantly higher than all feeding rate groups (P < 0.05). And in the monthly change of weight change and weight gain (WG), at March, 3.75DFW was significantly higher than all feeing rate groups (P < 0.05). The growth coefficient of thermal units (TGC) was decreased rapid since January, and 3.75 DFW was show significantly higher than all feeding rate groups (P < 0.05). In monthly change of feed efficiency (FE), at December, the 0.75 DFW was significantly higher than all feeding rate groups (P < 0.05), and in February and March, there was no significant difference between all feeding period. Therefore, In this study, was show that juvenile abalones can do to maintain or increasing from weight to supply commercial artificial diet during winter period when rearing into the indoor tank.

• Applied Biological Chemistry
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• v.6
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• pp.61-77
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• 1965

In this experiment, Akiochi was studied especially on plant growth on the degraded soils. Besides, such soils were carefully examined on its character and plant body was analysed to know the difference in various mineral contents. For this purpose, paddy cultivation was done with the variety Pal Dal at Suwon, Sosa and Pyungtak. Three plots were chosen at each location as the normal and 2 levels of akiochi, a-the stronger and b-the weaker. Harvests from these 9 plots were measured agronomically and also chemically analysised. As for soil, after an observation on vertical section of soil, samples from each layer were also studied both physically and chemically. The results are summarized as follows. 1. Outer changes in rice plant and changes in yield components. 1) Rice from Akiochi soil showed remarkably shortened culm length, head length, protrusoion length, blade length of boot leaf, and coleoptile length, compared with that from the normal paddy field. 2) There was a tendency for Akiochi rice to have more heads per plant. 3) Akiochi rice showed poorer intercalary growth of upper 3 internodes. The ratio of this upper internode length to total culm length was also smaller in this case. Consquently the ratio of lower internode length to total culm length became larger than that from normal peddy field. 4) Akiochi rice showed significantly fewer first spikelets and attached grains of head at main stem. 5) Maturing rate of both this main seem of whole plant body was remarkably lower than that of normal rice. 6) Akiochi rice showed lower head weight of main stem, total hulled rice weight, total grain yield, 1000-grain weight, straw weight and straw-hulled rice ratio. 2. Physical and chemical study on soil. 1) Akiochi soil showed thinner upper layer and total thickness of upper and lower parts was smaller than that of normal. 2) Akiochi soil of Suwon was mainly composed of sand, while that of Sosa and Pyungtak was composed of heavy clay. 3) Chemical analysis indicated that content of $SiO_2$ in upper layer is always lower than that of normal. But no other common tendencies were found. 4) This analysis further lillustrates lower content of Fe, & Mn at Suwon ; of Mn at Sosa and higher content of Fe at Sosa and organic matters at Pyungtak. 5) Some differences in the content of N in each plot could be marked though irregular. 3. Chemical Composition of plant body. 1) Chemical analysis on grain, boot leaf and straw did not suggest any remarkable differences between normal and Akiochi rice, except that the latter contains less Si in boot leaf and less Mn in straw. 2) Contents of each chemical element were measured in grain and straw to calculate the percentage of element content in grain to that of whole plant body including both grain and straw. Here, Akiochi rice always showed lower value in N, K and Mn. 4. Relationship between chemical composition of plant body and that of soil. Akiochi soil at Sosa marked lower content of Mn. This caused another lower content of this element in grain, boot leaf and straw. But except that, no remarkable relationship could be found in this study.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2004.09a
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• pp.119-120
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• 2004

Urban groundwater has a unique hydrologic system because of the complex surface and subsurface infrastructures such as deep foundation of many high buildings, subway systems, and sewers and public water supply systems. It generally has been considered that increased surface impermeability reduces the amount of groundwater recharge. On the other hand, leaks from sewers and public water supply systems may generate the large amounts of recharges. All of these urban facilities also may change the groundwater quality by the recharge of a myriad of contaminants. This study was performed to determine the factors controlling the recharge of deep groundwater in an urban area, based on the hydrogeochemical characteristics. The term ‘contamination’ in this study means any kind of inflow of shallow groundwater regardless of clean or contaminated. For this study, urban groundwater samples were collected from a total of 310 preexisting wells with the depth over 100 m. Random sampling method was used to select the wells for this study. Major cations together with Si, Al, Fe, Pb, Hg and Mn were analyzed by ICP-AES, and Cl, N $O_3$, N $H_4$, F, Br, S $O_4$and P $O_4$ were analyzed by IC. There are two groups of groundwater, based on hydrochemical characteristics. The first group is distributed broadly from Ca-HC $O_3$ type to Ca-C1+N $O_3$ type; the other group is the Na+K-HC $O_3$ type. The latter group is considered to represent the baseline quality of deep groundwater in the study area. Using the major ions data for the Na+K-HC $O_3$ type water, we evaluated the extent of groundwater contamination, assuming that if subtract the baseline composition from acquired data for a specific water, the remaining concentrations may indicate the degree of contamination. The remainder of each solute for each sample was simply averaged. The results showed that both Ca and HC $O_3$ represent the typical solutes which are quite enriched in urban groundwater. In particular, the P$CO_2$ values calculated using PHREEQC (version 2.8) showed a correlation with the concentrations of maior inorganic components (Na, Mg, Ca, N $O_3$, S $O_4$, etc.). The p$CO_2$ values for the first group waters widely ranged between about 10$^{-3.0}$ atm to 10$^{-1.0}$ atm and differed from those of the background water samples belonging to the Na+K-HC $O_3$ type (<10$^{-3.5}$ atm). Considering that the p$CO_2$ of soil water (near 10$^{-1.5}$ atm), this indicates that inflow of shallow water is very significant in deep groundwaters in the study area. Furthermore, the P$CO_2$ values can be used as an effective parameter to estimate the relative recharge of shallow water and thus the contamination susceptibility. The results of our present study suggest that down to considerable depth, urban groundwater in crystalline aquifer may be considerably affected by the recharge of shallow water (and pollutants) from an adjacent area. We also suggest that for such evaluation, careful examination of systematically collected hydrochemical data is requisite as an effective tool, in addition to hydrologic and hydrogeologic interpretation.ion.ion.

• Korean Journal of Environmental Agriculture
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• v.2 no.2
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• pp.98-102
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• 1983

The hydrogen fluoride gas generated from making the cement hardener injured the plants growing at the neighbour field. This investigation was conducted on sample analysis of hydrogen fluoride gas damage plants which included the ratios of destroyed leaves, damage symptoms, and nutrient elements in paddy rice and weeds. The results obtained were as follows; 1) The ratio of destroyed leaves at near HF source was very high reaching about 95% at 100m, 65% at 500m, 5% at 2㎞, respectively. 2) The necrosis was the characteristic symptom of fluoride injury on rice plant and occurred predominantly at the tip and margins of damage leaf. It developed along the tip and margins of leaves with a dull, gray-green, water soaked discoloration. 3) The fluorine content of tip and margins of damaged rice leaves were 1,600 ppm, 3 to 20 times higher than that of center part and it ranged from 130 to 242.5 ppm in weed leaves, but from 10 to 15 ppm in normal weed leaves. 4) The contents of calcium, potassium, silicon, iron and manganese were higher in tip and margins than in the center of rice damage leaves. 5) The Cocculus trilolous. D.C was the most resistant plant to HF gas than any other plant growing in this site, while wild berry and aralia tree belong to most sensitive plant group.

• Economic and Environmental Geology
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• v.22 no.1
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• pp.35-63
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• 1989

Geochemical characteristics of the Guryongsan (Ogcheon) uraniferous black slate show that this is an analogue to the conventional Chattanooga and Alum shales in occurrences. Whereas, its highest enrichment ratio in metals including uranium, among others, is explained by the cyclic sedimentation of the black muds and quartz-rich silts, and the uniform depositional condition with some what higher pH condition compared to the conditions of the known occurrences. The cyclic sedimentation, caused by the periodic open and close of the silled basin, has brought about the flush-out) of the uranium depleted water and the recharge with the new metal-rich sea water, which consequently contributed to the high concentration of metals in mud. The metal-rich marine black muds, which mostly occur in the early to middle Palaeozoic times, is attributed by the geologic conditions which related to the atmospheric oxygen contents, and these are scarcely met in the late Precambrian and/or with the onset of Palaeozoic era in the geologic evolution of the earth.