• Applied Biological Chemistry
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• v.35 no.3
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• pp.179-185
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• 1992

Rhizobium meliloti populated in five Korean pasture soils were characterized by symbiotic effectiveness and intrinsic antibiotic resistance using whole-soil inoculum and 11 antibiotics, respectively. Most probable number (MPN) of naturalized rhizobia counted with alfalfa Vernal[Medicago sativa (L.)] as a host ranged $1.7{\times}10^2\;cells/g$. soil(Chunghyo, Kyeongiu)-$1.0{\times}10^5\;cells/g$. soil(Gampo, Kyeongiu) and ended to be positively associated with soil pH. On the whole, the effectiveness of population as compared to TAL mix inoculum (TAL 380+TAL 1372+TAL 1373) was very low. Nevertheless, there were two highly effective strains, YCK 539 and YCK 542, which were not inferior to TAL 1372, from Ogpo, Dalseong among the total of 30 of 6 isolates per each soil. As long as mean $N_2$ fixing ability of each soil isolate, the isolates from Hyeongog, Kyeonju were outstanding and the rest were in order of Ogpo, Dalseong>Chunghyo, Kyeongju>Hwaweon, Dalseong>Gampo, Kyeongiu. Isolates as a whole were resistant to erythromycin(67崙), nalidixic acid(77%), and streptomycin sulfate(8051), which had the concentration of $100\;{\mu}g/ml$, $160\;{\mu}g/ml$, and $10\;{\mu}g/ml$, respectively and divided into 14 patterns of resistance. Association between resistances in each soil was not clear. And there was no relationship of resistance pattern to effectiveness. The best effective strain YCKa 542 exclusively fell into No. X pattern having resistance to erythromycin, nalidixic acid, and neomycin sulfate.

• Korean Journal of Soil Science and Fertilizer
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• v.30 no.1
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• pp.62-66
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• 1997

This study was designed to obtain the mean values of thirteen soil physico-chemical properties for different paddy soil management groups, and to serve the basic information for improving the soil using amendments. Computerized data on the results of detailed soil survey were used in this study. The clay contents in the B horizon of paddy soil management groups were 28.3% in the well adapted type, 11.8% in the sandy textured type, and 26.8% in the newly reclaimed type. Soil pH of B horizon in the paddy soil management groups except poorly drained type and acid sulfate type were higher than those of A horizon. In the river side paddy soils of well adapted type, the clay contents of A and B horizons were 16.8%, 23.1%, respectively, and soil organic matter contents of those horizons were 42g/kg, 18g/kg, respectively. And also available phosphate content of well adapted type was higher than the other types. Frequency of distribution of soil organic matter content levels in the B horizons of sandy textured type and newly reclaimed type were higher in the organic matter content range of below 10g/kg. And those of well adapted, poorly drained, and saline type were higher in the organic matter content range of 10~20g/kg. Correlation coefficients between 13 variables in the B horizon of well adapted type were all highly significant at 1% or 5% level, respectively.

• Applied Biological Chemistry
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• v.29 no.1
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• pp.62-72
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• 1986

At present, the definition and chemical analysis method of available soil phosphorus for plants have not been standardized because of the complexity of crop and soil characteristics in Korea and many analysis methods have been suggested with different extraction conditions. Suitable analytical method of available soil P should be established by the trial of various methods based on crop nutrition and soil conditions. To establish the most suitable analysis method of available soiIP, a pot experiment with young maize was conducted over 44 different upland soils collected over the land of Korea. The amount of uptaken P by the plant was determined by ten different chemical methods for the available soil P. The results obtained were as follows: 1. Total phosphorus content in the sample soils ranged ranged $533{\sim}4917\;ppm$, and showed significant positive correlation with the content of organic matter. 2. The P content was relatively low in the acid sulfate soil and very high in the volcanic ash soil although both types of soil contained high level of orgic matter. 3. The amount of extractable P determined by ten different methods were varied more or less, and the ratios of the extractable P to the total soil P were in the range of $1{\sim}48%$. 4. The relative values to the amount of extractable soil P by different methods were in the order of $H_2O(5\;min.)\;1.0\;<\;H_2O(60min.)\;2.27\;<\;NH_4HCO_3\;5.57\;<\;NaHCO_3\;7.42\;<\;Double\;lactate\;9.71\;<\;Bray\;No.1\;12.53\;<\;Lancaster\;17.63\;<\;Nelson\;25.96\;<\;AcOH\;27.6\;<\;CAL-method\;50.27$ 5. The amount of extractable P determined by all of applied methods was very low in acid sulfate soil, volcanic ash soil and coarse textured soil. 6. Soil pH and total soil P generally showed significant positive correlation with the chemically extracted P, and soil organic matter was negatively correlated with the determined by Nelson-and CAL-method. Olsen method which showed significant correlation with exchangeable calcium seemed to be recommendable for calcareous soils. 7. Total amount of uptaken P by Young maize through continuos twice cropping was 4.05% of total soil P in average, and the uptake in the second cropping was twice as much as that of the first cropping. 8. Three determination methods, i.e. Soltanpour-, Double lactate and Bray No. 1-method seemed to be more suitable than Lancaster method which is widely practiced at present in Korea. However, further study should be carried out with other crops and soils to most adequate chemical method for determination of available soil P.

• Korean Journal of Soil Science and Fertilizer
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• v.5 no.1
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• pp.41-47
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• 1972

An experiment was conducted to study the zinc deficiency of rice plant grown on Boeun soil of Korea and on Batangas soil of the philippines. The results obtained are summarized as follows: 1. Batangas soil was deficient in zinc because of the high pH, high organic matter and high calcium. Zinc content of the rice plant grown on Batangas soil was l6ppm. On the other hand, Boeun soil had low organic matter. Zinc content of the rice plant grown on Boeun soil was 33ppm. 2. The top leaf had higher zinc content than any other leaves. Zinc deficiency apparently occured when the zinc content of the rice plant was below 18ppm. 3. The physiologically acid fertilizer such as ammonium sulfate was more advantageous in improving zinc up take than the urea. 4. The zine deficiency was promoted when the Mn/Zn ratio is high, and zinc and manganess interact antagonistically in the growth of rice plant. 5. The zinc deficiency could be overcome by applying zinc chloride and fritted Trace elements to the Batangas soil, and the yield was significantly increased than conrtol.

• Korean Journal of Soil Science and Fertilizer
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• v.29 no.1
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• pp.60-66
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• 1996

Bradyrhizobium japonicum with different colony morphology populated in five Yeongnam soils of Korea was examined for intrinsic antibiotic resistance to eight antibiotics, serological property by immunoblot and immunodiffusion, and protein profile differentiation by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Colony morphological distribution of one hundred and twenty B. japonicum isolates was 47% for "dry". 41% for "wet", and 12% for "dry/wet" type. The total isolates showed such a strong correlation between the morphology and antibiotic resistance. Colony morphology, which though was dominantly consisted of the same type within a serogroup, wasn't absolutely linked to serological property of B. japonicum. Based on these data, colony morphology was too simple to identify variations with B. japonicum isolates : antibiotic resistance such complicated compared with serological analyses.

• Korean Journal of Soil Science and Fertilizer
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• v.18 no.1
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• pp.78-88
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• 1985

Nitrogen fertilizer effectiveness on rice production was studied to evaluate the different forms and sources. Seven kind of nitrogen fertilizers were applied in two levels, 15 and 30 kg per 10a on Jinjubyeo (Japonica type) in silt loam paddy soil of pot cultivation. The results were summerized as follows; 1. pH in soils was decreased with enhancement of ammonium sulfate application in $NH_4-N$, but it was increased with times after nitric-acid application and PH change in soil was not remarkable when $NO_3-N$ with accessory component was applied. 2. $NH_4-N$ contents in soil were the lowest at 2 weeks after application in N 15kg/10a regardless of different sources of nitrogen fertilizer. $NO_3-N$, in N 30kg/10a, was decreased continuously until 4 weeks, while $NH_4-N$, Urea-N were at minimum during 2-3 weeks. 3. Growth of culm length and straw weight applied with AN (Ammonium Nitrate), AS (Ammonium Sulfate) and urea were superior to the form of nitrate. While NA (Nitric Acid), PN (Potassium Nitrate) and CN (Calcium Nitrate) plot of the $NO_3-N$ was the dominant fertilizers for root elongation. 4. Brown rice yields were increased dominantly by $NH_4-N$ application such as AS or AP than $NO_3-N$ pot. But the yields in case of $NO_3-N$ application CN, PN and NA were decreased. 5. N, P, Mg and Mn content of straw ranked the effectiveness of nitrogen forms as $NH_4-N$, Urea-N and $NH_4-N+NO_3-N$, while K, Ca and $SiO_2$ content of straw in $NO_3-N$ fertilizer plot were high while N, P, Mg, Mn, Fe and Mg were low. 6. Increament of nitrogen absorption in straw was stimulated by enhancement of phosphorous absorption and the growth and yield of rice plant were increased. Absorption of N, P, Ca and Mg was decreased by CN application. Absorption of N, P and Mg also was decreased by $NO_3-N$ application and N, P, Mg or Ca content were seemed to simulated the growth and yield of rice plant. 7. $SiO_2$, Zn and Fe contents of the root at harvest stage were higher than those of the straw. N, P, Mg, Mn, Zn and Fe contents were high in $NH_4-N$ and Urea treatment. While K, ca and $SiO_2$ contents, however, were high in $NO_3-N$ treatment.

• Korean Journal of Soil Science and Fertilizer
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• v.43 no.2
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• pp.140-146
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• 2010

Monitoring of the dynamic changes at paddy rice agriculture is very important for agricultural sustainability. Field monitoring was performed to evaluate the soil chemical properties of 260 paddy soil samples every four years from 1999 to 2007 in Gyeongnam Province. Soil chemical properties such as pH, organic matter, available phosphate, silicate, exchangeable potassium, calcium, and magnesium contents were analyzed. The contents of exchangeable cations, and available silicate were significantly increased in 2007 compared to 1999. The chemical contents of organic matter, exchangeable potassium, and magnesium were significantly increased in acid sulfate soil, and silty clay loam compared to those of other soil types, and textures. Especially, content of organic matter was significantly increased in hill area compared to other soil topographies, while exchangeable potassium was significantly decreased. Principle component analysis (PCA) of chemical properties in paddy soils was obtained with eigenvalues > 1 summing 39.1%of variance for PC1, 20.4%of variance for PC2, and 59.5%of the total variance in the all of soil chemical properties. Therefore, principal component analysis is more effective for monitoring from chemical properties of paddy soil.