• Korean Journal of Soil Science and Fertilizer
• /
• v.15 no.3
• /
• pp.178-187
• /
• 1982

This pot experiment was undertaken to find out the optimum fertilization ratios of total anions to total cations, ${\Sigma}A/{\Sigma}C$, and the optimum application rates of total macro-nutrients in various soil conditions. Soil samples were collected from uncultivated mountains and hills where grassland development was under consideration. 1. The optimum application ratios of ${\Sigma}A/{\Sigma}C$ and the optimum application rates of total macro-nutrients for the high yields of mixed grass-clover sward in various grassland soils were computed by the Hom$\acute{e}$s systematic variation techniqu.e. 2. With respect to the optimum application ratios of ${\Sigma}A/{\Sigma}C$ in fertilization in a mixed grass-clover sward, the grass yield and botanical composition were distinctly proportional to ${\Sigma}A$ wheras the regume yield and botanical composition were proportional to ${\Sigma}C$. 3. The optimum fertilization rates of total macro-nutrients for the high legume yields were depended upon ${\Sigma}A/{\Sigma}C$ ratios. These optimum rates were in proportional to ${\Sigma}C$ ratios and were inversely proportional to ${\Sigma}A$ ratios. 4. The efficiencies of ${\Sigma}A$ and ${\Sigma}C$ in relation to the grass and grass plus legume yields were highest with the low ratios of each other and the low fertilization rates of total macronutrients. The ${\Sigma}A$ effieiency in the legume yield tended to be similar to that of ${\Sigma}A$ related to the grass yield noted above except Daegu soil. The ${\Sigma}C$ efficiency, however, was proportional to the ${\Sigma}C$ ratio, although that was varied with the fertilization rates of total macro-nutrients and with the kinds of soils. 5. The yield of mixed forages, yield component, and botanical composition in a mixed sward were greatly influenced by the ${\Sigma}A/{\Sigma}C$ ratios, the fertilization rates of total macronutrients, and the interactions of ratio and rate noted above. In addition, these effects were generally different and opposite according to grass and legume.

• Korean Journal of Soil Science and Fertilizer
• /
• v.26 no.3
• /
• pp.143-150
• /
• 1993

To gain the basic informations on soil management practices by determination of the differences of soil genetic characteristics and the contents of soil moisture due to slope aspects of hilly land, this study was conducted at 1992 on sweet persimmon orchard soils derived from porphyry in southern of Korea. The results obtained were summarized as follows. The soils studied were belong to fine loamy family. The degree of soil development was greater in the north than other slope aspects and the solum thickness also the same. The soil chemical properties such as pH and exchangeable cations except for potassium were low generally in the orchards studied but the content of organic matter was lack in the summit and south aspect. The contents of Fe oxide and extractable Al were higher in the subsurface than surface. Fe, Al and clay indexes which indicate relative intensity of B horizon development were higher in the side slope than summit and the highest in the north slope. The rate of solum to B horizon was higher as about 1.5 for summit and west aspect which had thiner B horizon thickness compared to other aspect. North and west aspect had certainly more amount of soil water at drought season than other slope aspects and was lower the difference of soil water between the drought and wet seasons. Therfore, the soil management such as erosion control and irrigation at drought season should be practices differently due to slope aspect and soil chararteristics in the sloped land.

• Korean Journal of Soil Science and Fertilizer
• /
• v.25 no.3
• /
• pp.249-254
• /
• 1992

This research was conducted to investigate the effects of fly ash applications on growth and yield parameters of corn (Zea mays L.), and soil chemical properties. Corn height at silking stage, and height and dry matter ratio at harvesting stage were enhanced by applications of fly ashes derived from bituminous coal and anthracite, respectively. Effects of fly ash treatment on growth parameters of corn were varied with kinds and levels of fly ash application and growth periods, but relatively small without revealing a major negative effect as compared to the control. Yield of corn was increased by applying fly ash of anthracite origin, but other yield components were not influenced negatively by fly ash treatment. Soil total carbon contents, cation exchange capacity, and phosphorus contents of soils sampled after harvest of corn were significantly increased by fly ash treatment, although there were slightly different effects according to kinds and levels of fly ash application. Exchangeable cations of soils were varied within an experimental error range. Phosphorus taken up by corn was enhanced by treating fly ash of the bituminous coal to the soil and there were a positive correlation between phosphorus uptake and soil Phosphorus level. Cation uptake by corn was changed a little, but no significant reduction was observed in cation uptake due to fly ash treatment. It seems to be difficult to figure out the mechanism of fly ash effects on growth and nutrient uptake by corn with one year field experiment, however treatment of fly ash enhanced some parameters of growth and yield, and nutrient uptake by corn without revealing any major negative effects. To determine the value of fly ash as a fertilizer source, continuous researches under various soil and crop conditions were considered to be necessary.

• Korean Journal of Soil Science and Fertilizer
• /
• v.41 no.5
• /
• pp.303-309
• /
• 2008

The physico-chemical properties of the rainfall interception culture (85 sites) and the open field culture soils (85 sites) in the area of Gochang-gun, Jeollabuk-do were surveyed. Soil textural distribution of the rainfall interception culture and the open field culture soils was 74% and 64% for silt loam, 16% and 35% for loam, and 10% and 1% for clay, respectively. The percentage of aggregate rates was higher in the open field culture soils (60.06%) than rainfall interception culture soils (55.84%). Electrical conductivity, exchangeable cations, and anions in the rainfall interception culture soils were higher than those in open field soils. Specially, accumulated amount of anion in rainfall interception culture soils was remarkably higher 2~3 times than open field culture soils. The results from the analyses of rainfall interception culture soils suggested that the most critical problem is the salts accumulation caused by over-fertilization of chemical fertilizer and compost. Therefore, application rates of chemical fertilizer and compost should be controlled in order to conservation of soil and water for sustainable agriculture.

• The Korean Journal of Ecology
• /
• v.23 no.5
• /
• pp.397-406
• /
• 2000

In order to clarify the ecophysiological characteristics of Chenopodiaceae which widely distribute on saline and arid habitats, we collected 10 chenopodiaceous plant species, examined their inorganic and organic solute patterns, and confirmed several common physiological characteristics. In spite of high soil Ca/sup 2＋/ contents, chenopodiaceous plants had a little water-soluble Ca within cells, but contained high contents of acid-soluble Ca particularly as a result of Ca-oxalate formation. These plant species also showed accumulation of inorganic ions such as K/sup ＋/, NO₃/sup －/ and Cl/sup －/, and Na/sup ＋/especially in saline habitats instead of K/sup ＋/ Meanwhile, with respect to nitrogen metabolism they retained high N contents in leaves, but showed very low amino acid contents. Additionally, they contained very little proline known to act as a cytoplasmic osmolyte. To ascertain whether this physiological characteristics in the field also can be found under controlled conditions, 7 chenopodiaceous plants (Atriplex gmelini, Corispermum stauntonii, Salicornia herbacea, Suaeda aspayagoides, Suaeda japonica, Chenopodium album var. centrorubrum, C. serotinum) were selected and cultivated under salt treatments. As well as field-grown plants, selected plant species showed similar solute pattern in growth experiment. In summary, the family of Chenopodiaceae represents the following physiological properties; high storage capacity for inorganic ions (especially alkali cations, nitrate and chloride), oxalate synthesis to maintain lower soluble Ca contents within cytoplasm, and low contents of amino acids. In addition to some characteristics mentioned above, the physiological plasticities of Chenopodiaceae which can properly regulate their ion and solute pattern according to soil conditions may enable its representative to grow in dry sand dune and salt marsh habitats.

• Asian-Australasian Journal of Animal Sciences
• /
• v.26 no.6
• /
• pp.845-855
• /
• 2013

Requirements of dietary chloride (dCl) and chloride salts were determined by using $4{\times}2$ factorial arrangement under four phase feeding program. Four levels (0.31, 0.45, 0.59 and 0.73%) and two sources ($NH_4Cl$ and $CaCl_2$) of the dCl were allocated to 1,472 chicks in eight dietary treatments in which each treatment was replicated four times with 46 birds per replicate. The four phase feeding program was comprised of four dietary phases: Prestarter (d 1 to 10), Starter (d 11 to 20), Grower (d 21 to 33) and Finisher (d 34 to 42); and diets were separately prepared for each phase. The cations, anions, pH, dissolved oxygen (DO), temperature, electrical conductivity (EC), total dissolved solids (TDS) and salinity were analyzed in drinking water and were not affected by dietary treatments. BW gain (BWG; $p{\leq}0.009$) and feed:gain (FG; $p{\leq}0.03$) were improved in $CaCl_2$ supplemented diets during d 1 to 10. The maximum response of BWG and FG was observed at 0.38% and 0.42% dCl, respectively, for d 34 to 42. However, the level of dCl for BWG during d 21 to 33 ($p{\leq}0.04$) and d 34 to 42 ($p{\leq}0.009$) was optimized at 0.60% and 0.42%, respectively. The level of dCl for optimized feed intake (FI; $p{\leq}0.006$), FG ($p{\leq}0.007$) and litter moisture (LM; $p{\leq}0.001$) was observed at 0.60%, 0.38% and 0.73%, respectively, for d 1 to 42. Water intake (DWI) was not affected by increasing dCl supplementation (p>0.05); however, the ratio between DWI and FI (DWI:FI) was found highest at 0.73% dCl during d 1 to 10 ($p{\leq}0.05$) and d 21 to 33 ($p{\leq}0.009$). Except for d 34 to 42 ($p{\leq}0.006$), the increasing level of dCl did not result in a significant difference in mortality during any phase. Blood pH and glucose, and breast and thigh weights (percentage of dressed weight) were improved while dressing percentage (DP) and gastrointestinal health were exacerbated with $NH_4Cl$ as compared to $CaCl_2$ supplemented diets ($p{\leq}0.001$). Higher plasma $Na^+$ and $HCO_3{^-}$ and lower $Cl^-$ and $Ca^{{+}{+}}$ were observed in $NH_4Cl$ supplemented diets ($p{\leq}0.001$). Increasing supplementation of dCl increased plasma $Cl^-$ ($p{\leq}0.04$; quadratically) and linearly reduced plasma $K^+$ ($p{\leq}0.001$), $Ca^{{+}{+}}$ ($p{\leq}0.003$), $HCO_3{^-}$ ($p{\leq}0.001$), and $Na^+$ ($p{\leq}0.001$; quadratically). Consequently, higher requirements of dietary chloride are suggested for feed intake; nevertheless, lower levels of dietary chloride are sufficient to support optimal BWG and FG with increasing age. The $NH_4Cl$ supplemented diets ameliorate breast and thigh meat yield along with overall energy balance (glucose).

• Journal of Korean Society of Forest Science
• /
• v.84 no.1
• /
• pp.103-113
• /
• 1995

To estimate buffer capacity and sensitivity of forest ecosystem to acid rain in Taejon, ionic components of throughfall, stemflow, soil leachate, and open rain in Pinus rigida and Quercus variabilis forest were analysed. The spatial sensitivity based on parent rock and forest type was given by IDRISI of GIS which created imagery conversion from soil and vegetation map. Parent rocks and soils were classified into acidic, sedimentary, metamorphic rock and then subdivided based on $SiO_2$ content. Average pH of vegetation leachate was higher in throughfall but lower in stemflow than open rain and higher in Quercus variabilis forest than in Pinus rigida forest. The flow of $SO{_4}^{2-}$, $NO_3{^-}$ and $Cl^-$ through vegetation leaching(throughfall plus stemflow) into soil were 7.2, 4.3, and 2.5 times, respectively, higher in Pinus rigida forest and 4.4, 2, and 2.5 times, respectively, higher in Quercus variabilis forest than in open field. But the concentration of exchangeable cations was 4.1 times higher in Pinus rigida forest and 4.6 times higher in Quercus variabilis forest than in open field. Average pH of soil leachate was lower than that of throughfall, but higher than that of stemflow. The concentration of exchangeable canons and $Al^{3+}$ in soil leachate were more in Pinus rigida forest than in Quercus variabilis forest and increase signficantly with the increase of acidic deposits. Pinus forest had more deposition and canopy interception of acidic pollutants and more nutrient loss than Quercus forest, and Quercus forest had more cation exchange and proton consumption and than consequently had less nutrient loss and better buffer capacity than Pinus forest. The 69% of forest soils was distributed on acidic rock, 25% of it on metamorphic rock, and 6% of it on intermediate and basic rock. Acidic rock residuals which had low very canon exchange capacity and high sensitivity to acid rain occupied a half of total forest land in Taejon area. Therefore forests in Taejon showed high vulnerability to acid rain and will receive much more stress with the increase of acid rain precursors.

• Restorative Dentistry and Endodontics
• /
• v.25 no.4
• /
• pp.561-574
• /
• 2000

Poly-P has been used to prevent decomposition of foods and has been shown to have inhibitory effect on the growth of gram positive bacteria. The purpose of this study was to evaluate the effect of poly-P on the growth of Porphyromonas endodontalis, a gram negative obligate anaerobic rod, endodontopathic bacterium. P. endodontalis ATCC 35406 was in BHI broth containing hemin and vitamin K with or without poly-P. Inhibitory effect of each poly-P which was added at the beginning(lag phase) or during(exponential phase) the culture, MIC(minimum inhibitory concentration) was determined by measuring the optical density of the bacterial cell at 540nm. Viable cell counts were measured to determined whether poly-P has a bactericidal effect. Leakage of intracellular nucleotides from P. endodontalis was determined at 260nm and morphological change of P. endodontalis was observed under the TEM(transmission electron microscope). Binding of 32P-labeled poly-P to P. endodontalis was examined. SDS-polyacrylamide gel electrophoresis and zymography were performed to observe the changes in protein and enzyme profiles of P. endodontalis, respectively. The results from this study were as follows : 1. The minimal inhibitory concentration(MIC) of poly-P to P. endodontalis appeared to be 0.04~0.05%. 2. Poly-P added to the P. endodontalis culture during the exponential phase of P. endodontalis was as much effective as poly-P added at the begining of the culture, suggesting that the antibacterial effect of poly-P is not much dependent on the initial inoculum size of P. endodontalis. 3. Poly-P are bactericidal to P. endodontalis, demonstrating the decrease of the viable cell counts. 4. Intracellular nucleotide release from the P. endodontalis, was not increased in the presence of poly-P and was not reversed by the addition of divalent cations like $Ca^{2+}$ and $Mg^{2-}$. 5. Under the TEM, it was observed that fine electro-dense materials were prominent in the poly-P grown P. endodontalis, appearing locally in the cell, and the materials were more abundant and more dispersed in the cell as the incubation time with poly-P increased. In addition, highly electron dense granules accumulated in many poly-P grown cells, most of which were atypical in their shape. 6. Binding of 32P-labeled poly-P to P. endodontalis appeared to be 32.8 and 45.5 and 53.4% at 30 minutes, 1 hours and 2 hours, respectively. 7. In the presence of poly-P. the synthesis of proteins with apparent molecular masses of 25, 27, 35, 45 was lost or drastically decreased whereas expression of a protein with an apparent molecular mass of 75 was elevated. 8. Proteolytic activity of P. endodontalis was decreased by poly-P. The overall results suggest that use of poly-P may affect the growth of P. endodontalis, and the anti-bacterial activity of poly-P seems largely bactericidal. Changes in shape, protein expression, and proteolytic activity of P. endodontalis by poly-P may be directly and indirectly attributed to the antibacterial effect of poly-P. Further studies will be needed to confirm the effect of poly-P.

• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.61 no.4
• /
• pp.290-296
• /
• 2016

Green manure has been used as alternative to chemical fertilizer. To evaluate the effect of green manure on the chemical properties of top-soil and sorghum yield, hairy vetch (Vicia villosa Roth, HV), manure barley (MB), and a mixture of hairy vetch and manure barley (HV+MB) were incorporated into the soil at a rate of $100kg-N\;N\;ha-1$ before the sorghum was transplanted. Total biomass of sorghum grown in the HV, MB, and HV+MB treatments was 13.1, 31.6, and $25.2t\;ha^{-1}$, respectively, and the nitrogen production of the treatments was 81, 74, and $145kg\;ha^{-1}$, respectively. The SPAD value of the uppermost leaf of sorghum plants grown in the soils with HV, MB, or HV+MB were very similar until heading stage; however, at maturity, the SPAD value of sorghum cultivated in the soils with HV was lower than that of sorghum in the soils with MB or HV+MB. This could be because the nitrogen release from HV was too rapid to supply nitrogen to sorghum during the later stage of grain filling. Compared with chemical fertilizers, the incorporation of green manure increased the pH, exchangeable cations ($K^+$, $Mg{^{+}^{+}}$, and $Ca{^{+}^{+}}$), and total nitrogen in soil postharvest, indicating an improvement in soil chemical properties. Total carbon content increased in soil with green manure incorporated, but decreased in the chemical fertilized soil, suggesting that sorghum cultivation using green manure may sequester carbon in soils. The yield of sorghum cultivated with green manure was not different from the yield of sorghum cultivated with chemical fertilizers. These results suggest that the mixture of hairy vetch and manure barley can be a useful chemical fertilizer alternative in sorghum cultivation.

• Economic and Environmental Geology
• /
• v.38 no.3 s.172
• /
• pp.207-219
• /
• 2005

The physical and chemical characteristics of soils in a small watershed were investigated and the effect of geology and land use on soil quality were examined by using multivariate statistical methods, principal components analysis and discriminant analysis. The soil developed from andesite had finer texture and higher contents of water extractable inorganic components, clay, and mafic minerals than the soil developed from granite. It is considered that the accumulation of salts in the farmland soils indicated by electrical conductivity, contents of cations and anions and pH was caused by fertilizer input during cultivation. The low contents of organic matter in the farmland soils was due to the enhanced oxidation of organic matter by tillage and by the harvest of crops. The contents of inorganic components are increased as following order: upland > orchard > paddy field > forest. The high contents of water soluble $SO_4\;^{2-}$ of paddy soils is due to the oxidation of sulfides mineral formed during the flooding period during the air-dry and extraction. The results of principal components analysis show the difference of soil quality was controlled by geology and land use. PCI indicate the input of fertilizer, mineral weathering and ion exchange reaction by application of nitrogenous fertilizers. The results of two discriminant analyses using water extractable inorganic components and their ratios by land use were also clearly classified by discriminant function 1 and 2. In discriminant analysis by components, discriminant function 1 indicated the effect of fertilizer application and increased as following order: upland > orchard > paddy field > forest soil. The investigated and predicted data for land use from discriminant analysis showed similar results. The discriminant analysis can be used as a useful method certifying the change of land use.