• Journal of Microbiology and Biotechnology
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• v.26 no.5
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• pp.867-875
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• 2016

Archaea substantially contribute to global geochemical cycling and energy cycling and are impacted by land-use change. However, the response of archaeal communities to a change from upland field to paddy field has been poorly characterized. Here, soil samples were collected at two depths (0-20 cm and 20-40 cm) from one upland field and six paddy fields that were established on former upland fields at different times (1, 5, 10, 20, 30, and 40 years before the study). Barcoded pyrosequencing was employed to assess the archaeal communities from the samples at taxonomic resolutions from phylum to genus levels. The total archaeal operational taxonomic unit (OTU) richness showed a significant positive correlation with the land-use change duration. Two phyla, Euryarchaeota and Crenarchaeota, were recorded throughout the study. Both the relative abundance and OTU richness of Euryarchaeota increased at both depths but increased more steadily at the subsurface rather than at the surface. However, these data of Crenarchaeota were the opposite. Additionally, the archaeal composition exhibited a significant relationship with C/N ratios, total phosphorus, soil pH, Olsen phosphorus, and the land-use change duration at several taxonomic resolutions. Our results emphasize that after a change from upland fields to paddy fields, the archaeal diversity and composition changed, and the duration is an important factor in addition to the soil chemical properties.

• Applied Biological Chemistry
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• v.26 no.4
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• pp.239-247
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• 1983

The effects of some soil conditions on the degradation rate and decomposing pattern of parathion were investigated and the obtained results are summarized as follows: Parathion degraded more rapidly in flooded soils than in non-flooded, in wet soils than in dry soils under non-flooded soils. The degradation rates in paddy and upland soils increased at high temperature than low temperature, higher pesticide concentration than low concentration and higher soil pH level. Parathion in paddy and upland soils was more persistent under soil sterilization than under non-sterilization and degraded rapidly in glucose application. Parathion was more persistent in upland soils than paddy soils under several factors described above. The metabolites identified from the paddy and upland soils by TLC include para-oxon (Rf 0.5), aminoparathion(Rf 0.27), p-nitrophenol(Rf 0.2), p-aminophenol(Rf 0.15). Soil enzyme, acid phosphatase activities decreased more at flooded soils than non-flooded, higher pesticide concentration than low concentration and higher soil pH level and the activity in glucose application was increased. Soil enzymes, urease and dehydrogenase activity decreased more at higher pesticide concentration than low concentration. Comparing with soil enzyme activity in paddy and upland soil, the former was higher than the latter.

• Korean Journal of Soil Science and Fertilizer
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• v.33 no.2
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• pp.92-99
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• 2000

To compare the effect of food waste compost(FWC) application on the sodicity of paddy and upland soil, laboratory experiment was conducted. Six kinds of FWC made of various mixing ratio of food waste and pig slurry as raw material were applied to paddy soil under submerged condition and to upland soil in field water capacity, and were kept at $25^{\circ}C$ under laboratory incubation. The higher the mixing ratio of food waste on making FWC, the higher the FWC showed Na content and EC. Mineralized ratio of cations in FWC during incubation showed no difference between paddy and upland soil. It was high in the order of Na>K>Mg>Ca as 99, 94, 71, and 71%, respectively. NaCl contents of FWC applied to soils against SAR and ESP were fitted well to first linear regression with extremely high significance($R^2=0.99$). Increasing rate of SAR and ESP was higher in upland soil than paddy soil by 2.3 times. The difference was considered to be caused by dilution effect which was exerted by the application of more soil to water ratio to paddy soil than to upland soil on SAR analysis in consideration of cultivating condition. The calculated values of $([Ca^{2+}+Mg^{2+}]/2)^{1/2}$ used as a denominator on SAR calculation showed a little difference among FWC treatments by 2.1~2.4, while [$Na^+$] used as a numerator showed much variance by 3.1~9.5. Therefore, as a parameter for the assessment of FWC quality affecting soil sodicity, the use of only Na content in FWC was proposed without regarding Ca and Mg contents. Soil Ex. Na contents showed extremely high correlation($R^2=0.99$) with ESP. Moreover, because the former can be more easily determined than the latter, soil Ex. Na content was proposed as a new sodicity index.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.51 no.5
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• pp.401-407
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• 2006

This study was conducted to investigate the effect of onion cultivation under paddy and upland condition on the yield and storage of onion bulbs. In comparison of soil conditions, nitrogen, phosphate, potassium content and average temperature in upland condition were higher than those of paddy condition, but calcium, magnesium, sodium and water content in paddy condition were higher than those of upland condition. The growth of aerial part was better in upland cultivated condition. It showed that bulb formation in paddy cultivated condition was faster during in early growth stage, but was slower during in late growth stage. Average bulb size and weight were higher in upland cultivated condition, but dry weight per 100 g fresh weight and bulb hardness were higher in paddy cultivated condition. Sugar contents, inorganic compounds, nitrogen, phosphate and potassium content of onion were higher in upland cultivated condition, but calcium, magnesium and sodium content of onion were higher in paddy cultivated condition. In distribution of onion bulb size, most of large sized onions were produced in upland cultivated condition. Average bulb production for seed harvesting were $63{\sim}70%$ higher in paddy cultivated condition than that of upland cultivated condition. The rotted rate of onion was about $27.2{\sim}34.6%$ in paddy, $37.5{\sim}51.4%$ in upland cultivated condition respectively, showed favorable result as the difference of $8.7{\sim}24.2%$ in paddy cultivated condition.

• Journal of Soil and Groundwater Environment
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• v.19 no.4
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• pp.45-51
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• 2014

In accordance with the view on remediated soil as a resource, this study assessed the applicability of soil washing with the neutral phosphate for remediation of arsenic (As)-contaminated soil. Three soil samples of different land uses (i.e., rice paddy, upland field and forest land) were collected from the study site, and the aqua regia-extractable As concentrations were 59.2, 30.8 and 53.1 mg/kg, respectively. Among the neutral phosphate reagents, ammonium phosphate showed the highest As washing efficiency. The optimized washing condition was 2-hr washing with 0.5M ammonium phosphate solution (pH 6) and soil to liquid ratio of 1 : 5. The extraction efficiencies of As did not guarantee the residual soil As concentrations to satisfy the Korea soil regulatory level (i.e., Worrisome level) in the three soil samples. To enhance washing efficiency, the As-contaminated soil was submerged in washing solution (1 : 1, w/v) for 24 hr and 1-hr washing with 0.5M ammonium phosphate solution was tested. As extraction efficiencies of 36.1 (rice paddy), 21.4 (upland field) and 26.4% (forest land) were attained, which satisfied the Worrisome level for Region 1 (25 mg/kg of As) in rice paddy, but not in upland field and forest land.

• Korean Journal of Soil Science and Fertilizer
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• v.46 no.3
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• pp.153-162
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• 2013

Most test methods for plant available soil phosphate are based on the extraction with a chemical solution. The objective of this study is to evaluate available phosphate of various tests at different soil phosphate levels. Two experiments were conducted as follows: i) Extracting capacities of soil phosphate tests - Mehlich III, Mehlich II, Bray I, Olsen, Kelowna, and Modified Lancaster(Mod. Lancaster) - were compared with that of Lancaster test for the soils collected from 32 paddy and 27 upland fields with various soil chemical properties. ii) Field trials on comparing to phosphate uptake by plant were accomplished by cultivating rice and corn plants in the pots filled with the soils. Available phosphate of Lancaster test was significantly correlated with those of Mehlich III, Mehlich II, Bray I, Olsen, Kelowna, and Mod. Lancaster. In upland soils, available phosphates of all the tests were curvilinearly regressed with phosphate uptake by corn. The determination coefficients ($R^2$) of the regression equation between available phosphate in soils and phosphate uptake by plants were ranged from 0.861 (Mehlich III) to 0.741 (Olsen). In paddy soils, the available phosphate measured by Mehlich III and Lancaster was significantly correlated with phosphate uptake by rice. In conclusion, Lancaster and Mehlich III tests could be used for predicting available phosphate in upland and paddy soils.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.38 no.4
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• pp.304-311
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• 1993

To find out suitable crops and their rotation years with rice for paddy-upland rotation, continuous rice cropping and rice with 1, 2 and 3 years cropping of upland crops(soybean, maize and job's tears) were tested for four years from 1989 to 1992. Rice yield, when averaged over rotation years for each crop, was increased ranging from 7% to 12% when compared with that of continuous rice cropping. With every crop, rice yield of 2 year upland rotation was higher than that of 1 year upland rotation, but rice quality seemed to deteriorate in paddy-upland rotation. When considering yields of the upland crops, 1 year rotation was the best condition for soybean and job's tears, with 3 years rotation being the best for maize. In paddy-upland rotation, number of weed species and its occurrence rates were reduced in paddy and upland condition and the reduction rates in paddy condition were higher than those in upland condition. Physical properties of soil were improved in paddy-upland rotation and airphase seemed to increase with increasing upland period.

• Korean Journal of Soil Science and Fertilizer
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• v.49 no.4
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• pp.341-346
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• 2016

This study was conducted to analyze soil physico-chemical properties of agricultural land composed from the river-bed sediments. We investigated the changes of soil physico-chemical properties at 30 different sampling sites containing paddy, upland and plastic film house from 2012 to 2015. pH, exchangeable calcium and magnesium decreased gradually in paddy soils during the four years, whereas the available $P_2O_5$, exchangeable Ca, Mg and EC increased in upland and plastic film house soil. For the soil physical properties, bulk density and hardness of topsoil were $1.47g\;cm^{-3}$ and 21.5 mm and those of subsoil were $1.71g\;cm^{-3}$ and 25.7 mm in paddy soils. In upland soils, bulk density and hardness of topsoil were $1.48g\;cm^{-3}$ and 15.9 mm and those of subsoil were $1.55g\;cm^{-3}$ and 16.9 mm. In plastic film house soils, bulk density and hardness of topsoil were $1.42g\;cm^{-3}$ and 14.4 mm and those of subsoil were $1.40g\;cm^{-3}$ and 18.5 mm, respectively. The penetration hardness was higher than 3 MPa below soil depth 20 cm, and it is impossible to measure below soil depth 50 cm. As these results, in agricultural anthropogenic soils dredged from river basins, the pH, amount of organic matter and exchangeable cations decreased and soil physical properties also deteriorated with time. Therefore, it is needed to apply more organic matters and suitable amount of fertilizer and improve the soil physical properties by cultivating green manure crops, deep tillage, and reversal of deep soils.

• Korean Journal of Plant Resources
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• v.10 no.2
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• pp.145-150
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• 1997

To find out the optimum fertilizer level for onion, early maturing cultivar Fechongjoseng, experiment with four fertilizer levels was conducted of the field of the paddy and upland in Muan and Changyeong from Sep.1993 to Feb.1995. The yield character of onion was higher and rate of the rottenness was lowest under the treatment of $N-P_2O_5-K_2O$=28-9.5-23Kg/10a in the soil of paddy and upland field of Muan area. But the onion yield was excellent and rate of the rottenness was lowest under the treatments, $N-P_2O_5-K_2O$=21-19-17.3Kg/10a, in the soil of paddy field and $N-P_2O_5-K_2O$=28-9.5-23Kg/10a, in the soil of upland field of Changyeong area.

• Korean Journal of Plant Resources
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• v.21 no.3
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• pp.178-183
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• 2008

The growth and yield performance of 19 new com hybrids were evaluated. Results showed that all hybrids had a superior growth performance in the drained-paddy than in the upland field except for daeyul ${\times}$ cheongdo and hyoryeong ${\times}$ cheongdo in plant height, cheongdoyeop ${\times}$ wx-3 in tassel1ength, and cheongdo (black) ${\times}$ wx-3 in number of tassel branch. The same hybrids, except cheongdoyeop ${\times}$ wx-3, obtained lower ear quality in drained-paddy field compared to upland in terms of ear weight, and ear and grain setting length. The highest yield in the drained-paddy and upland fields was obtained in the hybrids ks5wx ${\times}$ ks6wx ${\times}$ cheongdo (1,633.3kg ${\cdot}$ $10a^{-1}$) and daeyul ${\times}$ wx-3 (1,516.7kg ${\cdot}$ $10a^{-1}$), respectively. Highest yield among the wx-3 crosses was obtained in daeyul which was 1,583.3kg ${\cdot}$ $10a^{-1}$ and 1,516.7kg ${\cdot}$ $10a^{-1}$ in drained-paddy and upland field, respectively. For the crosses of wx-8, highest yields were recorded in the cultivar bugye50 (1,466.7kg ${\cdot}$ $10a^{-1}$) and seokgu12 (1,384.6kg ${\cdot}$ $10a^{-1}$) for drained-paddy and upland field, respectively. In the case of cheongdo, highest yields were obtained in ks5wx ${\times}$ ks6wx (1,633.3kg ${\cdot}$ $10a^{-1}$) and seokgu14 (1,111.1kg ${\cdot}$ $10a^{-1}$) for drained-paddy and upland field, respectively. Result also showed that the drained-paddy soil had better physicochemical properties than the upland. The relatively high performance in terms of growth parameters and yield of com hybrids planted in the drained-paddy field is in agreement with the higher organic matter and micro-element content of drained-paddy field.