• Asian-Australasian Journal of Animal Sciences
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• v.25 no.10
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• pp.1466-1472
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• 2012

A bacterial isolate derived from soil samples near a cattle farm was found to display extracellular phytase activity. Based on 16S rRNA sequence analysis, the strain was named Bacillus sp. T4. The optimum temperature for the phytase activity toward magnesium phytate (Mg-$InsP_6$) was $40^{\circ}C$ without 5 mM $Ca^{2+}$ and $50^{\circ}C$ with 5 mM $Ca^{2+}$. T4 phytase had a characteristic bi-hump two pH optima of 6.0 to 6.5 and 7.4 for Mg-$InsP_6$. The enzyme showed higher specificity for Mg-$InsP_6$ than sodium phytate (Na-$InsP_6$). Its activity was fairly inhibited by EDTA, $Cu^{2+}$, $Mn^{2+}$, $Co^{2+}$, $Ba^{2+}$ and $Zn^{2+}$. T4 phytase may have great potential for use as an eco-friendly feed additive to enhance the nutritive quality of phytate and reduce phosphorus pollution.

• Applied Biological Chemistry
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• v.38 no.1
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• pp.72-77
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• 1995

The relationships between the soil chemical properties of ginseng fields and the contents of effective constituents in ginseng roots was investigated. The $NO_3-N$ contents in soils showed highly negative correlations with the contents of total sugar and reducing sugar in ginseng roots. The organic matter contents in soils showed positive correlations with the contents of sugar and ginoside in ginseng roots, while the contents of available phosphorus and exchangeable cations in soils showed highly negative correlations with the those in ginseng roots. For the Production of ginseng root of higher saponin contents, increase of the organic matter contents, and decrease of the contents of available phosphorus and exchangeable cations in soils were recommended.

• BMB Reports
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• v.36 no.6
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• pp.597-602
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• 2003

Acid phosphatases (APases) play a role in the release of phosphate in organic complexes in soil. We investigated tissue- and isoform-specific responses of APases to phosphorus (P) deficiency in three rice genotypes; Dasan-byeo, Sobi-byeo, and Palawan. The levels of shoot APase activity per protein were similar in the three genotypes. They significantly decreased with P deprivation that was longer than seven days. Root APase activity per protein was two- to three-fold higher in Dasan than in Sobi and Palawan. In all genotypes the APase activity increased in P-deficient plants, but the increase was higher in Sobi and Palawan. After 21 days of P deprivation, secreted APase activity increased more than eight-fold in Dasan and two-fold in Sobi and Palawan. Isoform profiles of shoot and root APases were most diverse in Dasan. The activities of the major isoforms in P-deficient shoots decreased in all three genotypes. Depending on the genotypes, further increases in constitutive isoforms and new induction of one to four isoforms occurred in P-deficient roots. The results indicate that tissue and genotype differences in the response of APase to P deficiency are primarily facilitated by the different responses of the isoforms.

• Journal of Korean Society of Water and Wastewater
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• v.10 no.4
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• pp.103-110
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• 1996

Excessive phosphorus (P as orthophosphate) is one of the major pollutants in natural water that are responsible for algal blooms and eutrophication. P removal by slag is an attractive solution if the P sorption capacity of the slag is significant. To design an efficient land treatment facility, basic information on the behaviour of P in the media-water environment is required. In this study, detailed column experiments were conducted to study the P transport under dynamic condition, and mathematical models were developed to describe this process. The column experiments conducted with dust and cake waste products (slag) from BHP steel industry in Australia as adsorbing media indicated that they had higher sorption capacity of P than that of a sandy loam soil from North Sydney, Australia. P transport in the dust and cake columns exhibited characteristics S-shaped or curvilinear breakthrough curves. The simulated results from a dynamic physical non-equilibrium sorption model (DPNSM) and Freundlich isotherm constants satisfactorily matched the corresponding experimental breakthrough data. The mobility of P is restricted proportionally to the adsorbent's sorption capacity.

• Korean Journal of Agricultural Science
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• v.46 no.1
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• pp.103-111
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• 2019

Gray mold caused by Botrytis cinerea on strawberry plants is an economically significant disease in Korea. The rates for diseased fruits are high during the strawberry harvesting period from December to February, especially in hydroponic cultivation. This study assessed the effect of the nitrogen type in the soil culture and the electrical conductivity (EC) of the nutrient solution in a hydroponic culture on the gray mold incidence in 'Seolhyang' strawberry plants. The nitrogen sources assayed included calcium nitrate tetrahydrate (CN4), calcium nitrate decahydrate (CN10), ammonium sulfate (AS), and commercial fertilizer 213 (213). The effect of the EC was tested at 0.5, 0.8, 1.0, and $1.5dS{\cdot}m^{-1}$. The occurrence of gray mold varied according to the nitrogen type. The disease incidence and nitrogen content for the main nitrogen type were higher compared to the non-treated control. The AS treatment showed the highest occurrence of tipburn and gray mold. The incidence of gray mold as well as the nitrogen and phosphorus content of the leaves increased as the EC level was increased. These results indicate that the incidence of gray mold in strawberry plants is related to the nitrogen content of the leaf and the EC of the nutrient solution.

• Journal of Korean Society of Forest Science
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• v.108 no.3
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• pp.296-301
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• 2019

This study was conducted to measure litterfall and nutrient (P, K, Ca, Mg) inputs under varying degrees of disturbance by pine wilt disease in pine forests in southern Korea. Litterfall was collected to evaluate nutrient responses at different intensities of disturbance (various levels of basal area) by pine wilt disease across 2 years. Phosphorus, Ca, and Mg concentrations in needle litterfall were positively correlated (p < 0.05) with decreased disturbance intensities (increased basal area) depending on the time of sampling, whereas the nutrient concentrations in other litterfall components (branches, bark, reproductive organs, and miscellaneous litterfall) were not significantly correlated (p > 0.05) with the intensity of pine wilt disease disturbance. Dry weight and nutrient inputs through litterfall components decreased linearly with increasing intensity of disturbance by pine wilt disease (p < 0.05), except for the nutrient inputs of branch (K, Ca, Mg) and reproductive organ (K, Ca) litterfall. These results indicate that decreased litterfall across different levels of disturbance may be related to the reduced soil nutrients in pine wilt disease forests.

• Korean Journal of Soil Science and Fertilizer
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• v.50 no.2
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• pp.115-126
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• 2017

There is an increasing concern over arsenic (As) contamination in rice. This study was conducted to develope a prediction model for As uptake by rice based on the physico-chemical properties of soil. Soil and brown rice samples were collected from 46 sites in paddy fields near three different areas of closed mines and industrial complexes. Total As concentration, soil pH, Al oxide, available phosphorus (avail-P), organic matter (OM) content, and clay content in the soil samples were determined. Also, 1.0 N HCl, 1.0 M $NH_4NO_3$, 0.01 M $Ca(NO_3)_2$, and Mehlich 3 extractable-As in the soils were measured as phytoavailable As concentration in soil. Total As concentration in brown rice samples was also determined. Relationships among As concentrations in brown rice, total As concentrations in soils, and selected soil properties were as follows: As concentration in brown rice was negatively correlated with soil pH value, where as it was positively correlated with Al oxide concentration, avail-P concentration, and OM content in soil. In addition, the concentration of As in brown rice was statistically correlated only with 1.0 N HCl-extractable As in soil. Also, using multiple stepwise regression analysis, a modelling equation was created to predict As concentration in brown rice as affected by selected soil properties including soil As concentration. Prediction of As uptake by rice was delineated by the model [As in brown rice = 0.352 + $0.00109^*$ HCl extractable As in soil + $0.00002^*$ Al oxide + $0.0097^*$ OM + $0.00061^*$ avail-P - $0.0332^*$ soil pH] ($R=0.714^{***}$). The concentrations of As in brown rice estimated by the modelling equation were statistically acceptable because normalized mean error (NME) and normalized root mean square error (NRMSE) values were -0.055 and 0.2229, respectively, when compared with measured As concentration in the plant.

• Korean Journal of Environment and Ecology
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• v.22 no.3
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• pp.260-267
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• 2008

This study was carried out to investigated the relation between air depositions and soil properties in Gyeongsanman province. Soil pH was average 4.40 in regions, and was the highest soil pH value in Miryang-sanne(pH 5.02), the lowest pH value in Namhae-seomyeon(pH4.08). Soil pH, soil organic matter content, avail phosphorus, K, Ca and cation exchange capacity(CEC) were significantly different among regions(p<0.05). Pb in Heavy metal content was 3.86mg/kg average value, and was the highest in Keo-je region(9.87mg/kg), the lowest in Mryang-sanne (0.86mg/kg). Zn, Cd, Cr and Ni were significantly different among regions(p<0.05). Correlation between rainfall pH and soil properties were positive in soil $pH(r=0.7826^{**})$, Ca$(r=0.6278^*)$, Mg$(r=0.5841^*)$, CEC$(r=0.6341^{**})$ and Cd$(r=0.5995^*)$, and were negative in Pb$(r=-0.5283^*)$. Correlation between $SO_2$ concentration and soil properties was negative in soil pH$(r=-0.6796^{**})$, Ca$(r=-0.5810^*)$, Mg$(r=-0.5522^*)$) and CEC$(r=-0.5905^*)$. Correlation between $NO_2$ concentration and soil properties were positive in organic matter $(r=0.6208^*)$, K$(r=0.5380^*)$. It was predicted that rainfall and $SO_2$ concentration would affect soil acidification, and soil heavy metal content related Cd and Pb. Others soil heavy metal were not related.

• Korean Journal of Soil Science and Fertilizer
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• v.17 no.1
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• pp.1-6
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• 1984

Soils in Cheju Island, derived mostly from volcanic ashes, were collected for chemical analysis to determine the effect of land utilization pattern on soil chemical characteristics. The coastal area has long been used for intensive farming and some of the mid-mountain region were recently reclaimed for agricultural crop production. The cation exchange capacity and the organic matter in the soils increased in the order of coastal area < mid-mountain belt < upper mountain area, while pH, base saturation, available phosphorus and exchangeable bases decreased with the elevation. Generally, the organic matter, the cation exchange capacity and the exchangeable bases of the Cheju soils were found to be considerably higher than the Korean mainland soils. However, the base saturation and the available phosphorus were far below the mainland average. The ratio of monovalent basic cations to total exchangeable bases showed the highest in the soils of the mountain belts and the lowest in the coastal area soils. These data suggest that a higher soil pH in the coastal area as compared to the mountainous slopes has resulted not from the sea water but from continuous application of alkaline fertilizers and times.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.34 no.4
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• pp.396-399
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• 1989

Pearl millet (Pennisetum americanum (L.) Leeke) is a promising forage crop that is resistant to biotic and abiotic stresses, and has a capability to grow well not only in the fertile soil, but also in the poor and dry soil, The objective of the study was to investigate the effects of increased fertilizer application level on the productivity and Quality of pearl millet in the old and newly reclaimed upland soils of Suwon, Chungju, Jeonju, Jinju and Jeju in Korea from 1986 to 1988, Plant height, green fodder yield, protein content and digestibility were increased by the increased fertilizer application level. However, the increased fertilizer application caused lodging, so that the plants grown above one meter in canopy height would be desiable to be clipped remaining 20cm above the ground surface before lodging, and fed to cattle, Mean green yields of the N 45-60kg/l0a application were 12.7-13.4t/l0a in the old upland soil. Increased phosphorus and potash fertilizer application also increased productivity, especially with potash fertilizer effect being higher than that of phosphorus fertilizer, In the newly reclaimed upland soil, improved and doubled fertilizer application plot of 60-60-40-4000kg/10a in N-P$_2$O$\sub$5/-K$_2$O-Compost was 38％ higher being 12.6t/10a of green fodder yield as compared with standard fertilizer application plot, Pearl millet productivity and Quality were higher than those of maize and sorghum/sudan grass hybrids, particularly in green fodder yield, protein content and digestibility.