• Title/Summary/Keyword: Flooded soil

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Evaluation of Methane Emissions with Water Regime before the Cultivation Period in Paddy Fields

  • Park, Jun-Hong;Park, Sang-Jo;Kim, Jong-Su;Seo, Dong-Hwan;Park, So-Deuk;Kim, Jin-Ho
    • Korean Journal of Soil Science and Fertilizer
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    • v.48 no.4
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    • pp.271-277
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    • 2015
  • Anaerobic decomposition of organic material in flooded rice fields produces methane, which escapes to the atmosphere primarily by transport through the rice plants. The annual amount of $CH_4$ emitted from a given area of rice is a function of the number and duration of crops grown, water regimes before and during cultivation period, and organic and inorganic soil amendments. Soil type, temperature, and rice cultivar also affect $CH_4$ emissions. The field experiment was conducted for three years to develop methane emission factor for water regime before the cultivation period from the rice fields. It was treated with three different water regimes prior to rice cultivation, namely: non-flooded pre-season < 180 days, non-flooded pre-season > 180 days, flooded per-season in which the minimum flooding interval is set to 30 days. Methane emission increased with days after transplanting and soil redox potential (Eh) decreased rapidly after flooding during the rice cultivation. The average methane emission fluxes were $5.47kg\;CH_4\;ha^{-1}day^{-1}$in flooded pre-season > 30 days, 5.04 in non-flooded pre-season < 180 days and 4.62 in non-flooded pre-season > 180. Methane emission flux was highly correlated with soil temperature and soil Eh. Rice yields showed no difference among treatments with water regime before the cultivation period.

Degradation Patterns of BPMC and Carbofuran in Flooded Soils (담수토양(湛水土壤)중 BPMC 및 Carbofuran의 분해특성(分解特性))

  • Park, Chang-Kyu;Je, Yeon-Tae
    • Korean Journal of Environmental Agriculture
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    • v.2 no.2
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    • pp.65-72
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    • 1983
  • The effects of soil factors, pesticide application levels and environmental factors on the degradation of two carbamate insecticides, BPMC and carbofuran, in soil were studied under flooded and non-flooded conditions. The degradation patterns of BPMC or carbofuran were similar in flooded and non-flooded soils. It was also found that carbofuran was more persistent than BPMC in the test soil. Regards to organic contents of soils, high contents of organic matter reduced degradation of either BPMC or carbofuran and high soil pH accelerated degradation of both insecticides. Soil microorganisms seem to play an important role in the degradation of BPMC and carbofuran. Both chemical and biological degradations appear to contribute transformation of BPMC and carbofuran in the flooded soil.

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The Fate of As and Heavy Metals in the Flooded Paddy Soil Stabilized by Limestone and Steelmaking Slag (석회석과 제강슬래그를 이용하여 안정화한 담수된 논토양의 비소 및 중금속의 거동변화)

  • Koh, Il-Ha;Kim, Eui-Young;Ji, Won Hyun;Yoon, Dae-Geun;Chang, Yoon-Young
    • Journal of Soil and Groundwater Environment
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    • v.20 no.1
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    • pp.7-18
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    • 2015
  • The characteristics of As and heavy metals depend on the oxidation/reduction condition of the soil environment. The most heavy metals are immobilized by the reduction condition whereas As, Fe and Mn become more soluble. Therefore this study estimated the stabilization efficiency of the agricultural paddy soil in the vicinity of the abandoned mine using a flooded column test including analysis of the soil solution, contaminants fractionation and rice grain. Limestone and steelmaking slag were used as amendments for stabilization of the contaminated soil. In an analysis of the soil solution, the mobile characteristics of Fe and Mn, which were used as electron acceptors of the microorganisms, were controlled by increasing the pH by adding alkali amendments. This means that the contaminants combined with Fe and Mn can be stable under flooded reduction condition. However, the concentrations of cationic heavy metals (Cd, Pb, and Zn) were also decreased without amendments because the carbonates produced from microbial respiration increased the pH of the soil solution. In the amended soil, the specific sorbed fraction of As and carbonates fraction of heavy metals were increased when compared to the control soil at the end of the column test. Especially in heavy metals, the increase of carbonates fraction seems to be influenced by alkali amendments rather than microbial respiration. Because of the stabilization effect in the flooded paddy soil, the contents of As and Zn in rice grain from amended soil were lower than that of the control soil. But additional research is needed because of the relatively higher Pb content identified in the rice grain from the amended.

A Study on the Volatilization of Ammonia from Flooded Soils Mixed with Rice Straw and Liming Materials (담수토양(湛水土壤)에서 볏짚과 석회물질(石灰物質) 시용(施用)이 암모니아 휘산(揮散)에 미치는 영향(影響))

  • Oh, Wang-Keun;Hwang, Kwang-Nam;Lee, Myong-Gu
    • Korean Journal of Soil Science and Fertilizer
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    • v.15 no.3
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    • pp.166-171
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    • 1982
  • A laboratiory experiment incubated at about $30^{\circ}C$ for 34 days was conducted in order to learn the effect of liming materials and rice straw on the volatilization of ammonia from flooded soils applied with urea. 1. The application of calcium hydroxide and calcium silicate increased buffer action of flood soil, though it resulted in increase in the volatilization of ammonia through raising flooded soil pH containing bicarbonate. 2. The mixing of rice straw powder to soil lowered pH of flooded soil, and decreased the volatilization of ammonia. The effect was particulary large when noliming material was used. 3. Calcium hydroxide depressed the evolution of $CO_2$ in the early days of incubation after flooding, while calcium silicate promoted the ammonification of soil nitrogen from the begining of flooding giving slow change in soil chemical properties. The rice straw was also effective in providing a favorable soil condition for the ammonification rather quickly.

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Weed Emergence as Affected by Burying Depth and Water Management

  • Moon, Byeong-Cheul;Park, Sung-Tae;Kim, Soon-Chul;Kwon, Suk-Ju;Mortimer, Andrew-Martin;Collin Piggin
    • KOREAN JOURNAL OF CROP SCIENCE
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    • v.44 no.1
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    • pp.32-37
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    • 1999
  • The experiment was conducted to investigate emergence response of lowland weeds at different soil moisture contents, burying depths and upon changes in soil moisture. Rice germination was over 50% at all burying depths under aerobic condition, but the emergence rate of the soil surface placed seeds in saturated and flooded conditions decreased by 19% and 29%, respectively, as compared with that of aerobic condition. Rice seeds at burying depth of over 3 cm did not emerge at all. The emergence rate of Echinochloa crus­galli (L.) Beauv. in aerobic condition was lower than 30%, but the emergence pattern of E. crus galli (L.) Beauv. at different soil moisture contents and seeding depths was similar to that of rice. Emergence behavior of lschaemum rugosum Salisb., Ludwigia octovalvis (Jacq.) Raven and Sphenoclea zeylanica Gaertn. which are dominant lowland weed species in the Philippines also differed depending on soil moisture conditions and burying depths. lschaemum rugosum Salisb. emerged at all burying depths under aerobic condition, whereasLudwigia octovalvis (Jacq.) Raven emerged only at 0 cm deep under saturated and aerobic condition and Sphenoclea zeylanica Gaertn. at 0 cm deep under flooding condition. Weed seeds planted at 1, 3, and 5 cm deep in continuous flooded and saturated condition did not emerge at all, but upon a change of soil moisture condition from saturated to drainage (S$\rightarrow$D) and flooded to drainage (F$\rightarrow$D), grass weeds began to germinate again and the average emergence rate in S$\rightarrow$D and F$\rightarrow$D were 26% and 5% forE. crus­galIi (L.) Beauv., 9% and 8% forI. rugosum SaIisb., respectively. Weed seeds buried in soil in the pot showed great emergence at S$\rightarrow$D but did not emerge under continuous flooded condition. The diversity index accounting for dominance degree and occurrence aspect of weed, was the lowest at F$\rightarrow$D.

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Population Variations of Cylindrocarpon destructans Causing Root Rot of Ginseng and Soil Microbes in the Soil with Various Moisture Contents (토양수분 함량에 따른 인삼 뿌리썩음병균 Cylindrocarpon destructans 및 토양미생물의 밀도 변화)

  • 박규진;유연현;오승환
    • Korean Journal Plant Pathology
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    • v.13 no.2
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    • pp.100-104
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    • 1997
  • Influence of the moisture content in soils was examined on population variations of soil microbes, including Cylindrocarpon destructans causing root rot of ginseng, in vivo and under the field condition. Fungal populations decreased in soils treated with various moisture contents in vivo as days after the treatment in creased, but there was not a significant difference in the population among other treatments except 135% moisture content (flooding) at 15 weeks after the treatment. In flooded soils populations of total fungi and C. destructans were reduced to 1/10 and 1/50 of initial populations, respectively. There was, however, a little difference in the population of total bacteria or Actinomycetes between before and at 15 weeks after flooding. On the other hand, population variations of bacteria and Actinomycetes were much greater than those of fungi at different intervals after the moisture treatment. Variations of microbial populations in flooded soils under the field condition were similar to those in vivo. Especially, populations of Fusarium and pectolytic bacteria in flooded soils were reduced to 1/100 of populations in nonflooded soils at 170 days after treatment.

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Degradation Pattern and Rate of Some Pesticides in Soils -Part II. Degradation Pttern and Rate of Thiolix in Soils- (토양처리(土壤處理) 농약제(農藥劑)의 분해율(分解率)에 관한 연구(硏究) -제2보(第二報). Thiolix의 토양중(土壤中) 분해(分解)에 대하여-)

  • Lim, Sun-Uk;Choi, Yong-Lak
    • Applied Biological Chemistry
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    • v.26 no.4
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    • pp.248-254
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    • 1983
  • The effects of some soil conditions on the degradation rate and decomposing pattern of thiolix were investigated and the obtained results are summarized as follows: Thiolix degraded more rapidly in flood soils than in noon-flooded, and in wet soils than in dry soils under non-flooded soils. The degradation rates in non-flooded soils increased with higher pesticide concentration. Thiolix was more persistent in non-flooded soils under soil sterelization than under non-sterilization and degraded rapidly in glucose application. The metabolites identified from the soils by TLC and GLC include Thiolix alcohol, Thiolix sulfate, Thiolix ether and a unknown metabolite. Soil enzyme, acid phosphatase activity decreased at higher pesticide concentration, lower moisture contents of soil and the activity in glucose application was increased. Soil enzyme, urease and dehydrogenase activity decreased at higher pesticide concentrations.

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Effects of Bottom Ash Amendment on Soil Respiration and Microbial Biomass under Anaerobic Conditions (혐기조건에서 석탄바닥재가 토양호흡량 및 미생물 생체량에 미치는 영향)

  • Park, Jong-Chan;Chung, Doug-Young;Han, Gwang-Hyun
    • Korean Journal of Soil Science and Fertilizer
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    • v.45 no.2
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    • pp.260-265
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    • 2012
  • Soil respiration under flooded conditions is considered to be very small compared with aerobic soil respiration of soil organic matter. However, anaerobic decomposition of soil plays a key role in carbon cycling in flooded ecosystems. On the other hand, coal-ash wastes, such as fly ash and bottom ash, are known to function as a soil amendment for mitigating $CO_2$ emission and enhancing carbon sequestration in up land soils. In this study, we investigated bottom ash as a soil amendment for mitigating $CO_2$ emission, and thus enhancing carbon sequestration under anaerobic conditions. We observed that amendment of bottom ash without external organic source led to significant reduction in $CO_2$ emission rate and in total cumulative $CO_2$ emission flux over the incubation period, which was proportional to the amount of bottom ash applied. We also found that soil microbial biomass increased in response to application of bottom ash. These results suggest that bottom ash can be utilized to store $CO_2$ as a stable soil organic carbon in flooded ecosystems, as in aerobic situations.

Degradation Pattern and Rate of Some Pesticides in Soils -Part I. Degradation Pattern and Rate of Parathion in Soils- (토양처리(土壤處理) 농약제(農藥劑)의 분해율(分解率)에 관한 연구(硏究) -제1보(第一報). Parathion의 토양중(土壤中) 분해(分解)에 대하여-)

  • Lim, Sun-Uk;Kang, Kyu-Yung;Choi, Yong-Lak
    • 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.

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The Effect of Flooding on the pH Change of Soil with Calcium Carbonate (담수(湛水)가 탄산석회(炭酸石灰)를 시용(施用)한 토양(土壤)의 pH 변화(變化)에 미치는 영향(影響))

  • Oh, Wang Keun;Park, Young Sun;Choi, Young Sun
    • Korean Journal of Soil Science and Fertilizer
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    • v.4 no.2
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    • pp.149-154
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    • 1971
  • To elucidate the effects of calcium carbonate applied under upland and flooded conditions on the changes of soil pH, an incubation study of a soil was carried out. The experiment was conducted under the conditions with and without ground rice straw application. The results of the experiment are summarized as follows: 1. The incubation under the upland moisture condition after the application of calcium carbonate raised soil pH as high as calcium hydroxide did, whereas incubation with calos treatment under the flooded condition showed a low pH. 2. Reduction of a soil brought about by the application of ground rice straw has a significant effect on the rise of soil pH. The high pH of a soil thus brought about or raised by the use of lime is gradually reduced as the accumulation of bicarbonate ions and carbon dioxide increases in the soil solution. It may, however, be possible to keep the high pH of a flooded soil by practicing intermittent drainage or cultivation which reduces the content of bicarbonate and $CO_2$ pressure in soil solution. 3. Carbonate and bicarbonate salts which may be produced in flooded and reduced soil increases the buffering capacity of the soil.

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