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Sample records for acidic red soil

  1. Titratable Acidity and Alkalinity of Red Soil Surfaces

    Institute of Scientific and Technical Information of China (English)

    SHAOZONG-CHEN; HEQUN; 等

    1993-01-01

    The surfaces of red soils have an apparent amphoteric character,carrying titratable acidity and titratable alkalinity simultaneously.The titratable acidity arises from deprotonation of hydroxyl groups of hydrous oxide-type surfaces and dissociation of weak-acid functional groups of soil organic matter,while the titratable alkalinity is derived from release of hydroxyl groups of hydrous oxide-type surfaces.The titratable acidity and titratable alkalinity mainly depended on the composition and content of iron and aluminum oxides in the soils.The results showed that the titratable acidity and titratable alkalinity were in significantly positive correlation not only with the content of amorphous aluminum oxide(Alo) and iron oxide(Feo) extracted with acid ammonium oxalate solution,free iron oxide(Fed) extracted with sodium dithionite-citrate-bicarbonate(DCB) and clays,but also with the zero point of charge (ZPC) of the samples.Organic matter made an important contribution to the titratable acidity.the titratable alkalinity was closely correlated with the amount of fluoride ions adsorbed.The titratable acidity and titratable alkalinity of red soils were influenced by parent materials,being in the order of red soil derived from basalt> that from tuff> that from granite.The titratable acidity and titratable alkalinity ware closely related with origination of the variable charges of red soils,and to a certain extent were responsible for variable negative and positive charges of the soils.

  2. Interaction of Cd and citric acid, EDTA in red soil

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Adsorption and desorption process of cadmium in redsoil(Ferrisols) as well as the influence by media's pH were investigated in detail with and without citric acid and EDTA. Experimental results clearly showed that Cd adsorption in red soil was affected significantly by the coexisted organic chemicals. In the presence of citric acid and EDTA, Cd adsorption in red soil increased with pH in acid media but decreased in high pH one. Further studies placed stress on the adsorbed Cd in red soil which was found to be existed mainly as exchangeable one at pH<5.5, and desorption rate by 0.10 mol/L NaNO3 gave a peak-shaped curve due to the difference of specifically and nonspecifically adsorbed Cd with pH's change.

  3. Calibration of KE C Value in Acidic Red Soils with Fumigation-Extraction Method

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    Commonly used KEC value (0.45) of the fumigation-extraction (FE) method was obtained on the basis of temperate neutral soils. To ascertain its applicability to acidic red soils widespread in southern China and other subtropical regions, the KEC value was investigated based on 8 acidic red soils by in situ labelling of native soil microorganisms using 14C-labelled glucose. Realistic KEC value for red soils could be obtained by in situ 14C-labelling as long as an incubation period of 72 h is adopted after addition of 14C glucose to soil. The single KEC values for the eight red soils ranged from 0.27 to 0.35 and averaged 0.31. Lower KEC value obtained in red soils probably resulted from different soil quality, compared with other types of soil,which causes possible changes in microbial community structure and extractability of cellular component.Microbial biomass C contents of the eight red soils measured using a unique and constant KEC value of 0.45 decreased by 22.2%~40% in comparison to those using variable KEC values. The results suggest that microbial biomass C would be significantly underestimated using the present KEC value and a calibration of the KEC value is necessary for red soils.``

  4. Effect of copper on phospholipid fatty acid composition of microbial communities in two red soils

    Institute of Scientific and Technical Information of China (English)

    YAO Huai-ying; LIU Yue-yan; XUE Dong; HUANG Chang-yong

    2006-01-01

    The phospholipid fatty acid (PLFA) composition was analyzed in two red soils experimentally contaminated with copper at different concentrations. The total amounts ofphospholipid fatty acids (PLFAs) in both red soils were significantly correlated with soil microbial biomass C and N, which decreased consistently with increasing levels of copper. The relative quantities of the PLFAs 17:0(10 Me), i 16:0, il 5:0 and 16:1 w5c, decreased with increasing heavy metal concentration, while those of cy 17:0, which is an indicator of gram-negative bacteria, increased. The Shannon index calculated from the PLFA data indicated that Cu addition in the red soils decreased the population diversity of soil microbial communities. Multivariate analysis of PLFA data demonstrated that high levels of Cu application had a significant impact on microbial community structure and there is a threshold metal concentration for PLFA composition. Comparatively higher toxic effect on microbial biomass and community structure were found in the red sandy soil than those in the red clayey soil. The differential effect of Cu addition on microbial communities in the two soils may be due to differences in soil texture and cation exchange capacity.

  5. Effects of simulated acid rain on microbial characteristics in a lateritic red soil.

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    Xu, Hua-qin; Zhang, Jia-en; Ouyang, Ying; Lin, Ling; Quan, Guo-ming; Zhao, Ben-liang; Yu, Jia-yu

    2015-11-01

    A laboratory experiment was performed to examine the impact of simulated acid rain (SAR) on nutrient leaching, microbial biomass, and microbial activities in a lateritic red soil in South China. The soil column leaching experiment was conducted over a 60-day period with the following six SAR pH treatments (levels): 2.5, 3.0, 3.5, 4.0, 4.5, and 5.0 and one control treatment (pH = 7). Compared with the control treatment, the concentrations of soil organic matter, total nitrogen, total phosphorus, total potassium, soil microbial biomass carbon (MBC), soil microbial biomass nitrogen (MBN), and average well color density (AWCD) in the Ecoplates were all significantly decreased by leaching with SAR at different pH levels. The decrease in MBC and MBN indicated that acid rain reduced the soil microbial population, while the decrease in AWCD revealed that acid rain had a negative effect on soil bacterial metabolic function. Soil basal respiration increased gradually from pH 4.0 to 7.0 but decreased dramatically from pH 2.5 to 3.0. The decrease in soil nutrient was the major reason for the change of soil microbial functions. A principal component analysis showed that the major carbon sources used by the bacteria were carbohydrates and carboxylic acids.

  6. [Characteristics of soil pH and exchangeable acidity in red soil profile under different vegetation types].

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    Ji, Gang; Xu, Ming-gang; Wen, Shi-lin; Wang, Bo-ren; Zhang, Lu; Liu, Li-sheng

    2015-09-01

    The characteristics of soil pH and exchangeable acidity in soil profile under different vegetation types were studied in hilly red soil regions of southern Hunan Province, China. The soil samples from red soil profiles within 0-100 cm depth at fertilized plots and unfertilized plots were collected and analyzed to understand the profile distribution of soil pH and exchangeable acidity. The results showed that, pH in 0-60 cm soil from the fertilized plots decreased as the following sequence: citrus orchard > Arachis hypogaea field > tea garden. As for exchangeable acidity content, the sequence was A. hypogaea field ≤ citrus orchard soil (0-40 cm), compared with the deep soil (60-100 cm), and soil pH decreased by 0.55 and 0.17 respectively, but such changes did not occur in citrus orchard. Soil pH in 0-40 cm soil from the natural recovery vegetation unfertilized plots decreased as the following sequence: Imperata cylindrica land > Castanea mollissima garden > Pinus elliottii forest ≥ Loropetalum chinensis forest. As for exchangeable acidity content, the sequence was L cylindrica land Soil pH in surface soil (0-20 cm) from natural forest plots, secondary forest and Camellia oleifera forest were significantly lower than that from P. massoniana forest, decreased by 0.34 and 0.20 respectively. For exchangeable acidity content in 0-20 cm soil from natural forest plot, P. massoniana forest and secondary forest were significantly lower than C. oleifera forest. Compared with bare land, surface soil acidification in unfertilized plots except I. cylindrica land had been accelerated, and the natural secondary forest was the most serious among them, with surface soil pH decreasing by 0.52. However, the pH increased in deep soils from unfertilized plots except natural secondary forest, and I. cylindrica land was the most obvious among them, with soil pH increasing by 0.43. The effects of fertilization and vegetation type on pH and exchangeable acidity decreased with the

  7. Early indications of soil recovery from acidic deposition in U.S. red spruce forests

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    Lawrence, Gregory B.; Shortle, Walter C.; David, Mark B.; Smith, Kevin T.; Warby, Richard A.F.; Lapenis, Andrei G.

    2012-01-01

    Forty to fifty percent decreases in acidic deposition through the 1980s and 1990s led to partial recovery of acidified surface waters in the northeastern United States; however, the limited number of studies that have assessed soil change found increased soil acidification during this period. From existing data, it's not clear whether soils continued to worsen in the 1990s or if recovery had begun. To evaluate possible changes in soils through the 1990s, soils in six red spruce (Picea rubens Sarg.) stands in New York, Vermont, New Hampshire, and Maine, first sampled in 1992 to 1993, were resampled in 2003 to 2004. The Oa-horizon pH increased (P 42−, which decreased the mobility of Al throughout the upper soil profile. Results indicate a nascent recovery driven largely by vegetation processes.

  8. Capping hazardous red mud using acidic soil with an embedded layer of zeolite for plant growth.

    Science.gov (United States)

    Ma, Yingqun; Si, Chunhua; Lin, Chuxia

    2014-01-01

    A nearly three-year microcosm experiment was conducted to test the effectiveness of capping red mud using acidic soil with an embedded layer of zeolite in sustaining the growth of a grass species. This 'sandwich-structured' design allowed self-sustaining growth of the plants under rain-fed conditions no matter whether the underlying red mud was neutralized or not. During the initial stage, the plants grew better when the red mud was not neutralized with MgCl2 probably due to pH rise in the root zone. Neutralization of red mud led to salinization and pH decrease in the root zone. However, the difference in plant growth performance between these scenarios became less remarkable over time due to gradual improvement of soil conditions in the neutralized scenarios. Continuous leaching of soluble salts and alkali by rainwater extended the root zone to the red mud layer. As a result of vegetative production, soil organic matter rapidly accumulated. This, combined with increase in pH and decrease in salinity, markedly facilitated microbial activities and consequently improved the supply of nutrients. This study provides abasis for field-scale experimental design that will have implications for effectively establishing vegetative cover in red mud disposal sites to control dust hazards.

  9. Phospholipid Fatty Acid Profiles of Chinese Red Soils with Varying Fertility Levels and Land Use Histories

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Analysis of phospholipid fatty acids (PLFAs) was used to estimate the microbial community structures of eight Chinese red soils with different fertility levels and land use histories.The total amounts of PLFAs in the soils were significantly correlated with soil organic carbon,total nitrogen,microbial biomass C and basal respiration,indicating that total PLFA was closely related to fertility and sustalnability in these highly weathered soils.Soils for the eroded wasteland were rich in Gram-positive species.When the eroded soils were planted with citrus trees,the soil microbial population had changed little in 4 years but took up to 8~12 years before it reached a significantly different population.Multivariate analysis of PLFAs demonstrated that land use history and plant cover type had a significant impact on microbial community structure.However,the difference of soil microbial community structure in the paddy field compared to other land uses was not larger than expected in this experiment.

  10. [Effects of thiourea on pH and availability of metal ions in acid red soil].

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    Yang, Bo; Wang, Wen; Zeng, Qing-Ru; Zhou, Xi-Hong

    2014-03-01

    Through the simulation research, the effects of application of thiourea and urea on pH and availability of metal ions in acid red soil were studied, and the results showed that after applying urea, the soil pH increased in the first experimental stage and then reduced gradually to a low level, however, decreased trends of soil pH values were inhibited by the application of thiourea, especially when the concentration of thiourea reached to 5.0 mmol x kg(-1) dry soil, the soil pH was stable at high level, which exceeded to 6.0. It proved that the application of thiourea could inhibit the soil acidification due to urea application. After applying urea with different concentrations of thiourea, the available contents of Zn and Al decreased with the increasing concentration of thiourea, nevertheless, when the concentration of thiourea reached to 5.0 mmol x kg(-1), the available content of Mn was stable at high level which was over 110 mg x kg(-1). In addition, the results showed a highly significant negative correlation between the soil pH and the available content of Cu, Zn and Al, but for Mn, no discipline was found between the soil pH and the availability after applying thiourea. Moreover, the soil pH became higher after applying urea with thiourea compared to add urea only, which led to the decreasing of available content of Al, and it was benefited for the control of the phytotoxic effect of Al. The available content of Mn in the soil not only depended on soil pH but also the content of thiourea due to its redox and complexing reaction with Mn.

  11. Acid mist and soil Ca and Al alter the mineral nutrition and physiology of red spruce

    Energy Technology Data Exchange (ETDEWEB)

    Schaberg, P. G.; Murakami, P. F. [Northeastern Research Station, Burlington, VT (United States); Dehayes, D. H.; Hawley, G. J.; Strimbeck, G. R.; Borer, C. H. [Vermont Univ., School of Natural Resources, Burlington, VT (United States); Cumming, J. R. [West Virginia Univ, Dept. of Biology, Morgantown, WV (United States)

    2000-01-01

    The effects and potential interactions of acid mist and soil solutions of calcium and aluminium treatments on foliar cation concentrations, membrane-associated calcium leaching, growth, carbon exchange and cold tolerance in red spruce saplings was investigated. Results showed that soil solution calcium addition increased foliar calcium and zinc concentrations and increased the rate of respiration early in the growing season. Soil aluminium treatment reduced foliar concentrations of calcium, manganese, magnesium, phosphorus and zinc, which in turn, produced smaller stem diameters and shoot lengths. On the whole, aluminium -induced alterations in growth or physiology appeared to be independent of foliar calcium status. As a general rule, reduction in cation concentration associated with aluminium addition were greater for pH 5.0-treated saplings than for pH 3.0-treated saplings. This observation led the investigators to conclude that the mechanism underlying acid-induced reductions in foliar cold tolerance in red spruce is hydrogen ion-induced leaching of membrane-associated calcium from mesophyll cells. 93 refs., 6 tabs., 1 fig.

  12. Alleviation of Subsoil Acidity of Red Soil in Southeast China with Lime and Gypsum

    Institute of Scientific and Technical Information of China (English)

    SUNBO; R.MOREAU; 等

    1998-01-01

    Application of lime or gypsum is a common agricultrual practice to ameliorate soils with low pH which prohibits crop prduction,Its integrated effect on soil properties in a red soil derved from Quaternary red clay in Southeast China is discussed in this paper,Application of gypsum in the topsoil without leaching raised soil pH and promoted the production of soil NH4,but lime addition had a contrary effect.Generally,application of lime and /or gypsum has little on soil electrical properties.Gypsum had a little effect on soil exchange complex and its effect went down to 30 cm in depth ,The effect of lime reached only to 5 cm below its application layer.With leaching,Ca transferred from top soil to subsoil and decreased exchangeable Al in subsiol.Gypsum application led to a sharp decrease in soil exchangeable Mg but had no effect on K.

  13. Influence of Neutral Salts and pH on Exchangeable Acidity of Red Soil and Latosol Colloids

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    In the present work, the exchangeable acidity of a red soil colloid and a latosol colloid at different pH during reacting with four neutral salts was measured. The results show that the exchangeable acidity increased with increasing amounts of the neutral salts added, and the relation between them was almost linear. When the amount of the neutral salt added was lower than a certain value, the slope of the line was high, and the slope turned low when the amount exceeded that value, so there was a turning point in each line. The addition amounts of the neutral salts for the turning points were affected by the cation species of the neutral salts, but pH had less effect on them. After the turning points occurred, the exchangeable acidity of the red soil colloid still gradually increased with the addition amounts of the neutral salts, but that of the latosol colloid did not increase any more.The exchangeable acidity in NaClO4, KClO4 and NaCl solutions increased at first, and then decreased with increasing pH, that is to say, peak values appeared. The peak positions of the exchangeable acidity in relation to pH changed with neutral salt solutions and were affected by the surface characteristics of the soil colloids, but not affected by the amounts of the neutral salts added. The exchangeable acidity in the Ba(NO3)2 solution increased continuously with increasing pH. The exchangeable acidity of the red soil colloid was obviously larger than that of the latosol colloid.``

  14. [Release of Si, Al and Fe in red soil under simulated acid rain].

    Science.gov (United States)

    Liu, Li; Song, Cun-yi; Li, Fa-sheng

    2007-10-01

    bstract:A laboratory leaching experiment on simulated acid rain was carried out using soil columns. The release of Si, Al and Fe from soils and pH values of eluates were investigated. The results showed that under the given leaching volume, the release amounts of cations were influenced by the pH value of simulated acid rain, while their response to acid rain was different. Acid rain led to Si release, nearly none of Fe. Within the range from pH 3.0 to 5.6, a little Al release but mass Al only release at the pH below 3.0, both Si and Al had a declining release ability with the undergoing eluviation. At pH 2.5, the release amounts of Si and Al, especially Al, increased significantly with the strengthened weathering process of soil mineral. With an increase of the leaching amount of acid rain, the release of Si and Al increased, but acceleration of Si was slower than Al which was slower and slower. When the soil pH falling down to a certain grade, there are negative correlation between pH and both Al and DOC concentration of eluate. released, but most of Al derived from the aluminosilicates dissolved. Acid deposition can result in solid-phase alumino-organics broken and Al released, but most of Al derived from the aluminosilicates dissolved.

  15. [Responses of rhizosphere nitrogen and phosphorus transformations to different acid rain intensities in a hilly red soil tea plantation].

    Science.gov (United States)

    Chen, Xi; Chen, Fu-sheng; Ye, Su-qiong; Yu, Su-qin; Fang, Xiang-min; Hu, Xiao-fei

    2015-01-01

    Tea (Camellia sinensis) plantation in hilly red soil region has been long impacted by acid deposition, however its effects on nitrogen (N) and phosphorus (P) transformations in rhizosphere soils remain unclear. A 25-year old tea plantation in a typical hilly red soil region was selected for an in situ simulation experiment treated by pH 4.5, pH 3.5, pH 2.5 and control. Rhizosihere and bulk soils were collected in the third year from the simulated acid deposition experiment. Soil mineral N, available P contents and major enzyme activities were analyzed using the chemical extraction and biochemical methods, and N and P mineralization rates were estimated using the indoor aerobic incubation methods. Our results showed that compared to the control, the treatments of pH 4.5, pH 3.5 and pH 2.5, respectively decreased 7.1%, 42.1% and 49.9% NO3(-)-N, 6.4%, 35.9% and 40.3% mineral N, 10.5%, 41.1% and 46.9% available P, 18.7%, 30.1% and 44.7% ammonification rate, 3.6%, 12.7% and 38.8% net N-mineralization rate, and 31.5%, 41.8% and 63.0% P mineralization rate in rhizosphere soils; however, among the 4 treatments, rhizosphere soil nitrification rate was not significantly different, the rhizosphere soil urease and acid phosphatase activities generally increased with the increasing intensity of acid rain (Pacid intensity, the rhizosphere effects of NH4+-N, NO3(-)-N, mineral N, ammonification and net N-mineralization rates were altered from positive to negative effects, those of urease and acid phosphatease showed the opposite trends, those of available P and P mineralization were negative and that of nitrification was positive. In sum, prolonged elevated acid rain could reduce N and P transformation rates, decrease their availability, alter their rhizosphere effects, and have impact on nutrient cycling in tea plantation.

  16. Analysis of the Long-Term Corrosion Behavior of X80 Pipeline Steel in Acidic Red Soil Using Electrical Resistance Test Technique

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    Shuaixing Wang

    2015-01-01

    Full Text Available The long-term corrosion rate of X80 steel in an acidic red soil was monitored in situ by using a precise electrical resistance (ER test system. The corrosion characteristics of X80 steel were examined via SEM, EDS, and XRD. The results indicated that the corrosion rate determined from ER test was very similar to that obtained from the mass loss test. The ER test technique made it possible to predict the long-term corrosion rate of steel in soil in situ. The corrosion rate of X80 steel in acidic red soil was about 0.0902 mm/a at 38 weeks, but the corrosion rate was dropped to 0.0226 mm/a after 5 years. The final corrosion product layer was composed mainly of FeOOH, γ-Fe2O3, and FeCO3.

  17. Effects of Lanthanum on Hydrolytic Enzyme Activities in Red Soil

    Institute of Scientific and Technical Information of China (English)

    褚海燕; 朱建国; 谢祖彬; 李振高; 曹志洪; 曾青; 林先贵

    2002-01-01

    The effects of La on some hydrolytic enzyme activities in red soil were studied in incubation and pot culture experiments. In the incubation experiment, La slightly stimulates the activities of urease and acidic phosphatase in soil and strongly stimulates sucrase activity in soil. In the pot culture experiment, La stimulates the activities of urease, acidic phosphatase and sucrase to different degrees. The stimulative effects of rare earth elements (REE) on hydrolytic enzyme activities in soil may result in increasing yield of crops.

  18. Biodegradation of C.I. Acid Red 1 by indigenous bacteria Stenotrophomonas sp. BHUSSp X2 isolated from dye contaminated soil.

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    Kumari, Lata; Tiwary, Dhanesh; Mishra, Pradeep Kumar

    2016-03-01

    A significant proportion of xenobiotic recalcitrant azo dyes are being released in environment during carpet dyeing. The bacterial strain Stenotrophomonas sp. BHUSSp X2 was isolated from dye contaminated soil of carpet industry, Bhadohi, India. The isolated bacterial strain was identified morphologically, biochemically, and on the basis of 16S rRNA gene sequence. The isolate decolorized 97 % of C.I. Acid Red 1 (Acid RED G) at the concentration of 200 mg/l within 6 h under optimum static conditions (temperature -35 °C, pH 8, and initial cell concentration 7 × 10(7) cell/ml). Drastic reduction in dye degradation rate was observed beyond initial dye concentration from 500 mg/l (90 %), and it reaches to 25 % at 1000 mg/l under same set of conditions. The analysis related to decolorization and degradation was done using UV-Vis spectrophotometer, HPLC, and FTIR, whereas the GC-MS technique was utilized for the identification of degradation products. Phytotoxicity analysis revealed that degradation products are less toxic as compared to the original dye.

  19. Contrasting nutritional acclimation of sugar maple (Acer saccharum Marsh. and red maple (Acer rubrum L. to increasing conifers and soil acidity as demonstrated by foliar nutrient balances

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    Alexandre Collin

    2016-07-01

    Full Text Available Sugar maple (Acer saccharum Marshall, SM is believed to be more sensitive to acidic and nutrient-poor soils associated with conifer-dominated stands than red maple (Acer rubrum L., RM. Greater foliar nutrient use efficiency (FNUE of RM is likely the cause for this difference. In the context of climate change, this greater FNUE could be key in favouring northward migration of RM over SM. We used the concept of foliar nutrient balances to study the nutrition of SM and RM seedlings along an increasing gradient in forest floor acidity conditioned by increasing proportions of conifers (pH values ranging from 4.39 under hardwoods, to 4.29 under mixed hardwood-conifer stands and 4.05 under conifer-dominated stands. Nutrients were subjected to isometric log-ratio (ilr transformation, which views the leaf as one closed system and considers interactions between nutrients. The ilr method eliminates numerical biases and weak statistical inferences based on raw or operationally’’ log-transformed data. We analyzed foliar nutrients of SM and RM seedlings and found that the [Ca,Mg,K|P,N] and [Ca,Mg|K] balances of SM seedlings were significantly different among soil acidity levels, whereas they did not vary for RM seedlings. For SM seedlings, these differences among soil acidity levels were due to a significant decrease in foliar Ca and Mg concentrations with increasing forest floor acidity. Similar differences in foliar balances were also found between healthy and declining SM stands estimated from literature values. Conversely, foliar balances of RM seedlings did not differ among soil acidity levels, even though untransformed foliar nutrient concentrations were significantly different. This result highlights the importance of using ilr transformation, since it provides more sensitive results than standard testing of untransformed nutrient concentrations. The lower nutrient requirements of RM and its greater capacity to maintain nutrient equilibrium are

  20. Influence of Exogenous Lanthanum on Fertility Parameters of Red Soil and Paddy Soil

    Institute of Scientific and Technical Information of China (English)

    谢祖彬; 朱建国; 褚海燕; 曾青; 张雅丽; 曹志洪

    2001-01-01

    The effects of exogenous La on the fertility parameters such as cation exchange capacity (CEC), exchangeable basic cations, and exchangeable acidity in red soil and paddy soil were studied with soil column simulation. The results show that with increasing amount of the added La, the proportion of exchangeable La in soils increases and there is more exchangeable La in red soil than in paddy soil. When the concentration of La is more than 600 mg*kg-1, the proportion of exchangeable La almost remains constant. When the concentration of La is less than 1200 mg*kg-1, there is no significant effect on CEC in red soil. But when the concentration of La is more than 1200 mg*kg-1, it has significant effect on CEC in paddy soil. The application of La resulted in increasing exchangeable aluminum, Ca and Mg in soil solution, and decreasing exchangeable Ca and Mg retained in soils. But when the concentration of La is less than 150 mg*kg-1, it has no significant influence on CEC, exchangeable Ca and Mg, and exchangeable acidity in red soil and paddy soil.

  1. 红壤中低分子量有机酸的吸附特征%Adsorption Characteristics of Low Molecular Weight Organic Acids in Red Soil

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    喻艳红; 李清曼; 张桃林; 王兴祥

    2011-01-01

    应用平衡法研究了红壤对草酸、柠檬酸、酒石酸和苹果酸的吸附行为.结果表明:红壤对有机酸的吸附量随着有机酸平衡溶液浓度的增加而增加,有机酸种类不同,吸附量也不同.有机酸在红壤中的吸附行为均可以很好地用Langrnuir、Freundlich和Temkim方程描述,其中以Langmnuir方程的拟合效果最好.红壤对有机酸均具有较高的吸附率,在0.5~20mmol L-1初始浓度范嗣内,草酸、柠檬酸、酒石酸和苹果酸的吸附率最大分别可达89.2%、77.5%、67.4%和47.1%.红壤对柠檬酸、酒石酸和苹果酸的吸附率均随着有机酸初始浓度的增加先急剧下降(<5 mmol L-1),之后缓慢下降至趋于平稳;草酸的吸附率则随着初始浓度的增加而增加,在3 mmol L-1左右时达到最大,随后降低至趋于平稳.%This research investigated the adsorption behaviours of oxalic, citric, tartaric and malic acids in red soil by a batch equilibrium method. The results indicated that the adsorption amount increased with the increase of equilibrium concentration, and the adsorption amount was different with the different type of organic acids. The adsorption characteristics of oxalic, citric, tartaric and malic all could be well described by Langmuir, Freundlich and Temkim equations, and the Langmuir equation was the best one. The adsorption ratios of organic acids in red soil were all high. When the initial concentrations ranged from 0.5 to 20 mmol L-1, the maximum adsorption ratio of oxalic,citric, tartaric and malic acids could reach 89.2%, 77.5%, 67.4% and 47.1%, respectively. The adsorption ratios of citric, tartaric and malic acids in red soil all dramatically decreased with the increasing initial concentrations of organic acids (< 5 mmol L-1), and then decreased slowly to be steady with the further increase of initial concentrations. The adsorption ratio of oxalic acid increased first with the increase of its initial concentration and

  2. Effects of four soil conditioners on alleviating aluminum toxicity in acid red soil%4种土壤调理剂改良红壤铝毒害的效果研究

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    李昂; 王旭; 范洪黎

    2014-01-01

    A pot experiment was conducted to investigate the effects of soil conditioner on alleviating aluminum toxicity in acid red soil. The result revealed that all the four soil conditioner could significantly reduce the exchangeable aluminum content and the toxic aluminum content in soil, increase maize height and biomass. Soil exchangeable aluminum content were significantly correlated with plant height and biomass in all treatments. When 0. 2% soil conditioner was added, the soil exchangeable alumi-num of oyster shell, dolomite, potassium feldspar, maifan stone decreased by 63. 8%, 70. 5%, 53. 0%, 12. 3% respectively;and when 0. 4% soil conditioner was added, the soil exchangeable aluminum decreased by 90. 5%, 92. 0%, 80. 5%, 23. 4%respectively. The exchangeable aluminum and toxic aluminum in soil decreased with the increase of the application of soil condi-tioner. The toxic aluminum content in soil was: dolomite

  3. Remediation of copper polluted red soils with clay materials

    Institute of Scientific and Technical Information of China (English)

    Gangya Zhang; Yunqing Lin; Mingkuang Wang

    2011-01-01

    Attapulgite and montmorillonite were utilized to remediate heavy metal polluted red soils in Guixi City, Jiangxi Province, China.The effects of clay minerals on availability, chemical distribution, and biotoxicity of Cu and Zn were evaluated.The results provided a reference for the rational application of clay materials to remediate heavy metal contaminated soils.From the sorption experiment,the maximum adsorbed Cu2+ by attapulgite and montmorillonite was 1501 and 3741 mg/kg, respectively.After polluted red soil was amended with attapulgite or montmorillonite and cultured at 30 and 60 days, soil pH increased significantly compared to the control.An 8% increase in the amount of montmorillonite in soil and 30 days incubation decreased acid exchangeable Cu by 24.7% compared to the control red soil.Acid exchangeable Cu decreased with increasing amounts of attapulgite and montmorillonite, with best remediation effect reached at a dose of 8%.Results also showed that the Cu poisoning effect on earthworms was reduced with the addition of attapulgite and montmorillonite.Montmoriilonite showed the best effect, with the addition of a 2% dose the mortality of earthworms decreased from 60% to zero compared to the control.Our results indicated that the bioavailability of Cu in soils was reduced more effectively with the application of montmorillonite than attapulgite.

  4. Remediation of copper polluted red soils with clay materials.

    Science.gov (United States)

    Zhang, Gangya; Lin, Yunqing; Wang, Mingkuang

    2011-01-01

    Attapulgite and montmorillonite were utilized to remediate heavy metal polluted red soils in Guixi City, Jiangxi Province, China. The effects of clay minerals on availability, chemical distribution, and biotoxicity of Cu and Zn were evaluated. The results provided a reference for the rational application of clay materials to remediate heavy metal contaminated soils. From the sorption experiment, the maximum adsorbed Cu2+ by attapulgite and montmorillonite was 1501 and 3741 mg/kg, respectively. After polluted red soil was amended with attapulgite or montmorillonite and cultured at 30 and 60 days, soil pH increased significantly compared to the control. An 8% increase in the amount of montmorillonite in soil and 30 days incubation decreased acid exchangeable Cu by 24.7% compared to the control red soil. Acid exchangeable Cu decreased with increasing amounts of attapulgite and montmorillonite, with best remediation effect reached at a dose of 8%. Results also showed that the Cu poisoning effect on earthworms was reduced with the addition of attapulgite and montmorillonite. Montmorillonite showed the best effect, with the addition of a 2% dose the mortality of earthworms decreased from 60% to zero compared to the control. Our results indicated that the bioavailability of Cu in soils was reduced more effectively with the application of montmorillonite than attapulgite.

  5. Effect of Liming on Cadmium Forms and Its Toxicity in Red Soils

    Institute of Scientific and Technical Information of China (English)

    A.M.FARAH; XIEZHENGMIAO; 等

    1996-01-01

    The effect of liming 4 soils developed from Quaternary red clay and red sandstone on the cadmium forms and its toxicity were investigated.Liming the acid red soils could greatly reduce Cd toxicity to plants because the soluble Cd and organic Cd in the soils decreased significantly while Cd bound to minerals/oxides and residual Cd increased markedly with increasing lime rates(pH).

  6. Aluminum extractability in red soils as influenced by land use patterns

    Institute of Scientific and Technical Information of China (English)

    叶兰军; 谢正苗; 黄昌勇; 徐建明

    2002-01-01

    This study on the effect of land use on soil quality in relation to forms and toxicity of aluminum in red soils (Ultisol) in southeast China showed that in general, the extractable order for soil active aluminum by four extractants was: NaOH 0.5 mol/L > HCl 1 mol/L > NH4Ac 1 mol/L > KCl 1 mol/L . Different uses of the red soils, developed from Quarternary red clay with the similar hydrogeological environment, greatly affected the amount of active aluminum, especially the exchangeable Al3+. The order of exchangeable Al3+ (Al mg/kg) in the red soils with different land uses was: barren land (740) > tea garden (663) > peach garden (432) > citrus garden (234) > paddy soil (127). The content of water soluble aluminum in the red soils was highly sensitive to soil acidity.

  7. Accumulation of Organic Matter in Infertile Red Soils and Its Ecological Importance

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    Field experiments on the decomposition of organic materials and the accumulation of organic carbon in infertile red soils were conducted at the Ecological Experimental Station of Red Soil, the Chinese Academy of Sciences, and the potential of CO2 sequestration by reclamation and improving the fertility of these soils was estimated. Results showed that in infertile red soils, the humification coefficients of organic materials were rather high, ranging from 0.28 to 0.63 with an average of 0.43, which was 41% higher than those in corresponding red soils with medium fertility. This was mainly attributed to the high clay content, high acidity and low native organic matter content of infertile red soils. Compared to those in corresponding normal red soils, the decomposition rates of organic materials were significantly lower in infertile red soils in the first 2 years, thereafter no significant difference was observed between those in the two kinds of soils. Depending on the kind and amount of organic manure applied, the soil properties and the rotation systems, annual application of organic manure with a rate of 4 500 to 9 000 kg ha-1 increased the organic carbon content in surface 20 cm of infertile red soils by 2.1~7.5 g kg-1 with an average of 4.7 g kg-1 within the first 5 years. The organic carbon content in infertile red soils which received organic manure annually increased linearly in the first 10 years, thereafter it slowed down, implying that the fertility of the infertile red soils could reach middle or high level in 10 years if the soil was managed properly. It was estimated that through exploitation of wastelands, re-establishment of fuel forests and improvement of soil fertility, soils in red soil region of China could sequester an extra 1.50×1015 g of atmospheric CO2.

  8. Restoration effect of different fertilizations on the acidic and exchange property of eroded red soil%不同施肥处理对侵蚀性红壤酸性和交换性能的修复效应

    Institute of Scientific and Technical Information of China (English)

    和利钊; 张杨珠; 刘杰; 廖超林; 黄运湘

    2012-01-01

    为探讨不同施肥处理对侵蚀性红壤的修复效应,研究了施化肥(NPK)、化肥+有机肥(NPKM)、化肥+土壤调理剂2号(NPKR2)与不施肥(CK)处理对不同母质发育的侵蚀性红壤酸性和交换性能的修复效应.结果表明:NPKM及NPKR2处理均可明显提高各种酸性土壤的pH缓冲能力,NPK处理效果则不明显;NPKR2可改良和降低土壤酸化程度,NPKM处理则只能增大土壤的pH缓冲容量,对改良土壤酸化的效果不显著;NPKM处理可提高土壤有机质含量,但土壤有机质含量与土壤pH缓冲能力不成正比;各施肥处理均能显著降低板页岩红壤、网纹层红壤和均质层红壤铝离子的活性,但只有NPKR2处理能明显降低花岗岩红壤的铝离子活性,其他施肥处理的效果不明显;各施肥处理的土壤阳离子交换量(CEC)均差异不大;NPKR2处理的土壤有效阳离子交换量(ECEC)显著高于其他处理;不同施肥处理下网纹层红壤和均质层红壤的ECEC均显著高于对照,而花岗岩红壤和板页岩红壤仅NPKR2处理有显著提高.%In order to understand the remediation effect of different fertilization structure on eroded soil, a pot experiment was conducted to investigate the restoration effects of Chemical fertilizer (NPK), NPK + Organic fertilizer (NPKM), NPK.+ Soil conditioner R2 (NPKR2), No fertilization (CK) on the acidic and exchange properties of eroded red soil which developed from different parent materials. The results indicated that treatments of combined application of organic and inorganic fertilizers (NPKM) and combined application of inorganic fertilizer and soil conditioner 2 (NPK.R2) could increase pH and buffer capacity significantly while the single fertilizer treatment (NPK) had no obvious effect. Treatment NPKR2 could ameliorate and decrease the acidic property of soil. Treatment NPKM could only increase pH buffer capacity of the soil, but not increase soil pH significantly. Treatment NPKM

  9. Dynamics of ryegrass P in red soils

    Institute of Scientific and Technical Information of China (English)

    XiHai-Fu; ZhangQin-Zheng; 等

    1998-01-01

    An investigation on the dynamics of transformation of P from 32P-labelled ryegrass in red soils was conducted in laboratory.The results showed thast the rapid increase in flush 32P related with biomass P was accompanied with the decrease in extractable 32P on the first 3d of incubation in both sandy and clayey soils,and afterwards,itdisplayed great fluctuation in sandy soil,but hadlittle fluctuaston in clayey soil during 3-20d of incubation.At the later stage of incubation,the increase in extractable 32P was accompanied with decrease in flush 32P.The opposite changes in content of extractable 32P and flush 32P suggested transformation of ryegrass P was clkosely related to its utilization and its release from microorganisms in red soils.It can be concluded that addition of organic matter accelerated the release of soil native P according to the changes in the extractable soil P during incubation.

  10. Combined Heavy Metal Pollution in Red Soil

    Institute of Scientific and Technical Information of China (English)

    CHENHUAIMAN; ZHENGCHNURONG

    1996-01-01

    The effects of combined heavy metal pollution of red soil on the growth of wetland rice and the transfer of Pb,Cd,Cu and Zn from soil into plants were sudied by greenhouse pot experiment,The results showed that the plantyields were markedly affected by heavy metals,with the exception of Pb,in soils under the experimental conditions,without taking into consideration all the interactions among the elements.The concentrations of the elemets in plants were mainly affected by the specific element added to the soil.The effect of interactions among the heavy metals was very significant either on plant yields or on the concentration of the elements in plants.The risk assessment of a combined pollution by heavy metals in the soil is discussed preliminarily in terms of the relative pollution equivalent.

  11. Effect of Low-Molecular-Weight Organic Acids on Cl- Adsorption by Variable Charge Soils

    Institute of Scientific and Technical Information of China (English)

    XU Ren-Kou; ANG Ma-Li; WANG Qiang-Sheng; JI Guo-Liang1

    2004-01-01

    Low-molecular-weight (LMW) organic acids exist widely in soils and have been implicated in many soil processes.The objective of the present paper was to evaluate effect of two LMW organic acids, citric acid and oxalic acid, on Cl- adsorption by three variable charge soils, a latosol, a lateritic red soil and a red soil, using a batch method. The results showed that the presence of citric acid and oxalic acid led to a decrease in Cl- adsorption with larger decreases for citric acid. Among the different soils Gl- adsorption in the lateritic red soil and the red soil was more affected by both the LMW organic acids than that in the latosol.

  12. Effects of Biochar and Lime on Soil Physicochemical Properties and Tobacco Seedling Growth in Red Soil

    Directory of Open Access Journals (Sweden)

    ZHU Pan

    2015-12-01

    Full Text Available Red soil, mainly found in the southern China, is developed in a warm, moist climate. The main property of the soils is strong acidity, aluminum toxicity, and low available nutrients. In this study, different effects of biochar and lime on soil physicochemical properties and tobacco growth were determined in red soil, so as to provide a scientific foundation for soil improvement tobacco field. A pot experiment was designed and conducted at four biochar levels(0, 0.5%, 1%, 2% and normal lime level (0.3% to study effects of two different soil amendments on red soil pH, exchangeable aluminum(Exc-Al and exchangeable manganese(Exc-Mn, available nutrients and organic carbon (SOC. Meanwhile, agronomic traits, biomass and leaves elements of tobacco were also tested. Results showed that the agronomic characters and biomass of tobacco seedling had changed effectively after biochar or lime was added. Under 0.5%, 1% biochar treatment, the content of nitrogen(N, phosphorus(P, potassium(K, calcium(Ca and magnesium(Mg in tobacco leaves substantially raised. However, when 2% biochar was applied, leaves N content declined by 9.3%. Compared with the control, leaves N, P and Ca content increased observably in the lime treatment. However, its K and Mg content decreased by 9.0% and 13.3% respectively. Alkaline nitrogen(SAN, available phosphorus (SAP, available potassium (SAK, and exchangeable calcium (Exc-Ca and exchangeable magnesium (Exc-Mg were improved obviously in soil applied with biochar. Only the content of Exc-Ca was significantly increased in lime treatment. In addition, it was beneficial to improve soil pH and reduce soil Exc-Al when biochar or lime had been used. Thus, both biochar and lime are propitious to increase soil pH value, lessen soil Exc-Al content, and improve the growth of tobacco seedling. Furthermore, biochar application also can raise the content of available nutrient and SOC in red soil.

  13. Factors Affecting Sensitivity of Variable Charge Soils to Acid Rain

    Institute of Scientific and Technical Information of China (English)

    WANGJING-HUA

    1995-01-01

    The sensitivity of a large number of variable charge soils to acid rain was evaluated through examining pH-H2SO4 input curves.Two derivative parameters,the consumption of hydrogen ions by the soil and the acidtolerant limit as defined as the quantity of sulfuric acid required to bring the soil to pH 3.5 in a 0.001mol L-1 Ca(NO3)2 solution,were used.The sensitivity of variable charge soils was higher than that of constant charge soils,due to the predominance of kaolinite in clay mineralogical composition.Among these soils the sensitivity was generally of the order lateritic red soil>red soil> latosol.For a given type of soil within the same region the sensitivity was affected by parent material,due to differences in clay minerals and texture.The sensitivity of surface soil may be lower or higher than that of subsiol,depending on whether organic matter or texture plays the dominant role in determining the buffering capacity.Paddy soils consumed more acid within lower range of acid input when compared with upland soils,due to the presence of more exchangeable bases,but consumed less acid within higher acid input range,caused by the decrease in clay content.

  14. Effects of red-yellow soil acidification on seed germination of Chinese pine

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    Acid treatments significantly change the physical and chemical properties of red-yellow soil by lowering its pH value and leaching out aluminum (Al) ions that are harmful to the growth of plants. The structure of soil will be damaged, resulting in higher viscosity, higher water retention rate and lower air permeability of the soil. The germination rate of Chinese pine (Pinus tabulacformic Carr.) seeds sowed in soil treated with sulphuric acid (H2SO4) decreased compared to that for untreated soil. The direct cause was the large amount of Al ions leached out because of low pH values (*3.5). The added acid decreased the soil aggregation and increased the number of micro-aggregates (under 250 μin diameter). Such changes increased the soil's viscosity, which tied the pine needles to the soil after the seeds had germinated and prevented the seedlings from fully developing.

  15. Composition and Characteristics of Organo—Mineral Complexes of Red Soils in South China

    Institute of Scientific and Technical Information of China (English)

    XUJIAN-MING; HOUHUI-ZHEN; 等

    1992-01-01

    The objective of the present study is to reveal the composition and characteristics of organo-mineral complexes in red soils (red soil,lateritic red soil and latosol) of south China in terms of chemical dissolution and fractional peptization methos.In the combined humus,most of the extractable humus could dissolve in 0.1 M NaOH extractant and belonged to active humus (H1),and there was only a small amount of humus which could be further dissolved in 0.1 M Na4P2O7 extractant at pH 13 and was stably combined humus (H2).The H1/H2 ratio ranged from 3.3 to 33.8 in red soils,and the proportions of both H1 and total extractable organic carbon (H1+H2) in total soil organic carbon and the ratios of H1 to H2 and H1 to (H1+H2) were all higher in lateritic red soil and latosol than in red soil.The differences of combined humus composition in various red soils were directly related to the content of Fe and Al oxides.In organo-mineral complexes,the ratio of Na-dispersed fraction (G1) to Na-ground-dispersed fraction (G2) was generally smaller than 1 for red soils,but there was a higher G1/G2 ratio in red soil than in lateritic red soil and latosol.G1 fraction had a higher content of fulvic acid (FA),but G2 fraction had a higher content of humic acid (HA).The ratios of H1 to H2 and HA to FA were higher in G2 than in G1.The differences in the composition and activity of humus between G1 and G2 fractions were related to the content of free Fe and Al oxides.The quantities of complex Fe and Al,the Fe/C and Al/C atomic ratios were higher in G2 than in G1,and the ratio of Al/C was much higher than that of Fe/C.It may be deduced that aluminum plays a more important role than iron in the formation process of organo-mineral complexes in red soils.

  16. Electrokinetics removal of lead from lead-contaminated red soils

    Institute of Scientific and Technical Information of China (English)

    刘云国; 李欣; 曾光明; 黄宝荣; 张慧智

    2003-01-01

    Ex-situ electroremediation tests were conducted on the lead-contaminated red soils to find out the optimum condition for the most efficient removal of lead pollution from the red soil,and to examine the relation of the pH of the soil with the electroremediation efficiency.The results show that the electroremediation technology is efficient to remedy Pb contaminated red soils,and the removal efficiency can be enhanced by controlling pH value in the cathode reservoir with HNO3.The average removal efficiency of Pb is enhanced from 24.5% to 79.5%,and the energy consumption reaches 285kW·h per m3 red soil.

  17. Genotypic Differences of Forage Crop Tolerance to Acid Soils

    Institute of Scientific and Technical Information of China (English)

    YANGYUAI; CHUXIANGYUN; 等

    1998-01-01

    Twenty eight species of forage crops were planted on acid soils derived from Quaternary red clay(pH4.16) and red sandstone(pH4.55) to study genotypic differences of the forage crops in tolerance to acid soils as affected by liming,phosporus and potassium fertilizer application.Eight forage species,Lolium nultiflorum L., Brachiaria decumbens,Digitaria sumtisii,Melinis minutiflora,Paspalum dilatatum,Paspalum wettsteinii,Sataria viridis Beanv and Shcep's Festuca,were highly toleran to acid soils,and grew relatively well in the tested soils without lime application,whereas most of the other 20 tested forage species such as Lolium perenne L., Meadow Festuca and Trifolium praense L. were intolerant to acid soil ,showing retarded growth when the soil pH was below 5.5 and significant increase in dry matter yields by phosphrus fertilizer application at soil pH 6.0 Results showed that large differences in tolerance to acid soils existed among the forage species,and tolerance of the froage species to acid soils might be closely associated with their tolerance to Al and P efficiency.

  18. [Variations of soil fertility level in red soil region under long-term fertilization].

    Science.gov (United States)

    Yu, Han-qing; Xu, Ming-gang; Lü, Jia-long; Bao, Yao-xian; Sun, Nan; Gao, Ju-sheng

    2010-07-01

    Based on the long-term (1982-2007) field experiment of "anthropogenic mellowing of raw soil" at the Qiyang red soil experimental station under Chinese Academy of Agricultural Sciences, and by using numerical theory, this paper studied the variations of the fertility level of granite red soil, quaternary red soil, and purple sandy shale soil under six fertilization patterns. The fertilization patterns included non-fertilization (CK), straw-returning without fertilizers (CKR), chemical fertilization (NPK), NPK plus straw-return (NPKR), rice straw application (M), and M plus straw-return (MR). The soil integrated fertility index (IFI) was significantly positively correlated with relative crop yield, and could better indicate soil fertility level. The IFI values of the three soils all were in the order of NPK, NPKR > M, MR > CK, CKR, with the highest value in treatment NPKR (0.77, 0.71, and 0.71 for granite red soil, quaternary red soil, and purple sandy shale soil, respectively). Comparing with that in the treatments of no straw-return, the IFI value in the treatments of straw return was increased by 6.72%-18.83%. A turning point of the IFI for all the three soils was observed at about 7 years of anthropogenic mellowing, and the annual increasing rate of the IFI was in the sequence of purple sandy shale soil (0.016 a(-1)) > quaternary red clay soil (0.011 a(-1)) > granite red soil (0.006 a(-1)). It was suggested that a combined application of organic and chemical fertilizers and/or straw return could be an effective and fast measure to enhance the soil fertility level in red soil region.

  19. Arabian Red Sea coastal soils as potential mineral dust sources

    KAUST Repository

    Prakash, P. Jish

    2016-09-26

    Both Moderate Resolution Imaging Spectroradiometer (MODIS) and Spinning Enhanced Visible and InfraRed Imager (SEVIRI) satellite observations suggest that the narrow heterogeneous Red Sea coastal region is a frequent source of airborne dust that, because of its proximity, directly affects the Red Sea and coastal urban centers. The potential of soils to be suspended as airborne mineral dust depends largely on soil texture, moisture content and particle size distributions. Airborne dust inevitably carries the mineralogical and chemical signature of a parent soil. The existing soil databases are too coarse to resolve the small but important coastal region. The purpose of this study is to better characterize the mineralogical, chemical and physical properties of soils from the Arabian Red Sea coastal plain, which in turn will help to improve assessment of dust effects on the Red Sea, land environmental systems and urban centers. Thirteen surface soils from the hot-spot areas of windblown mineral dust along the Red Sea coastal plain were sampled for analysis. Analytical methods included optical microscopy, X-ray diffraction (XRD), inductively coupled plasma optical emission spectrometry (ICP-OES), ion chromatography (IC), scanning electron microscopy (SEM) and laser particle size analysis (LPSA). We found that the Red Sea coastal soils contain major components of quartz and feldspar, as well as lesser but variable amounts of amphibole, pyroxene, carbonate, clays and micas, with traces of gypsum, halite, chlorite, epidote and oxides. The range of minerals in the soil samples was ascribed to the variety of igneous and metamorphic provenance rocks of the Arabian Shield forming the escarpment to the east of the Red Sea coastal plain. The analysis revealed that the samples contain compounds of nitrogen, phosphorus and iron that are essential nutrients to marine life. The analytical results from this study will provide a valuable input into dust emission models used in climate

  20. Arabian Red Sea coastal soils as potential mineral dust sources

    Science.gov (United States)

    Jish Prakash, P.; Stenchikov, Georgiy; Tao, Weichun; Yapici, Tahir; Warsama, Bashir; Engelbrecht, Johann P.

    2016-09-01

    Both Moderate Resolution Imaging Spectroradiometer (MODIS) and Spinning Enhanced Visible and InfraRed Imager (SEVIRI) satellite observations suggest that the narrow heterogeneous Red Sea coastal region is a frequent source of airborne dust that, because of its proximity, directly affects the Red Sea and coastal urban centers. The potential of soils to be suspended as airborne mineral dust depends largely on soil texture, moisture content and particle size distributions. Airborne dust inevitably carries the mineralogical and chemical signature of a parent soil. The existing soil databases are too coarse to resolve the small but important coastal region. The purpose of this study is to better characterize the mineralogical, chemical and physical properties of soils from the Arabian Red Sea coastal plain, which in turn will help to improve assessment of dust effects on the Red Sea, land environmental systems and urban centers. Thirteen surface soils from the hot-spot areas of windblown mineral dust along the Red Sea coastal plain were sampled for analysis. Analytical methods included optical microscopy, X-ray diffraction (XRD), inductively coupled plasma optical emission spectrometry (ICP-OES), ion chromatography (IC), scanning electron microscopy (SEM) and laser particle size analysis (LPSA). We found that the Red Sea coastal soils contain major components of quartz and feldspar, as well as lesser but variable amounts of amphibole, pyroxene, carbonate, clays and micas, with traces of gypsum, halite, chlorite, epidote and oxides. The range of minerals in the soil samples was ascribed to the variety of igneous and metamorphic provenance rocks of the Arabian Shield forming the escarpment to the east of the Red Sea coastal plain. The analysis revealed that the samples contain compounds of nitrogen, phosphorus and iron that are essential nutrients to marine life. The analytical results from this study will provide a valuable input into dust emission models used in climate

  1. Phosphorus Sorption Characteristics of Red Soils from Lampung, West- and Central Java

    Directory of Open Access Journals (Sweden)

    Syamsul Arifin Siradz

    2009-01-01

    Full Text Available Phosphorus Sorption Characteristics of Red Soils from Lampung, West- and Central Java (S.A. Siradz : Red soilis a common name used to identify any soil showing yellowish to reddish colour, these soils mainly occur in tropicaland subtropical regions. The term is frequently used to convey an image of red, infertile, acid soils in the tropics andis associated with tropical and subtropical climates which are characterized by high temperature and humidity. Majorsoil constraints to crop production may include low pH, low available P and high P fixation capacity, toxicity due toAl and sometimes Mn and Fe, deficiencies of N, Ca, Mg, K, and micronutrients e.g. Mo, Zn and Cu, low CEC and lowbase saturation, and very low content of weatherable minerals. The aim of this study was to determine the phosphorussorption characteristics of red soils from Lampung, West Java and Central Java. Soils were sampled at depth of 0-20cm from minimally disturbed sites after discarding the uppermost few cm consisting of an accumulation of litter. Thesamples were air-dried, crushed using a ceramic mortar and pestle and then passed through a 0.5 mm stainless steelsieve. Measurements of P sorption were conducted by equilibrating 200 mg of air dry soil ( West Java and Central Java. Values of pH(NaF, Ald, and exchangeable Ca were most predictive of Psorption in these soils.

  2. [Effects of low molecular weight organic acids on speciation of exogenous Cu in an acid soil].

    Science.gov (United States)

    Huang, Guo-Yong; Fu, Qing-Ling; Zhu, Jun; Wan, Tian-Ying; Hu, Hong-Qing

    2014-08-01

    In order to ascertain the effect of LMWOA (citric acid, tartaric acid, oxalic acid) on Cu-contaminated soils and to investigate the change of Cu species, a red soil derived from quartz sandstone deposit was added by Cu (copper) in the form of CuSO4 x 5H2O so as to simulate soil Cu pollution, keeping the additional Cu concentrations were 0, 100, 200, 400 mg x kg(-1) respectively. After 9 months, different LMWOA was also added into the simulated soil, keeping the additional LMWOAs in soil were 0, 5, 10, 20 mmol x kg(-1) respectively. After 2 weeks incubation, the modified sequential extraction method on BCR (European Communities Bureau of Reference) was used to evaluate the effects of these LMWOAs on the changes of copper forms in soil. The result showed that the percentage of weak acid dissolved Cu, the most effective form in the soil increased with three organic acids increase in quantity in the simulated polluted soil. And there was a good activation effect on Cu in the soil when organic acid added. Activation effects on Cu increased with concentration of citric acid increasing, but it showed a rise trend before they are basically remained unchanged in the case of tartaric acid and oxalic acid added in the soil. On the contrary, the state of the reduction of copper which was regarded as a complement for effective state decreased with the increased concentration of organic acid in the soil, especially with citric acid. When 20 mmol x kg(-1) oxalic acid and citric acid were added into the soil, the activation effect was the best; whereas for tartaric, the concentration was 10 mmol x kg(-1). In general, the effect on the changes of Cu forms in the soil is citric acid > tartaric acid > oxalic acid.

  3. Effect of Electrolytes on Surface Charge Characteristics of Red Soils

    Institute of Scientific and Technical Information of China (English)

    SHAOZONG-CHEN; HEQUN; 等

    1992-01-01

    The zero point of charge (ZPC) and the remaining charge σp at ZPC are two important parameters characterizing surface charge of red soils.Fourteen red soil samples of different soil type and parent material were treated with dithionite-citrate-dicarbonate (DCB) and Na2CO3 respectively.ZPC and σp of the samples in three indifferent electrolytes (NaCl,Na2SO4,and NaH2PO4) were determined.Kaolinite was used as reference.The results showed that ZPC of red soils was affected by the composition of parent materials and clay minerals and in significantly positive correlation with the content of total iron oxide (Fet),free iron oxide (Fed),amorphous iron oxide (Feo),aluminum oxide (Alo) and clay,but it was negatively correlated with the content of total silica (Sit).The σp of red soils was also markedly influenced by mineral components.Organic components were also contributing factor to the value of σp.The surface charges of red soils were evidently affected by the constitution of the electrolytes.Specific adsorption of anions in the electrolytes tended to make the ZPC of red soils shift to a higher pH value and to increase positive surface charges of the soils,thus leading to change of the σp value and decrease of the remaining net negative charges,even to the soils becoming net positive charge carriers.The effect of phosphate anion was greater than that of sulfate ion.

  4. Effects of Multiple Soil Conditioners on a Mine Site Acid Sulfate Soil for Vetiver Growth

    Institute of Scientific and Technical Information of China (English)

    LIN Chu-Xia; LONG Xin-Xian; XU Song-Jun; CHU Cheng-Xing; MAI Shao-Zhi; JIANG Dian

    2004-01-01

    A pot experiment was conducted to investigate the effects of various soil treatments on the growth of vetiver grass ( Vetiveria zizanioides (L.) Nash) with the objective of formulating appropriate soil media for use in sulfide-bearing mined areas. An acidic mine site acid sulfate soil (pH 2.8) was treated with different soil conditioner formula including hydrated lime, red mud (bauxite residues), zeolitic rock powder, biosolids and a compound fertilizer. Soils treated with red mud and hydrated lime corrected soil acidity and reduced or eliminated metal toxicity enabling the establishment of vetiver grass.Although over-liming affected growth, some seedlings of vetiver survived the initial strong alkaline conditions. Addition of appropriate amounts of zeolitic rock powder also enhanced growth, but over-application caused detrimental effects. In this experiment, soil medium with the best growth performance of vetiver was 50 g of red mud, 10 g of lime, 30 g of zeolitic rock powder and 30 g of biosolids with 2000 g of mine soils (100% survival rate with the greatest biomass and number of new shoots), but adding a chemical fertilizer to this media adversely impacted plant growth. In addition, a high application rate of biosolids resulted in poorer growth of vetiver, compared to a moderate application rate.

  5. Effect of Selected Organic Acids on Cadmium Sorption by Variable-and Permanent-Charge Soils

    Institute of Scientific and Technical Information of China (English)

    HU Hong-Qing; LIU Hua-Liang; HE Ji-Zheng; HUANG Qiao-Yun

    2007-01-01

    Batch equilibrium experiments were conducted to investigate cadmium (Cd) sorption by two permanent-charge soils, a yellow-cinnamon soil and a yellow-brown soil, and two variable-charge soils, a red soil and a latosol, with addition of selected organic acids (acetate, tartrate, and citrate). Results showed that with an increase in acetate concentrations from 0 to 3.0 mmol L-1, Cd sorption percentage by the yellow-cinnamon soil, the yellow-brown soil, and the latosol decreased. The sorption percentage of Cd by the yellow-cinnamon soil and generally the yellow-brown soil (permanent-charge soils)decreased with an increase in tartrate concentration, but increased at low tartrate concentrations for the red soil and the latosol. Curves of percentage of Cd sorption for citrate were similar to those for tartrate. For the variable-charge soils with tartrate and citrate, there were obvious peaks in Cd sorption percentage. These peaks, where organic acids had maximum influence, changed with soil type, and were at a higher organic acid concentration for the variable-charge soils than for the permanent charge soils. Addition of cadmium after tartrate adsorption resulted in higher sorption increase for the variable-charge soils than permanent-charge soils. When tartrate and Cd solution were added together, sorption of Cd decreased with tartrate concentration for the yellow-brown soil, but increased at low tartrate concentrations and then decreased with tartrate concentration for the red soil and the latosol.

  6. Effect of Oxalic Acid on Potassium Release from Typical Chinese Soils and Minerals

    Institute of Scientific and Technical Information of China (English)

    TU Shu-Xin; GUO Zhi-Fen; SUN Jin-He

    2007-01-01

    Oxalic acid plays an important role in improving the bioavailability of soil nutrients. Batch experiments were employed to examine the influences of oxalic acid on extraction and release kinetics of potassium (K) from soils and minerals along with the adsorption and desorption of soil K+. The soils and minerals used were three typical Chinese soils, black soil (Mollisol), red soil (Ultisol), and calcareous alluvial soil (Entisol), and four K-bearing minerals, biotite, phlogopite, muscovite, and microcline. The results showed that soil K extracted using 0.2 mol L-1 oxalic acid was similar to that using 1 mol L-1 boiling HNO3. The relation between K release (y) and concentrations of oxalic acid (c) could be best described logarithmically as y=a+blogc, while the best-fit kinetic equation of K release was y=a +b√t, where a and b are the constants and t is the elapsed time. The K release for minerals was ranked as biotite> phlogopite>> muscovite> microcline and for soils it was in the order: black soil> calcareous alluvial soil> red soil. An oxalic acid solution with low pH was able to release more K from weathered minerals and alkaline soils. Oxalic acid decreased the soil K+ adsorption and increased the soil K+ desorption, the effect of which tended to be greater at lower solution pH, especially in the red soil.

  7. Impact of pH on Microbial Biomass Carbon and Microbial Biomass Phosphorus in Red Soils

    Institute of Scientific and Technical Information of China (English)

    CHEN Guo-Chao; HE Zhen-Li; WANG Yi-Jun

    2004-01-01

    The impact of pH changes on microbial biomass carbon (Cmic) and microbial biomass phosphorus (Pmic)were examined for 3 red soils under citrus production with different lengths of cultivation. Soil pH significantly affected Cmic and Pmic. The Cmic and Pmic changes, as a function of soil pH, appeared to follow a normal distribution with the original soil pH value at the apex and as pH increased or decreased compared to the original soil pH, Cmic and Pmic declined. Moreover, there were critical pH values at both extremes (3.0 on the acidic side and 8.0 to 8.5 on the alkaline side), beyond which most of microorganisms could never survive.The effect of pH on Cmic and Pmic was also related to the original soil pH. The higher the original soil pH was, the less Cmic or Pmic were affected by pH change. It is suggested that soil microorganisms that grow in a soil environment with a more neutral soil pH range (I.e. pH 5.5-7.5) may have a greater tolerance to pH changes than those growing in more acidic or more alkaline soil pH conditions.

  8. Effect of Lanthanum on Major Microbial Populations in Red Soil

    Institute of Scientific and Technical Information of China (English)

    CHUHAIYAN; WANGJUNHUA; 等

    2001-01-01

    Pure culture and pot culture experiments were carried out to study the effect of lanthanum(La)on bacteria,actinomyces and fungus,and some microbial physiological groups,nitrifir,azotobacter and phos-phobacteria in a red soil taken form the Ecological Experimental Station of Red Soil,the Chinese Academy of Sciences,Jiangxi Province.LaCl3 was added into media at levels of 0,25,50,100,150,200,250 and 500 mg L-1 in the pure culture experiment ,and into soil samples in porcelain pots before rice growing at levles of 0,6,30,150,300,600 and 900 mg kg-1 dry soil in the pot culture experiment.The populations of the three soil microbes in the pure cultre experiment decreased with the addition level of La,indicating that La was toxic to the soil microbes in pure culture ,and the sensitivity of the 3 major mircrobial types to La was in a decreasing order of actinomyces>bacteria>fungus.In the pot experiment,La had slightly stimulaive effect on soil bacteria and actinomyces when applied at olw concentrations while had inhibitory effect on soil bacteria,actinomyces and fungus at high concentrations.When the concentration of La Was low,soil azotobacter was stimulated slightly while soil nitrifier was stimulated strongly and the maximum increase was up to 50%.When the concentration of La was highy,both soil aztobacter and nitrifier ware inhibited ,and the inhibition of La to the nitrifier increased with La conentration,La added at all the levels had stimulative effect on soil inorgaic and organic phosphobacteria.Among the 4 physiological groups,soil nitrifier was most sensitive to La,so,it migh be reasonble to assume that soil nitrifier was a sensitive indicator for evaluating the biological and environmental effects of rare earths.

  9. GIS—Based Red Soil Resources Classification and Evaluation

    Institute of Scientific and Technical Information of China (English)

    HUYUEMING; WANGRENCHAO; 等

    1999-01-01

    A small scale red soil resources information system(RSRIS) with applied mathematical models was developed and applied in red soil resources(RSR) classification and evaluation,taking Zhejiang Province,a typical distribution area of red soil,as the study area.Computer-aided overlay was conductied to classifty RSR types.The evaluation was carried out by using three methods,i.e.,index summation,square root of index multiplication and fuzzy comprehensive assessment,with almost identical results,The result of index summation could represent the basic qualitatie condition of RSR,that of square root of index miltiplication reflected the real condition of RSR qualitative rank,while fuzzy comprehensive assessment could satisfactorily handle the relationship between the evaluation factors and the qualitative rank of RSR,and therefore it is a feasible method for RSR evaluation.

  10. Toxicity induced by Basic Violet 14, Direct Red 28 and Acid Red 26 in zebrafish larvae.

    Science.gov (United States)

    Shen, Bing; Liu, Hong-Cui; Ou, Wen-Bin; Eilers, Grant; Zhou, Sheng-Mei; Meng, Fan-Guo; Li, Chun-Qi; Li, Yong-Quan

    2015-12-01

    Basic Violet 14, Direct Red 28 and Acid Red 26 are classified as carcinogenic dyes in the European textile ecology standard, despite insufficient toxicity data. In this study, the toxicity of these dyes was assessed in a zebrafish model, and the underlying toxic mechanisms were investigated. Basic Violet 14 and Direct Red 28 showed acute toxicity with a LC50 value at 60.63 and 476.84 µg ml(-1) , respectively, whereas the LC50 of Acid Red 26 was between 2500 and 2800 µg ml(-1) . Treatment with Basic Violet 14, Direct Red 28 and Acid Red 26 resulted in common developmental abnormalities including delayed yolk sac absorption and swimming bladder deflation. Hepatotoxicity was observed in zebrafish treated with Basic Violet 14, and cardiovascular toxicity was found in zebrafish treated with Acid Red 26 at concentrations higher than 2500 µg ml(-1) . Basic Violet 14 also caused significant up-regulation of GCLC gene expression in a dose-dependent manner whereas Acid Red 26 induced significant up-regulation of NKX2.5 and down-regulation of GATA4 at a high concentration in a dose-dependent manner. These results suggest that Basic Violet 14, Direct Red 28 and Acid Red 26 induce developmental and organ-specific toxicity, and oxidative stress may play a role in the hepatotoxicity of Basic Violet 14, the suppressed GATA4 expression may have a relation to the cardiovascular toxicity of Acid Red 26. Copyright © 2015 John Wiley & Sons, Ltd.

  11. 植被刈割对红壤酸度及有机无机复合状况的影响%EFFECTS OF CUTTING FREQUENCY OF NATURAL VEGETATION ON ACIDITY AND ORGANO-MINERAL COMPLEX IN RED SOILS

    Institute of Scientific and Technical Information of China (English)

    曾希柏; 刘更另

    2000-01-01

    在红壤地区自然植被(白茅)条件下,不同的刈割周期对土壤交换性盐基离子组成、土壤有机质、有机无机复合体、腐殖质组成及铁、铝氧化物含量等均具有较大的影响。从1年刈割一次至6年刈割一次处理,虽然土壤酸度的变化无明显规律,但土壤交换性钾、无定形铁、无定形铝、络合态铁的含量及铁活化度值均呈增加趋势,且土壤有机质和复合体的含量相应增高,松结态腐殖质/紧结态腐殖质的比值亦增大,即腐殖质的活性较强、质量较高,土壤肥力在一定程度上得以进化;而交换性钠、交换性钙及游离铁、铝氧化物的含量则呈相应的下降趋势。%Based on the long-term experiments of different cutting frequency of natural vegetation (Imperata cylindrica var. major), in red soils of south of Hunan Province, the changes of contents of organo-mineral complex, acidity and Fe, Al oxides were studied. The results showed that the changes of the soil acidity were not any regular,but the contents of organic matter, organo-mineral complex, exchangeable K, amorphous Fe and Al, complex Fe and value of loosely combined/ tightly combined, activation degree of Fe in the soil had a tendency of increasing, whereas the contents of exchangeable Na and Ca, free Fe and Al were decreased relatively when the cutting frequency treatments from one year to 6 years.

  12. Effects of Different Phosphorus Rates on Variations of Mn, Al, Mg and Ca Concentrations in Soil Solution and Wheat Growth in Acid Red Soil%不同磷水平对红壤溶液中锰、铝、镁和钙浓度变化以及小麦生长的影响

    Institute of Scientific and Technical Information of China (English)

    邵继锋; 陈荣府; 董晓英; 沈仁芳

    2016-01-01

    为了探明不同磷水平对红壤中土壤溶液主要金属离子变化的影响以及小麦对磷的响应,确定红壤中小麦适宜的施磷水平,采用原位提取土壤溶液和比较生物量的方法,监测了短期内红壤溶液中主要金属离子浓度变化及小麦生物量的变化.结果表明:碳酸钙的加入可以显著升高酸性红壤的pH,土壤溶液中铝、锰和镁浓度显著低于未加碳酸钙处理;800 mg/kg磷处理后铝、锰、镁和钙的浓度要比未加磷处理分别至少降低47%、44%、37%和33%.随着施磷量的增加,小麦在200 mg/kg磷处理时积累的生物量最大,随后磷增加,小麦生物量反而降低.而加碳酸钙处理小麦地下部生物量随着施磷量增加则降低.结果表明碳酸钙不仅可以有效升高土壤pH,降低土壤溶液铝浓度,还降低土壤溶液中锰的浓度.磷的加入同样可以降低锰和铝的浓度,缓解铝和锰毒害.红壤中生长小麦的适宜施磷量为200 mg/kg.%To investigate the effects of different phosphorus rates on the variations of Mn, Al, Mg and Ca concentrations in soil solutions and wheat responses to phosphorus in acid red soil, a pot experiment with a non-destructive soil-solution sampler preinstalled were conducted with increasing phosphorus fertilizer levels from 0 to 800 mg/kg. The results showed that pH was increased while the concentrations of Mn, Al, Mg and Ca in soil solutions were significance lower amended with CaCO3 than without CaCO3. Compared to 0 mg/kg phosphorus treatment the concentrations of Al, Mn, Mg and Ca at least decreased 47%, 44%, 37% and 33% after 800 mg/kg phosphorus treatment no matter amended with CaCO3 or not. Wheat biomass was accumulated highest in 200 mg/kg phosphorus treatment then decreased as phosphorus rates increased. However, the root biomass trended to decline as phosphorus rate increased while the soil was amended with CaCO3. Those results indicated that CaCO3 could increase pH and decrease Mn

  13. 不同作物对赤红壤酸铝毒害的响应研究%Response of Different Crops to Acid & Aluminum Toxicity in Latosol Red Soil

    Institute of Scientific and Technical Information of China (English)

    于智卫; 傅友强; 沈春鹏; 李子荣; 沈宏

    2011-01-01

    为评价赤红壤酸铝对作物的毒害作用,本文用氧化钙和硫酸铝将典型赤红壤pH值调节为4.01、4.52、5.02、5.52,研究了7种作物对不同酸铝土壤的响应。结果表明,不同酸铝土壤中,7种作物相对根长与相对根干重呈相似变化趋势,均表现为pH 5.02土壤〉pH 4.52土壤〉pH 4.01土壤,水稻的相对根长与相对根干重较大,而大麦较小,通菜、玉米、菜豆、豆角、大豆位于其中。铝溶液处理下不同作物的相对根伸长均以水稻、大豆、菜豆、豆角〉玉米〉通菜〉大麦,与土培结果基本一致;作物根系的苏木精染色程度随酸铝毒害程度的上升而加深,与作物铝吸收结果趋势相同。大麦、水稻、豆角染色较深,但其相对根长差异显著,表明它们具有不同的耐铝机制。%To evaluate the toxic effects of aluminum on crops in acidic soils,latosol red soil pH values were adjusted to 4.01,4.52,5.02 and 5.52,respectively,by using calcium oxide and aluminum sulfate.Responses of 7 kinds of crops to acid aluminum soil were investigated.Results indicated that the relative root length and relative dry weight of these crops showed similar trend as pH 5.02pH 4.52pH 4.01.The values of relative root length and dry weight of rice were relatively high,and those of barley were low,and other crops were in between,which being similar to the results of soil incubation.Hematoxylin is considered to stain Al deposits in root tips.Result from root-hematoxylin staining indicated the color of crop roots became deeper and darker with decrease of soil pH,which was consistent with the changes of Al uptake in crops.Barley,rice and long bean had more Al uptake and differential Al tolerance,suggesting the involvement of different Al-tolerance mechanisms.

  14. 赤红壤蔗地土壤酸缓冲性能与调控研究%Acidic buffering ability and regulation in latosolic red soil of sugarcane fields

    Institute of Scientific and Technical Information of China (English)

    江泽普; 韦广泼; 苏天明; 蒙炎成; 谭宏伟; 李杨瑞

    2008-01-01

    To study the acidic buffering ability in the latosolic soil of sugarcane predudng regions of Guangxi, a method for soil acidity determination by titration with 0.1 mol/L sulphuric acid was used. The results showed that the soil acid buffering ability of sugarcane fields in Guangxi were weak and sensitive to acid, the turning point of the soil acidification in sugarcane fields was pH 3.0-3.5 for added acid rain. Acid rain falling into the soil could acidify it, and the effect of using 75 t/hm2 vinasse on the soil acidification in the soil of sugarcane soils was much less. The factors affecting the soil acid buffering ability were mainly organic matter, physical clay, total salt and exchangeable Ca. Based on the results of the present study, three basic measures are put forward to increase the soil acid buffering ability and improve soil fertility: applying organic fertilizer and alkaline matter such as lime or alkaline fertilizer such as fused calcium-magnesium phosphate, covering soil with sugarcane leaves or grass, and planting along contour line, etc., which could increase the contents of soil organic matter and exchangeable cations, decrease the loss of soil clay and cations,and the soil acidity, increase the soil acid buffering ability, and improve the soil ecological environment.%采用酸滴定土壤酸度的方法研究广西蔗地土壤对酸的缓冲性能,结果表明,广西赤红壤蔗地土壤酸缓冲能力不强且对酸敏感,其土壤酸化转折点在加入模拟酸雨pH值3.0-3.5之间.酸雨会造成蔗地土壤严重酸化,而年施用75t/hm2酒精废液对蔗地土壤酸化影响较小.影响土壤酸缓冲性能因素主要为有机质、物理性粘粒、盐基总量和交换钙.据此可采取增施有机肥,施用碱性物质如石灰或碱性肥料如钙镁磷肥,以及增加土壤覆盖如蔗叶还田,或采取等高种植等措施,增加土壤有机质和交换性阳离子含量,减少土壤粘粒及阳离子流失,降低土壤酸度,

  15. Effect of Lanthanum on Major Microbial Populationsin Red Soil

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Pure culture and pot culture experiments were carried out to study theeffect of lanthanum (La) on bacteria, actinomyces and fungus, and somemicrobial physiological groups, nitrifier, azotobacter andphosphobacteria, in a red soil taken form the Ecological ExperimentalStation of Red Soil, the Chinese Academy of Sciences, Jiangxi Province.LaCl{3 was added into media at levels of 0, 25, 50, 100, 150,200, 250 and 500 mg L-1 in the pure culture experiment, and intosoil samples in porcelain pots before rice growing at levels of 0, 6,30, 150, 300, 600 and 900 mg kg-1 dry soil in the pot cultureexperiment. Thepopulations of the three soil microbes in the pure culture experimentdecreased with the addition level of La, indicating that La was toxicto the soil microbes in pure culture, and the sensitivity of the 3major microbial types to La was in a decreasing order ofactinomyces > bacteria > fungus. In the pot experiment, Lahad slightly stimulative effect on soil bacteria and actinomyces whenapplied at low concentrations while had inhibitory effect on soilbacteria, actinomyces and fungus at high concentrations. When theconcentration of La was low, soil azotobacter was stimulated slightlywhile soil nitrifier was stimulated strongly and the maximum increasewas up to 50%. When the concentration of La was high, both soilazotobacter and nitrifier were inhibited, and the inhibition of La tothe nitrifier increased with La concentration. La added at all thelevels had stimulative effect on soil inorganic and organicphosphobacteria. Among the 4 physiological groups, soil nitrifier wasmost sensitive to La, so, it might be reasonable to assume that soilnitrifier was a sensitive indicator for evaluating the biological andenvironmental effects of rare earths.

  16. [Effects of long-term fertilization on soil organic nitrogen components in paddy soil derived from red earth].

    Science.gov (United States)

    Zong, Hai-ying; Wang, Kai-rong; Xie, Xiao-li

    2008-08-01

    A 16-year long-term fertilization experiment was conducted on paddy soil derived from red earth to investigate the effects of different fertilization patterns on the concentrations of soil organic nitrogen (N) components. When chemical fertilizers were applied only, the soil nitrogen content was slightly influenced. Organic fertilization, especially its combination with chemical fertilization, could significantly increase the contents of soil mineralizable N and organic nitrogen by 55.2% and 38.8%, respectively. In addition, organic fertilization could significantly improve the components of acid hydrolysable N, and lead to the increase of ammonium N (AN) , amino sugar N (ASN), and hydrolysable unidentified N (HUN) by 36.5%, 68.4%, and 73.9%, respectively. When the organic fertilization was combined with chemical fertilization, soil amino acid N content was increased by 71.1%, while HUN content was decreased by 34.5%. In all fertilization treatments, the cumulative amount of soil mineralized N increased with increasing incubation time. The content of soil mineralized N under organic fertilization and its combination with chemical fertilization was higher than that under chemical fertilization.

  17. Comparative mineralogical characteristics of red soils from South Bulgaria

    Directory of Open Access Journals (Sweden)

    Marlena Yaneva

    2015-01-01

    Full Text Available The present study aims to compare mineralogical composition of red soils, formed on marbles in South Bulgaria. We used mineralogical analysis of heavy and light mineral fraction in immersion under polarizing microscope and X-ray diffraction analysis of bulk sample and clay fraction. Three test polygons, located in South Bulgaria were examined: Petrovo, Nova Lovcha and Dobrostan, which are characterized with different latitude, altitude, and exposition. Three or more sites from each polygon were sampled and analyzed. The red soils are formed on white and gray calcite and calcite-dolomite marbles, impure silicate-rich marbles and only in one site – on marble breccias. We determined the following mineral phases in red soils: calcite, dolomite, quarts, and feldspars, mica, illite-type mica, illite, smectite, vermiculite-smectite, and kaolinite. Heavy minerals are represented by amphibole, titanite and epidote, and minor amounts of zircon, garnet, tourmaline, rutile, pyroxene, andalusite, kyanite, sillimanite and apatite. Opaque minerals are predominantly goethite and hematite. Plant tissue is abundant in light fraction from the uppermost soil horizons. Analyses of heavy mineral fraction show presence of metamorphic and igneous minerals which indicate participation of weathering products from other rock types in the nearby area. The types of heavy minerals in soils depend more on composition of parent rocks and geomorphic position than on climate type. Soils from Nova Lovcha show similar composition, but the quantity of goethite and hematite significantly increase in soil from plain. Typical high-metamorphic minerals as andalusite, kyanite and sillimanite present only in Nova Lovcha, while garnet dominates in Petrovo and opaque minerals - in Dobrostan. Red soils, formed on slopes, where erosion prevails over accumulation, contain more illite, smectite and vermiculite-smectite, and very few or no kaolinite, whereas the kaolinite is dominant in soils

  18. Nature of the elements transporting long-chain fatty acids through the red cell membrane

    DEFF Research Database (Denmark)

    Bojesen, Inge Norby; Bojesen, Eigil

    1998-01-01

    Docosahexaenoic acid, linoleic acid, red cell membrane, transporting elements, transport kinetics, fatty acid transport......Docosahexaenoic acid, linoleic acid, red cell membrane, transporting elements, transport kinetics, fatty acid transport...

  19. The red mud accident in ajka (hungary): plant toxicity and trace metal bioavailability in red mud contaminated soil.

    Science.gov (United States)

    Ruyters, Stefan; Mertens, Jelle; Vassilieva, Elvira; Dehandschutter, Boris; Poffijn, André; Smolders, Erik

    2011-02-15

    The red mud accident of October 4, 2010, in Ajka (Hungary) contaminated a vast area with caustic, saline red mud (pH 12) that contains several toxic trace metals above soil limits. Red mud was characterized and its toxicity for plants was measured to evaluate the soil contamination risks. Red mud radioactivity (e.g., (238)U) is about 10-fold above soil background and previous assessments revealed that radiation risk is limited to indoor radon. The plant toxicity and trace metal availability was tested with mixtures of this red mud and a local noncontaminated soil up to a 16% dry weight fraction. Increasing red mud applications increased soil pH to maximally 8.3 and soil solution EC to 12 dS m(-1). Shoot yield of barley seedlings was affected by 25% at 5% red mud in soil and above. Red mud increased shoot Cu, Cr, Fe, and Ni concentrations; however, none of these exceed toxic limits reported elsewhere. Moreover, NaOH amended reference treatments showed similar yield reductions and similar changes in shoot composition. Foliar diagnostics suggest that Na (>1% in affected plants) is the prime cause of growth effects in red mud and in corresponding NaOH amended soils. Shoot Cd and Pb concentrations decreased by increasing applications or were unaffected. Leaching amended soils (3 pore volumes) did not completely remove the Na injury, likely because soil structure was deteriorated. The foliar composition and the NaOH reference experiment allow concluding that the Na salinity, not the trace metal contamination, is the main concern for this red mud in soil.

  20. Arsenic mobilization by citrate and malate from a red mud-treated contaminated soil.

    Science.gov (United States)

    Castaldi, Paola; Silvetti, Margherita; Mele, Elena; Garau, Giovanni; Deiana, Salvatore

    2013-01-01

    The mobility and bioavailability of As in the soil-plant system can be affected by a number of organic acids that originate from the activity of plants and microorganisms. In this study we evaluated the ability of citrate and malate anions to mobilize As in a polluted subacidic soil (UP soil) treated with red mud (RM soil). Both anions promoted the mobilization of As from UP and RM soils, with citrate being more effective than malate. The RM treatment induced a greater mobility of As. The amounts of As released in RM and UP soils treated with 3.0 mmol L citric acid solution were 2.78 and 1.83 μmol g respectively, whereas an amount equal to 1.73 and 1.06 μmol g was found after the treatment with a 3.0 mmol L malic acid solution. The release of As in both soils increased with increasing concentration of organic acids, and the co-release of Al and Fe in solution also increased. The sequential extraction showed that Fe/Al (oxi)hydroxides in RM were the main phases involved in As binding in RM soil. Two possible mechanisms could be responsible for As solubilization: (i) competition of the organic anions for As adsorption sites and (ii) partial dissolution of the adsorbents (e.g., dissolution of iron and aluminum oxi-hydroxides) induced by citrate or malate and formation of complexes between dissolved Fe and Al and organic anions. This is the first report on the effect of malate and citrate on the As mobility in a polluted soil treated with RM.

  1. Removal of cadmium from cadmium-contaminated red soils using electrokinetic soil processing

    Institute of Scientific and Technical Information of China (English)

    LIU Yun-guo; LI Cheng-feng; ZENG Guang-ming; YUE Xiu; LI Xin; XU Wei-hua; TANG Chun-fang; YUAN Xing-zhong

    2005-01-01

    To investigate the feasibility of electrokinetic soil processing on the removal of Cd from Cd-contaminated red soils, a laboratory experiment was conducted. A constant direct current density of 0.5mA/cm2 was applied. The result shows that the Cd-removal efficiency is remarkably pH-dependent, which is caused by the change of Cd retention capacity of the red soils under different pH conditions. The initial Cd concentration is 1.490g/kg and over 79% of it is removed from the red soils after treatment for 96h. The energy expenditure per unit volume at the end of experiment is about 77.6kW·h/m3 and the capital consumed by the whole experiment is 42.6RMB Yuan/m3, which suggests that the electrokinetic soil processing is a promising technology for remedying Cd-contaminated red soils due to its high removal efficiency and low energy consumption.

  2. Comprehensive evaluation of multiple cropping systems on upland red soil

    Institute of Scientific and Technical Information of China (English)

    Guoqin HUANG; Xiuying LIU; Longwang LIU; Fang YE; Mingling ZHANG; Yanhong SHU

    2008-01-01

    According to the principles and methods of ecology and system engineering,we set up an evaluation indicator system for multi-component and multiple crop-ping systems,evaluated the comprehensive benefits of multi-component and multiple cropping systems using grey relation clustering analysis and screened out the opti-mized model based on research done in the upland red soil in Jiangxi Agricultural University from 1984 to 2004.The results show that the grey relation degree of "cabbage/ potato/maize-sesame" was the highest among 23 multi-component and multiple cropping systems and was clustered into the optimized system.This indicates that "cabbage/potato/maize - sesame" can bring the best social,economic and ecological benefits,increase product yield and farmers' income and promote sustainable development of agricultural production.Therefore,it is suitable for promotion on upland red soil.The grey rela-tion degree of "canola/Chinese milk vetch/maize/mung bean/maize" was second,which is suitable for imple-mentation at the city outskirts.In conclusion,these two planting patterns are expected to play important roles in the reconstruction of the planting structure and optimiza-tion of the planting patterns on upland red soil.

  3. Mobility of selected trace elements in Mediterranean red soil amended with phosphogypsum: experimental study.

    Science.gov (United States)

    Kassir, Lina Nafeh; Darwish, Talal; Shaban, Amin; Ouaini, Naim

    2012-07-01

    Soil amendment by phosphogypsum (PG) application becomes of increasing importance in agriculture. This may lead, however, to soil, plant, and groundwater contamination with trace elements (TEs) inherently present in PG. Monitoring of selected TEs (Pb, Zn, Cu, and Cd) distribution and mobility in a Mediterranean red soil profile has been performed in soil parcels applied with PG over a 16-month period. Concentrations were measured in soil and plant samples collected from various depth intervals at different points in time. TEs sequential extraction was performed on soil and PG samples. Results showed soil profile enrichment peaked 5 months after PG application for Cd, and 12 months for Pb, Zn, and Cu. Rainwater, pH, total organic carbon, and cationic exchange capacity were the main controlling factors in TEs accumulation in soils. Cd was transferred to a soil depth of about 20 cm. Zn exhibited mobility towards deeper layers. Pb and Cu were accumulated in around 20-55-cm-deep layers. PG increased the solubility of the studied TEs; PG-applied soils contained TEs bound to exchangeable and acid-soluble fractions in higher percentages than reference soil. Pb, Zn, and Cu were sorbed into mineral soil phases, while Cd was mainly found in the exchangeable (bio-available) form. The order of TEs decreasing mobility was Zn > Cd > Pb > Cu. Roots and leaves of existed plants, Cichorium intybus L., accumulated high concentrations of Cd (1-2.4 mg/kg), exceeding recommended tolerable levels, and thus signifying potential health threats through contaminated crops. It was therefore recommended that PG should be applied in carefully established, monitored, and controlled quantities to agricultural soils.

  4. How important is a detailed hydrological representation when modelling soil carbon dynamics in Chinese red soils.

    Science.gov (United States)

    Oyesiku-Blakemore, Joseph; Verrot, Lucile; Geris, Josie; Zhang, Ganlin; Peng, Xinhua; Hallett, Paul; Smith, Jo

    2017-04-01

    Soil carbon and nitrogen processing are strongly influenced by the hydrology of soils. When simulating these processes models represent soil hydrology in some way. The hydrological components of soil carbon and nitrogen models vary greatly in their complexity, as does the burden of simulation time and data requirements. Hydrology specific models, such as Hydrus, have more detailed representations of soil hydrology than those used in some soil carbon and nitrogen models, such as ECOSSE, and can provide a more accurate and precise description of the movement and content of water in soil. Moisture content is one of the key variables controlling the processing of carbon and nitrogen in soil models. A higher soil moisture content results in increased methane production through the anaerobic decomposition of soil carbon pools. It also alters the rate at which aerobic decomposition occurs, with low and high soil moisture contents limiting the decomposition of SOC. An inaccurate estimate of soil moisture will introduce errors in the estimated rates of model SOC transformations, which would result in errors in the simulated SOC. In order to shed light on this uncertainty we use the same input data to simulate soil moisture contents in a Red Soil region of China, using both the ECOSSE model and Hydrus 2D. We compare the simulations of both models with measurements of soil moisture at the site and each other. We highlight where the models differ and identify the conditions under which errors are likely to occur. We then simulate SOC dynamics using the ECOSSE model and its original hydrology with the ECOSSE model simulations using the Hydrus 2D simulations. This shows the importance of including a detailed representation of soil moisture when simulating soil organic matter dynamics.

  5. Chemical evaluation of soil-solution in acid forest soils

    Science.gov (United States)

    Lawrence, G.B.; David, M.B.

    1996-01-01

    Soil-solution chemistry is commonly studied in forests through the use of soil lysimeters.This approach is impractical for regional survey studies, however, because lysimeter installation and operation is expensive and time consuming. To address these problems, a new technique was developed to compare soil-solution chemistry among red spruce stands in New York, Vermont, New Hampshire, Maine. Soil solutions were expelled by positive air pressure from soil that had been placed in a sealed cylinder. Before the air pressure was applied, a solution chemically similar to throughfall was added to the soil to bring it to approximate field capacity. After the solution sample was expelled, the soil was removed from the cylinder and chemically analyzed. The method was tested with homogenized Oa and Bs horizon soils collected from a red spruce stand in the Adirondack Mountains of New York, a red spruce stand in east-central Vermont, and a mixed hardwood stand in the Catskill Mountains of New York. Reproducibility, effects of varying the reaction time between adding throughfall and expelling soil solution (5-65 minutes) and effects of varying the chemical composition of added throughfall, were evaluated. In general, results showed that (i) the method was reproducible (coefficients of variation were generally reaction-time did not affect expelled solution concentrations, and (iii) adding and expelling solution did not cause detectable changes in soil exchange chemistry. Concentrations of expelled solutions varied with the concentrations of added throughfall; the lower the CEC, the more sensitive expelled solution concentrations were to the chemical concentrations of added throughfall. Addition of a tracer (NaBr) showed that the expelled solution was a mixture of added solution and solution that preexisted in the soil. Comparisons of expelled solution concentrations with concentrations of soil solutions collected by zero-tension and tension lysimetry indicated that expelled

  6. Replenishing Humic Acids in Agricultural Soils

    Directory of Open Access Journals (Sweden)

    Michael Susic

    2016-09-01

    Full Text Available For many decades, it was commonly believed that humic acids were formed in soils by the microbial conversion of plant lignins. However, an experiment to test whether these humic acids were formed prior to plant matter reaching the soil was never reported until the late 1980s (and then only as a side issue, even though humic acids were first isolated and reported in 1786. This was a serious omission, and led to a poor understanding of how the humic acid content of soils could be maintained or increased for optimum fertility. In this study, commercial sugar cane mulch and kelp extracts were extracted with alkali and analyzed for humic acid content. Humic acids in the extracts were positively identified by fluorescence spectrophotometry, and this demonstrated that humic acids are formed in senescent plant and algal matter before they reach the soil, where they are then strongly bound to the soil and are also resistant to microbial metabolism. Humic acids are removed from soils by wind and water erosion, and by water leaching, which means that they must be regularly replenished. This study shows that soils can be replenished or fortified with humic acids simply by recycling plant and algal matter, or by adding outside sources of decomposed plant or algal matter such as composts, mulch, peat, and lignite coals.

  7. [Response of mineralization of dissolved organic carbon to soil moisture in paddy and upland soils in hilly red soil region].

    Science.gov (United States)

    Chen, Xiang-Bi; Wang, Ai-Hua; Hu, Le-Ning; Huang, Yuan; Li, Yang; He, Xun-Yang; Su, Yi-Rong

    2014-03-01

    Typical paddy and upland soils were collected from a hilly subtropical red-soil region. 14C-labeled dissolved organic carbon (14C-DOC) was extracted from the paddy and upland soils incorporated with 14C-labeled straw after a 30-day (d) incubation period under simulated field conditions. A 100-d incubation experiment (25 degrees C) with the addition of 14C-DOC to paddy and upland soils was conducted to monitor the dynamics of 14C-DOC mineralization under different soil moisture conditions [45%, 60%, 75%, 90%, and 105% of the field water holding capacity (WHC)]. The results showed that after 100 days, 28.7%-61.4% of the labeled DOC in the two types of soils was mineralized to CO2. The mineralization rates of DOC in the paddy soils were significantly higher than in the upland soils under all soil moisture conditions, owing to the less complex composition of DOC in the paddy soils. The aerobic condition was beneficial for DOC mineralization in both soils, and the anaerobic condition was beneficial for DOC accumulation. The biodegradability and the proportion of the labile fraction of the added DOC increased with the increase of soil moisture (45% -90% WHC). Within 100 days, the labile DOC fraction accounted for 80.5%-91.1% (paddy soil) and 66.3%-72.4% (upland soil) of the cumulative mineralization of DOC, implying that the biodegradation rate of DOC was controlled by the percentage of labile DOC fraction.

  8. Tolerance of VA Mycorrhizal Fungi to Soil Acidity

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    A 45-day greenhouse experiment was carried out to determine effect of vesicular-arbuscular (VA) mycorrhizai fungi on colonization rate,plant height, plant growth,hyphae length,total Al in the plants,exchangeable A1 in the soil and soil pH by comparison at soil pH 3.5,4.5 and 6.0.Plant mung bean (Phaseolus radiatus L.) and crotalaria (Crotalaria mucronata Desv.) were grown with and without VA mycorrhizal fungi in pots with red soil.Ten VA mycorrhizal fungi strains were tested,including Glomus epigaeum (No.90001),Glomus caledonium (No.90036),Glomus mosseae (No.90107), Acaulospora spp.(No.34),Scutellospora heterogama (No.36),Scutellospora calospora (No. 37),Glomus manihotis (No.38),Gigaspora spp.(No.47),Glomus manihotis (No.49),and Acaulospora spp.(No.53).Being the most tolerant to acidity,strain 34 and strain 38 showed quicker and higher-rated colonization without lagging,three to four times more in number of nodules,two to four times more in plant dry weight,30% to 60% more in hyphae length,lower soil exchangeable Al,and higher soil pH than without VA mycorrhizal fungi (CK).Other strains also could improve plant growth and enhance plant tolerance to acidity,but their effects were not marked.This indicated that VA mycorrhizal fungi differed in the tolerance to soil acidity and so did their inoculation effects.In the experiment,acidic soil could be remedied by inoculation of promising VA mycorrhizal fungi tolerant of acidity.

  9. Effects of Lanthanum on Microbial Biomass Carbon and Nitrogen in Red Soil

    Institute of Scientific and Technical Information of China (English)

    褚海燕; 朱建国; 谢祖彬; 曹志洪; 李振高; 曾青

    2001-01-01

    The result of soil culture experiment shows that lanthanum has inhibitory effect on the microbial biomass C and N in red soil, and the inhibition is strengthened with increasing concentration of La. The result of rice pot culture experiment shows that low concentration of La has slight stimulative effect on the microbial biomass C and N in red soil, but its high concentration has inhibitory effect and the inhibition is strengthened with increasing concentration of La. Soil microbial biomass is an important indicator for evaluating rare earths-polluted soil. It is assumed that the critical La concentration is 100 mg*kg-1 at which red soil tends to be polluted.

  10. Ecological and Economic Benefits of Vegetation Management Measures in Citrus Orchards on Red Soils

    Institute of Scientific and Technical Information of China (English)

    SHUI Jian-Guo; WANG Qiu-Zhen; LIAO Gen-Qing; J.AU; J.L.ALLARD

    2008-01-01

    A three-year experiment was conducted to investigate and compare the economic and ecological benefits of six types of vegetation management measures in citrus orchards of the hilly red soil region of the eastern part of China.Six vegetation treatments,including tillage without herbicide (clean tillage) and no tillage without herbicide (sod culture)and with herbicide paraquat (paraquat),glyphosate (glyphosate),glyphosate-glyphosate-paraquat (G-G-P),and paraquatparaquat-glyphosate (P-P-G),were applied in the citrus orchards on a clayey red soil with slopes of 8° and 13° and a sandy soil with slope of 25°.The results showed that the sod culture,paraquat,glyphosate,G-G-P,and P-P-G treatments reduced surface runoff by 38.8%,42.5%,18.7%,28.7%,and 37.5%,then the soil-water losses by 55.5%,51.7%,39.9%,46.8%,and 50.0%,and the N,P,and K nutrient losses by 60.3%,50.2%,37.0%,41.8%,and 45.4%,respectively,as compared with the clean tillage treatment.The weed regeneration ratios with the treatments of clean tillage without herbicide,paraquat,glyphosate,G-G-P,and P-P-G were reduced by 55.1%,67.2%,30.3%,36.8%,and 51.2%,respectively,as compared withthe sod culture.The sod culture,paraquat,glyphosate,G-G-P,and P-P-G treatments could increase the soil fertility (annual accumulation of N,P,K,and OM) by 7.1%,6.9%,5.3%,6.2%,and 6.6%,respectively,whereas the clean tillage treatment without herbicide reduced soil fertility by 4.4% after the three-year experiment.The citrus fruit yields in the treatments of paraquat,glyphosate,G-G-P,and P-P-G increased by 7%-10%;the soluble solid,total sugar,total acidity,sugar-acid ratio,and single fruit weight of citrus fruits of all treatments except sod culture significantly (P > 0.05)exceeded that of the clean tillage treatment.In general,the paraquat treatment showed the best economic and ecological benefits among the six treatments;therefore,it could be regarded as the best available vegetation management measure in citrus orchards of hilly red

  11. Effect of Reduction Associated with Organic Matter Decomposition on Magnetic Properties of Red Soils

    Institute of Scientific and Technical Information of China (English)

    DONG RUIBIN; ZHANG WEIGUO; LU SHENGGAO; YU LIZHONG; YU JINYAN

    2003-01-01

    Five soils derived from different parent materials were sampled from red soil region of southern China and studied by magnetic methodology to understand to what extent iron reduction would affect soil magnetic properties and how iron reduction would affect the magnetic minerals in soils. Reduction associated with organic matter decomposition strongly affected soil magnetic parameters at low pH. The losses of orition (SIRM) at pH 4~6 during the two-month saturation treatment, were 66%~94%, 54%~90%, 64%~95% and 33%~83%, respectively. These changes were interpreted as a consequence of substantial dissolution of maghaemite and haematite in the soils. At pH 10, however, there was no significant magnetic change observed. Moreover, stable single domain soil maghaemite grains were also sensitive to reduction, which suggested that both pedogenic and detrital maghaemite were not stable in acid and reducing environments.Goethite, instead, was the most stable iron form under reducing conditions.

  12. Preliminary Study on Element Leaching and Current Soil—Forming Process of Red Soils

    Institute of Scientific and Technical Information of China (English)

    ZHANQI-GUO; XUESHI-KUI; 等

    1991-01-01

    The leaching characteristics and the element concentration in soil solution of red soils derived from sandstone,granite,Quaternary red clay and basalt have been studied in the Red Earth Ecological Experimental Station,Academia Sinica,using 12 lysimeters.Results obtained show that the element leaching process of red soils occurs mainly from January to the beginning of July annually.The elements with higher concentration in leaching solution of red soils are Si,Ca,Na,K,Mg,and N.The desilication and the leaching process of base cations occur simultaneously in the red soils.Using the first order differential equation and measured parameters of Si leaching,the leaching models of Si for red soils derived from different parent materials are constructed.The leaching process of Si is simulated with the models.Both the absolute and relative ages of red soils derived from different parent materials are discussed based on the simulation result.On the basis of element leaching,composition of soil solution and thermodynamics,the current soil-forming process is discussed.According to the phase diagram,the kaolinization is prevailing in the current formation of different red soils.

  13. Kinetics comparison on simultaneous and sequential competitive adsorption of heavy metals in red soils

    Institute of Scientific and Technical Information of China (English)

    王艳; 李忠武; 黄斌; 蒋卫国; 郭亮; 黄金权; 曾光明

    2015-01-01

    To compare the adsorption kinetics of Cu, Zn and Cd introduced into red soils simultaneously and sequentially as well as their distribution coefficients, the ability of red soils to retain heavy metals was evaluated by performing batch experiments. The results indicate that Cu is preferentially adsorbed by red soils no matter in simultaneous or in sequential situation. The adsorption amount of Cd is the minimum in simultaneous competitive adsorption experiment. As heavy metals are added into red soils sequentially, the heavy metal adsorptions are relatively hard to reach equilibrium in 2 h. Red soils retain more Cd than Zn, which is opposite to the result in simultaneous adsorption. The addition sequences of heavy metals affect their adsorbed amounts in red soils to a certain extent. The joint distribution coefficients of metals in simultaneous adsorption are slightly higher than those in sequential adsorption.

  14. Mineralogical Characteristics of Yellow—Red Soils Derived from Granite

    Institute of Scientific and Technical Information of China (English)

    LUOJIA-XIAN; YANGDE-YONG; 等

    1993-01-01

    Mineral constituents and their weathering in yellow-red soils derived from granite in middle and lower reaches of the yangtze River were studied.Light minerals in fractions greater than silt contained over 80% quartz and feldspar,and heavy ones contained more than 60% various iron minerals and about 30% mica and bornblende.Kaolinite was the main clay mineral,the content of which was about 300-400g/kg.Quartz was weathered very weakly,Ca-feldspar was weathered over 65%,and about 25% of Na-feldspar was weathered.The vermiculitisation of mica was relativly obvious,>50% of mica being eathered to vermiculite.Weatherable minerals were also obviously eathered,the weathering being about 60%.Soil vermiculite was evolved through the process of mica→hydromica→vermiculite-chlorite→vermiculite,which was closely related to leaching situation and oxidic condition.

  15. Differentiation of Soil Fauna Populations in Conventional Tillage and No—Tillage Red Soil Ecosystems

    Institute of Scientific and Technical Information of China (English)

    HUFENG; LIHUIXIN; 等

    1997-01-01

    In a field experiment ,the popultions of major soil fauna groups including earthworms,enchytraeids,arthropods and nematodes were examined in conventional tillage(CT) and no-tillage(NT) red soil ecosystems to evaluate their responses to tillage disturbance.Earthworms,macro- and micro-arthropods were stimulated under NT with earthworms showing the highest population increase by four times ,while enchytraeids and nematodes favored CT system predicting certain adaptability of these animals to plow-disturbed soil envi-ronment ,On the basis of relative response index it was found that soil fauna was more sensitive to tillage than soil resource base(C and N pools) and microflora.The population structure of soil fauna was also affected by tillage treatments.Analysis on nematode trophic groups showed that bacteria-feeding and plant parasitic nematodes were more abundant in CT soil whereas the proportions of fungivores and onmivore-predators increased in NT soil.Possible reasons for the differentiaion in both size and structure of the fauna populaion were discussed and the ecological significance involved in these changes was emphasized.

  16. Application of Ground Phosphate Rock to Diminish the Effects of Simulated Acid Rain of Soil Properties

    Institute of Scientific and Technical Information of China (English)

    DONGYUAN-YAN; LIXUE-YUAN

    1992-01-01

    The effects of simulated acid rain retained in soil on the properties of acid soil and its diminishing by application of ground phosphate rock were investigated by using the sorption method.Results show as follows:(1)For yellow brown soil,the effect of simulated acid rain on the properties of soil with a pH value of 5.9 was relatively small,except a great quantity of acid rain deposited on it.(2) for red soil,the effect of simulated acid rain on the properties of soil was significant.With the increase of the amount of acid deposition,the pH value of soil was declined,but the contents of exchangeable H+,Al3+ and Mn2+ and the amount of SO41- retention were increased.(3) Many properties of acid soils could be improved by applying ground phosphate rock.For example,pH value of soils and the amounts of available P and exchangeable Ca2+ and Mg2+ were increased,and the amounts of exchangeable H+ and Al3+ and SO42- retained was reduced.The application of ground posphate rock could effctively diminish the pollution of acid rain to soil.

  17. Effect of Different Vegetation Systems on Soil Erosion and Soil Nutrients in Red Soil Region of Southeastern China

    Institute of Scientific and Technical Information of China (English)

    TIAN GUANGMING; WANG FEIER; CHEN YINGXU; HE YUNFENG; FU QINGLIN; S.KUMAR; LIN QI

    2003-01-01

    The effect of different vegetation systems including bamboo plantation (BP), forest ecosystem (CF),citrus orchard (Ctr) and farmland (FL) on erosion and nutrients of red soil were investigated in hilly region of southeastern China to find effective control measures for soil erosion. The results showed that all the vegetation systems could significantly reduce soil erosion and nutrient losses compared to bare land (Br).The ability of different vegetation systems to conserve soil and water was in the order of Ctr > BP > CF > FL > Br. Vegetation could also improve soil fertility. The soil organic matter, total N and total P contents were much higher in all the vegetation systems than in bare land, especially for the top soils. Vegetation systems improved soil physical properties remarkably. Compared to the bare land, soil organic matter, TP,TK and available K, especially soil microbial biomass C, N and P, increased under all the vegetation covers.However, they were still much lower than expected, thus these biological measurements are still needed to be carried out continuously.

  18. Response of agricultural soils to acid deposition

    Energy Technology Data Exchange (ETDEWEB)

    Arthur, M.F.; Wagner, C.K.

    1982-07-01

    Proceedings of the workshop, Response of Agricultural Soils to Acid Deposition, which was held May 12-13 1981, in Columbus, Ohio, and which evaluated the potential beneficial and harmful impacts of atmospheric acid deposition on agricultural soils are presented. Those issues requiring further research are also identified. Five working papers and a literature review prepared by soils specialists are included as is a summary of conclusions reached by the participants. Each of the five working papers has been abstracted and indexed individually for ERA/EDB. (JGB)

  19. Study of organic N transformation in red soils by 15N tracer method

    Institute of Scientific and Technical Information of China (English)

    YeQing-Fu; ZhangQin-Zheng; 等

    1997-01-01

    Uniformly 15N-labelled ryegrass was used to investigate NH4+-production,microbial transformation and humification of organic N in two types of red soils by incubating the soils amended with labelled material.The results showed that there was little significant difference in biomass N transformation in the tested solis between 15N tracer method and conventional method,but the amount of NH4++-N released form the ryegrass in the clayey soil than in the sandy soil at all sampling time .By 120d of incubation,humified N was less than 10% of the amount of the applied N in two types of red soils and the amount of residual N in the clayey red soil was obviously higher than that in the sandy red soil.

  20. Alleviating soil acidity through plant organic compounds

    Directory of Open Access Journals (Sweden)

    Meda Anderson R.

    2001-01-01

    Full Text Available A laboratory experiment was conducted to evaluate the effects of water soluble plant extracts on soil acidity. The plant materials were: black oat, oil seed radish, white and blue lupin, gray and dwarf mucuna, Crotalaria spectabilis and C. breviflora, millet, pigeon pea, star grass, mato grosso grass, coffee leaves, sugar cane leaves, rice straw, and wheat straw. Plant extracts were added on soil surface in a PVC soil column at a rate of 1.0 ml min-1. Both soil and drainage water were analyzed for pH, Ca, Al, and K. Plant extracts applied on the soil surface increased soil pH, exchangeable Ca ex and Kex and decreased Al ex. Oil seed radish, black oat, and blue lupin were the best and millet the worst materials to alleviate soil acidity. Oil seed radish markedly increased Al in the drainage water. Chemical changes were associated with the concentrations of basic cations in the plant extract: the higher the concentration the greater the effects in alleviating soil acidity.

  1. Field corrosion characterization of soil corrosion of X70 pipeline steel in a red clay soil

    Institute of Scientific and Technical Information of China (English)

    Shengrong Wang; Cuiwei Dun; Xiaogang Li; Zhiyong Liunn; Min Zhu; Dawei Zhang

    2015-01-01

    The corrosion behavior of X70 pipeline steel buried in red soil environment has been studied. The surface morphology and elemental distribution were determined by scanning electron microscopy (SEM),energy dispersive X-ray spectroscopy (EDS), and X-ray diffraction (XRD). The corrosion kinetics was evaluated by weight loss measurement. The results show that in red soil, the corrosion rate of X70 steel decreases with time, and follows the exponential decay law. General corrosion with non-uniform and localized pitting occurred on the steel surface.α-FeOOH was the dominate products during corrosion in whole buried periods, and the corrosion products exhibited well protective properties. The potentiodynamic polarization tests revealed that icorr decreased with time, indicating the improvement of corrosion resistance. The results of Electrochemical impendence spectroscopy (EIS) are consistent with potentiodynamic polarization tests.

  2. Field corrosion characterization of soil corrosion of X70 pipeline steel in a red clay soil

    Directory of Open Access Journals (Sweden)

    Shengrong Wang

    2015-06-01

    Full Text Available The corrosion behavior of X70 pipeline steel buried in red soil environment has been studied. The surface morphology and elemental distribution were determined by scanning electron microscopy (SEM,energy dispersive X-ray spectroscopy (EDS, and X-ray diffraction (XRD. The corrosion kinetics was evaluated by weight loss measurement. The results show that in red soil, the corrosion rate of X70 steel decreases with time, and follows the exponential decay law. General corrosion with non-uniform and localized pitting occurred on the steel surface. α-FeOOH was the dominate products during corrosion in whole buried periods, and the corrosion products exhibited well protective properties. The potentiodynamic polarization tests revealed that icorr decreased with time, indicating the improvement of corrosion resistance. The results of Electrochemical impendence spectroscopy (EIS are consistent with potentiodynamic polarization tests.

  3. The use of red mud as an immobiliser for metal/metalloid-contaminated soil: A review.

    Science.gov (United States)

    Hua, Yumei; Heal, Kate V; Friesl-Hanl, Wolfgang

    2017-03-05

    This review focuses on the applicability of red mud as an amendment for metal/metalloid-contaminated soil. The varying properties of red muds from different sources are presented as they influence the potentially toxic element (PTE) concentration in amended soil. Experiments conducted worldwide from the laboratory to the field scale are screened and the influencing parameters and processes in soils are highlighted. Overall red mud amendment is likely to contribute to lowering the PTE availability in contaminated soil. This is attributed to the high pH, Fe and Al oxide/oxyhydroxide content of red mud, especially hematite, boehmite, gibbsite and cancrinite phases involved in immobilising metals/metalloids. In most cases red mud amendment resulted in a lowering of metal concentrations in plants. Bacterial activity was intensified in red mud-amended contaminated soil, suggesting the toxicity from PTEs was reduced by red mud, as well as indirect effects due to changes in soil properties. Besides positive effects of red mud amendment, negative effects may also appear (e.g. increased mobility of As, Cu) which require site-specific risk assessments. Red mud remediation of metal/metalloid contaminated sites has the potential benefit of reducing red mud storage and associated problems. Copyright © 2016 Elsevier B.V. All rights reserved.

  4. Unique characteristics of Pb in soil contaminated by red lead anti-corrosion paint

    NARCIS (Netherlands)

    Brokbartold, M.; Temminghoff, E.J.M.; Weng, L.; Marschner, B.

    2013-01-01

    Red lead (Pb3O4) has been extensively used in the past in anti-corrosion paints for the protection of steel constructions such as electricity pylons or bridges. Until recently, little has been known about the behavior of these Pb compounds in soils. Therefore, three pylon soils and six red lead anti

  5. HONO (nitrous acid) emissions from acidic northern soils

    Science.gov (United States)

    Maljanen, Marja; Yli-Pirilä, Pasi; Joutsensaari, Jorma; Martikainen, Pertti J.

    2015-04-01

    The photolysis of HONO (nitrous acid) is an important source of OH radical, the key oxidizing agent in the atmosphere, contributing also to removal of atmospheric methane (CH4), the second most important greenhouse gas after carbon dioxide (CO2). The emissions of HONO from soils have been recently reported in few studies. Soil HONO emissions are regarded as missing sources of HONO when considering the chemical reactions in the atmosphere. The soil-derived HONO has been connected to soil nitrite (NO2-) and also directly to the activity of ammonia oxidizing bacteria, which has been studied with one pure culture. Our hypothesis was that boreal acidic soils with high nitrification activity could be also sources of HONO and the emissions of HONO are connected with nitrification. We selected a range of dominant northern acidic soils and showed in microcosm experiments that soils which have the highest nitrous oxide (N2O) and nitric oxide (NO) emissions (drained peatlands) also have the highest HONO production rates. The emissions of HONO are thus linked to nitrogen cycle and also NO and N2O emissions. Natural peatlands and boreal coniferous forests on mineral soils had the lowest HONO emissions. It is known that in natural peatlands with high water table and in boreal coniferous forest soils, low nitrification activity (microbial production of nitrite and nitrate) limits their N2O production. Low availability of nitrite in these soils is the likely reason also for their low HONO production rates. We also studied the origin of HONO in one peat soil with acetylene and other nitrification inhibitors and we found that HONO production is not closely connected to ammonium oxidation (nitrification). Acetylene blocked NO emissions but did not affect HONO or N2O emissions, thus there is another source behind HONO emission from these soils than ammonium oxidation. It is still an open question if this process is microbial or chemical origin.

  6. The Potential Consequences of the Hungarian Red Mud Disaster for Soil

    OpenAIRE

    RUYTERS, Stefan; Mertens, Jelle; Smolders, Erik

    2011-01-01

    In October 2010 a dam of a waste reservoir of the Hungarian Aluminium Cooperation broke resulting in a red mud (pH=12) spill across the Torna river flooding the cities of Devecser and Kolontar in Hungary. Approximately 800 ha of land have been contaminated with red mud. Red mud was characterized and its toxicity for plants was measured to evaluate the soil contamination risks. Increasing red mud doses were mixed into the soil up to a 16.5% dry weight fraction resulting in a maximal soil pH in...

  7. Some adverse effects of soil amendment with organic Materials-The case of soils polluted by copper industry phytostabilized with red fescue.

    Science.gov (United States)

    Cuske, Mateusz; Karczewska, Anna; Gałka, Bernard; Dradrach, Agnieszka

    2016-08-02

    The study was aimed to examine the effects of soil amendment with organic waste materials on the growth of red fescue and the uptake of Cu and Zn by this grass, in view of its potential usage for phytostabilization of Cu-polluted soils. Five soils, containing 301-5180 mg/kg Cu, were collected from the surroundings of copper smelter Legnica, and amended with lignite (LG) and limed sewage sludge (SS). Plant growth and the concentrations of Cu and Zn in the shoots and roots of grass were measured in a pot experiment and related to the results of Pytotoxkit and Microtox® tests performed on soil solution. The effects of soil amendment with LG and SS differed greatly, and depended on soil properties. In some cases, the application of alkaline SS resulted in dramatic increase of Cu phytotoxicity and its enhanced uptake by plants, while application of LG to slightly acidic soil caused increased accumulation of Zn in plants, particularly in their roots. The study confirmed good suitability of red fescue for phytostabilization of Cu-contaminated soils except for those extremely polluted. Organic amendments to be used for metal immobilization should be thoroughly examined prior to application.

  8. Interactions between red light, abscisic acid, and calcium in gravitropism

    Science.gov (United States)

    Leopold, A. C.; LaFavre, A. K.

    1989-01-01

    The effect of red light on orthogravitropism of Merit corn (Zea mays L.) roots has been attributed to its effects on the transduction phase of gravitropism (AC Leopold, SH Wettlaufer [1988] Plant Physiol 87:803-805). In an effort to characterize the orthogravitropic transduction system, comparative experiments have been carried out on the effects of red light, calcium, and abscisic acid (ABA). The red light effect can be completely satisfied with added ABA (100 micromolar) or with osmotic shock, which is presumed to increase endogenous ABA. The decay of the red light effect is closely paralleled by the decay of the ABA effect. ABA and exogenous calcium show strong additive effects when applied to either Merit or a line of corn which does not require red light for orthogravitropism. Measurements of the ABA content show marked increases in endogenous ABA in the growing region of the roots after red light. The interpretation is offered that red light or ABA may serve to increase the cytoplasmic concentrations of calcium, and that this may be an integral part of orthogravitropic transduction.

  9. Effect of different fertilizer application on the soil fertility of paddy soils in red soil region of southern China.

    Science.gov (United States)

    Dong, Wenyi; Zhang, Xinyu; Wang, Huimin; Dai, Xiaoqin; Sun, Xiaomin; Qiu, Weiwen; Yang, Fengting

    2012-01-01

    Appropriate fertilizer application is an important management practice to improve soil fertility and quality in the red soil regions of China. In the present study, we examined the effects of five fertilization treatments [these were: no fertilizer (CK), rice straw return (SR), chemical fertilizer (NPK), organic manure (OM) and green manure (GM)] on soil pH, soil organic carbon (SOC), total nitrogen (TN), C/N ratio and available nutrients (AN, AP and AK) contents in the plowed layer (0-20 cm) of paddy soil from 1998 to 2009 in Jiangxi Province, southern China. Results showed that the soil pH was the lowest with an average of 5.33 units in CK and was significantly higher in NPK (5.89 units) and OM (5.63 units) treatments (Pfertilizers have remarkably improved SOC and TN values compared with the CK, Specifically, the OM treatment resulted in the highest SOC and TN concentrations (72.5% and 51.2% higher than CK) and NPK treatment increased the SOC and TN contents by 22.0% and 17.8% compared with CK. The average amounts of C/N ratio ranged from 9.66 to 10.98 in different treatments, and reached the highest in OM treatment (Psoil fertility in this region and K fertilizer should be simultaneously applied considering the soil K contents. Considering the long-term fertilizer efficiency, our results also suggest that annual straw returning application could improve soil fertility in this trial region.

  10. Mobility and speciation of Cd,Cu,and Zn in two acidic soils affected by simulated acid rain

    Institute of Scientific and Technical Information of China (English)

    GUO Zhao-hui; LIAO Bo-han; HUANG Chang-yong

    2005-01-01

    Through a batch experiment, the mobility and speciation of heavy metals(Cd, Cu, Zn) in two acidic forest soils from Hunan Province were studied. The results showed that the release and potential active speciation of Cd, Cu, and Zn in the tested contaminated red soil(CRS) and yellow red soil(CYRS) increased significantly with pH decreasing and ion concentrations increasing of simulated acid rain, and these effects were mainly decided by the pH value of simulated acid rain. Cd had the highest potential risk on the environment compared with Cu and Zn. Cd existed mainly in exchangeable form in residual CRS and CYRS, Cu in organically bound and Mn-oxide occluded forms, and Zn in mineral forms due to the high background values.

  11. Leaching of Nutrient Elements in a Red Soil Derived from Quaternary Red Clay

    Institute of Scientific and Technical Information of China (English)

    SHENRENFANG; ZHAOQIGUO

    1998-01-01

    A red soil derived from Quaternary red clay was employed to study nutrient leaching with woil columns repacked in laboratory,The objective was to identify the effects of fertilization practices on leaching patterns and magnitudes of Ca2+,Mg2+,K+,NH4+,and NO3-,The treatments were CK (as a control),CaCO3, CaSO4,MgCO3,Ca(H2PO4)2,urea,KCl,and multiple (a mixture of the above-mentioned fertilizers),The fertilizers were added to the bare surface of the soil columns,and then the columns were leached with 120 mL deionized water daily through peristaltic pumps over a period of 92 days.Leaching processes of NH4+,and NO3- wer e only measured in CK,ured,and multiple treatments which were directly related to N leaching, Results showed that sole application of CaSO4,and Ca(H2PO4)2 scarcely hd any effect on the leching losses of Ca2+,Mg2+,and K+; the application of MgCO3 sthimulated the leaching of Mg2+;the application of CaCO3 promoted the leaching of Ca2+,Mg2+ and K+; urea treatment also promoted the leaching of K+ and NH4+,and NO3- leaching mainly occurred at late stage of leaching process in particular;under KCl treatment,leaching of Ca2+,Mg2+,and K+ was promoted to a large extent;under multiple treatment, leaching of Ca2+,Mg2+,K+,NH4+,and NO3- was all increased and NO3- was mainly leached at the end of leaching process and still had a trend of increase.

  12. Effects of atmospheric deposition nitrogen flux and its composition on soil solution chemistry from a red soil farmland, southeast China.

    Science.gov (United States)

    Cui, Jian; Zhou, Jing; Peng, Ying; Chan, Andrew; Mao, Jingdong

    2015-12-01

    A detailed study on the solution chemistry of red soil in South China is presented. Data are collected from two simulated column-leaching experiments with an improved setup to evaluate the effects of atmospheric N deposition (ADN) composition and ADN flux on agricultural soil acidification using a (15)N tracer technique and an in situ soil solution sampler. The results show that solution pH values decline regardless of the increase of the NH4(+)/NO3(-) ratio in the ADN composition or ADN flux, while exchangeable Al(3+), Ca(2+), Mg(2+), and K(+) concentrations increase at different soil depths (20, 40, and 60 cm). Compared with the control, ADN (60 kg per ha per year N, NH4(+)/NO3(-) ratio of 2 : 1) decreases solution pH values, increases solution concentrations of NO3(-)-N, Al(3+), Ca(2+) and Mg(2+) at the middle and lower soil depths, and promotes their removal. NH4(+)-N was not detected in red soil solutions of all the three soil layers, which might be attributed to effects of nitrification, absorption and fixation in farmland red soil. Some of the NO3(-)-N concentrations at 40-60 cm soil depth exceed the safe drinking level of 10 mg L(-1), especially when the ADN flux is beyond 60 kg ha(-1) N. These features are critical for understanding the ADN agro-ecological effects, and for future assessment of ecological critical loads of ADN in red soil farmlands.

  13. Abundance and Diversity of CO2-Assimilating Bacteria and Algae Within Red Agricultural Soils Are Modulated by Changing Management Practice.

    Science.gov (United States)

    Yuan, Hongzhao; Ge, Tida; Chen, Xiangbi; Liu, Shoulong; Zhu, Zhenke; Wu, Xiaohong; Wei, Wenxue; Whiteley, Andrew Steven; Wu, Jinshui

    2015-11-01

    Elucidating the biodiversity of CO(2)-assimilating bacterial and algal communities in soils is important for obtaining a mechanistic view of terrestrial carbon sinks operating at global scales. "Red" acidic soils (Orthic Acrisols) cover large geographic areas and are subject to a range of management practices, which may alter the balance between carbon dioxide production and assimilation through changes in microbial CO(2)-assimilating populations. Here, we determined the abundance and diversity of CO(2)-assimilating bacteria and algae in acidic soils using quantitative PCR and terminal restriction fragment length polymorphism (T-RFLP) of the cbbL gene, which encodes the key CO(2) assimilation enzyme (ribulose-1,5-bisphosphate carboxylase/oxygenase) in the Calvin cycle. Within the framework of a long-term experiment (Taoyuan Agro-ecosystem, subtropical China), paddy rice fields were converted in 1995 to four alternative land management regimes: natural forest (NF), paddy rice (PR), maize crops (CL), and tea plantations (TP). In 2012 (17 years after land use transformation), we collected and analyzed the soils from fields under the original and converted land management regimes. Our results indicated that fields under the PR soil management system harbored the greatest abundance of cbbL copies (4.33 × 10(8) copies g(-1) soil). More than a decade after converting PR soils to natural, rotation, and perennial management systems, a decline in both the diversity and abundance of cbbL-harboring bacteria and algae was recorded. The lowest abundance of bacteria (0.98 × 10(8) copies g(-1) soil) and algae (0.23 × 10(6) copies g(-1) soil) was observed for TP soils. When converting PR soil management to alternative management systems (i.e., NF, CL, and TP), soil edaphic factors (soil organic carbon and total nitrogen content) were the major determinants of bacterial autotrophic cbbL gene diversity. In contrast, soil phosphorus concentration was the major regulator

  14. Microbial biomass in red soils and its significance in plant availability of nitrogen

    Institute of Scientific and Technical Information of China (English)

    姚槐应; 何振立; 黄昌勇

    2002-01-01

    A series of laboratory and pot experiments carried out to examine the role of soil microbial biomass in red soils' nitrogen availability and productivity showed that soil available N (NA), dry matter yield (DMY) of ryegrass, and plant uptake of nitrogen were each closely correlated with microbial biomass-C (Cmic) or -N (Nmic), suggesting that soil microbial biomass is a very important nitrogen pool available to plants in red soils. After correction for the substrate effect, the computed turnover of the Nmic in three tested soils ranged from 63 to 250 days. Soils with low Nmic or light texture generally had higher Nmic turnover rate than those with high Nmic or heavy texture. These results showed that soils with low Nmic, microbial biomass could also play an important role in the availability of nitrogen to plants due to these soils' high turnover rate.

  15. Gypsum addition to soils contaminated by red mud: implications for aluminium, arsenic, molybdenum and vanadium solubility.

    Science.gov (United States)

    Lehoux, Alizée P; Lockwood, Cindy L; Mayes, William M; Stewart, Douglas I; Mortimer, Robert J G; Gruiz, Katalin; Burke, Ian T

    2013-10-01

    Red mud is highly alkaline (pH 13), saline and can contain elevated concentrations of several potentially toxic elements (e.g. Al, As, Mo and V). Release of up to 1 million m(3) of bauxite residue (red mud) suspension from the Ajka repository, western Hungary, caused large-scale contamination of downstream rivers and floodplains. There is now concern about the potential leaching of toxic metal(loid)s from the red mud as some have enhanced solubility at high pH. This study investigated the impact of red mud addition to three different Hungarian soils with respect to trace element solubility and soil geochemistry. The effectiveness of gypsum amendment for the rehabilitation of red mud-contaminated soils was also examined. Red mud addition to soils caused a pH increase, proportional to red mud addition, of up to 4 pH units (e.g. pH 7 → 11). Increasing red mud addition also led to significant increases in salinity, dissolved organic carbon and aqueous trace element concentrations. However, the response was highly soil specific and one of the soils tested buffered pH to around pH 8.5 even with the highest red mud loading tested (33 % w/w); experiments using this soil also had much lower aqueous Al, As and V concentrations. Gypsum addition to soil/red mud mixtures, even at relatively low concentrations (1 % w/w), was sufficient to buffer experimental pH to 7.5-8.5. This effect was attributed to the reaction of Ca(2+) supplied by the gypsum with OH(-) and carbonate from the red mud to precipitate calcite. The lowered pH enhanced trace element sorption and largely inhibited the release of Al, As and V. Mo concentrations, however, were largely unaffected by gypsum induced pH buffering due to the greater solubility of Mo (as molybdate) at circumneutral pH. Gypsum addition also leads to significantly higher porewater salinities, and column experiments demonstrated that this increase in total dissolved solids persisted even after 25 pore volume replacements. Gypsum

  16. [Variation characteristics of soil carbon sequestration under long-term different fertilization in red paddy soil].

    Science.gov (United States)

    Huang, Jing; Zhang, Yang-zhu; Gao, Ju-sheng; Zhang, Wen-ju; Liu, Shu-jun

    2015-11-01

    The objective of this study was to clarify the changes of soil organic carbon (SOC) content, the saturation capacity of soil carbon sequestration and its cooperation with carbon input (crop source and organic fertilizer source carbon) under long-term (1982-2012) different fertilization in red paddy soil. The results showed that fertilization could increase SOC content. The SOC content of all the fertilization treatments demonstrated a trend of stabilization after applying fertilizer for 30 years. The SOC content in the treatments applying organic manure with mineral fertilizers was between 21.02 and 21.24 g · kg(-1), and the increase rate ranged from 0.41 to 0.59 g · kg(-1) · a(-1). The SOC content in the treatments applying mineral fertilizers only was 15.48 g · kg(-1). The average soil carbon sequestration in the treatments that applied organic manure with mineral fertilizers ranged from 43.61 to 48.43 t C · hm(-2), and the average SOC storage over the years in these treatments was significantly greater than those applying mineral fertilizers only. There was an exponentially positive correlation between C sequestration efficiency and annual average organic C input. It must input exogenous organic carbon at least at 0. 12 t C · hm(-2) · a(-1) to maintain the balance of soil organic carbon under the experimental conditions.

  17. Red soil as a regenerable sorbent for high temperature removal of hydrogen sulfide from coal gas.

    Science.gov (United States)

    Ko, Tzu-Hsing; Chu, Hsin; Lin, Hsiao-Ping; Peng, Ching-Yu

    2006-08-25

    In this study, hydrogen sulfide (H(2)S) was removed from coal gas by red soil under high temperature in a fixed-bed reactor. Red soil powders were collected from the northern, center and southern of Taiwan. They were characterized by XRPD, porosity analysis and DCB chemical analysis. Results show that the greater sulfur content of LP red soils is attributed to the higher free iron oxides and suitable sulfidation temperature is around 773K. High temperature has a negative effect for use red soil as a desulfurization sorbent due to thermodynamic limitation in a reduction atmosphere. During 10 cycles of regeneration, after the first cycle the red soil remained stable with a breakthrough time between 31 and 36 min. Hydrogen adversely affects sulfidation reaction, whereas CO exhibits a positive effect due to a water-shift reaction. COS was formed during the sulfidation stage and this was attributed to the reaction of H(2)S and CO. Results of XRPD indicated that, hematite is the dominant active species in fresh red soil and iron sulfide (FeS) is a product of the reaction between hematite and hydrogen sulfide in red soils. The spinel phase FeAl(2)O(4) was found during regeneration, moreover, the amount of free iron oxides decreased after regeneration indicating the some of the free iron oxide formed a spinel phase, further reducting the overall desulfurization efficiency.

  18. Red Soil Resource Information System and Its Prelimi—nary Application

    Institute of Scientific and Technical Information of China (English)

    WANGRENCHAO; SHIZHOU

    1998-01-01

    Red soil is a very important soil resource in southern China.However,due to being simultaneously of high productive potentialities and severely degraded,it needs harnessing urgently.Red Soil Resource Information System(RSRIS) based on remolte sensing and geographic information system(GIS) plays an important role in survey,evaluation ,utilziation and management of red soil resource.RSRIS of Quzhou City,Zhejiang Province (1:250 000) and RSRIS of Longyou County,Zhejiang Province(1:50 000) have been made respectively on SUN SPARC station and using RC/INFO .This paper introduces the system design,databse creation and system functions ,and it particularly focuses on developing applied models, such as red soil resource divison and mapping,suitability evaluation,erosion risk evaluation,plant utilization zone etc.The problems on study of RSRIS and its developing strategy are also discussed.

  19. [Influences of biochar and nitrogen fertilizer on soil nematode assemblage of upland red soil].

    Science.gov (United States)

    Lu, Yan-yan; Wang, Ming-wei; Chen, Xiao-vun; Liu, Man-qiang; Chen, Xiao-min; Cheng, Yan-hong; Huang, Qian-ru; Hu, Feng

    2016-01-01

    The use of biochar as soil remediation amendment has received more and more concerns, but little attention has been paid to its effect on soil fauna. Based on the field experiment in an upland red soil, we studied the influences of different application rates of biochar (0, 10, 20, 30, 40 t · hm⁻²) and nitrogen fertilizer (60, 90, 120 kg N · hm⁻²) on soil basic properties and nematode assemblages during drought and wet periods. Our results showed that the biochar amendment significantly affect soil moisture and pH regardless of drought or wet period. With the increasing of biochar application, soil pH significantly increased, while soil moisture increased first and then decreased. Soil microbial properties (microbial biomass C, microbial biomass N, microbial biomass C/N, basal respiration) were also significantly affected by the application of biochar and N fertilizer. Low doses of biochar could stimulate the microbial activity, while high doses depressed microbial activity. For example, averaged across different N application rates, biochar amendment at less than 30 t · hm⁻² could increase microbial activity in the drought and wet periods. Besides, the effects of biochar also depended on wet or drought period. When the biochar application rate higher than 30 t · hm⁻², the microbial biomass C was significantly higher in the drought period than the control, but no differences were observed in the wet period. On the contrary, microbial biomass N showed a reverse pattern. Dissolved organic matter and mineral N were affected by biochar and N fertilizer significantly in the drought period, however, in the wet period they were only affected by N fertilizer rather than biochar. There was significant interaction between biochar and N fertilizer on soil nematode abundance and nematode trophic composition independent of sampling period. Combined high doses of both biochar and N fertilization promoted soil nematode abundance. Moreover, the biochar amendment

  20. [Biological properties of lateritic red soil and their relationships with soil fertility in Southern China under different land use types].

    Science.gov (United States)

    Zhang, Jing; Gao, Yun-Hua; Zhang, Chi; Zhou, Bo; Li, Jing-Juan; Yang, Xiao-Xue; Xu, Huan; Dai, Jun

    2013-12-01

    Taking the lateritic red soil on a typical slopeland in Southern China as test object, this paper studied the soil microbial properties, enzyme activities, and their relationships with soil fertility under four land use types (newly cultivated dryland, shrub land, Eucalyptus land, and orchard). There existed significant differences in the soil biological properties under different land use types, among which, orchard soil had the highest microbial quantity and enzyme activities, newly cultivated dryland soil had the fastest soil respiration rate, the fewest soil microorganism quantity, and the lowest enzyme activities, whereas shrub land and woodland soils had the biological properties ranged between newly cultivated dryland and orchard soils, and there was a high similarity in the biological properties between shrub land and woodland soils. Under different land use types, the soil microbial quantity and enzyme activities were positively correlated with soil organic carbon and most of the soil nutrients. It was suggested the soils with high soil organic matter content and high fertility level were beneficial to the soil microbial growth and enzyme activities.

  1. 10Be concentrations of Red soils in Southwest Japan and its possibility of dating

    Science.gov (United States)

    Maejima, Y.; Matsuzaki, H.; Nakano, C.

    2004-08-01

    10Be concentrations of six Red soils distributed in Southwest Japan ranged from 0.8 × 108 to 2.7 × 109 atoms g-1, and minimum absolute ages were estimated by inventory of meteoric 10Be. The results are follows: Red soils on Toyota derived from granite (⩽25 ka), Kashii derived from Tertiary shale (⩽24 ka), Akiyoshidai derived from limestone (⩽110 ka), Okinawa Island derived from Kunigami gravel bed (⩽9 ka) and Ogasawara Island derived from agglomerate and Boninite (⩽22 and ⩽7 ka) were obtained, respectively. Soil age except with Akiyoshidai indicated younger age. It suggested that the loss of 10Be from the soil was caused by leaching of 10Be or by soil erosion, and 10Be is susceptible to leaching out from these Red soils under the humid climate condition such as Southwest Japan.

  2. Formation and Water Stability of Aggregates in Red Soils as Affected by Organic Matter

    Institute of Scientific and Technical Information of China (English)

    ZHANGMINGKUI等; M.J.WILSON; 等

    1996-01-01

    The water stability of aggregates in various size classes separated from 18 samples of red soils under different managements,and the mechanisms responsible for the formation of waer-stable soil aggregates were studied.The results showed that the water stbility of soil aggregates declined with increasing size,especially for the low organic matter soils.Organic matter plays a key role in the formation of water-stable soil aggregates.The larger the soil aggregate size.the greater the impact of organic matter on the water stability of soil aggregates.Removal of organic matter markedly disintegrated the large water-stable aggregates(>2.0mm)and increased the small ones(2.0mm)were mainly glued up by organic mater,Both free oxides and organic matter contribute to the formation and water stability of aggregates in red soils.

  3. Effects of Northern red oak (Quercus rubra L. and sessile oak (Quercus petraea (Mattusch. Liebl. on the forest soil chemical properties

    Directory of Open Access Journals (Sweden)

    Miltner Stanislav

    2016-09-01

    Full Text Available Northern red oak (Quercus rubra L. is one of the most important introduced tree species in the Czech Republic, occupying about 6,000 ha with ca. 900,000 m3 of the standing volume. The presented study aims to evaluate its soil forming effects on natural oak sites. Soil chemistry of the upper soil layers (F+H, Ah, B horizons was studied in three pairs of stands of both species. In each stand, four bulk samples were taken separately for particular horizons, each consisting of 5 soil-borer cores. The soil characteristics analysed were: pH (active and potential, soil adsorption complex characteristics (content of bases, exchangeable cation capacity, base saturation, exchangeable acidity (exchangeable Al and H, total carbon and nitrogen content, and plant available nutrients content (P, K, Ca, Mg. Total macronutrient content (P, K, Ca, Mg was analysed only in holorganic horizons. Results confirmed acidification effects of red oak on the upper forest soil layers such as decreased pH, base content, base saturation, all nutrient contents in total as well as plant-available form and increased soil exchangeable acidity (exchangeable Al in comparison to the sessile oak stands, especially in holorganic horizons and in the uppermost mineral layer (Ah horizon. Northern red oak can be considered as a slightly site-soil degrading species in the studied sites and environmental conditions in comparison to native oak species.

  4. Organic Matter Decomposition in Red Soil as Affected by Earthworms

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    The earthworms Pheretima carnosa, Drawida gisti and Eisenia foetida were studied to compare their contributions to the decomposition of various organic materials surface-applied on red soil in a 165-day greenhouse experiment. The native species Pheretima carnosa and Drawida gisti were equally effective in accelerating the decomposition of maize residue, according to fresh body weight, while commercial species Eisenia foetida had no significant influence on dry mass loss of maize residue. Liming with CaCO3 or CaO showed little effect on maize residue breakdown involved by Pheretima carnosa, but it inhibited this process involved by Drawida gisti. The capability of Pheretima carnosa to the decomposition of five kinds of organic materials was thoroughly examined. The dry mass losses in worm treatments were in the order of soybean residue > maize residue > pig manure > semi-decayed maize > ryegrass. However, the relative contributions of the earthworm to dry mass loss were in the order of pig manure (89.8%) > semi-decayed maize residue (49.1%) > maize residue (29.4%) > soybean residue (20.9%) > ryegrass residue (16.5%). Pheretima carnosa consumed 20~120 mg dry weight of organic material per gram fresh weight of biomass per day.

  5. Characteristics of C and N Accumulation in Infertile Red Soil Under Different Rotation Systems

    Institute of Scientific and Technical Information of China (English)

    LI Zhong-pei; TANG Yong-liang; SHI Hua; ZHANG Tao-lin

    2002-01-01

    A long-term experiment was conducted at the Ecological Experimental Station of Red Soil, Chinese Academy of Sciences to investigate the characteristics of material cycling and C, N accumulation in infertile red soil under different treatments of rotation systems for 11 years. Plant biomass, amount of organic materials returned to the soil, and budget of nitrogen in soil were obviously different under conventional cultivation, coverage by shrubs ( Lespedeza formosa ), rotation of shrubs ( Lespedeza formosa ) and crops (PeanutBuckwheat). Rotation of shrubs and crops with a combination of rational fertilization would be 75 - 100% of biomass and a similar amount of organic materials returned to the soil compared with that under coverage shrubs, more input than output of nitrogen, high system stability, and increasing crop productivity. With distinct cycling, different treatments of rotation systems influenced discriminatorily soil fertility. Soil organic carbon and nitrogen were respectively less than 7 and 0.6 g kg-1 for conventional cultivation, 9- 11 and 0.6-0.9 g kg-1 for rotation of shrubs and crops, 14 - 16 g kg-1 and more than 1 g kg-1 for coverage by shrubs after 11 years, which represent low, middle and high levels of upland red soil fertility at the current situation. It implied that with cultivation system and fertilization measures, the infertile red soil could have middle to high fertility after about 10 years rational utilization. Comparison of results from different treatments showed that a large loss of organic carbon and nitrogen was caused by soil erosion which resulted in a low level of C and N in upland red soil. It could be suggested that increasing carbon storage in infertile red soil would sequester a great amount of atmospheric CO2 and mitigate the global warming potentially.

  6. Effects of biochar on soil infiltration, runoff and sediment production on a slopeland red soil

    Science.gov (United States)

    Jien, Shih-Hao; Chen, Jyun-Yuan; Liao, Chien-Sen

    2016-04-01

    Biochar has been considered as a useful amendment to ameliorate soil physical and chemical properties. This study aims to incorporate a wood biochar (WB), pyrolized by 400℃, into a clayey red soil with a slope gradient of 5o to improve infiltration and reduce runoff and sediment production. Field trials were conducted in four treatments including control, biochar (4%, w/w) (WB), compost (1%) + biochar (4%) (CWB) and polyacrylamide in 50 ppm (PAM) in this study. An erosion experiment was performed by a rainfall simulator in a rainfall intensity of 70 mm/hr after 12 months. The runoff and sediments were collected and weighted for each treatment. The results displayed that runoff amounts were obviously reduced by 2.3% -6.3% in treatments of WB and CWB compared with the control, but not in PAM. On contrary, the infiltration rates were obviously increased by 7.4%-18% in the treatment of WB and CWB compared with the control, but reduced by 25% in PAM treatment. After 12 months, all treatments could effectively prevent clayey soil from erosion, particularly in PAM. In conclusion, biochar could be an alternative strategy for improvement of permeability and erodibility compared with PAM practice on mild slopeland soils.

  7. The characteristics of soil and water loss in Pinus Massoniana forest in Quaternary red soil area of south China

    Science.gov (United States)

    Song, Yuejun; Huang, Yanhe; Jie, Yang

    2017-08-01

    The soil and water loss in Pinus massoniana forests is an urgent environmental problem in the red soil region of southern China.Using the method of field monitoring, by analogy and statistical analysis, The characteristics of soil and water loss of Pinus massoniana forests in Quaternary red soil region under 30 rainfall were analyzed,the results show that the relationship models of rainfall,runoff and sediment of pure Pinus massoniana plot were slightly different from the naked control plot,were all the univariate quadratic linear regression models.the contribution of runoff and sediment in different rain types were different, and the water and soil loss in Pinus massoniana forest was most prominent under moderate rain.The merging effect of sparse Pinus massoniana forest on raindrop, aggravated the degree of soil and water loss to some extent.

  8. NIR-red spectral space based new method for soil moisture monitoring

    Institute of Scientific and Technical Information of China (English)

    ZHAN ZhiMing; QIN QiMing; GHULAN Abduwasit; WANG DongDong

    2007-01-01

    Drought is a complex natural disaster that occurs frequently. Soil moisture has been the main issue in remote monitoring of drought events as the most direct and important variable describing the drought. Spatio-temporal distribution and variation of soil moisture evidently affect surface evapotranspiration, agricultural water demand, etc. In this paper, a new simple method for soil moisture monitoring is developed using near-infrared versus red (NIR-red) spectral reflectance space. First, NIR-red spectral reflectance space is established using atmospheric and geometric corrected ETM+ data, which is manifested by a triangle shape, in which different surface covers have similar spatial distribution rules. Next, the model of soil moisture monitoring by remote sensing (SMMRS) is developed on the basis of the distribution characteristics of soil moisture in the NIR-red spectral reflectance space. Then, the SMMRS model is validated by comparison with field measured soil moisture data at different depths. The results showed that satellite estimated soil moisture by SMMRS is highly accordant with field measured data at 5 cm soil depth and average soil moisture at 0―20 cm soil depths, correlation coefficients are 0.80 and 0.87, respectively. This paper concludes that, being simple and effective, the SMMRS model has great potential to estimate surface moisture conditions.

  9. NIR-red spectral space based new method for soil moisture monitoring

    Institute of Scientific and Technical Information of China (English)

    GHULAN; Abduwasit

    2007-01-01

    Drought is a complex natural disaster that occurs frequently. Soil moisture has been the main issue in remote monitoring of drought events as the most direct and important variable describing the drought. Spatio-temporal distribution and variation of soil moisture evidently affect surface evapotranspiration, agricultural water demand, etc. In this paper, a new simple method for soil moisture monitoring is de- veloped using near-infrared versus red (NIR-red) spectral reflectance space. First, NIR-red spectral reflectance space is established using atmospheric and geometric corrected ETM+ data, which is manifested by a triangle shape, in which different surface covers have similar spatial distribution rules. Next, the model of soil moisture monitoring by remote sensing (SMMRS) is developed on the basis of the distribution characteristics of soil moisture in the NIR-red spectral reflectance space. Then, the SMMRS model is validated by comparison with field measured soil moisture data at different depths. The results showed that satellite estimated soil moisture by SMMRS is highly accordant with field measured data at 5 cm soil depth and average soil moisture at 0―20 cm soil depths, correlation coef- ficients are 0.80 and 0.87, respectively. This paper concludes that, being simple and effective, the SMMRS model has great potential to estimate surface moisture conditions.

  10. Effects of Long-Term Application of Inorganic Fertilizers on Biochemical Properties of a Rice-Planting Red Soil

    Institute of Scientific and Technical Information of China (English)

    ZHONG Wen-Hui; CAI Zu-Cong; ZHANG He

    2007-01-01

    A long-term experiment was set up in Yingtan of Jiangxi Province to investigate the effects of long-term application of inorganic fertilizers on the biochemical properties of a rice-planting soil derived from Quaternary red earth. Noncultivated soils are extremely eroded and characterized by a low pH and deficiencies in available nutrients, in particular P and N. After 13 years of inorganic fertilization in cultivation for double-cropped rice, the biochemical properties of the soil were changed. The nitrification potential and urease activity were higher in the treatments with N application than those without N application. Acid phosphatase activity and dehydrogenase activity were also higher in the treatments with P application than in those without P application. The dehydrogenase activity correlated well with the concentrations of both total P and hydrolysable N and with rice crop yield, suggesting that dehydrogenase activity might be a suitable indicator for improvement in soil fertility.

  11. Impact of Seasalt Deposition on Acid Soils in Maritime Regions

    Institute of Scientific and Technical Information of China (English)

    ZHANG Zhen-Hua

    2003-01-01

    The characteristics of seasalt deposition and its impact on acid soils in maritime regions are reviewed. It is pointed out that studies involving the impact of seasalt deposition on acid soils have been concentrated on short-term effects on soil and water acidification. A deep consideration of long-term effects on soil acidification in maritime regions is still needed.

  12. Some Fertility Characteristics and Fertilizer Requirements of a Newly Reclaimed Upland Red Soil Derived from Quaternary Red Clay

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    A series of field experiments from 1990 to 1994 in Yingtan, Jiangxi Province, were conducted on an upland red soil derived from Quaternary red clay which had been reclaimed three years before the experiments, in order to study the fertility characteristics and fertilizer requirements of the newly reclaimed soil. The field experiments included that on nutrient characteristics and fertilizer effect, that on K-supplying potential and K-Mg relationship, that on fertilization rates of K and N, etc. The newly reclaimed upland soil was low in both N and P, and its responses to nitrogen and phosphate application were very significant. The K-supplying potential was also low, so the soil was highly responsive to K fertilizer. The effect of Ca and Mg fertilizers was not so great for the reason that certain amounts of Ca and Mg were incorporated into the soil through application of calcium magnesium phosphate during land leveling before the experiments. Among the four micronutrients, B, Mo, Zn and Cu, B had the greatest effect on the soil. The fertilizer requirements of the soil were in an order of P and N > K > lime and B > Mg > Mo, Zn and Cu. Eight crops tested had different fertilizer-requiring characteristics. Rapeseed was very sensitive to P and B fertilizers. Barely was especially sensitive to P and lime and it also responded to B, Mo, Zn and Cu. And sweet potato was especially sensitive to K.

  13. Construction and Application of Soil Erosion Control and Circular Agriculture Mode in Hilly Red Soil of Southern China

    Institute of Scientific and Technical Information of China (English)

    Boqi WENG; Zhenmei ZHONG; Xuhui LUO; Zhaoyang YING; Yixiang WANG; Jing YE

    2012-01-01

    Abstract [Objective] The paper was to construct agriculture mode in hilly red [Method] The cause of soil soil of southern China, erosion in hilly red so soil erosion control and circular and analyze its application effort. of southern China and the rea- son for long-term treatment without remarkable effort were analyzed. On this basis, the key technology, economic benefit, ecological service function and carbon se- questration sink enhancement effect of various modes were further analyzed. [Result] The basic idea for comprehensive control of hilly soil erosion in southern China was as follows: the control of soil erosion was combined with modern agricultural produc- tion, in order to build "fruit (tea)-grass-livestock-methane" circular agriculture mode with comprehensive control of soil erosion; application effect analysis showed that the establishment of circular agriculture mode in southern hilly area to control soil erosion ~lad remarkable effect, which could simultaneously meet the coordinated de- velopment of ecological, economic and social benefits. [Conclusion] This study estab- lished an effective mode suitable for soil erosion control and agricultural protection development in southern red soil mountain, which could drive the sustainable devel- opment of ecological restoration of mountainous area and rural agricultural economy.

  14. Spectroscopic study on sorption of hydrogen sulfide by means of red soil.

    Science.gov (United States)

    Ko, T H; Chu, H

    2005-07-01

    This paper reports the results of the characterization of red soils in relation to the sorption of H2S from coal gas at 500 degrees C by spectroscopic techniques in order to provide more information on red soils' structural change both before and after reaction. In addition, by-products analysis has also been studied using Fourier transform infrared (FTIR) spectroscopy. Before and after the experiments the red soils were characterized with X-ray powder diffraction (XRPD), energy dispersion spectrum (EDS), X-ray photoelectron spectroscopy (XPS) and FTIR spectroscopy. XRPD results indicate that iron oxide species disappear from the original to reacted red soil. EDS analysis shows that a significant amount of sulfur is present in the reacted red soil, which is in agreement with the results of the elemental analysis and the calculated value based on breakthrough curve. XPS regression fitting results further indicate that sulfur retention may be associated with the iron oxides. S 2p XPS fittings point out that the major sulfur species present in the reacted red soil are composed of S(-2), elemental sulfur, polysulfide, sulfite and sulfate. Additionally, the binding energy of iron shifts to a lower position for the reacted red soil, which indicates that iron oxides in the original red soil have been converted into iron sulfide. Appreciable amounts of the by-products CO2, SO2 and COS are detected by on-line FTIR spectroscopy during the initial and later stages of the sorption process. The formation of CO2 is related to the water-shift reaction, and SO2 is probably attributable to the reaction of organic matters and H2S. The concentration of COS is quantified by GC/FPD and found it to be about 350 ppm, which is close to the equilibrium concentration of the reaction of inlet CO and H2S at a temperature of 500 degrees C.

  15. Spectroscopic study on sorption of hydrogen sulfide by means of red soil

    Science.gov (United States)

    Ko, T. H.; Chu, H.

    2005-07-01

    This paper reports the results of the characterization of red soils in relation to the sorption of H 2S from coal gas at 500 °C by spectroscopic techniques in order to provide more information on red soils' structural change both before and after reaction. In addition, by-products analysis has also been studied using Fourier transform infrared (FTIR) spectroscopy. Before and after the experiments the red soils were characterized with X-ray powder diffraction (XRPD), energy dispersion spectrum (EDS), X-ray photoelectron spectroscopy (XPS) and FTIR spectroscopy. XRPD results indicate that iron oxide species disappear from the original to reacted red soil. EDS analysis shows that a significant amount of sulfur is present in the reacted red soil, which is in agreement with the results of the elemental analysis and the calculated value based on breakthrough curve. XPS regression fitting results further indicate that sulfur retention may be associated with the iron oxides. S 2p XPS fittings point out that the major sulfur species present in the reacted red soil are composed of S -2, elemental sulfur, polysulfide, sulfite and sulfate. Additionally, the binding energy of iron shifts to a lower position for the reacted red soil, which indicates that iron oxides in the original red soil have been converted into iron sulfide. Appreciable amounts of the by-products CO 2, SO 2 and COS are detected by on-line FTIR spectroscopy during the initial and later stages of the sorption process. The formation of CO 2 is related to the water-shift reaction, and SO 2 is probably attributable to the reaction of organic matters and H 2S. The concentration of COS is quantified by GC/FPD and found it to be about 350 ppm, which is close to the equilibrium concentration of the reaction of inlet CO and H 2S at a temperature of 500 °C.

  16. Study of Arabian Red Sea coastal soils as potential mineral dust sources

    KAUST Repository

    Prakash, P. Jish

    2016-03-23

    Both Moderate Resolution Imaging Spectroradiometer (MODIS) and Spinning Enhanced Visible and InfraRed Imager (SEVIRI) satellite observations suggest that the narrow heterogeneous Red Sea coastal region is a frequent source of airborne dust that, because of its proximity, directly affects the Red Sea and coastal urban centers. The potential of soils to be suspended as airborne mineral dust depends largely on soil texture, moisture content, and particle size distributions. Airborne dust inevitably carries the mineralogical and chemical signature of a parent soil. The existing soil databases are too coarse to resolve the small but important coastal region. The purpose of this study is to better characterize the mineralogical, chemical and physical properties of soils from the Red Sea Arabian coastal plane, which in turn will help to improve assessment of dust effect on the Red Sea and land environmental systems and urban centers. Thirteen surface soils from the hot-spot areas of wind-blown mineral dust along the Red Sea coastal plain were sampled for analysis. Analytical methods included Optical Microscopy, X-ray diffraction (XRD), Inductively Coupled Plasma Optical Emission Spectrometry (ICP-OES), Ion Chromatography (IC), Scanning Electron Microscopy (SEM), and Laser Particle Size Analysis (LPSA). We found that the Red Sea coastal soils contain major components of quartz and feldspar, as well as lesser but variable amounts of amphibole, pyroxene, carbonate, clays, and micas, with traces of gypsum, halite, chlorite, epidote and oxides. The wide range of minerals in the soil samples was ascribed to the variety of igneous and metamorphic provenance rocks of the Arabian Shield forming the escarpment to the east of the Red Sea coastal plain. The analysis revealed that the samples contain compounds of nitrogen, phosphorus and iron that are essential nutrients to marine life. The analytical results from this study will provide a valuable input into dust emission models used

  17. Water and heat transport in hilly red soil of southern China: I. Experiment and analysis

    Institute of Scientific and Technical Information of China (English)

    LU Jun; HUANG Zhi-zhen; HAN Xiao-fei

    2005-01-01

    Studies on coupled transfer of soil moisture and heat have been widely carried out for decades. However, little work has been done on red soils, widespread in southern China. The simultaneous transfer of soil moisture and heat depends on soil physical properties and the climate conditions. Red soil is heavy clay and high content of free iron and aluminum oxide. The climate conditions are characterized by the clear four seasons and the serious seasonal drought. The great annual and diurnal air temperature differences result in significant fluctuation in soil temperature in top layer. The closed and evaporating columns experiments with red soil were conducted to simulate the coupled transfer of soil water and heat under the overlaying and opening fields' conditions, and to analyze the effects of soil temperature gradient on the water transfer and the effects of initial soil water contents on the transfer of soil water and heat. The closed and evaporating columns were designed similarly with about 18 ℃ temperatures differences between the top and bottom boundary, except of the upper end closed or exposed to the air, respectively.Results showed that in the closed column, water moved towards the cold end driven by temperature gradient, while the transported water decreased with the increasing initial soil water content until the initial soil water content reached to field capacity equivalent,when almost no changes for the soil moisture profile. In the evaporating column, the net transport of soil water was simultaneously driven by evaporation and temperature gradients, and the drier soil was more influenced by temperature gradient than by evaporation. In drier soil, it took a longer time for the temperature to reach equilibrium, because of more net amount of transported water.

  18. Genesis and solution chemistry of acid sulfate soils in Thailand

    NARCIS (Netherlands)

    Breemen, van N.

    1976-01-01

    To study short-term and long-term chemical processes in periodically flooded acid sulfate soils in the Bangkok Plain and in various smaller coastal plains along the Gulf of Thailand, 16 acid sulfate soils and one non-acid marine soil were examined for distribution of iron-sulfur compounds, elemental

  19. Genesis and solution chemistry of acid sulfate soils in Thailand

    NARCIS (Netherlands)

    Breemen, van N.

    1976-01-01

    To study short-term and long-term chemical processes in periodically flooded acid sulfate soils in the Bangkok Plain and in various smaller coastal plains along the Gulf of Thailand, 16 acid sulfate soils and one non-acid marine soil were examined for distribution of iron-sulfur compounds, elemental

  20. Leaching and Redistribution of Nutrients in Surface Layer of Red Soils in Southeast China

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    The leaching and redistribution of nutrients in the surface layer of 4 types of red soils in Southeast China were studied with a lysimeter experiment under field conditions. Results showed that the leaching concentrated in the rainy season (from April to June). Generally, the leaching of soil nutrients from the surface layer of red soils was in the order of Ca > Mg > K > NO3-N. In fertilization treatment, the total amount of soil nutrients leached out of the surface layer in a red soil derived from granite was the highest in all soils. The uptake by grass decreased the leaching of fertilizer ions in surface layer, particularly for NO3-N. Soil total N and exchangeable K, Ca and Mg in the surface layer decreased with leaching and grass uptake during the 2 years without new fertilization of urea, Ca(H2PO4)2, KCl, CaCO3 and MgCO3. Ca moved from the application layer (0~5 cm) of fertilizer and accumulated in the 10~30 cm depth in the soils studied except that derived from Quaternary red clay. The deficiency of soil exchangeable K will become a serious degradation process facing the Southeast China.

  1. Regularity of Erosion and Soil Loss Tolerance in Hilly Red-Earth Region of China

    Institute of Scientific and Technical Information of China (English)

    SHUI Jian-guo; YE Yuan-lin; LIU Cha-cha

    2002-01-01

    The observations from 14-yr long-term investigation on the soil-water losses in the sloping redearth (slope 8°- 15°) showed that soil-water losses were closely correlated with land slope and vegetative coverage. Runoff rate in sloping red-earth could be reduced doubly by exploitation, while the soil erosion was enhanced doubly during the first two years after exploitation. Subsequently, it tended to be stable. Soil erosion was highly positively correlated with land slope, I.e. Soil erosion increased by 120 t km-2 yr-1 with a slope increase of 1°. On the contrary, soil erosion was highly negatively correlated with vegetative coverage, I.e. Soil erosion was limited at 200 t km-2 yr-1 below as the vegetative coverage exceeded 60 %. Furthermore, soil erosion was highly related with planting patterns, I.e. Soil erosion in contour cropping pattern would be one sixth of that in straight cropping. Based on the view of soil nutrient balance and test data, it was first suggested that the soil loss tolerance in Q2 red clay derived red-earth should be lower than 300 t km-2 yr-1.

  2. Effect of red clay on diesel bioremediation and soil bacterial community.

    Science.gov (United States)

    Jung, Jaejoon; Choi, Sungjong; Hong, Hyerim; Sung, Jung-Suk; Park, Woojun

    2014-08-01

    Red clay is a type of soil, the red color of which results from the presence of iron oxide. It is considered an eco-friendly material, with many industrial, cosmetic, and architectural uses. A patented method was applied to red clay in order to change its chemical composition and mineral bioavailability. The resulting product was designated processed red clay. This study evaluates the novel use of red clay and processed red clay as biostimulation agents in diesel-contaminated soils. Diesel biodegradation was enhanced in the presence of red clay and processed red clay by 4.9- and 6.7-fold, respectively, and the number of culturable bacterial cells was correlated with the amount of diesel biodegradation. The growth of Acinetobacter oleivorans DR1, Pseudomonas putida KT2440, and Cupriavidus necator was promoted by both types of red clays. Culture-independent community analysis determined via barcoded pyrosequencing indicated that Nocardioidaceae, Xanthomonadaceae, Pseudomonadaceae, and Caulobacteraceae were enriched by diesel contamination. Bacterial strain isolation from naphthalene- and liquid paraffin-amended media was affiliated with enriched taxa based on 16S rRNA gene sequence identity. We suggest that the biostimulating mechanism of red clay and processed red clay is able to support bacterial growth without apparent selection for specific bacterial species.

  3. Alleviation of Soil Acidity and Aluminium Phytotoxicity in Acid Soils by Using Alkaline-Stabilised Biosolids

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    A pot experiment was carried out to study alleviation of soil acidity and Al toxicity by applying an alkaline-stabilised sewage sludge product (biosolids) to an acid clay sandy loam (pH 5.7) and a strongly acid sandy loam (pH 4.5). Barley (Hordeum vulgare L. cv. Forrester) was used as a test crop and was grown in the sewage sludge-amended (33.5 t sludge DM ha-1) and unamended soils. The results showed that the alkaline biosloids increased soil pH from 5.7 to 6.9 for the clay sandy loam and from 4.5 to 6.0 for the sandy loam. The sludge product decreased KCl-extractable Al from 0.1 to 0.0 cmol kg-1 for the former soil and from 4.0 to 0.1 cmol kg-1 for the latter soil. As a result, barley plants grew much better and grain yield increased greatly in the amended treatments compared with the unamended controls. These observations indicate that alkaline-stabilised biosolids can be used as a liming material for remedying Al phytotoxicity in strongly acid soils by increasing soil pH and lowering Al bioavailability.

  4. The effects of acid precipitation and ozone on the ectomycorrhizae of red spruce saplings

    Energy Technology Data Exchange (ETDEWEB)

    Roth, D.R.; Fahey, T.J. [Cornell University, Ithaca, NY (United States). Dept. of Natural Resources

    1998-04-01

    The effects of acid precipitation and ozone on the composition of the ectomycorrhizal community of red spruce saplings were evaluated. In 1986, saplings were excavated from a site in Maine that had been clear-cut in 1979. Saplings were then potted in native soil and transported to Ithaca, New York. With the exception of an ambient control treatment, trees were grown in open-top chambers. Saplings were exposed to five levels of ozone and three levels of acid precipitation beginning in July 1987. Ectomycorrhizae were sampled in 1988 and 1991 after one and four years of treatment, respectively. Although the percentage of root tips infected by ectomycorrhizal fungi was not affected by treatments, a shift in the composition of the ectomycorrhizal community occurred in response to acid precipitation treatments for both sampling years. Among the seven ectomycorrhizal morphotypes identified, the percent composition of one morphotype increased and another decreased in response to higher rain acidity. Alone, ozone treatments did not influence ectomycorrhizal composition however, a significant interactive response to ozone and acid precipitation was observed in the organic soil horizon in 1988. Such shifts in the composition of the ectomycorrhizal community may indicate that the experimental trees were stressed by pollution treatments. 38 refs.

  5. Effect of Soil Sampling Density on Detected Spatial Variability of Soil Organic Carbon in a Red Soil Region of China

    Institute of Scientific and Technical Information of China (English)

    YU Dong-Sheng; ZHANG Zhong-Qi; YANG Hao; SHI Xue-Zheng; TAN Man-Zhi; SUN Wei-Xia; WANG Hong-Jie

    2011-01-01

    Spatial variability of soil organic carbon (SOC) of different land use patterns and soil types was examined in a county-wide red soil region of South China, using six sampling densities, 14, 34, 68, 130, 255, and 525 samples designed by the method of grid sampling in 6 different grid sizes, labeled as D14, D34, D68, D130, D255, and D525, respectively. The results showed that the coefficients of variation (CVs) of SOC decreased gradually from 62.8% to 47.4% with the increase in soil sampling densities. The SOC CVs in the paddy field change slightly from 30.8% to 28.7%, while those of the dry farmland and forest land decreased remarkably from 58.1%to 48.7% and from 99.3% to 64.4%, respectively. The SOC CVs of the paddy soil change slightly, while those of red soil decreased remarkably from 82.8% to 63.9%. About 604, 500, and 353 (P < 0.05) samples would be needed a number of years later if the SOC change was supposedly 1.52 g kg-2, based on the CVs of SOC acquired from the present sampling densities of D14, D68, and D525,respectively. Moreover, based on the same SOC change and the present time CVs at D255, the ratio of samples needed for paddy field, dry farmland, and forest land should be 1:0.81:3.33, while the actual corresponding ratio in an equal interval grid sampling was 1:0.74:0.46. These indicated that the sampling density had important effect on the detection of SOC variability in the county-wide region, the equal interval grid sampling was not efficient enough, and the respective CV of each land use or soil type should be fully considered when determining the sampling number in the future.

  6. Isolation and Characterization of Soil Fulvic Acid

    Directory of Open Access Journals (Sweden)

    Mir Munsif Ali Talpur

    2016-06-01

    Full Text Available Fulvic acid was isolated from the agriculture soil of District Naushahro Feroz, Sindh, Pakistan by International Humic Substances Society (IHSS method. The nutrient contents of the soil like N. P, K, Ca, Mg, Fe and Zn were determined by using the Atomic Absorption spectrophotometer (AAS. The Spectroscopic analysis was carried out by studying the UV-Vis, FT-IR and NIR spectra of isolated compounds. The data has been compared with the literature and correlated. Moisture as well as texture shows good water holding capacity and silt- loam type of soil. pH and EC are indicators of the fertility of soil to be beneficial for plantation. The spectral data (UV-Visible, FTIR and NIR supports the characteristic functional groups (-COOH, C=O, -OH, -NH2, C=C, CH2 and Polysaccharides present in Fulvic acid. E4/E6 values depict its hydrophilic nature, having less aromatic and more aliphatic groups. The presence of metal ions indicates its chelating ability.

  7. Characterization of Soil Humin by Acid Hydrolysis

    Institute of Scientific and Technical Information of China (English)

    李云峰; 徐建民; 等

    1999-01-01

    Studies were conducted to characterize soil humin by acid hydrolysis.Two humin samples collected from two different types of soil,namely chernozem and laterite,which are widespread over a vast area from the north to south of China,were hyrolyzed under reflux with 0.5M H2SO4or 3M H2SO4for 4h.The results showed that 25%-29% of organic carbon and 46%-54%of organic nitrogen could be hydrolyzed by 0.5M H2SO4;36%-40%of organic carbon and 93%-97% of organic nitrogen hydrolyzed by 3M H2SO4.The C/N ration in hydrolyzed organic matter is lower than that in soil humin and that in organic matter hydrolyzed by 3M H2SO4 is lower than that in organic matter hydrolyzed by 0.5M H2SO4.The proportion of nitrogen hydrolyzed from humin is markedly larger than that from the original soil and also markedly larger than that from humic acid fraction.Only 3%-7% of nitrogen in humin exists in a relatively stable from,which is not easy to hydrolyze.There in little nitrogen that occurs in the form of heterocyclic rings in humin.Incubation experiments showed that the newly formed organic matter can be hydrolyzed more easily.

  8. Nutrient Cycling and Balance in Red Soil Agroecosystem and Their Management

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    An experiment was conducted in a red soil derived from Quaternary red clay in the Ecological Experiment Station of Red Soil, the Chinese Academy of Sciences, located in Yingtan (28°15' 30" N, 116°55' 30" E), Jiangxi Province. The results show that the major ways of nutrient loss are leaching and nitrogen volatilization. Rationalizing crop distribution, stimulating nutrient recycling, and improving internal nutrient flow are effective measures to decrease nutrient loss and to promote nutrient utilization efficiency. The important ways of regulating nutrient cycling and balance in the agroecosystem of the red soil are to establish optimal eco-agricultural models, practice balanced fertilization and combine the cropping system with the livestock system.

  9. Effect of different fertilizer application on the soil fertility of paddy soils in red soil region of southern China.

    Directory of Open Access Journals (Sweden)

    Wenyi Dong

    Full Text Available Appropriate fertilizer application is an important management practice to improve soil fertility and quality in the red soil regions of China. In the present study, we examined the effects of five fertilization treatments [these were: no fertilizer (CK, rice straw return (SR, chemical fertilizer (NPK, organic manure (OM and green manure (GM] on soil pH, soil organic carbon (SOC, total nitrogen (TN, C/N ratio and available nutrients (AN, AP and AK contents in the plowed layer (0-20 cm of paddy soil from 1998 to 2009 in Jiangxi Province, southern China. Results showed that the soil pH was the lowest with an average of 5.33 units in CK and was significantly higher in NPK (5.89 units and OM (5.63 units treatments (P<0.05. The application of fertilizers have remarkably improved SOC and TN values compared with the CK, Specifically, the OM treatment resulted in the highest SOC and TN concentrations (72.5% and 51.2% higher than CK and NPK treatment increased the SOC and TN contents by 22.0% and 17.8% compared with CK. The average amounts of C/N ratio ranged from 9.66 to 10.98 in different treatments, and reached the highest in OM treatment (P<0.05. During the experimental period, the average AN and AP contents were highest in OM treatment (about 1.6 and 29.6 times of that in the CK, respectively and second highest in NPK treatment (about 1.2 and 20.3 times of that in the CK. Unlike AN and AP, the highest value of AK content was observed in NPK treatments with 38.10 mg·kg(-1. Thus, these indicated that organic manure should be recommended to improve soil fertility in this region and K fertilizer should be simultaneously applied considering the soil K contents. Considering the long-term fertilizer efficiency, our results also suggest that annual straw returning application could improve soil fertility in this trial region.

  10. Acidification Sources in Red Alder and Douglas-Fir Soils -- Importance of Nitrification

    OpenAIRE

    Miegroet, Helga Van; Cole, D. W.

    1985-01-01

    Precipitation, throughfall, forest floor, and soil leachate samples were monitored continuously in 1981 and 1982 in a N-poor Douglas-fir [Pseudotsuga menziesii (Mirb.) Franco] forest and a red alder (Alnus rubra Bong.) forest growing adjacently on a glacial soil in western Washington. The purpose of the study was to quantify the relative importance of atmospheric vs. natural sources of H+ input to forest soil acidification, and to determine the role of N transformation processes in the overa...

  11. Pioneering the red planet; adventures on Martian soil

    NARCIS (Netherlands)

    Van der Peijl, I.; Veraart, M.

    2013-01-01

    Mars has always obsessed humankind - the Red planet, the ‘New Earth’. And with the recent successful landing of NASA’s Curiosity rover, Mars is closer than ever. Ever since 1960, we have actively been sending probes and rovers to observe the planet, but not without defeat. The road to the red planet

  12. Pioneering the red planet; adventures on Martian soil

    NARCIS (Netherlands)

    Van der Peijl, I.; Veraart, M.

    2013-01-01

    Mars has always obsessed humankind - the Red planet, the ‘New Earth’. And with the recent successful landing of NASA’s Curiosity rover, Mars is closer than ever. Ever since 1960, we have actively been sending probes and rovers to observe the planet, but not without defeat. The road to the red planet

  13. Integration of Soil Information System and Interactive Self—Organizing Data for Agricultural Developing Zones in Red Soil Region

    Institute of Scientific and Technical Information of China (English)

    SHIZHOU; WANGRENCHAO; 等

    1999-01-01

    Integration of soil information system (SIS) and interactive self-organizing data(ISODATA) was studied to establish proper agricultural developing zones in red soil region of southern China which are of crucial importance to farmers,researchers,and decision maders while utilizing and managing red soil resources.SIS created by using ARC/INFO was used to provide data acquisition,systematic model parameter assignment,and visual display of analytic results.Topography,temperature,soil component(e.g.,organic matter and pH) and condition of agricultural production were selected as parameters of ISODATA model.Taking Longyou County,Zhejiang Province as the case study area,the effect of the integration and recommendations are discussed for future research.

  14. Acetic acid bacteria spoilage of bottled red wine -- a review.

    Science.gov (United States)

    Bartowsky, Eveline J; Henschke, Paul A

    2008-06-30

    Acetic acid bacteria (AAB) are ubiquitous organisms that are well adapted to sugar and ethanol rich environments. This family of Gram-positive bacteria are well known for their ability to produce acetic acid, the main constituent in vinegar. The oxidation of ethanol through acetaldehyde to acetic acid is well understood and characterised. AAB form part of the complex natural microbial flora of grapes and wine, however their presence is less desirable than the lactic acid bacteria and yeast. Even though AAB were described by Pasteur in the 1850s, wine associated AAB are still difficult to cultivate on artificial laboratory media and until more recently, their taxonomy has not been well characterised. Wine is at most risk of spoilage during production and the presence of these strictly aerobic bacteria in grape must and during wine maturation can be controlled by eliminating, or at least limiting oxygen, an essential growth factor. However, a new risk, spoilage of wine by AAB after packaging, has only recently been reported. As wine is not always sterile filtered prior to bottling, especially red wine, it often has a small resident bacterial population (bacteria. This spoilage is evident as a distinct deposit of bacterial biofilm in the neck of the bottle at the interface of the wine and the headspace of air, and is accompanied with vinegar, sherry, bruised apple, nutty, and solvent like off-aromas, depending on the degree of spoilage. This review focuses on the wine associated AAB species, the aroma and flavour changes in wine due to AAB metabolism, discusses the importance of oxygen ingress into the bottle and presents a hypothesis for the mechanism of spoilage of bottled red wine.

  15. Root interactions in a maize/soybean intercropping system control soybean soil-borne disease, red crown rot.

    Directory of Open Access Journals (Sweden)

    Xiang Gao

    Full Text Available BACKGROUND: Within-field multiple crop species intercropping is well documented and used for disease control, but the underlying mechanisms are still unclear. As roots are the primary organ for perceiving signals in the soil from neighboring plants, root behavior may play an important role in soil-borne disease control. PRINCIPAL FINDINGS: In two years of field experiments, maize/soybean intercropping suppressed the occurrence of soybean red crown rot, a severe soil-borne disease caused by Cylindrocladium parasiticum (C. parasiticum. The suppressive effects decreased with increasing distance between intercropped plants under both low P and high P supply, suggesting that root interactions play a significant role independent of nutrient status. Further detailed quantitative studies revealed that the diversity and intensity of root interactions altered the expression of important soybean PR genes, as well as, the activity of corresponding enzymes in both P treatments. Furthermore, 5 phenolic acids were detected in root exudates of maize/soybean intercropped plants. Among these phenolic acids, cinnamic acid was released in significantly greater concentrations when intercropped maize with soybean compared to either crop grown in monoculture, and this spike in cinnamic acid was found dramatically constrain C. parasiticum growth in vitro. CONCLUSIONS: To the best of our knowledge, this study is the first report to demonstrate that intercropping with maize can promote resistance in soybean to red crown rot in a root-dependent manner. This supports the point that intercropping may be an efficient ecological strategy to control soil-borne plant disease and should be incorporated in sustainable agricultural management practices.

  16. Reclamation of an acidic soil of Rwanda's central upland by ...

    African Journals Online (AJOL)

    user

    Keywords: acidic soil, compost, exchangeable aluminium, soil pH, Rwanda. Résumé ... as organic amendment source (compost, green manure, mulch, etc.). ..... from the addition of farm manure and/or household wastes that gave very.

  17. A Standardized Soil Ecotoxicological Test Using Red Worms (Eisenia fetida).

    Science.gov (United States)

    Paradise, Christopher J.

    2001-01-01

    Describes a simple, inexpensive test for soil contamination that can be used in a variety of courses to examine the effects of soil toxicity, to practice standardized laboratory procedures, to study experimental design and data analysis, or to investigate earthworm ecology. Presents background information along with details regarding equipment,…

  18. Microbial production of CO2 in red soil in Stone Forest National Park

    Institute of Scientific and Technical Information of China (English)

    LIANGFuyuan; SONGLinhua; TANGTao

    2003-01-01

    Lunan stone forest is a kind of typical karst in China,Which is mainly developed under red soil.In the winter of 1999,three study sites were chosen in stone forest national park according to vegetation cover,geomporphologic location and soil types,CO2 concentration was measured with Gastec punp at different dephts of soil (20,40,60cm) and at the same time soil samples were gatered and soil properties such as soil moisure,pH,soil organic content were analyzed and the total nmuber of viable microbes were counted in laboratory,In the study,dependent variable was chosen as the mean soil log(PCO2),and soil properties were chosen as the independent variables.Multiple stepwise regression analysis showed that the totla amount of microbes and soil moisture are the best indicators of the CO2 production,With the equation LOG(PCO2)=-0.039(TNM)-0.056 (Mo)+1.215 accounting for 86% of the variation of the soil CO2 concentration,where TNM is the total number of microbes in teh soil and Mo is the moisture of soil sample.

  19. 赤泥耕土制备技术%Preparation Process of Cultivated Soil Rehabilitated from Red Mud

    Institute of Scientific and Technical Information of China (English)

    彭光菊; 张健伟; 张磊; 饶玉学

    2011-01-01

    Taking the plant waste as modifier of red mud, the preparation process of cultivated soil rehabilitated from red mud with wide applicability, which can treat with a large number of red mud was investigated. The basic principle of this technique was that the harmful elements in red mud are diluted by and made a complex ( sequestration) process with humic acids produced by the hydrolysis and fermentation of plant waste and with the alkaline in humus and red mud so as to improve the porosity for the red mud and supply with the needs for plant growth. Good results have been achieved to prepare the cultivated soil rehabilitated from red mud by using com stalks, bagasse and wastewater, weeds as modifier of red mud respectively in the tests, Among these, the test with com stalks as a modifier showed that the plants grew normally in the cultivated soil with the bulk density of 1. 3 g/cm3, and pH value at 7.9.%以植物性废料为赤泥的改性剂,研发了适用性广、可大量消纳赤泥的赤泥耕土制备技术.该技术的基本原理是利用植物废料水解、发酵产生的腐殖酸和腐殖质中和赤泥的碱性、稀释并络(鳌)合赤泥中的有害元素、提高赤泥的疏松度、为赤泥添加植物生长所需养分.分别以玉米秸秆、蔗渣和废醪液、杂草为赤泥改性剂进行的赤泥耕土制备试验均取得了良好效果,其中以玉米秸秆为改性剂的试验表明,所得赤泥耕土的容重为1.3 g/cm3,pH值为7.9,养分增加,植物可在其中正常生长.

  20. Effect of Lanthanum on Nitrification, Phosphorus Transformation and Phenol Decomposition in Red Soil

    Institute of Scientific and Technical Information of China (English)

    褚海燕; 朱建国; 谢祖彬; 李振高; 曹志洪; 曾青

    2002-01-01

    The effect of La on nitrification, P transformation and phenol decomposition in red soil was studied by incubation and pot culture experiments. La at low concentration has stimulative effect on soil nitrification and P transformation while its high concentration has inhibitory effects, and the inhibition is strengthened with increasing concentration of La. La has strongly inhibitory effect on soil phenol decomposition and the inhibition is strengthened with increasing concentration of La. When the incubation time is prolonged, the inhibitory effect of La on soil nitrification and phenol decomposition tends to decrease.

  1. Red/Far Red Light Controls Arbuscular Mycorrhizal Colonization via Jasmonic Acid and Strigolactone Signaling.

    Science.gov (United States)

    Nagata, Maki; Yamamoto, Naoya; Shigeyama, Tamaki; Terasawa, Yohei; Anai, Toyoaki; Sakai, Tatsuya; Inada, Sayaka; Arima, Susumu; Hashiguchi, Masatsugu; Akashi, Ryo; Nakayama, Hideyuki; Ueno, Daisuke; Hirsch, Ann M; Suzuki, Akihiro

    2015-11-01

    Establishment of a nitrogen-fixing symbiosis between legumes and rhizobia not only requires sufficient photosynthate, but also the sensing of the ratio of red to far red (R/FR) light. Here, we show that R/FR light sensing also positively influences the arbuscular mycorrhizal (AM) symbiosis of a legume and a non-legume through jasmonic acid (JA) and strigolactone (SL) signaling. The level of AM colonization in high R/FR light-grown tomato and Lotus japonicus significantly increased compared with that determined for low R/FR light-grown plants. Transcripts for JA-related genes were also elevated under high R/FR conditions. The root exudates derived from high R/FR light-grown plants contained more (+)-5-deoxystrigol, an AM-fungal hyphal branching inducer, than those from low R/FR light-grown plants. In summary, high R/FR light changes not only the levels of JA and SL synthesis, but also the composition of plant root exudates released into the rhizosphere, in this way augmenting the AM symbiosis.

  2. Molecular Mechanism of Macrophage Activation by Red Ginseng Acidic Polysaccharide from Korean Red Ginseng

    Directory of Open Access Journals (Sweden)

    Se Eun Byeon

    2012-01-01

    Full Text Available Red ginseng acidic polysaccharide (RGAP, isolated from Korean red ginseng, displays immunostimulatory and antitumor activities. Even though numerous studies have been reported, the mechanism as to how RGAP is able to stimulate the immune response is not clear. In this study, we aimed to explore the mechanism of molecular activation of RGAP in macrophages. RGAP treatment strongly induced NO production in RAW264.7 cells without altering morphological changes, although the activity was not strong compared to LPS-induced dendritic-like morphology in RAW264.7 cells. RGAP-induced NO production was accompanied with enhanced mRNA levels of iNOS and increases in nuclear transcription factors such as NF-κB, AP-1, STAT-1, ATF-2, and CREB. According to pharmacological evaluation with specific enzyme inhibitors, Western blot analysis of intracellular signaling proteins and inhibitory pattern using blocking antibodies, ERK, and JNK were found to be the most important signaling enzymes compared to LPS signaling cascade. Further, TLR2 seems to be a target surface receptor of RGAP. Lastly, macrophages isolated from RGS2 knockout mice or wortmannin exposure strongly upregulated RGAP-treated NO production. Therefore, our results suggest that RGAP can activate macrophage function through activation of transcription factors such as NF-κB and AP-1 and their upstream signaling enzymes such as ERK and JNK.

  3. [Dynamics of unprotected soil organic carbon with the restoration process of Pinus massoniana plantation in red soil erosion area].

    Science.gov (United States)

    Lü, Mao-Kui; Xie, Jin-Sheng; Zhou, Yan-Xiang; Zeng, Hong-Da; Jiang, Jun; Chen, Xi-Xiang; Xu, Chao; Chen, Tan; Fu, Lin-Chi

    2014-01-01

    By the method of spatiotemporal substitution and taking the bare land and secondary forest as the control, we measured light fraction and particulate organic carbon in the topsoil under the Pinus massoniana woodlands of different ages with similar management histories in a red soil erosion area, to determine their dynamics and evaluate the conversion processes from unprotected to protected organic carbon. The results showed that the content and storage of soil organic carbon increased significantly along with ages in the process of vegetation restoration (P soil organic carbon content and distribution proportion to the total soil organic carbon increased significantly (P soil organic carbon mostly accumulated in the form of unprotected soil organic carbon during the initial restoration period, and reached a stable level after long-term vegetation restoration. Positive correlations were found between restoration years and the rate constant for C transferring from the unprotected to the protected soil pool (k) in 0-10 cm and 10-20 cm soil layers, which demonstrated that the unprotected soil organic carbon gradually transferred to the protected soil organic carbon in the process of vegetation restoration.

  4. Amendment of Acid Soils with Crop Residues and Biochars

    Institute of Scientific and Technical Information of China (English)

    YUAN Jin-Hua; XU Ren-Kou; WANG Ning; LI Jiu-Yu

    2011-01-01

    The liming potential of some crop residues and their biochars on an acid Ultisol was investigated using incubation experiments. Rice hulls showed greater liming potential than rice hull biochar, while soybean and pea straws had less liming potential than their biochars. Due to their higher alkalinity, biochars from legume materials increased soil pH much compared to biochars from non-legume materials. The alkalinity of biochars was a key factor affecting their liming potential,and the greater alkalinity of biochars led to greater reductions in soil acidity. The incorporation of biochars decreased soil exchangeable acidity and increased soil exchangeable base cations and base saturation, thus improving soil fertility.

  5. Soils and climate: redness and weathering as indicators of mean annual precipitation

    Science.gov (United States)

    Lucke, Bernhard

    2016-04-01

    Paleosols can be used as archives of past changes of climate and landscapes, but their interpretation has to be based on modern analogies such as Budyko's law of soil zonality. These can be very useful if the respective processes of soil formation are sufficiently well understood. However, some soils such as the Terra Rossa or Red Mediterranean Soils, that are widespread at the fringes of the steppes and deserts, are still disputed with regard to their genesis and environmental significance. In particular, there is no agreement whether they resemble current environmental conditions, or are inherited from climates or sediments of the past. In this context, a remarkable change of the color of surface soils can be observed when driving from the city of Irbid in Jordan towards the east. Soil color apparently changes slowly, but steadily from dark red to yellow colors. However, attempting to express these color changes in numerical form is challenging, and it seemed questionable whether color is indeed connected with soil weathering intensity, or an optical illusion. However, a systematic comparison of different approaches of calculating soil redness found that the CIELAB-color system is suited for numerical expressions of soil redness and performs better than the Munsell charts. Along the investigated transect in Jordan, soil color seems strongly connected with weathering intensity, since various weathering indicators point to a steady increase of soil development with moisture. This suggests that such indices can well be used in semi-arid areas of 250-600 mm of mean annual precipitation. A very strong correlation of magnetic enhancement and rainfall indicates that the investigated soils are forming in equilibrium with current climatic conditions, and regressions based on this gradient might be suited for estimating paleorainfalls recorded by buried paelosols. It seems therefore that surface Terra Rossa soils in Jordan can be in equilibrium with current climate

  6. Natural abiotic formation of oxalic acid in soils: results from aromatic model compounds and soil samples.

    Science.gov (United States)

    Studenroth, Sabine; Huber, Stefan G; Kotte, Karsten; Schöler, Heinz F

    2013-02-05

    Oxalic acid is the smallest dicarboxylic acid and plays an important role in soil processes (e.g., mineral weathering and metal detoxification in plants). We have first proven its abiotic formation in soils and investigated natural abiotic degradation processes based on the oxidation of soil organic matter, enhanced by Fe(3+) and H(2)O(2) as hydroxyl radical suppliers. Experiments with the model compound catechol and further hydroxylated benzenes were performed to examine a common degradation pathway and to presume a general formation mechanism of oxalic acid. Two soil samples were tested for the release of oxalic acid and the potential effects of various soil parameters on oxalic acid formation. Additionally, the soil samples were treated with different soil sterilization methods to prove the oxalic acid formation under abiotic soil conditions. Different series of model experiments were conducted to determine a range of factors including Fe(3+), H(2)O(2), reaction time, pH, and chloride concentration on oxalic acid formation. Under certain conditions, catechol is degraded up to 65.6% to oxalic acid referring to carbon. In serial experiments with two soil samples, oxalic acid was produced, and the obtained results are suggestive of an abiotic degradation process. In conclusion, Fenton-like conditions with low Fe(3+) concentrations and an excess of H(2)O(2) as well as acidic conditions were required for an optimal oxalic acid formation. The presence of chloride reduced oxalic acid formation.

  7. Biodegradation of azo dyes acid red 183, direct blue 15 and direct red 75 by the isolate Penicillium oxalicum SAR-3.

    Science.gov (United States)

    Saroj, Samta; Kumar, Karunesh; Pareek, Nidhi; Prasad, R; Singh, R P

    2014-07-01

    Soils contaminated with dyes were collected and screened for obtaining potential fungal strains for the degradation of azo dyes. A strain that demonstrated broad spectrum ability for catabolizing different azo dyes viz. Acid Red 183 (AR 183), Direct Blue 15 (DB 15) and Direct Red 75 (DR 75) at 100 mg L(-1) concentration was subsequently identified as Penicillium oxalicum SAR-3 based on 18S and internal transcribed spacer (ITS) rDNA gene sequence analysis. The strain has shown remarkably higher levels of degradation (95-100%) for almost all the dyes within 120 h at 30°C at pH 7.0. Notable levels of manganese peroxidase (659.4 ± 20 UL(-1)) during dye decolorization indicated the involvement of this enzyme in the decolorization process. The dyes following decolorization were catabolized as evident by spectroscopic analyses.

  8. Effect of heavy metals on soil microbial activity and diversity in a reclaimed mining wasteland of red soil area

    Institute of Scientific and Technical Information of China (English)

    LIAO Min; CHEN Cheng-li; HUANG Chang-yong

    2005-01-01

    The microbial biomass, basal respiration and substrate utilization pattern in copper mining wasteland of red soil area, southern China, were investigated. The results indicated that soil microflora were obviously different compared with that of the non-mine soil.Microbial biomass and basal respiration were negatively affected by the elevated heavy metal levels. Two important microbial ecophysiological parameters, namely, the ratio of microbial biomass C( Cmic )/organic C( Corg ) and metabolic quotient(qCO2 ) were closely correlated to heavy metal stress. There was a significant decrease in the Cmic/Corg ratio and an increase in the metabolic quotient with increasing metal concentration. Multivariate analysis of Biolog data for sole carbon source utilization pattern demonstrated that heavy metal pollution had a significant impact on microbial community structure and functional diversity. All the results showed that soil microbiological parameters had great potential to become the early sensitive, effective and liable indicators of the stresses or perturbations in soils of mining ecosystems.

  9. [Responses of soil nematode communities to long-term application of inorganic fertilizers in upland red soil].

    Science.gov (United States)

    Zhang, Wei; Liu, Man-Qiang; He, Yuan-Qiu; Fan, Jian-Bo; Chen, Yan

    2014-08-01

    Soil biota plays a key role in ecosystem functioning of red soil. Based on the long-term inorganic fertilization field experiment (25-year) in an upland red soil, the impacts of different inorganic fertilization managements, including NPK (nitrogen, phosphorus and potassium fertilizers), NPKCaS (NPK plus gypsum fertilizers), NP (nitrogen and phosphorus fertilizers), NK (nitrogen and potassium fertilizers) and PK (phosphorus and potassium fertilizers), on the assemblage of soil nematodes during the growing period of peanut were investigated. Significant differences among the treatments were observed for total nematode abundance, trophic groups and ecological indices (P NPKCaS > NPK > NP > NK. The total number of nematodes was significantly higher in NPKCaS and PK than in NPK, NP and NK except in May. Plant parasitic nematodes were the dominant trophic group in all treatments excepted in NPKCaS, and their proportion ranged between 38% and 65%. The dominant trophic group in NPKCaS was bacterivores and represented 42.1%. Furthermore, the higher values of maturity index, Wasilewska index and structure index in NPKCaS indicated that the combined application of NPK and gypsum could remarkably relieve soil acidification, resulting in a more mature and stable soil food web structure. While, that of the NK had the opposite effect. In conclusion, our study suggested that the application of both gypsum and phosphate is an effective practice to improve soil quality. Moreover, the analysis of nematode assemblage is relevant to reflect the impact of different inorganic fertilizer on the red soil ecosystem.

  10. Red Yeast Rice Increases Excretion of Bile Acids in Hamsters

    Institute of Scientific and Technical Information of China (English)

    KA-YING MA; ZE-SHENG ZHANG; SHU-XIN ZHAO; QI CHANG; YIN-MEI WONG; SAI YING VENUS YEUNG; YU HUANG; ZHEN-YU CHEN

    2009-01-01

    Objectives To investigate the hypocholesterolemic activity of red yeast rice (RYR) and its underlying mechanism. Methods Three groups of hamsters were fed either the control diet or one of the two experimental diets containing by weight 0.1% RYR (0.1RYR) or 0.3% RYR (0.3RYR). Blood (0.5 mL) was collected from the retro-orbital sinus into a heparinized capillary tube at the end of week 0,3, and 6.Plasma lipoproteins were measured using enzymatic kits, while fecal neutral and acidic sterols were quantified using a gas-liquid chromatography. Results Plasma total cholesterol was reduced by 12% in 0.1RYR group and by 18% in 0.3RYR group compared with the control value. Similarly, plasma triacylglycerol was decreased by ll% in 0.1RYR group and by 24% in 0.3RYR group. Western blotting analysis demonstrated that RYR had no effect on sterol regulatory element binding protein 2, liver X receptor, 3-hydroxy-3-methylglutary-CoA reductase, LDL receptor, and cholesterol-7α-hydroxylase. HPLC analysis confirmed that RYR contained 0.88% monacolin K.It was recently found that RYR supplementation increased excretion of fecal acidic sterols by 3-4 folds compared with the control value. Conclusion Hypocholesterolemic activity of RYR is mediated at least partially by enhancement of acidic sterol excretion.

  11. New fatty acids from the Red Sea sponge Mycale euplectellioides.

    Science.gov (United States)

    Mohamed, Gamal A; Abd-Elrazek, Ali E E; Hassanean, Hashim A; Alahdal, Abdulrahman M; Almohammadi, Ameen; Youssef, Diaa T A

    2014-01-01

    Chemical investigation of the Red Sea sponge Mycale euplectellioides afforded two new compounds; hexacosa-(6Z,10Z)-dienoic acid methyl ester (1) and hexacosa-(6Z,10Z)-dienoic acid (2), along with two known compounds: icosa-(8Z,11Z)-dienoic acid methyl ester (3) and β-sitosterol (4). The structures were elucidated by the interpretation of their spectral data. The total methanol extract (TME) of the sponge exhibited potent antimicrobial activity against the different strains at a concentration of 100 mg/mL. All tested fractions did not exhibit any activity against Serratia marcescens and tested fungal strains. The TME and different fractions displayed anti-inflammatory and antipyretic activities at doses of 100 and 200 mg/kg compared with indomethacin (8 mg). The TME exhibited a remarkable hepato-protective effect in CCl4-induced liver damage compared with silymarin. Furthermore, compounds 1 and 2 displayed weak activity against A549 non-small cell lung cancer, the U373 glioblastoma and the PC-3 prostate cancer cell lines.

  12. Paleomagnetic Results of the Red Soil-Volcanic Rock Series of Yingfengling Section, Southern Leizhou Peninsula

    Institute of Scientific and Technical Information of China (English)

    王俊达; 梁池生

    2002-01-01

    The Yingfengling section composed of red soil and volcanic rocks can be distinguished into 8 stratigraphic units and 4 red soil-volcanic rock cycles. 64 paleomagnetic-orientated sam ples were collected from the bottom to the top of the section. Natural remanent magnetization and magnetic susceptibility were firstly measured. All the samples were stepwisely treated with thermal or/and alternating fields. Four clear polarity segments were recorded in the section.Compared with the geo-magnetic polarity scale, the section was formed since the late Olduvai subchron, about 1.37 Ma. B. P.

  13. Changes of Organic Matter, N, P and K Content of Soils in Red Soil Areas Under Long-Term Experiment

    Institute of Scientific and Technical Information of China (English)

    JIANG Duan-sheng; ZENG Xi-bai; GAO Ju-sheng; LI Lian-fang

    2008-01-01

    The content of organic matter (OM), nitrogen (N), phosphorus (P), and potassium (K) in the three selected soils, including Calcaric Purpli-Orthic Primosols (purple sand-shale parent material), Dystric Turbi-Anthric Primosols (quaternary red clay parent material) and Typic Udi-Sandic Primosols (granite parent material) were studied under a long-term experiment by using crop straw and inorganic fertilizers at the Hunan Red Soil Experiment Station of Chinese Academy of Agricultural Sciences. The results showed that the contents of OM, N, P and K in the three selected soils increased after 23 years application of crop straw and inorganic fertilizers, but the contents increased much less when crop straw or inorganic fertilizers was applied alone. The nutrient contents in the three soils developed from granite changed more remarkably than those in the soil derived from quaternary red clay and purple sand-shale. It was also found that the contents of OM, N, and P increased slightly in the treatments without applying fertilizers or returning the crop straw to the root bed. Combined application of inorganic fertilizers and crop straw could remarkably increase the contents of OM, alkali- hydrolyzable N and available K, the positive correlation between application of organic fertilizers and increase of OM in soil did not always happened, it provided evidence for the relation between appropriate C/N ratio and accumulation of OM in soil. The increase of nutrient content was influenced by the soil properties. By comparing the contents of nutrient in 0-20 cm depth in the three different soils, it was concluded that the most increases of OM, alkali-hydrolyzable N, and available P were observed in Typic Udi-Sandic Primosols with the average increase by 3.03, 27.38, and 21.73 mg kg-1, respectively. The available K increased in Dystric Turbi-Anthric Primosols with the average increase by 25.82 mg kg-1, while it decreased in Calcaric Purpli-Orthic Primosols and Typic Udi

  14. Effects of grass contour hedgerow systems on controlling soil erosion in red soil hilly areas, Southeast China

    Institute of Scientific and Technical Information of China (English)

    Ji Fan; Lijiao Yan; Pei Zhang; Ge Zhang

    2015-01-01

    abstract Soil erosion by water is a well-recognized serious environmental problem in the world. While contour hedgerow systems are an effective method for soil water conservation, there are a few studies on its effect in the red soil hilly areas in Southeast China. With a fixed field experiment, we constructed a runoff plot at hilly area in Zhuji County, Zhejiang province, to evaluate the effect of the grass hedgerows in soil water conservation, and to determine the optimized hedgerow patterns. Hemerocallis citrine (HC) and Ophiopogon japonicas (OJ) were selected to build the hedgerows in patterns of one row and two rows. The REE method was used to trace the source of the sediment for a better understanding of the characteristic and mechanism of erosion with hedgerows control. Our results showed that (1) hedgerows reduced erosion and surface runoff by 31.99–67.22% and 15.44–45.11%, respectively; (2) hedgerows delayed the development of rills;(3) hedgerows reduced the soil nutrients loss;(4) hedgerows reshaped the soil physical properties, especially in increasing 4 0.25 mm water-stable aggregates. Taken together, our results suggest that two-row OJ is the optimized contour hedgerow pattern in the experiment condition, and downward sloping land should have the highest priority to take measures for soil water conservation. This research comprehensively studied the effects and mechanism of contour hedgerows in controlling soil and water loss in red soil hilly areas, Southeast China, so that the practice of soil and water conservation can be implemented more effectively in these areas.

  15. [Identification of aluminum toxicity of soybean in red soil region with FTIR, TG and DT technology].

    Science.gov (United States)

    Yu, Hui-na; Liu, Peng; Xu, Gen-di

    2008-12-01

    Aluminum (Al) toxicity is one of the major constraints to crop production in acid soils. In order to provide a correct and effective identification method of aluminum toxicity of soybean in red soil regions, Fourier transform infrared spectroscopy (FTIR), thermogravimetry (TG) and differential thermal (DT) analysis were adopted to study the soybean root under different Al treatments. The results showed that the aluminum contents of soybean roots treated with 60 and 90 mg x L(-1) Al concentration were higher than that with other aluminum treatment, and the Al content reached significant aluminum toxicity level. In the same wavenumber range, the character, wavenumber and absorption peak of infrared spectra were different from those under different Al treatments. In summary, the absorption peaks at 3300, 2 930, 1542 and 721 cm(-1) were the characteristic peaks for identification that can be used to evaluate the Al toxicity of soybean. Detailed description is as follows: with the high aluminum treatment (60 and 90 mg x L(-1)), the characteristic peaks at 3300 and 2930 cm(-1) were higher than those with other aluminum treatment. There are no infrared bands at 1542 cm(-1) under 90 mg x L(-1) aluminum treatment, as the characteristic peak of Amide II. However, the characteristic peak at 721 cm(-1) was clearly shown at 60 and 90 mg x L(-1), but no sign was shown in 0, 10 and 30 mg x L(-1) aluminum concentration. Curves of TG and DT revealed the greatest difference with different Al treatment in the range of temperature of 400-500 degrees C. Under the Al treatment above 30 mg x L(-1), TG curve had less weight than that at 0 mg x L(-1), which indicated that the root system may be more lignified, producing some material hard to be burned. DT curve had double peaks at 60 and 90 mg x L(-1) Al treatments, which may also be used as identification mark of Al toxicity. Because some features were expressed under Al treatment with FTIR, TG and DT, the technology of FTIR, TG and DT

  16. Correlation of Red Mud Consolidation with its Soil Properties

    Science.gov (United States)

    Stinson, John M.

    Consolidation tests of red muds from various bauxites allow the prediction of the extent of settlement in a mud lake and the rate of consolidation. Differences in the consolidation properties have been shown to correlate with the moisture contents at which the various muds change from a liquid to a plastic state, as indicated by the Atterberg Liquid and Plastic Limits.

  17. Phenolic Acids in Plant-Soil-Microbe System: A Review

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    Phenolic acids are very common compounds in pedosphere. The objective of this review was to summarize the current knowledge of the behaviors of phenolic acids in plant-soil-microbe system. When phenolic acids originated from leaching, decomposition and exudation of living and dead plant tissues enter soils, they can react physicochemically with soil particle surfaces and/or incorporate into humic matter. Phenolic acids desorbed from soil particle surfaces and remained in solution phase can be utilized by microbe as carbon sources and absorbed by plants. The degradation products of phenolic acids by microbe include some organic and/or inorganic compounds such as new phenolic acids. In addition, phenolic acids in soils can stimulate population and activity of microbe. Phenolic acids can inhibit plants growth by affecting ion leakage, phytohormone activity, membrane permeability, hydraulic conductivity, net nutrient uptake, and enzyme activity. Behaviors of phenolic acids in soils are influenced by other organic compounds (phenolic acids, methionine, glucose, etc.) and/or inorganic ions. The role of phenolic acids as allelopathic agents should not be neglected only based on their low specific concentrations in natural soils, because numbers and interactions of phenolic acids will increase their allelopathic activities.

  18. HEAVY METAL ANALYSIS IN RED OAK (QUERCUS RUBRA POPULATIONS FROM A MINING REGION IN NORTHERN ONTARIO (CANADA: EFFECT OF SOIL LIMING AND ANALYSIS OF GENETIC VARIATION

    Directory of Open Access Journals (Sweden)

    Anh Tran

    2014-01-01

    Full Text Available Understanding the dynamic of metals in soil and plants and population diversity in Northern Ontario is essential in determining progress toward ecosystem sustainability in reclaimed sites. The objectives of the present study were to assess the levels of metal content in soils and their accumulation in red oak plants from limed and unlimed sites. Genetic variation in red oak populations from the Northern Ontario region was also analyzed. The levels of soil acidity was lower in limed areas compared to un limed sites, an indication of the prolonged beneficial effect of liming 20 to 30 years ago on soil toxicity. The levels of total metals were very high for most elements, but the proportion of metals that were bio available and readily available to plants was very small. The enrichment factors were16.78, 4.98 and 2.94 for total arsenic, copper and nickel, respectively. The Translocation Factor (TF values for available metals from soil to branches were high. There was more metal accumulation in leaves compared to branches. The degrees of genetic variability in red oak populations from limed and unlimed areas were compared using ISSR markers. The levels of polymorphic loci were moderate to high ranging from 44 to 65%. There were no significant differences in polymorphisms between areas that were limed and unlimed. Overall the red oak populations in stressed areas in Northern Ontario are sustainable.

  19. Improvement of red pepper yield and soil environment by summer catch aquatic crops in greenhouses

    Science.gov (United States)

    Du, X. F.; Wang, L. Z.; Peng, J.; Wang, G. L.; Guo, X. S.; Wen, T. G.; Gu, D. L.; Wang, W. Z.; Wu, C. W.

    2016-08-01

    To investigate effects of the rotation of summer catch crops on remediation retrogressed soils in continuous cropping, a field experiment was conducted. Rice, water spinach, or cress were selected as summer catch crops; bare fallow during summer fallow was used as the control group. Results showed that aquatic crops grown in summer fallow period could effectively reduce soil bulk density and pH, facilitate soil nutrient release, and improve soil physical and chemical properties compared with those grown in fallow period. Paddy-upland rotation could improve soil microbial members and increase bacterial and actinomycete populations; by contrast, paddy-upland rotation could reduce fungal populations and enhance bacterium-to-fungus ratio. Paddy-upland rotation could also actively promote activities of soil enzymes, such as urease, phosphatase, invertase, and catalase. The proposed paddy-upland rotation significantly affected the growth of red pepper; the yield and quality of the grown red pepper were enhanced. Summer catch crops, such as rice, water spinach, and cress significantly increased pepper yield in the following growing season by 15.4%, 10.2% and 14.0%, respectively, compared with those grown in fallow treatment. Therefore, the proposed paddy-upland crop rotation could be a useful method to alleviate continuous cropping problems involved in cultivating red pepper in greenhouses.

  20. Effects of a manganese oxide-modified biochar composite on adsorption of arsenic in red soil.

    Science.gov (United States)

    Yu, Zhihong; Zhou, Li; Huang, Yifan; Song, Zhengguo; Qiu, Weiwen

    2015-11-01

    The arsenic adsorption capacity of a manganese oxide-modified biochar composite (MBC), prepared by pyrolysis of a mixture of potassium permanganate and biochar, was investigated in red soil. Adsorption experiments using batch procedures were used to estimate the arsenic adsorption capacities of the absorbent materials. Adsorption and desorption isotherms, Fourier-transform infrared spectroscopy (FTIR), and X-ray photoelectron spectroscopy (XPS) were used to characterise the prepared adsorbent materials, and a plausible mechanism for arsenic removal by MBC was proposed. Arsenic in red soil-MBC mixtures exhibited lower mobility than that in soils amended with pristine biochar. The improved removal performance of soil-MBC mixtures was attributed to a lower H/C ratio, higher O/C ratio, higher surface hydrophilicity, and higher surface sorption capacity, even though the impregnation of manganese oxide decreased the specific surface area of the biochar. Arsenic retention increased as the biochar content increased, mainly owing to an increase in soil pH. Several oxygenated functional groups, especially O-H, CO, Mn-O, and Si-O, participated in the adsorption process, and manganese oxides played a significant role in the oxidation of arsenic. This study highlights the potential of MBC as an absorbent to immobilise arsenic for use in contaminated land remediation in the red soils region.

  1. Bioaccumulation of Lanthanum and Its Effect on Growth of Maize Seedlings in a Red Loamy Soil

    Institute of Scientific and Technical Information of China (English)

    HU Xin; WANG Xiao-Rong; WANG Chao

    2006-01-01

    Through a pot culture lanthanum nitrate was applied to maize seedlings grown in a red loamy soil to investigate the physiological and toxic effects of added La on the growth of crop seedlings and La bioaccumulation to help understand the environmental chemistry behaviors of rare earth element as fertilizers in soils. Compared to the control, La concentrations in shoots and especially in roots of maize seedlings increased with an increase of La in the soil. Also, with added concentrations of La > 0.75 g La kg-1 soil and > 0.05 g La kg-1 soil, the dry weight of shoots and roots of maize seedlings was significantly reduced (P ≤ 0.05), respectively, compared with the control. Additionally, La ≥ 0.5 g kg-1in the soil significantly inhibited (P ≤ 0.05) primary root elongation. Roots were more sensitive to La stress than shoots and thus could be used as a biomarker to La stress. Overall, in the red loamy soil studied, La had no significant beneficial effects on the growth of maize at the added La levels above 0.1 g kg-1 soil.

  2. Response of aluminum solubility to elevated nitrification in soil of a red spruce stand in eastern Maine

    Science.gov (United States)

    Lawrence, G.B.; David, M.B.

    1997-01-01

    Elevated concentrations of soluble Al can impair tree growth and be toxic to aquatic biota, but effects of acidic deposition on Al solubility in forest soils are only partially understood because of complex interactions with H+ and organic matter. We therefore evaluated Al solubility in two red spruce stands in eastern Maine, one of which received dry (NH4)2SO4 at a rate of 1800 equiv ha-1 yr-1 during 19891995. Samples of soil (Spodosol Oa and Bh horizons) and soil solution were collected on five dates from 1992 to 1995. The treatment elevated nitrification, causing an increase in acid input that led to inorganic Al concentrations of greater than 60 ??mol L-1 in both the Oa and Bh horizons. Solubility of Al was also lower in the Bh horizon of the treated stand than in the reference stand, a response related to higher DOC concentrations in the treated stand. Concentrations of CuCl2 and pyrophosphate-extractable Al were higher in the Oa horizon of the treated watershed than the reference stand, a result of accelerated weathering of mineral particles caused by lower solution pH in the treated stand (3.47) than in the reference stand (3.69). Dissolved Al concentrations in these soils are the result of complex mechanisms through which mineral matter, organic matter, and pH interact to control Al solubility; mechanisms that are not incorporated in current Al solubility models.

  3. Water and heat transport in hilly red soil of southern China: Ⅱ. Modeling and simulation

    Institute of Scientific and Technical Information of China (English)

    LU Jun; HUANG Zhi-zhen; HAN Xiao-fei

    2005-01-01

    Simulation models of heat and water transport have not been rigorously tested for the red soils of southern China.Based on the theory of nonisothermal water-heat coupled transfer, a simulation model, programmed in Visual Basic 6.0, was developed to predict the coupled transfer of water and heat in hilly red soil. A series of soil column experiments for soil water and heat transfer, including soil columns with closed and evaporating top ends, were used to test the simulation model. Results showed that in the closed columns, the temporal and spatial distribution of moisture and heat could be very well predicted by the model,while in the evaporating columns, the simulated soil water contents were somewhat different from the observed ones. In the heat flow equation by Taylor and Lary (1964), the effect of soil water evaporation on the heat flow is not involved, which may be the main reason for the differences between simulated and observed results. The predicted temperatures were not in agreement with the observed one with thermal conductivities calculated by de Vries and Wierenga equations, so that it is suggested that Kh, soil heat conductivity, be multiplied by 8.0 for the first 6.5 h and by 1.2 later on. Sensitivity analysis of soil water and heat coefficients showed that the saturated hydraulic conductivity, Ks, and the water diffusivity, D(θ), had great effects on soil water transport; the variation of soil porosity led to the difference of soil thermal properties, and accordingly changed temperature redistribution,which would affect water redistribution.

  4. Fatty Acid and Cholesterol Composition, and Tissues Description of Fresh and Fried Red Snapper Fillet

    Directory of Open Access Journals (Sweden)

    Agoes Mardiono Jacoeb

    2015-06-01

    Full Text Available Red Snapper is a widely consumed fish. The aim of this research was to determine the fatty acid and the cholesterol composition and to observe the tissues description of fresh and fried red snapper fillet. The fatty acid composition was tested using Gas Chromatography (GC and the cholesterol with Bohac test. Fresh red snapper had moisture and protein content about 79.31% and 16.30%, respectively. Meanwhile fried red snapper contained mosture and protein about 1.98% and 28.40%, respectively.The highest compound of saturated fatty acid on red snapper were myristic acid; while of monounsaturated fatty acid were palmitoleat acid (C16:1. Of the polyunsaturated fatty acids, linoleic acid (C18:2 was found dominantly. Frying increased the cholesterol content from 20 mg/100 g to 60 mg/100 g of tissue. Tissue structure of fresh red snapper was found in not compact form because of low quality meat, however more compact structure was found on fried flesh of red snapper. Keywords: Cholesterol, fatty acids, meat tissue, proximate, red snapper (L. argentimaculatus

  5. Response of runoff and soil loss to reforestation and rainfall type in red soil region of southern China.

    Science.gov (United States)

    Huang, Zhigang; Ouyang, Zhiyun; Li, Fengrui; Zheng, Hua; Wang, Xiaoke

    2010-01-01

    To evaluate the long-term effects of reforestation types on soil erosion on degraded land, vegetation and soil properties under conventional sloping farmland (CSF) and three different reforestation types including a Pinus massoniana secondary forest (PSF), an Eucommia ulmoides artificial economic forest (EEF) and a natural succession type forest (NST), were investigated at runoff plot scale over a six-year period in a red soil region of southern China. One hundred and thirty erosive rainfall events generating runoff in plots were grouped into four rainfall types by means of K-mean clustering method. Erosive rainfall type I is the dominant rainfall type. The amount of runoff and the soil loss under erosive rainfall type III were the most, followed by rain-fall type II, IV and I. Compared with CSF treatment, reforestation treatments decreased the average annual runoff depth and the soil loss by 25.5%-61.8% and 93.9%-96.2% during the study period respectively. Meanwhile, runoff depth at PSF and EEF treatments was significantly lower than that in NST treatment, but no significant difference existed in soil erosion modulus among the three reforestation treatments. This is mainly due to the improved vegetation properties (i.e., vegetation coverage, biomass of above- and below-ground and litter-fall mass) and soil properties (i.e., bulk density, total porosity, infiltration rate and organic carbon content) in the three reforestation treatments compared to CSF treatment. The PSF and EEF are recommended as the preferred reforestation types to control runoff and soil erosion in the red soil region of southern China, with the NST potentially being used as an important supplement.

  6. The stability of textile azo dyes in soil and their impact on microbial phospholipid fatty acid profiles.

    Science.gov (United States)

    Imran, Muhammad; Shaharoona, Baby; Crowley, David E; Khalid, Azeem; Hussain, Sabir; Arshad, Muhammad

    2015-10-01

    The aim of this study was to examine the stability of structurally different azo dyes in soil and their impact on the microbial community composition by analyzing phospholipid fatty acid (PLFA) profiles. Sterile and non-sterile soils were amended with three azo dyes, including: Direct Red 81, Reactive Black 5 and Acid Yellow 19 at 160mgkg(-1) soil. The results showed that the azo dyes were quite stable and that large amounts of these dyes ranging from 17.3% to 87.5% were recoverable from the sterile and non-sterile soils after 14 days. The maximum amount of dye was recovered in the case of Direct Red 81. PLFA analysis showed that the azo dyes had a significant effect on microbial community structure. PLFA concentrations representing Gram-negative bacteria in dye-amended soil were substantially less as compared to the PLFA concentration of Gram-positive bacteria. Acid Yellow 19 dye had almost similar effects on the PLFA concentrations representing bacteria and fungi. In contrast, Reactive Black 5 had a greater negative effect on fungal PLFA than that on bacterial PLFA, while the opposite was observed in the case of Direct Red 81. To our knowledge, this is the first study reporting the stability of textile azo dyes in soil and their effects on soil microbial community composition.

  7. Reduced carbon sequestration potential of biochar in acidic soil.

    Science.gov (United States)

    Sheng, Yaqi; Zhan, Yu; Zhu, Lizhong

    2016-12-01

    Biochar application in soil has been proposed as a promising method for carbon sequestration. While factors affecting its carbon sequestration potential have been widely investigated, the number of studies on the effect of soil pH is limited. To investigate the carbon sequestration potential of biochar across a series of soil pH levels, the total carbon emission, CO2 release from inorganic carbon, and phospholipid fatty acids (PLFAs) of six soils with various pH levels were compared after the addition of straw biochar produced at different pyrolysis temperatures. The results show that the acidic soils released more CO2 (1.5-3.5 times higher than the control) after the application of biochar compared with neutral and alkaline soils. The degradation of both native soil organic carbon (SOC) and biochar were accelerated. More inorganic CO2 release in acidic soil contributed to the increased degradation of biochar. Higher proportion of gram-positive bacteria in acidic soil (25%-36%) was responsible for the enhanced biochar degradation and simultaneously co-metabolism of SOC. In addition, lower substrate limitation for bacteria, indicated by higher C-O stretching after the biochar application in the acidic soil, also caused more CO2 release. In addition to the soil pH, other factors such as clay contents and experimental duration also affected the phsico-chemical and biotic processes of SOC dynamics. Gram-negative/gram-positive bacteria ratio was found to be negatively related to priming effects, and suggested to serve as an indicator for priming effect. In general, the carbon sequestration potential of rice-straw biochar in soil reduced along with the decrease of soil pH especially in a short-term. Given wide spread of acidic soils in China, carbon sequestration potential of biochar may be overestimated without taking into account the impact of soil pH.

  8. Soil Acidification due to Acid Deposition in Southern China

    Energy Technology Data Exchange (ETDEWEB)

    Liao, Bohan

    1998-12-31

    Anthropogenic emission of SO{sub 2} and NO{sub x} to the atmosphere has made acid deposition one of the most serious environmental problems. In China, acid deposition research started in the late 1970s. The present thesis is part of a joint Chinese-Norwegian research project. The main goal of the thesis was to investigate the mechanism of soil acidification, to estimate soil responses to acid deposition, and to compare relative soil sensitivity to acidification in southern China. Laboratory experiments and modelling simulations were included. Specifically, the thesis (1) studies the characteristics of anion adsorption and cation release of the soils from southern China, (2) examines the effects of increased ionic strength in the precipitation and the effects of anion adsorption on cation release from the soils, (3) compares the relative sensitivity of these soils to acidification and the potentially harmful effects of acid deposition, (4) estimates likely soil responses to different deposition scenarios, including changes in soil waters and soil properties, and (5) investigates long-term changes in soils and soil waters in the Guiyang catchment due to acid deposition. 218 refs., 31 figs., 23 tabs.

  9. Spatial variation in organic carbon,nutrients and microbial biomass contents of paddy soils in a hilly red soil region

    Institute of Scientific and Technical Information of China (English)

    TANG Guoyong; XIAO Heai; SU Yirong; HUANG Daoyou; LIU Shoulong; HUANG Min; TONG Chengli; WU Jinshui

    2007-01-01

    The contents of soil organic C (SOC),total N (TN),total P (TP),dissolved N (DN),Olsen-P,and microbial biomass C,N,P (BC,BN,BP) of 254 paddy soils (0-18 cm in depth) in a hilly red soil region of subtropical zone of China were studied.The results showed that the contents of SOC,TN,BC,BN and DN of paddy soils at the bottom of hills were 14.6%,13.6%,24.6%,20.4% and 95.8% higher than those at the foothill,respectively.The Olsen-P content of paddy soils at the foothill was 33.3% higher than that at the bottom of hills.However,the differences in TP,Bp and available P (the sum of Bp and Olsen-P) contents were not significant between the two positions.In addition,the ratios of soil C/P,BC/BP and BC/SOC of paddy soils at the bottom of hills were 12.7%,28.5% and 8.2% higher than those at the foothill,respectively,but the differences in ratios of soil C/N,BC/BN,BN/TN and Bp/TP were not statistically significant between various positions.

  10. Red cabbage yield, heavy metal content, water use and soil chemical characteristics under wastewater irrigation.

    Science.gov (United States)

    Tunc, Talip; Sahin, Ustun

    2016-04-01

    The objective of this 2-year field study was to evaluate the effects of drip irrigation with urban wastewaters reclaimed using primary (filtration) and secondary (filtration and aeration) processes on red cabbage growth and fresh yield, heavy metal content, water use and efficiency and soil chemical properties. Filtered wastewater (WW1), filtered and aerated wastewater (WW2), freshwater and filtered wastewater mix (1:1 by volume) (WW3) and freshwater (FW) were investigated as irrigation water treatments. Crop evapotranspiration decreased significantly, while water use efficiency increased under wastewater treatments compared to FW. WW1 treatment had the lowest value (474.2 mm), while FW treatments had the highest value (556.7 mm). The highest water use efficiency was found in the WW1 treatment as 8.41 kg m(-3), and there was a twofold increase with regard to the FW. Wastewater irrigation increased soil fertility and therefore red cabbage yield. WW2 treatment produced the highest total fresh yield (40.02 Mg ha(-1)). However, wastewater irrigation increased the heavy metal content in crops and soil. Cd content in red cabbage heads was above the safe limit, and WW1 treatment had the highest value (0.168 mg kg(-1)). WW3 treatment among wastewater treatments is less risky in terms of soil and crop heavy metal pollution and faecal coliform contamination. Therefore, WW3 wastewater irrigation for red cabbage could be recommended for higher yield and water efficiency with regard to freshwater irrigation.

  11. Mobilisation of arsenic from bauxite residue (red mud) affected soils: Effect of pH and redox conditions

    OpenAIRE

    Lockwood, Cindy L.; Mortimer, Robert J. G.; Stewart, Douglas I.; Mayes, William M.; Peacock, Caroline L.; Polya, David A.; Lythgoe, Paul R.; Lehoux, Alizée P.; Gruiz, Katalin; Burke, Ian T.

    2014-01-01

    The tailings dam breach at the Ajka alumina plant, western Hungary in 2010 introduced ~1 million m3 of red mud suspension into the surrounding area. Red mud (fine fraction bauxite residue) has a characteristically alkaline pH and contains several potentially toxic elements, including arsenic. Aerobic and anaerobic batch experiments were prepared using soils from near Ajka in order to investigate the effects of red mud addition on soil biogeochemistry and arsenic mobility in soil–water experim...

  12. A conceptual framework: Redefining forest soil's critical acid loads under a changing climate

    Energy Technology Data Exchange (ETDEWEB)

    McNulty, Steven G., E-mail: steve_mcnulty@ncsu.ed [USDA Forest Service, Eastern Forests Environmental Assessment Threats Center, Southern Global Change Program, 920 Main Campus Dr. Suite 300, Raleigh, NC 27606 (United States); Boggs, Johnny L. [USDA Forest Service, Eastern Forests Environmental Assessment Threats Center, Southern Global Change Program, 920 Main Campus Dr. Suite 300, Raleigh, NC 27606 (United States)

    2010-06-15

    Federal agencies of several nations have or are currently developing guidelines for critical forest soil acid loads. These guidelines are used to establish regulations designed to maintain atmospheric acid inputs below levels shown to damage forests and streams. Traditionally, when the critical soil acid load exceeds the amount of acid that the ecosystem can absorb, it is believed to potentially impair forest health. The excess over the critical soil acid load is termed the exceedance, and the larger the exceedance, the greater the risk of ecosystem damage. This definition of critical soil acid load applies to exposure of the soil to a single, long-term pollutant (i.e., acidic deposition). However, ecosystems can be simultaneously under multiple ecosystem stresses and a single critical soil acid load level may not accurately reflect ecosystem health risk when subjected to multiple, episodic environmental stress. For example, the Appalachian Mountains of western North Carolina receive some of the highest rates of acidic deposition in the eastern United States, but these levels are considered to be below the critical acid load (CAL) that would cause forest damage. However, the area experienced a moderate three-year drought from 1999 to 2002, and in 2001 red spruce (Picea rubens Sarg.) trees in the area began to die in large numbers. The initial survey indicated that the affected trees were killed by the southern pine beetle (Dendroctonus frontalis Zimm.). This insect is not normally successful at colonizing these tree species because the trees produce large amounts of oleoresin that exclude the boring beetles. Subsequent investigations revealed that long-term acid deposition may have altered red spruce forest structure and function. There is some evidence that elevated acid deposition (particularly nitrogen) reduced tree water uptake potential, oleoresin production, and caused the trees to become more susceptible to insect colonization during the drought period

  13. Adsorption of Acid Red 114 onto Fe3O4@Caffeic acid recycable magnetic nanocomposite

    OpenAIRE

    YILDIZ, Aylin

    2016-01-01

    In this study, the adsorption capacity of caffeic acid (CFA) functionalized Fe3O4 magnetic recyclable nanocomposite (Fe3O4@CFA MNCs) for removal of industrial dye Acid Red 114 (AR 114) was investigated. The max. adsorption (qm) of the Fe3O4@CFA MNCs for AR114 was 333 mg/g without pH correction of the solution. Compared with other studies these adsorbent possess very adsorption capacity for AR114 dye. The adsorption isotherm data and the process of adsorption kinetics were fitted using the Lan...

  14. Liming of acid soils in Osijek-Baranja county

    Directory of Open Access Journals (Sweden)

    Dolijanović Željko

    2011-01-01

    Full Text Available The negative trend of soil degradation process increases with intensive agricultural production. Therefore, there is a need for soil conditioning like liming, humification, fertilization, etc. to improve soil quality. One of the major problems that occur on agricultural soils of Croatia is acidification. A downward trend of soil pH is mainly present in soils of poor structure with intensive agricultural production. In agricultural practice liming often needs to rely only on the pH value, without determining the hydrolytic acidity, CEC or soil texture. Due to the above mentioned facts, calculation of liming for Osijek-Baranja County was conducted with the help of ALRxp calculator, which takes CEC, soil pH in KCl, hydrolytic acidity, bulk density of soil, soil textural class and depth of the plow layer to 30 cm into account. Low soil pH values have a great influence on soil suitability for crops as well as on the deficit of calcium and magnesium. All of these lead to the degradation of soil structure, and can even lead to disturbances of plant nutrition in some production areas. On such soils, liming would be imperatively required, but with caution because an excessive intake of lime materials, especially without the necessary analysis, causes a decline in organic matter and reduces accessibility for plant uptake of microelements.

  15. Effect of anions on Toxicity of Cadmium Applied to MIcrobial Biomass in Red Soil

    Institute of Scientific and Technical Information of China (English)

    K.S.KHAN; XIEZHENGMIAO; 等

    1997-01-01

    A laboratory incubation experiment was conducted to elucidat the effects of associated anions on toxicity of cadmium applied to microbial biomass in the red soil. Cadmium was applied at six different levels,i.e.,O(background),5,15,30,60 and 100μg g-1 soil in the form of either cadmium acetate or cadmium chloride. Application of cadmium as cadmium acetate markedly reduced the soil microbial biomass carbon compared to cadmium applied as cadmium chlorde at all the tested levels.Similarly,organic carbon to biomass carbon ration in the soil was markedly increased by increasing the level of the cadmium in the soil as cadmium acetate,while the change wa much smaller in the case of cadmium chloride at the same cadmium levels.The results suggested that due consideration should be given to the source of cadmium while deciding the cadmium levles in experiments.

  16. A conceptual framework: redefining forest soil's critical acid loads under a changing climate.

    Science.gov (United States)

    McNulty, Steven G; Boggs, Johnny L

    2010-06-01

    Federal agencies of several nations have or are currently developing guidelines for critical forest soil acid loads. These guidelines are used to establish regulations designed to maintain atmospheric acid inputs below levels shown to damage forests and streams. Traditionally, when the critical soil acid load exceeds the amount of acid that the ecosystem can absorb, it is believed to potentially impair forest health. The excess over the critical soil acid load is termed the exceedance, and the larger the exceedance, the greater the risk of ecosystem damage. This definition of critical soil acid load applies to exposure of the soil to a single, long-term pollutant (i.e., acidic deposition). However, ecosystems can be simultaneously under multiple ecosystem stresses and a single critical soil acid load level may not accurately reflect ecosystem health risk when subjected to multiple, episodic environmental stress. For example, the Appalachian Mountains of western North Carolina receive some of the highest rates of acidic deposition in the eastern United States, but these levels are considered to be below the critical acid load (CAL) that would cause forest damage. However, the area experienced a moderate three-year drought from 1999 to 2002, and in 2001 red spruce (Picea rubens Sarg.) trees in the area began to die in large numbers. The initial survey indicated that the affected trees were killed by the southern pine beetle (Dendroctonus frontalis Zimm.). This insect is not normally successful at colonizing these tree species because the trees produce large amounts of oleoresin that exclude the boring beetles. Subsequent investigations revealed that long-term acid deposition may have altered red spruce forest structure and function. There is some evidence that elevated acid deposition (particularly nitrogen) reduced tree water uptake potential, oleoresin production, and caused the trees to become more susceptible to insect colonization during the drought period

  17. Succession of Soil Acidity Quality and its Influence on Soil Phosphorus Types

    Institute of Scientific and Technical Information of China (English)

    DUANWenbiao; CHENLixin

    2004-01-01

    Succession rules of soil acidity quality of larch plantations in first rotation at different development stages, succession rules of soil acidity quality of young stand of larch plantations in second rotation and the relationship between soil acidity and various forms of organic phosphorus and inorganic phosphorus were studied in mountainous area of eastern part of Northeastern China. The results showed that active acidity (pH value) inrhizosphere soil decreased continually with stand age increasing from young stand, half-mature stand, near mature stand to mature stand, but active acidity (pH value) in non-rhizosphere soil, exchange acidity, exchangeable aluminium, total hydrolytic acidity, and the ratio of exchange acidity and total hydrolytic acidity in rhizosphere soil and in non-rhizosphere soil increased apparently; total organic P, moderately resistant organic P, and highly resistant organic P in soil decreased at all age stages in larch plantations when soil acidity added. For rhizosphere soil of all stands of larch plantations at different development stages,there was positive correlation between Ca-P (except in young stand), Al-P(except in half-mature stand), Fe-P (except in near mature stand and mature stand), O-P (except in young stand), and soil active acidity,respectively; For rhizosphere soil, there was negative correlation between Ca-P (except in half-mature stand), Al-P(except in young stand), O-P, and exchange acidity, exchangeable aluminium, there was also negative correlation between Ca-P, Al-P(except in young stand and half-mature stand), Fe-P, O-P, and total hydrolytic acidity respectively. For rhizosphere soil, the correlation coefficient between Ca-P, O-P and total hydrolytic aciditydecreased, respectively, as stand ages up and that between Fe-P and exchange acidity,exchangeable aluminium increased, respectively, as stand ages grew. For non-rhizosphere soil, there was not significant correlation between soil acidity and various forms of

  18. Predictive mapping of the acidifying potential for acid sulfate soils

    DEFF Research Database (Denmark)

    Boman, A; Beucher, Amélie; Mattbäck, S

    Developing methods for the predictive mapping of the potential environmental impact from acid sulfate soils is important because recent studies (e.g. Mattbäck et al., under revision) have shown that the environmental hazards (e.g. leaching of acidity) related to acid sulfate soils vary depending...... on their texture (clay, silt, sand etc.). Moreover, acidity correlates, not only with the sulfur content, but also with the electrical conductivity (EC) measured after incubation. Electromagnetic induction (EMI) data collected from an EM38 proximal sensor also enabled the detailed mapping of acid sulfate soils...... over a field (Huang et al., 2014).This study aims at assessing the use of EMI data for the predictive mapping of the acidifying potential in an acid sulfate soil area in western Finland. Different supervised classification modelling techniques, such as Artificial Neural Networks (Beucher et al., 2015...

  19. Isolation of Burkholderia cepacia JB12 from lead- and cadmium-contaminated soil and its potential in promoting phytoremediation with tall fescue and red clover.

    Science.gov (United States)

    Jin, Zhong Min; Sha, Wei; Zhang, Yan Fu; Zhao, Jing; Ji, Hongyang

    2013-07-01

    Phytoremediation combined with suitable microorganisms and biodegradable chelating agents can be a means of reclaiming lands contaminated by toxic heavy metals. We investigated the ability of a lead- and cadmium-resistant bacterial strain (JB12) and the biodegradable chelator ethylenediamine-N,N'-disuccinic acid (EDDS) to improve absorption of these metals from soil by tall fescue and red clover. Strain JB12 was isolated from contaminated soil samples, analysed for lead and cadmium resistance, and identified as Burkholderia cepacia. Tall fescue and red clover were grown in pots to which we added JB12, (S,S)-EDDS, combined JB12 and EDDS, or water only. Compared with untreated plants, the biomass of plants treated with JB12 was significantly increased. Concentrations of lead and cadmium in JB12-treated plants increased significantly, with few exceptions. Plants treated with EDDS responded variably, but in those treated with combined EDDS and JB12, heavy metal concentrations increased significantly in tall fescue and in the aboveground parts of red clover. We conclude that JB12 is resistant to lead and cadmium. Its application to the soil improved the net uptake of these heavy metals by experimental plants. The potential for viable phytoremediation of lead- and cadmium-polluted soils with tall fescue and red clover combined with JB12 was further enhanced by the addition of EDDS.

  20. Fatty Acid and Cholesterol Composition, and Tissues Description of Fresh and Fried Red Snapper Fillet

    Directory of Open Access Journals (Sweden)

    Agoes Mardiono Jacoeb

    2015-06-01

    Full Text Available Red Snapper is a widely consumed fish. The aim of this research was to determine the fatty acid and the cholesterol composition and to observe the tissues description of fresh and fried red snapper fillet. The fatty acid composition was tested using Gas Chromatography (GC and the cholesterol with Bohac test. Fresh red snapper had moisture and protein content about 79.31% and 16.30%, respectively. Meanwhile fried red snapper contained mosture and protein about 1.98% and 28.40%, respectively.The highest compound of saturated fatty acid on red snapper were myristic acid; while of monounsaturated fatty acid were palmitoleat acid (C16:1. Of the polyunsaturated fatty acids, linoleic acid (C18:2 was found dominantly. Frying increased the cholesterol content from 20 mg/100 g to 60 mg/100 g of tissue. Tissue structure of fresh red snapper was found in not compact form because of low quality meat, however more compact structure was found on fried flesh of red snapper.

  1. Effect of Nitrogen Fertilizers on Movement and Transformation of Phosphorus in an Acid Soil

    Institute of Scientific and Technical Information of China (English)

    DU Zhen-Yu; ZHOU Jian-Min; WANG Huo-Yan; DU Chang-Wen; CHEN Xiao-Qin

    2005-01-01

    The effects of two different nitrogen fertilizers (urea and NH4Cl) with monocalcium phosphate (MCP) on the movement and transformation of fertilizer P in soil microsites along with soil pH changes at different distances from the fertilizer application site were studied in an incubation experiment. A highly acidic red soil (Ultisol, pH 4.57) from south China with MCP fertilizer alone or in combination with NH4Cl or urea was added to the surface of soil cylinders and packed in wax blocks. After 7 and 28 days, the extraction and analysis of each 2 mm layer from the interface of the soil and fertilizer showed that added NH4Cl or urea did not change the movement distance of fertilizer P. However, P transformation was significantly affected (P < 0.05). After 7 days, at 0-8 mm distance from the fertilizer site the addition of urea significantly decreased the water-extractable P concentration; however, after 28 days the effect of N addition had disappeared. Also,at limited distances close to the fertilizer site NH4Cl application with MCP significantly increased acid-extractable P and available P, while with the addition of urea they significantly decreased. Compared with application of MCP alone,addition of urea significantly increased soil pH in fertilizer microsites, whereas the addition of NH4Cl significantly decreased soil pH.

  2. Soil Quality Assessment of Acid Sulfate Paddy Soils with Different Productivities in Guangdong Province, China

    Institute of Scientific and Technical Information of China (English)

    LIU Zhan-jun; ZHOU Wei; SHEN Jian-bo; LI Shu-tian; LIANG Guo-qing; WANG Xiu-bin; SUN Jing-wen; AI Chao

    2014-01-01

    Land conversion is considered an effective measure to ensure national food security in China, but little information is available on the quality of low productivity soils, in particular those in acid sulfate soil regions. In our study, acid sulfate paddy soils were divided into soils with high, medium and low levels based on local rice productivity, and 60 soil samples were collected for analysis. Twenty soil variables including physical, chemical and biochemical properties were determined. Those variables that were signiifcantly different between the high, medium and low productivity soils were selected for principal component analysis, and microbial biomass carbon (MBC), total nitrogen (TN), available silicon (ASi), pH and available zinc (AZn) were retained in the minimum data set (MDS). After scoring the MDS variables, they were integrated to calculate a soil quality index (SQI), and the high, medium and low productivity paddy soils received mean SQI scores of 0.95, 0.83 and 0.60, respectively. Low productivity paddy soils showed worse soil quality, and a large discrepancy was observed between the low and high productivity paddy soils. Lower MBC, TN, ASi, pH and available K (AK) were considered as the primary limiting factors. Additionally, all the soil samples collected were rich in available P and AZn, but deifcient in AK and ASi. The results suggest that soil AK and ASi deifciencies were the main limiting factors for all the studied acid sulfate paddy soil regions. The application of K and Si on a national basis and other sustainable management approaches are suggested to improve rice productivity, especially for low productivity paddy soils. Our results indicated that there is a large potential for increasing productivity and producing more cereals in acid sulfate paddy soil regions.

  3. Coastal acid sulphate soils in Poland: a review

    Directory of Open Access Journals (Sweden)

    Hulisz Piotr

    2017-03-01

    Full Text Available This paper presents the state of knowledge on coastal acid sulphate soils in Poland. The properties of these soils are closely related to the influence of brackish water from the Baltic Sea, high accumulation of organic matter and human activity. The obtained results demonstrate that the sulphide accumulation in soils refers to a relatively small areas of the Polish coastal zone with the unique and very valuable habitats. They require an adequate regulation of the water relations to avoid the risk of strong soil acidification and environmental pollution by heavy metals. Currently, there are no relevant criteria for classification of acid sulphate soil materials in the Polish Soil Classification (2011. Therefore, based on the presented data, the authors proposed to identify these features at the lower classification level (for different soil types. The criteria for the Thionic and Sulfidic qualifiers used in the WRB classification (IUSS Working Group WRB 2015 could be accepted for this purpose.

  4. Oxidation of phenolic acids by soil iron and manganese oxides

    Energy Technology Data Exchange (ETDEWEB)

    Lehmann, R.G.; Cheng, H.H.; Harsh, J.B.

    Phenolic acids are intermediary metabolites of many aromatic chemicals and may be involved in humus formation, allelopathy, and nutrient availability. Depending on their structures, six phenolic acids were shown to react at different rates with oxidized forms of Fe and Mn in a Palouse soil (fine-silty, mixed, mesic Pachic Ultic Haploxeroll). Increasing methoxy substitution on the aromatic ring of phenolic acids increased the reaction rate. Reaction rate was also increased for longer carboxyl-containing side chains. After 4 h reaction, little of the applied (10 mg kg/sup -1/ soil) p-hydroxybenzoic or p-coumaric acids had reacted, while 0 to 5, 70, 90, and 100% of the vanillic, ferulic, syringic, and sinapic acids, respectively, had reacted. After 72 h under conditions limiting microbial growth, none of the p-hydroxybenzoic, 30% of the p-coumaric, and 50% of the vanillic acids had reacted. The reaction was shown to be predominantly chemical, and not biological, since phenolic acid extractabilities were similar for Palouse soil and for Palouse soil pretreated with LiOBr to remove organic matter. When the Palouse soil was pretreated with a sodium dithionite-citrate solution to remove Fe and Mn oxides, none of the phenolic acids reacted after 1 h. The reaction of sinapic acid with Palouse soil was shown to produce Fe(II) and soluble Mn as reaction products. The reaction of phenolic acids with soil was thus shown to be an oxidation of the phenolic acids, coupled with a reduction of soil Fe and Mn oxides.

  5. Ferrosilt (Red Mud): Geotechnical Properties and Soil Mechanical Considerations

    Science.gov (United States)

    Jenny, F. C.

    The disposal of ferrosilt tailings creates problems because of the rather unusual geotechnical properties. Ferrosilt samples from three different bauxites were tested in connection with the alumina plant project in Wilhelmshaven (West Germany). The results of these laboratory tests explain various ferrosilt slides experienced during the past. Should ferrosilt be utilized for application where better physical qualities of the material are required it is possible to separate the coarser fraction from the finer fractions by using cyclons. The soil mechanical properties of the coarser fraction — called ferrosilt-sand — is of much better quality than the ferrosilt proper. On the other hand the quality of the finder fractions is not much inferior to the ferrosilt.

  6. Water Budget Analysis of Red Soils in Central Jiangxi Province,China

    Institute of Scientific and Technical Information of China (English)

    CHEN Jia-Zhou; HE Yuan-Qiu; CHEN Ming-Liang

    2004-01-01

    The daily soil water budgets in the red soil areas of central Jiangxi Province,southern China,were investigated with a large-scale weighing lysimeter and runoff plots. From 1998 to 2000,peanuts (Arachis hypogaea L.) and rape (Brassica napus L.) were planted in the lysimeter and in 1999,peanuts were planted in the runoff plots. The soil water budget components including rainfall,runoff,percolation and evapotranspiration were measured directly or calculated by Richards' equation and water balance equation. The results showed that most rainfall,including rainstorms,occurred from March to July,and induced the greatest soil water percolation during the year. The evapotranspiration was still large from July to September when rainfall was minimal. Thus,the lack of synchronization in soil water inputs and losses was disadvantageous to crops growing in this region. Among the soil water losses,percolation was the largest,followed by evapotranspiration,and then soil runoff. Runoff was very small on farmland with crops. It was significantly different from the uncultivated uplands where large-scale runoff was usually reported. The soil water storage fluctuated sinusoidally,with a large amplitude in the rainy season and a small amplitude in the dry season.

  7. Effect of Lead—Zinc Interaction on Size of Microbial Biomss in Red Soil

    Institute of Scientific and Technical Information of China (English)

    K.S.KHAN; HUANGCHANGYONG

    1998-01-01

    A laboratory incubation experiment was onducted to evaluate the effects of lead and zinc applied alone or in various combinations on the size of microbial biomass in a red soil.Treatments included the application of lead at six different levels i.e.,0(background),100,200,300,450 and 600μg g-1 soil along with each of the four levels of zinc(0,50,150 or 250μg g-1 soil).Application of lead or zinc alone to soil significantly(P<0.001) affected the soil microbial biomass,The microbial biomass carbon(Cmic) ,bimass nitrogen(Nmic) and biomass phosphours(Pmic) decreased sharply in soils contaminted with led or zinc. Combinewd application of lead and zinc resulted in a greater biocidal effect on soil microbial biomass,which was signifcantly higher(P<0.001) than that when either lead or zinc was applied alone.Consistent increased in the biomass C:N and decline in the biomass C:P rations were aslo observed with the increased metal(Pb and Zn) toxictiy in the soil.

  8. Effect of acetate on lead toxicity to microbial biomass in a red soil

    Institute of Scientific and Technical Information of China (English)

    1999-01-01

    A laboratory incubation experiment was conducted to elucidate the effect of acetate on lead bioavailability and toxicity to microbial biomass in a red soil. Treatment included the application of lead at six different levels i.e., 0(background), 100, 200, 300, 450 and 600μg/g soil with three levels of the acetate(0, 900 and 2700 μg/g soil). Results indicated that the application of acetate along or at the lower lead levels of 100 and 200μg/g soil stimulated the soil microbial biomass. The addition of acetate at the higher lead levels of 300, 450 and 600 μg/g soil caused significantly greater reductions in the biomass carbon(Cmic) and the biomass nitrogen(Nmic), compared with the control or the same lead levels applied individually. A greater increase in the biomass C:N ratio occurred by acetate addition at the same lead levels. The concentration of 0.01mol/L CaCl2-extractable lead was considerably higher in the lead plus acetate treatments than at the same lead levels with no acetate.Based on these results, it was concluded that the application of acetate might have suppressed the lead adsorption in the soil which in turn resulted in its more bioavailability and hence more toxicity to the soil microbial biomass.

  9. Modeling the influence of organic acids on soil weathering

    Science.gov (United States)

    Lawrence, Corey; Harden, Jennifer; Maher, Kate

    2014-08-01

    Biological inputs and organic matter cycling have long been regarded as important factors in the physical and chemical development of soils. In particular, the extent to which low molecular weight organic acids, such as oxalate, influence geochemical reactions has been widely studied. Although the effects of organic acids are diverse, there is strong evidence that organic acids accelerate the dissolution of some minerals. However, the influence of organic acids at the field-scale and over the timescales of soil development has not been evaluated in detail. In this study, a reactive-transport model of soil chemical weathering and pedogenic development was used to quantify the extent to which organic acid cycling controls mineral dissolution rates and long-term patterns of chemical weathering. Specifically, oxalic acid was added to simulations of soil development to investigate a well-studied chronosequence of soils near Santa Cruz, CA. The model formulation includes organic acid input, transport, decomposition, organic-metal aqueous complexation and mineral surface complexation in various combinations. Results suggest that although organic acid reactions accelerate mineral dissolution rates near the soil surface, the net response is an overall decrease in chemical weathering. Model results demonstrate the importance of organic acid input concentrations, fluid flow, decomposition and secondary mineral precipitation rates on the evolution of mineral weathering fronts. In particular, model soil profile evolution is sensitive to kaolinite precipitation and oxalate decomposition rates. The soil profile-scale modeling presented here provides insights into the influence of organic carbon cycling on soil weathering and pedogenesis and supports the need for further field-scale measurements of the flux and speciation of reactive organic compounds.

  10. Modeling the influence of organic acids on soil weathering

    Science.gov (United States)

    Lawrence, Corey R.; Harden, Jennifer W.; Maher, Kate

    2014-01-01

    Biological inputs and organic matter cycling have long been regarded as important factors in the physical and chemical development of soils. In particular, the extent to which low molecular weight organic acids, such as oxalate, influence geochemical reactions has been widely studied. Although the effects of organic acids are diverse, there is strong evidence that organic acids accelerate the dissolution of some minerals. However, the influence of organic acids at the field-scale and over the timescales of soil development has not been evaluated in detail. In this study, a reactive-transport model of soil chemical weathering and pedogenic development was used to quantify the extent to which organic acid cycling controls mineral dissolution rates and long-term patterns of chemical weathering. Specifically, oxalic acid was added to simulations of soil development to investigate a well-studied chronosequence of soils near Santa Cruz, CA. The model formulation includes organic acid input, transport, decomposition, organic-metal aqueous complexation and mineral surface complexation in various combinations. Results suggest that although organic acid reactions accelerate mineral dissolution rates near the soil surface, the net response is an overall decrease in chemical weathering. Model results demonstrate the importance of organic acid input concentrations, fluid flow, decomposition and secondary mineral precipitation rates on the evolution of mineral weathering fronts. In particular, model soil profile evolution is sensitive to kaolinite precipitation and oxalate decomposition rates. The soil profile-scale modeling presented here provides insights into the influence of organic carbon cycling on soil weathering and pedogenesis and supports the need for further field-scale measurements of the flux and speciation of reactive organic compounds.

  11. Characteristics of Phosphorus in Some Eastern Australian Acid Sulfate Soils

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    Forty-five acid sulfate topsoil samples (depth < 0.5 m) from 15 soil cores were collected from 11 locations along the New South Wales coast, Australia. There was an overall trend for the concentration of the HC1extractable P to increase along with increasing amounts of organic C and the HCl-extractable trivalent metals in the topsoils of some less-disturbed acid sulfate soils (pH <4.5). This suggests that inorganic P in these soils probably accumulated via biological cycling and was retained by complexation with trivalent metals or their oxides and hydroxides. While there was no clear correlation between pH and the water-extractable P, the concentration of the water-extractable P tended to increase with increasing amounts of the HCl-extractable P. This disagrees with some established models which suggest that the concentration of solution P in acid soils is independent of total P and decreases with increasing acidity. The high concentration of sulfate present in acid sulfate soils appeared to affect the chemical behavior of P in these soil systems. Comparison was made between a less disturbed wetland acid sulfate soil and a more intensively disturbed sugarcane acid sulfate soil.The results show that reclamation of wetland acid sulfate soils for sugarcane production caused a significant decrease in the HCl-extractable P in the topsoil layer as a result of the reduced bio-cycling of phosphorus following sugarcane farming. Simulation experiment shows that addition of hydrated lime had no effects on the immobilization of retained P in an acid sulfate soil sample within a pH range 3.5~4.6. When the pH was raised to above 4.6, soluble P in the soil extracts had a tendency to increase with increasing pH until the 15th extraction (pH 5.13). This, in combination with the poor pH-soluble P relationship observed from the less-disturbed acid sulfate soils, suggests that soluble P was not clearly pH-dependent in acid sulfate soils with pH < 4.5.

  12. Transformation of organic N newly added to red soil treated with different cultural practices

    Institute of Scientific and Technical Information of China (English)

    ZhangQin-Zheng; YeQing-Fu; 等

    1998-01-01

    By using 15N tracer method,transformation of organic N,which wqas newly added to red soil treated with different cultural practices,was studied under thelaboratory incubation condition.The experimental results showed that the transformation of N from newly added organic matter and soil native pool during incubation was influenced by cultural practice treatment beforeincubation.Fallow was favorable to the mineralization of newly added organic N and soil N compared with the planting wheat treatment.Planting wheat greatly increased the loss of soil N.Application of fertilizers stimulated the mineralization of newly added organic N and application of organic matter reduced the mineralization,but stimulated microbialtransformation of newly adde4d organic N.

  13. Hydraulic conductivity of natural soils permeated with acid mine drainage

    Energy Technology Data Exchange (ETDEWEB)

    Yanful, E.K.; Shikatani, K.S.; Quirt, D.H. [University of Western Ontario, London, ON (Canada). Department of Civil Engineering

    1995-08-01

    The results of a laboratory study on the interactions of three natural soils (some under consideration as candidate cover materials) with acid mine drainage (AMD) are presented. Soil hydraulic conductivity measurements were used to assess soil compatibility with AMD. A silty clay from the decommissioned Waite Amulet tailings site in Quebec, glacial tills from the Heath Steele mine site in New Brunswick, and soil from the Faro mine site in the Yukon Territory were examined. Soil mineralogy and chemistry were examined before and after hydraulic conductivity testing to identify any changes. 20 refs., 25 figs., 8 tabs.

  14. Leaching of copper and nickel in soil-water systems contaminated by bauxite residue (red mud) from Ajka, Hungary: the importance of soil organic matter.

    Science.gov (United States)

    Lockwood, Cindy L; Stewart, Douglas I; Mortimer, Robert J G; Mayes, William M; Jarvis, Adam P; Gruiz, Katalin; Burke, Ian T

    2015-07-01

    Red mud is a highly alkaline (pH >12) waste product from bauxite ore processing. The red mud spill at Ajka, Hungary, in 2010 released 1 million m(3) of caustic red mud into the surrounding area with devastating results. Aerobic and anaerobic batch experiments and solid phase extraction techniques were used to assess the impact of red mud addition on the mobility of Cu and Ni in soils from near the Ajka spill site. Red mud addition increases aqueous dissolved organic carbon (DOC) concentrations due to soil alkalisation, and this led to increased mobility of Cu and Ni complexed to organic matter. With Ajka soils, more Cu was mobilised by contact with red mud than Ni, despite a higher overall Ni concentration in the solid phase. This is most probably because Cu has a higher affinity to form complexes with organic matter than Ni. In aerobic experiments, contact with the atmosphere reduced soil pH via carbonation reactions, and this reduced organic matter dissolution and thereby lowered Cu/Ni mobility. These data show that the mixing of red mud into organic rich soils is an area of concern, as there is a potential to mobilise Cu and Ni as organically bound complexes, via soil alkalisation. This could be especially problematic in locations where anaerobic conditions can prevail, such as wetland areas contaminated by the spill.

  15. Glyphosate and aminomethylphosphonic acid chronic risk assessment for soil biota.

    Science.gov (United States)

    von Mérey, Georg; Manson, Philip S; Mehrsheikh, Akbar; Sutton, Peter; Levine, Steven L

    2016-11-01

    Glyphosate is a broad-spectrum herbicide used widely in agriculture, horticulture, private gardens, and public infrastructure, where it is applied to areas such as roadsides, railway tracks, and parks to control the growth of weeds. The exposure risk from glyphosate and the primary soil metabolite aminomethylphosphonic acid (AMPA) on representative species of earthworms, springtails, and predatory soil mites and the effects on nitrogen-transformation processes by soil microorganisms were assessed under laboratory conditions based on internationally recognized guidelines. For earthworms, the reproductive no-observed-effect concentration (NOEC) was 472.8 mg glyphosate acid equivalent (a.e.)/kg dry soil, which was the highest concentration tested, and 198.1 mg/kg dry soil for AMPA. For predatory mites, the reproductive NOEC was 472.8 mg a.e./kg dry soil for glyphosate and 320 mg/kg dry soil for AMPA, the highest concentrations tested. For springtails, the reproductive NOEC was 472.8 mg a.e./kg dry soil for glyphosate and 315 mg/kg dry soil for AMPA, the highest concentrations tested. Soil nitrogen-transformation processes were unaffected by glyphosate and AMPA at 33.1 mg a.e./kg soil and 160 mg/kg soil, respectively. Comparison of these endpoints with worst-case soil concentrations expected for glyphosate (6.62 mg a.e./kg dry soil) and AMPA (6.18 mg/kg dry soil) for annual applications at the highest annual rate of 4.32 kg a.e./ha indicate very low likelihood of adverse effects on soil biota. Environ Toxicol Chem 2016;35:2742-2752. © 2016 The Authors. Environmental Toxicology and Chemistry Published by Wiley Periodicals, Inc. on behalf of SETAC. © 2016 The Authors. Environmental Toxicology and Chemistry Published by Wiley Periodicals, Inc. on behalf of SETAC.

  16. Mid-Pleistocene vermiculated red soils in southern China as an indication of unusually strengthened East Asian monsoon

    Institute of Scientific and Technical Information of China (English)

    YIN Qiuzhen; GUO Zhengtang

    2006-01-01

    The mid-Pleistocene vermiculated red soils (VRS) from Xuancheng (Anhui Province) and Bose (Guangxi) are studied through soil micromorphological, mineralogical and chemical approaches. The results indicate a polygenetic nature of the VRS, having experienced multiple soil-forming stages. Three main stages have been recognized, attributable to distinct climate regimes. They include the formation of the homogeneous matrix of a red soil (stage 1), development of the white veins within the soil profile (stage 2), and formation of juxtaposed textural features (stage 3). The white veins, resulting from iron-depletion in the groundmass of the homogeneous matrix of a red soil, required abundant rainfall without significant seasonal desiccations. The geographically widely spread VRS south of the Yangtze River in China implies a Mid-Pleistocene extreme East Asian summer monsoon. This climate extreme might be closely linked with the changes in the strength of NADW.

  17. Effect of Lanthanum Accumulation on Cation Exchange Capacity and Solution Composition of Red Soil

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    Pot and adsorption-exchange experiments were carried out by collecting the soil samples from the surface layer (0~15 cm) of red soil at the Ecological Experiment Station of Red Soil, the Chinese Academy of Sciences, in Jiangxi Province of China. When concentration of the exogenous La3+ exceeded 400 mg kg-1, there was less non-exchangeable La3+ than exchangeable La3+ in the soil. Cation exchange capacity of the soil changed slightly with increasing concentration of the exogenous La3+ in both experiments. However, in the adsorption-exchange experiment, when concentration of the exogenous La3+ was higher than 300 mg kg-1, exchangeable basic cations decreased significantly, while exchangeable hydrogen and exchangeable aluminum increased significantly compared with the control treatments. The amounts of base cations (Ca2+, Mg2+, K+ and Na+) exchanged by La3+ in the supernatant solution increased with the concentration of the exogenous La3+, especially when concentration of the exogenous La3+ was higher than 50 mg kg-1.

  18. In Vitro Bile Acid Binding Capacities of Red Leaf Lettuce and Cruciferous Vegetables.

    Science.gov (United States)

    Yang, Isabelle F; Jayaprakasha, Guddadarangavvanahally K; Patil, Bhimanagouda S

    2017-09-13

    In the present study, we tested the bile acid binding capacity of red leaf lettuce, red cabbage, red kale, green kale, and Brussels sprouts through in vitro digestion process by simulating mouth, gastric, and intestinal digestion using six bile acids at physiological pH. Green and red kale exhibited significantly higher (86.5 ± 2.9 and 89.7 ± 0.9%, respectively) bile acid binding capacity compared to the other samples. Further, three different compositions of bile acids were tested to understand the effect on different health conditions. To predict the optimal dose for bile acid binding, we established a logistic relationship between kale dose and bile acid binding capacity. The results indicated that kale showed significantly higher bile acid binding capacity (82.5 ± 2.9% equivalent to 72.06 mg) at 1.5 g sample and remained constant up to 2.5 g. In addition, minimally processed (microwaved 3 min or steamed 8 min) green kale showed significantly enhanced bile acid binding capacity (91.1 ± 0.3 and 90.2 ± 0.7%, respectively) compared to lyophilized kale (85.5 ± 0.24%). Among the six bile acids tested, kale preferentially bound hydrophobic bile acids chenodeoxycholic acid and deoxycholic acid. Therefore, regular consumption of kale, especially minimally processed kale, can help excrete more bile acids and, thus, may lower the risk of hypercholesterolemia.

  19. Arsenic removal from contaminated soil using phosphoric acid and phosphate

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    Laboratory batch experiments were conducted to study Arsenic (As) removal from a naturally contaminated soil using phosphoric acid (H3PO4) and potassium dihydrogen phosphate (KH2PO4). Both H3PO4 and KH2PO4 proved to clearly reduce toxicity of the soil in terms of soil As content, attaining more than 20% As removal at a concentration of 200 mmol/L, although soil As tolerance limit of 30 mg/kg, according to Chinese Environmental quality standard for soil (EQSS), was not satisfied by using these two extractants. At the same time, acidification of soil and dissolution of soil components (Ca, Mg, and Si) resulted from using these two extractants, especially H3PO4. The effectiveness of these two extractants could be attributed to the replacement of As by phosphate ions (PO43-). The function of H3PO4 as an acid to dissolve soil components had little effects on As removal. KH2PO4 almost removed as much As as H3PO4, but it did not result in serious damage to soils, indicating that it was a more promising extractant. The results of a kinetic study showed that As removal reached equilibrium after incubation for 360 min, but dissolution of soil components, especially Mg and Ca, was very rapid. Therefore dissolution of soil components would be inevitable if As was further removed. Elovich's model best described the kinetic data of As removal among the four models used in the kinetic study.

  20. Effect of Enhancing Urea-Humic Acid Mixture with Refined Acid Sulphate Soil

    Directory of Open Access Journals (Sweden)

    Mohd T.M. Yusuff

    2009-01-01

    Full Text Available Problem statement: Acid Sulphate Soil (ASS is a problem soil partly because of its high acidity. This low pH could be exploited to reduce ammonia loss from urea by reducing soil microsite pH. The use Humic Acid (HA to control ammonia loss from urea has been reported but the cost of this material is high. This laboratory study compared the effect of enhancing urea-humic acid mixtures with acid sulphate soil on NH3 loss, pH, exchangeable ammonium and available nitrate contents. Approach: Humic acid, acid sulfate soil and soil used in the incubation study were analyzed for selected soil physical-chemical properties using standard procedures. Urea-HA-ASS mixtures were prepared and ammonia volatilization of the mixtures was evaluated by the closed-dynamic air flow system. The treatments were evaluated in a randomized complete block design with 3 replications. Standard procedures were used to determine ammonia loss, soil pH, exchangeable ammonium and available nitrate at 22 days of incubation. Data obtained were analyzed using analysis of variance and Duncan's test using Statistical Analysis System (SAS version 9.2. Results: Urea amended with 0.75 g ASS significantly reduced ammonia volatilization. Although the use of appropriate amount of acid sulphate soil to control ammonia loss is possible, excessive use of this material is not recommended because of Fe in it. Conclusion: Urea amended with 0.75 g ASS reduced ammonia.

  1. Acid soils of western Serbia and their further acidification

    Science.gov (United States)

    Mrvic, Vesna

    2010-05-01

    Acid soils cause many unfavorable soil characteristics from the plant nutrition point of view. Because of increased soil acidity the violation of buffering soil properties due to leaching of Ca and Mg ions is taking place that also can cause soil physical degradation via peptization of colloids. Together with increasing of soil acidity the content of mobile Al increases that can be toxic for plants. Easily available nutritive elements transforms into hardly avaialble froms. The process of deactivation is especially expressed for phosphorous that under such conditions forms non-soluble compounds with sesqui-oxides. From the other hand the higher solubility of some microelements (Zn and B) can cause their accelerated leaching from root zone and therefore, result in their deficiency for plant nutrition. Dangerous and toxic matters transforms into easly-available forms for plants, especially, Cd and Ni under the lower soil pH. The studied soil occupies 36675 hectare in the municipality of Krupan in Serbia, and are characterized with very unfavorable chemical properties: 26% of the territory belongs to the cathegory of very acidic, and 44 % belongs to the cathegory of acidic. The results showed that the soil of the territory of Krupan is limited for agricultural land use due to their high acidity. Beside the statement of negative soil properties determined by acidity, there is a necessity for determination of soil sensitivity for acidification processes toward soil protection from ecological aspect and its prevention from further acidification. Based on such data and categorization of soils it is possible to undertake proper measures for soil protection and melioration of the most endangered soil cover, where the economic aspect of these measures is very important. One of the methods of soil classification based on sensitivity for acidification classification the determination of soil categories is based on the values of soil CEC and pH in water. By combination of these

  2. Ecological Effects of Land Use Patterns in Red Soil Hilly Region

    Institute of Scientific and Technical Information of China (English)

    WANGXIAO-JU; GONGZI-TONG

    1995-01-01

    Plant biomass and biodiversity,element accumulation and return,water loss and soil erosion,and changes in soil properties were studied for up to 10 years after conversiton of sparse tree-shrubby grass land into the following four land use patterns:masson pine(Pinus massoniana Lamb.) land,beautiful sweetgum(Liquidambar formosana Hance)land,vegetation reservation aldn,and artificial mowing land.Thie annual biomass production of the masson pine land was 5060kg ha-1,being 4.9,2.1,and 6.0 times that of the beautiful sweetgum land,the vegetation reservation land,and the artificial mowing land,respectively,Compared with the background values,the number of plant species for the vegetation reservation and increased by 10 species after 10 years of land utilization,while for the masson pine and the beautiful weetgum decreased by 4,and for the artifiucial mowing land by 9.For masson pine land,total amount of N,P,K,Ca,and Mg needed for producing 1000kg dry matter was only 3.5kg,annual element return through litter was 22 kg ha-1,both of which were much lower than those of the other patterns.Vegetation reservation was an effective measure to conserve soil and water and improve soil fertility in the red soil hilly region.Artificial mowing aroused serous degradation of vegetation and soil.Some measures and suggestions for management and exploitation of the red soil hilly region such masson pine planting,closing hills for afforestation,and stereo-agriculture on one hill are proposed.

  3. Adsorption of 2,4-dinitrophenol and 2,4-dichlorohpenol on Cationic Surfactant Modified Red Soil

    Institute of Scientific and Technical Information of China (English)

    廖敏

    2004-01-01

    Adsorption isotherms of 2,4-dinitrophenol and 2,4-dichlorophenol on hexadecyltrimethylammonium (HDTMA) bromide modified red soil under different ionic strength, divalent cation Cu+2 or different pH conditions were studied. All the adsorption isotherms were well fitted to the Freundlich equation. The adsorption capacities of 2,4-dinitrophenol or 2,4-dichlorophenol were dramatically enhanced by HDTMA treatment of red soil. The increase of ionic strength and the addition of divalent heavy metal cation Cu+2 significantly enhanced the adsorption of 2,4-dinitrophenol or 2,4-dichlorophenol on the HDTMA-modified red soil. Adsorption capacities of HDTMA-modified red soil for 2,4-dinitrophenol and 2,4-dichlorophenol gradually increased with decreasing pH in the aqueous phase.

  4. Ethanol fermentation of red oak acid prehydrolysate by the yeast Pichia stipitis CBS 5776

    Energy Technology Data Exchange (ETDEWEB)

    Tran, A.V.; Chambers, R.P.

    1986-07-01

    Xylose, the dominant sugar in red oak acid prehydrolysate, was fermented to ethanol. In batch cultures of xylose concentrations ranging from 10 to 100 g/l, Pichia stipitis CBS 5776 yielded 0.50-0.40 g ethanol per g xylose consumed. Model compounds of inhibitors generated in the acid prehydrolysis of red oak hemicelluloses, lignin and extractives, hindered the fermentation. Recycled yeasts and treatments with molecular sieve or mixed bed ion resins facilitated the ethanol fermentation of red oak acid prehydrolysate. A maximal ethanol concentration of 9.9 g/l was obtained from an acid prehydrolysate containing 21.7 g/l of xylose. Fermentation inhibitors derived from red oak lignin and extractives were identified. 20 references.

  5. [Effects of long-term fertilization on microbial biomass carbon and nitrogen and on carbon source utilization of microbes in a red soil].

    Science.gov (United States)

    Sun, Feng-xia; Zhang, Wei-hua; Xu, Ming-gang; Zhang, Wen-ju; Li, Zhao-qiang; Zhang, Jing-ye

    2010-11-01

    In order to explore the effects of long-term fertilization on the microbiological characters of red soil, soil samples were collected from a 19-year long-term experimental field in Qiyang of Hunan, with their microbial biomass carbon (MBC) and nitrogen (MBN) and microbial utilization ratio of carbon sources analyzed. The results showed that after 19-year fertilization, the soil MBC and MBN under the application of organic manure and of organic manure plus inorganic fertilizers were 231 and 81 mg x kg(-1) soil, and 148 and 73 mg x kg(-1) soil, respectively, being significantly higher than those under non-fertilization, inorganic fertilization, and inorganic fertilization plus straw incorporation. The ratio of soil MBN to total N under the application of organic manure and of organic manure plus inorganic fertilizers was averagely 6.0%, significantly higher than that under non-fertilization and inorganic fertilization. Biolog-ECO analysis showed that the average well color development (AWCD) value was in the order of applying organic manure plus inorganic fertilizers = applying organic manure > non-fertilization > inorganic fertilization = inorganic fertilization plus straw incorporation. Under the application of organic manure or of organic manure plus inorganic fertilizers, the microbial utilization rate of carbon sources, including carbohydrates, carboxylic acids, amino acids, polymers, phenols, and amines increased; while under inorganic fertilization plus straw incorporation, the utilization rate of polymers was the highest, and that of carbohydrates was the lowest. Our results suggested that long-term application of organic manure could increase the red soil MBC, MBN, and microbial utilization rate of carbon sources, improve soil fertility, and maintain a better crop productivity.

  6. Mercury in Red Aspen Boletes (Leccinum aurantiacum) mushrooms and the soils.

    Science.gov (United States)

    Falandysz, Jerzy; Kowalewska, Izabela; Nnorom, Innocent C; Drewnowska, Małgorzata; Jarzyńska, Grażyna

    2012-01-01

    This communication reports data on the mercury contents of Red Aspen Boletes (Leccinum aurantiacum) mushrooms and the forest soils substrate layer (0-10 cm) underneath the fruit bodies collected from nine spatially distant sites across Poland. Total Hg concentration in soil substrate in seven of the nine sites studied varied from 0.0078 ± 0.0012 to 0.028 ± 0.007 μg/g dry weight (dw) and this could be considered baseline concentrations for uncontaminated forest soils in Poland. The arithmetic mean of mercury in Red Aspen Bolete caps varied, depending on the site from 0.27 ± 0.07 to 1.3 ± 0.6 μg/g dw. The lowest Hg contents in soil (0.011 ± 0.006 μg/g and 0.009 ± 0.002 μg/g) were observed for the sites of Wandalin and Opole Lubelskie (from Lubelska Upland region) with the corresponding highest bioconcentration factor (BCF) values of 130 ± 66 and 110 ± 13 for the mushroom caps and 58 ± 29 and 64 ± 8 for the stipes, respectively. The BCF values in caps showed a downward trend with increasing mercury content of soil. A meal of 300 g of fresh caps of Red Aspen Bolete from Aleksandrów Kujawski region could expose a consumer to 8.1 μg Hg, while this will be 39 μg at the Lubelska Upland amounting to 39 and 186 % of daily Hg reference dose, respectively.

  7. Biochemical degradation of soil humic acids and fungal melanins

    Energy Technology Data Exchange (ETDEWEB)

    Zavgorodnyaya, Y.A.; Demin, V.V.; Kurakov, A.V. [Moscow MV Lomonosov State University, Moscow (Russian Federation). Dept. of Soil Science

    2002-07-01

    Studies were conducted to compare properties and biodegradation of fungal melanins from Aspergillus niger and Cladosporium cladosporiodes with those of humic acids from soils and brown coal. Compared to the humic acids the fungal melanins contained more functional groups, were less hydrophilic and had relatively high molecular weights. Under the conditions of incubation the melanins were found to be more readily degradable than the humic acids studied. The changes in elemental composition, optical parameters and the decrease of molecular weight, observed for both fungal melanins during degradation, made them more similar to soil humic acids.

  8. Adsorption and desorption dynamics of citric acid anions in soil

    KAUST Repository

    Oburger, E.

    2011-07-26

    The functional role of organic acid anions in soil has been intensively investigated, with special focus on (i) microbial respiration and soil carbon dynamics, (ii) nutrient solubilization or (iii) metal detoxification and reduction of plant metal uptake. Little is known about the interaction dynamics of organic acid anions with the soil matrix and the potential impact of adsorption and desorption processes on the functional significance of these effects. The aim of this study was to characterize experimentally the adsorption and desorption dynamics of organic acid anions in five agricultural soils differing in iron and aluminium oxide contents and using citrate as a model carboxylate. Results showed that both adsorption and desorption processes were fast in all soils, reaching a steady state within approximately 1 hour. However, for a given total soil citrate concentration (ct) the steady state was critically dependent on the starting conditions of the experiment, whether most of the citrate was initially present in solution (cl) or held on the solid phase (cs). Specifically, desorption-led processes resulted in significantly smaller steady-state solution concentrations than adsorption-led processes, indicating that hysteresis occurred. As it is not possible to distinguish between different adsorption and desorption pools in soil experimentally, a new dynamic hysteresis model that relies only on measured soil solution concentrations was developed. The model satisfactorily explained experimental data and was able to predict dynamic adsorption and desorption behaviour. To demonstrate its use, we applied the model to two relevant situations involving exudation and microbial degradation. The study highlighted the complex nature of citrate adsorption and desorption dynamics in soil. We conclude that existing models need to incorporate both temporal and hysteresis components to describe realistically the role and fate of organic acids in soil processes. © 2011 The

  9. Acid soil indicators in forest soils of the Cherry River Watershed, West Virginia.

    Science.gov (United States)

    Farr, C; Skousen, J; Edwards, P; Connolly, S; Sencindiver, J

    2009-11-01

    Declining forest health has been observed during the past several decades in several areas of the eastern USA, and some of this decline is attributed to acid deposition. Decreases in soil pH and increases in soil acidity are indicators of potential impacts on tree growth due to acid inputs and Al toxicity. The Cherry River watershed, which lies within the Monongahela National Forest in West Virginia, has some of the highest rates of acid deposition in Appalachia. East and West areas within the watershed, which showed differences in precipitation, stream chemistry, and vegetation composition, were compared to evaluate soil acidity conditions and to assess their degree of risk on tree growth. Thirty-one soil pits in the West area and 36 pits in the East area were dug and described, and soil samples from each horizon were analyzed for chemical parameters. In A horizons, East area soils averaged 3.7 pH with 9.4 cmol(c) kg(-1) of acidity compared to pH 4.0 and 6.2 cmol(c) kg(-1) of acidity in West area soils. Extractable cations (Ca, Mg, and Al) were significantly higher in the A, transition, and upper B horizons of East versus West soils. However, even with differences in cation concentrations, Ca/Al molar ratios were similar for East and West soils. For both sites using the Ca/Al ratio, a 50% risk of impaired tree growth was found for A horizons, while a 75% risk was found for deeper horizons. Low concentrations of base cations and high extractable Al in these soils translate into a high degree of risk for forest regeneration and tree growth after conventional tree harvesting.

  10. [Effects of organic fertilization on arsenic absorption of pakchoi (Brassica chinensis) on arsenic-contaminated red soil].

    Science.gov (United States)

    Li, Lian-Fang; Geng, Zhi-Xi; Zeng, Xi-Bai; Bai, Ling-Yu; Su, Shi-Ming

    2011-01-01

    A pot experiment with arsenic-contaminated red soil was conducted to study the effects of applying pig dung and chicken manure on the growth and arsenic absorption of pakchoi (Brassica chinensis), and on soil available arsenic. Applying pig dung and chicken manure to the arsenic-contaminated red soil increased the biomass of pakchoi to some extent. Comparing with the control, applying pig dung increased the pakchoi biomass significantly (P Organic fertilization promoted the arsenic absorption of pakchoi, with the arsenic uptake after applying pig dung increased by 20.7%-53.9%. The application of pig dung and chicken manure to arsenic-contaminated red soil could somewhat increase the soil available arsenic content and the arsenic uptake by crops, and thus, increase the risks of agricultural product quality and environment.

  11. Nitrogen utilization and transformation in red soil fertilized with urea and ryegrass

    Institute of Scientific and Technical Information of China (English)

    WuGang; HeZhen-Li

    1998-01-01

    The influence of fertilization with urea and ryegrass on nitrogen utilization and transformation in red soil has been studied by using 15N tracer method.When urea and ryegrass were applied alone or in combination,the percentage of N uptaken by ryegrass from labelled urea was 3 and 1.7 times that from labelled ryegrass for the application rate of 200mgN.kg-1 and 100mgN.kg-1,respectively;combining application of ryegrass and ureareduced uptake of urea N and increased uptake of ryegrass N by ryegrass plant,but the percentage of N residued in soil increased for urea and decreased for ryegrass.when urea and ryegrass were applied alone,the percentage of N residued in soil from labelled ryegrass was more than 69% while that from labelled urea was less than 25%,and much more ryegrass N was incorporated into humus than urea N.

  12. Dynamic compaction treatment technology research of red clay soil embankment in southern mountains

    Institute of Scientific and Technical Information of China (English)

    刘建华; 袁剑波; 熊虎; 陈伟

    2008-01-01

    High liquid limit soil generally adopted in expressway embankment construction of southern mountains, which often expresses some characteristics including high moisture content, high porosity ratio, low permeability, high compressibility, certain disintegration, and so on. Spring soil phenomenon and inhomogeneous compaction have effects on the quality of embankment construction, just because the water in soil is difficult to evaporate. Based on the study of reinforcement mechanism for high liquid limit soil, in situ tests for dynamic compaction treatment in Yizhang-Fengtouling expressway embankment were developed. The reliable and economical dynamic compaction treatment methods and the construction technology for large range high liquid limit soil embankment in southern mountains expressway were discussed. In the process, convenient measurement methods were adopted to evaluate the treatment effects. The test results show that the dynamic compaction method has good treatment effects on the local red clay embankment. The embankment compaction degree is improved with compactness coming to 90% around tamping pits and compactness over 95% in tamping pits interior after tamping. The bearing capacity, the physical mechanic-property and the shear strength for soil are obviously improved, which are enhanced with cohesive strength increasing over 10 kPa and compression modulus increasing over 3 MPa.

  13. Soil physical properties and sugarcane root growth in a red oxiso

    Directory of Open Access Journals (Sweden)

    José Euripides Baquero

    2012-02-01

    Full Text Available Sugarcane, which involves the use of agricultural machinery in all crop stages, from soil preparation to harvest, is currently one of the most relevant crops for agribusiness in Brazil. The purpose of this study was to investigate soil physical properties and root growth in a eutroferric red Oxisol (Latossolo Vermelho eutroférrico after different periods under sugarcane. The study was carried out in a cane plantation in Rolândia, Paraná State, where treatments consisted of a number of cuts (1, 3, 8, 10 and 16, harvested as green and burned sugarcane, at which soil bulk density, macro and microporosity, penetration resistance, as well as root length, density and area were determined. Results showed that sugarcane management practices lead to alterations in soil penetration resistance, bulk density and porosity, compared to native forest soil. These alterations in soil physical characteristics impede the full growth of the sugarcane root system beneath 10 cm, in all growing seasons analyzed.

  14. Toxicological responses of red-backed salamanders (Plethodon cinereus) to soil exposures of copper.

    Science.gov (United States)

    Bazar, Matthew A; Quinn, Michael J; Mozzachio, Kristie; Bleiler, John A; Archer, Christine R; Phillips, Carlton T; Johnson, Mark S

    2009-07-01

    Copper (Cu) has widespread military use in munitions and small arms, particularly as a protective jacket for lead projectiles. The distribution of Cu at many US military sites is substantial and sites of contamination include habitats in and around military storage facilities, manufacturing, load and packing plants, open burning/open detonation areas, and firing ranges. Some of these areas include habitat for amphibian species, which generally lack toxicity data for risk assessment purposes. In an effort to ascertain Cu concentrations in soil that are toxic to terrestrial amphibians, 100 red-backed salamanders (Plethodon cinereus) were randomly sorted by weight, assigned to either a control soil or one of four treatments amended with copper acetate in soil, and exposed for 28 days. Analytical mean soil concentrations were 18, 283, 803, 1333, and 2700 mg Cu/kg soil dry weight. Food consisted of uncontaminated flightless Drosophila melanogaster. Survival was reduced in salamanders exposed to 1333 and 2700 mg/kg by 55% and 100%, respectively. Mortality/morbidity occurred within the first 4 days of exposure. These data suggest that a Cu soil concentration of and exceeding 1333.3 +/- 120.2 mg/kg results in reduced survival, whereas hematology analyses suggest that a concentration of and exceeding 803.3 +/- 98.4 mg/kg might result in reduced total white blood cell count. No effects were observed at 283.3 +/- 36.7 mg/kg.

  15. Managing Actual Problems of Peatsoils Associated with Soil Acidity

    Directory of Open Access Journals (Sweden)

    M Edi Armanto

    2016-12-01

    Full Text Available The research objective is to manage actual problems of peatsoils associated with soil acidity. The research has been conducted on peatsoils in river backswamps located in Subdistricts of East Pedamaran and Pedamaran, District of OKI South Sumatra. Soil sampling was taken in cultivated and uncultivated types of landuse; cultivated peatsoils consist of Site A (intercropping between oil palm and pineapple and Site B (oil palm, uncultivated peatsoils are divided into Site C (peat forest, Site D (swamp bush and Site E (swamp grass. The research resulted that actual problems of soil acidity is associated with base saturation, cations exchange capacity, soil organic matters and C/N ratio, balances of soil nutrients, and toxicity potency. The climatic condition and drought can accelerate the occurrence of actual problems of peatsoils associated with acidity peatsoils. Some ameliorant have been applied in order of importance in the fields, namely lime/dolomite, mineral soils, organic fertilizers, combustion ash, and volcanic ash. Application of ameliorant materials is capable to minimize the actual problems of peatsoils associated with soil acidity.

  16. Analytical Methods for Environmental Risk Assessment of Acid Sulfate Soils: A Review

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Assessment of acid sulfate soil risk is an important step for acid sulfate soil management and its reliability depends very much on the suitability and accuracy of various analytical methods for estimating sulfide-derived potential acidity, actual acidity and acid-neutralizing capacity in acid sulfate soils. This paper critically reviews various analytical methods that are currently used for determination of the above parameters, as well as their implications for environmental risk assessment of acid sulfate soils.

  17. Crop Yield and Soil Responses to Long-Term Fertilization on a Red Soil in Southern China

    Institute of Scientific and Technical Information of China (English)

    ZHANG Hui-Min; WANG Bo-Ren; XU Ming-Gang; FAN Ting-Lu

    2009-01-01

    A 15-year fertilization experiment with different applications of inorganic N,P and K fertilizers and farmyard manure (M) was conducted to study the yield and soil responses to long-term fertilization at Qiyang,Hunan Province,China.Average grain yields of wheat and corn (1 672 and 5 111 kg ha-1,respectively) for the treatment NPKM were significantly higher than those (405 and 310 kg ha-1) of the unfertilized control and single inorganic fertilizer treatments.Compared with the corresponding initial values of the experiment,all treatments showed a yield decline of 9 to 111 kg ha-1 year-1 in wheat and 35 to 260 kg ha-1 year-1 in corn,respectively,and a significant pH decline of 0.07 to 0.12 pH year-1,except for the treatments PK and NPKM.After long-term fertilization,the soil organic C,soil available P,exchangeable Ca2+ and Mg2+ and available Cu2+ and Zn2+ contents were higher in the treatment NPKM than in the treatments applied with inorganic fertilizer only.Compared to the treatment NPK,the treatment NPKM,where manure partially replaced inorganic N,had a positive impact on arresting the decline of soil pH.This improved grain yields of wheat and corn,suggesting that application of NPK fertilizer in combination with farmyard manure is important to maintain soil fertility and buffering capacity in red soil.

  18. Chemical Species of Aluminum Lons in Acid Soils

    Institute of Scientific and Technical Information of China (English)

    XURENKOU; JIGUOLIANG

    1998-01-01

    Soil samples collected from several acid soils in Guangdong,Fujian,Zhejiang and Anhui provinces of the southern China were employded to characterize the chemical species of aluminum ions in the soils.The proportion or monoeric inorganic Al to total Al in soil solution was in the range of 19% to 70%,that of monomeric organlic Al (Al-OM) to total Al ranged from 7.7% to 69%,and that of the acid-soluble Al to total Al was generally smaller and was lower than 20% in most of the acid soils studied ,The Al-OM concentration in soil solution was postively correlated with the content of dissolved organic carbon(DOC) and aslo affected by the concentration of Al3+,The complexes of aluminum with fluoride(Al-F) were the predominant forms of inorganic Al,and the proportion of Al-F compexes to total inorganic Al increased with pH.Under strongly acid ondition,Al3+ was also a mjaor form of inorganic Al,and the proportio of Al3+ to total inorganic Al decreased with increasing pH.The,proportions of Al-OH and Al-SO4 complexes to total inorganic Al were small and were not larger than 10% in the most acid soils.The concentration of inorganic Al in solution depended largely on pH and the concentration of total F in soil solution,The concentrations of Al-OM,Al3+,Al-F and Al-OH complexes in topsoil were higher than those in subsoil and decreased with the increase in soil depth,The chemical species of aluminum ions were influenced by pH,The concentrations of Al-OM, Al3+,Al-F complexes and Al-OH complexes decreased with the increase in pH.

  19. Magnetism of a red soil core derived from basalt, northern Hainan Island, China: Volcanic ash versus pedogenesis

    Science.gov (United States)

    Liu, Zhifeng; Ma, Jinlong; Wei, Gangjian; Liu, Qingsong; Jiang, Zhaoxia; Ding, Xing; Peng, Shasha; Zeng, Ti; Ouyang, Tingping

    2017-03-01

    Similar to loess-paleosol sequences in northwestern China, terrestrial sedimentary sequences (red soils) in southern China also provide sensitive Quaternary records of subtropical/tropical paleoclimate and paleoenvironment. Compared with red clay sequences originated from eolian dust, red soils derived from bedrock have received little attention. In this study, a long core of red soil derived from weathered basalt in northern Hainan Island, China, was systematically investigated by using detailed magnetic measurements and rare earth element analyses. The results show that an extremely strong magnetic zone with a maximum magnetic susceptibility (>10 × 10-5 m3 kg-1) is interbedded in the middle of the core profile. This layer contains a significant amount of superparamagnetic magnetite/maghemite particles that primarily originated from volcanic ash, with secondary contributions from pedogenesis. The former has an average grain size of 19 nm with a normal distribution of volume, and the latter has a much wider grain size distribution. The presence of volcanic ash within the red soil indicates that these Quaternary basalts were not formed by continuous volcanic eruptions. Moreover, the magnetic enhancement patterns differ between the upper and lower zones. The upper zone is more magnetically enhanced and experienced higher precipitation and temperature than the lower zone. Discrimination of superparamagnetic particles originating from pedogenic processes and volcanic ash thus provides a sound theoretical base for accurate interpretation of magnetism in red soils in this region.

  20. Effects of pig slurry application on soils and soil humic acids.

    Science.gov (United States)

    Plaza, César; Senesi, Nicola; García-Gil, Juan C; Brunetti, Gennaro; D'Orazio, Valeria; Polo, Alfredo

    2002-08-14

    The effect of three annually consecutive additions of pig slurry at two rates (90 and 150 m3 x ha(-1) x year(-1) on soils and soil humic acids (HAs) was investigated in a field experiment under semiarid conditions. Soils and pig slurries were analyzed by standard methods. The HAs were isolated from soils and pig slurry by a conventional procedure based on alkaline extraction, acidic precipitation to pH 1, purification by repeated alkaline dissolutions and acidic precipitations, water washing, dialysis, and final freeze-drying. The HAs obtained were analyzed for elemental (C, H, N, S, and O) and acidic functional group (carboxylic and phenolic) composition, and by UV-vis, FT-IR, fluorescence, and ESR spectroscopies. With respect to the control soil, the pig slurry amended soils had greater pH and electrical conductivity, slightly larger total N content, and smaller values of C/N ratio. A decrease of total organic C was observed only in soils amended for 2 and 3 years at the higher slurry rate. With respect to control soil HA, pig slurry HA was characterized by larger contents of S- and N-containing groups, smaller acidic functional group and organic free radical contents, a prevalent aliphatic character, extended molecular heterogeneity, and smaller aromatic polycondensation and humification degrees. Amendment with pig slurry HA determines a number of modifications in soil HAs, including increase of C, S, and COOH contents, C/N ratios, and aliphaticity and decrease of extraction yields and N, O, phenolic OH, and organic free radical contents. These effects are generally more evident after the first year of slurry application and tend to disappear with increasing number of treatments. Most probably, over the years the slightly humified slurry HA is mineralized through extended microbial oxidation, whereas only the most recalcitrant components, such as S-containing, phenolic, and aliphatic structures, are partially accumulated by incorporation into soil HA.

  1. Evident bacterial community changes but only slight degradation when polluted with pyrene in a red soil

    Directory of Open Access Journals (Sweden)

    Gaidi eRen

    2015-01-01

    Full Text Available Understanding the potential for PAH degradation by indigenous microbiota and the influence of PAHs on native microbial communities is of great importance for bioremediation and ecological evaluation. Various studies have focused on the bacterial communities in the environment where obvious PAH degradation was observed, little is known about the microbiota in the soil where poor degradation was observed. Soil microcosms were constructed with a red soil by supplementation with a high-molecular-weight PAH (pyrene at three dosages (5, 30, and 70 mg.kg-1. Real-time PCR was used to evaluate the changes in bacterial abundance and pyrene dioxygenase gene (nidA quantity. Illumina sequencing was used to investigate changes in diversity, structure, and composition of bacterial communities. After 42 days of incubation, no evident degradation was observed. The poor degradation ability was associated with the stability or significant decrease of abundance of the nidA gene. Although the abundance of the bacterial 16S rRNA gene was not affected by pyrene, the bacterial richness and diversity were decreased with increasing dosage of pyrene and the community structure was changed. Phylotypes affected by pyrene were comprehensively surveyed: (1 at the high taxonomic level, seven of the abundant phyla/classes (relative abundance >1.0% including Chloroflexi, AD3, WPS-2, GAL5, Alphaproteobacteria, Actinobacteria, and Deltaproteobacteria and one rare phylum Crenarchaeota were significantly decreased by at least one dosage of pyrene, while 3 phyla/classes (Acidobacteria, Betaproteobacteria, and Gammaproteobacteria were significantly increased; and (2 at the lower taxonomic level, the relative abundances of twelve orders were significantly depressed, whereas those of nine orders were significantly increased. This work enhanced our understanding of the biodegradation potential of pyrene in red soil and the effect of pyrene on soil ecosystems at the microbial community

  2. Effects of Cadmium,Lead ,and Zinc on Size of Microbial Biomass in Red Soil

    Institute of Scientific and Technical Information of China (English)

    K.S.KHAN; XIEZHENGMIAO; 等

    1998-01-01

    A laboratory incubation experiment was conducted to study the influence of cadmium(Cd),lead (Pb) and zinc( Zn) on the size of the microbial biomass in red soil.All the three metals were applied,separately,at five different levels that were:Cd at 5,15,30,60, and 100μgg-1;Pb at 100,200,300,450 and 600μg g-1 and Zn at 50,100,150,200 and 250μg g-1 soil,In Comparison to uncaontaminated soil ,the microbial biomass carbon and biomass nitrogen decreased sharply in soils contaminated with Cd,Pb and Zn,A more considerable increase in the microbial biomass C:N ratio was observed in the metal contaminated soils than the non-treated control.Among the tested metals ,Cd displayed the greatest biocidal effect followed by Zn and Pb,showin their relative toxicity in the order of Cd>Zn>Pb.

  3. Heavy metals availability and soil fertility after land application of sewage sludge on dystroferric Red Latosol

    Directory of Open Access Journals (Sweden)

    Rodrigo Santos Moreira

    2013-12-01

    Full Text Available Sewage sludge is the solid residue obtained from urban sewage treatment plants. It is possible to use the sludge in a sustainable way as fertilizer and as soil conditioner due to its high levels of organic matter and nutrients. Besides pathogens and volatile organic compounds, the residue may also contain heavy metals which may accumulate and contaminate crops and the food chain. The aim of this study was evaluates the changes in the fertility of dystrophic Red Latosol and in the availability of heavy metals following application of sewage sludge. It was assessed whether organic matter supplied to the soil as large amounts of sewage sludge would decrease availability of heavy metals in the soil due to of insoluble compounds formation. From this, an experiment was carried out in polyethylene pots using lettuce plant for test. Sewage sludge were applied to the soil in concentrations equivalent to 60, 120 and 180 t ha-1, and a control without sludge, in four replicates, in a completely randomized design. The results show that sewage sludge led to an increase of organic matter contents, of the cation exchange capacity (CEC and of nutrients found in the soil. It also improved plant growth up to a concentration of 120 t ha-1. Availability of heavy metals, however, was reduced in sludge concentrations starting with 120 t ha-1.

  4. Effects of different fertilization on microbial biomass carbon from the red soil in tea garden

    Institute of Scientific and Technical Information of China (English)

    Huaqin XU; Runlin XIAO; Tongqing SONG

    2008-01-01

    The present study examined the influence of the different fertilization on the dynamic of soil microbial biomass carbon (SMBC) of red soil in tea gardens. The results showed that straw mulching, intercropping, chem-ical fertilizer could all improve the amount of the soil microbial biomass C. The annual variation of microbial biomass C showed the tendency of"low-high-low high", and the influences were variable with the time. For the annual average of soil microbial biomass C, Treatment l(T1) (straw mulching+100% organic manure), Treatment 2 (T2) (straw mulching+75% organic man-ure+25% fertilizer), Treatment 3 (T3) (straw mulch-ing+ 50% organic manure + 50% fertilizer), Treatment 4 (T4) (straw mulching + 25% organic manure + 75% fert-ilizer), Treatment 5 (T5) (100% fertilizer),Treatment 6 (T6) (intercropping white clover) were 17.05%, 32.38%, 32.05%, 24.30%, 26.23%, 24.63% higher, respectively, than CK, and the differences among all the treatments were significant (P<0.05). The correlation of the SMBC with the active organic matter, the total nitrogen, the microbial biomass N, the microbial biomass P were remarkable, but no significant correlation was found with available nitrogen, total phosphorus, total potassium and moisture. Compared with other treatments, those mixed with organic matter and chemical fertilizer were more advantageous to enhance the soil fertility.

  5. Influence of insecticides flubendiamide and spinosad on biological activities in tropical black and red clay soils.

    Science.gov (United States)

    Mohiddin, G Jaffer; Srinivasulu, M; Subramanyam, K; Madakka, M; Meghana, D; Rangaswamy, V

    2015-02-01

    A laboratory experiment has been conducted to investigate the ecological toxicity of flubendiamide and spinosad at their recommended field rates and higher rates (1.0, 2.5, 5.0, 7.5, 10.0 kg ha(-1)) on cellulase, invertase and amylase in black and red clay soils after 10, 20, 30 and 40-day exposure under controlled conditions in groundnut (Arachis hypogaea L.) soils of Anantapur District, Andhra Pradesh, India. Flubendiamide and spinosad were stimulatory to the activities of cellulase, invertase and amylase at lower concentrations at 10-day interval. The striking stimulation in soil enzyme activities noticed at 2.5 kg ha(-1), persists for 20 days in both soils. Overall, the higher concentrations (5.0-10.0 kg ha(-1)) of flubendiamide, and spinosad were toxic or innocuous to cellulase, invertase and amylase activities, respectively. The results of the present study thus, clearly, indicate that application of the insecticides in cultivation of groundnut, at field application rates improved the activities of cellulase, invertase and amylase in soils.

  6. Influence of tebuconazole and copper hydroxide on phosphatase and urease activities in red sandy loam and black clay soils

    OpenAIRE

    B. Anuradha; Rekhapadmini, A.; Rangaswamy, V.

    2016-01-01

    The efficacy of two selected fungicides i.e., tebuconazole and coppoer hydroxide, was conducted experiments in laboratory and copper hydroxide on the two specific enzymes phosphatase and urease were determined in two different soil samples (red sandy loam and black clay soils) of groundnut (Arachis hypogaea L.) from cultivated fields of Anantapuramu District, Andhra Pradesh. The activities of the selected soil enzymes were determined by incubating the selected fungicides-treated (1.0, 2.5, 5....

  7. Specific transformations of mineral forms of nitrogen in acid soils

    Directory of Open Access Journals (Sweden)

    MIRJANA KRESOVIC

    2009-01-01

    Full Text Available Investigations were performed on soils of different acidity, ranging in the pH interval 4.65–5.80 (in water. Changes of the mineral nitrogen forms in the examined soils were studied by applying short-term incubation experiments performed under aerobic conditions, with a humidity of 30 % and a temperature of 20 °C, both with and without the addition of 100 and 300 ppm NH4–N. The results of the incubation experiments showed that retarded nitrification was present in all the examined soils. Increased and toxic quantities of nitrites (35.7 ppm were formed during the incubation, which remained in the soil solution for several days, and even weeks, in spite of favorable conditions of moisture, aeration and temperature for the development of the process of chemo-autotrophic nitrification. Decelerated chemoautotrophic nitrification was the source of the occurrence of nitrite in the examined less acid soil (soil 1, while in soils of higher acidity (soils 2 and 3 after addition of 100 and 300 ppm NH4–N, nitrite occurred due to chemical denitrification (chemodenitrification. Nitrites formed in the process of chemodenitrification underwent spontaneous chemical oxidation resulting in nitrate formation (chemical nitrification. The content of mineral nitrogen (NH4 + NO3 + NO2–N decreased during the incubation period, proving gaseous losses from the examined soils. Application of lower doses of nitrogen fertilizers could decrease nitrogen losses by denitrification as well as the occurrence of nitrite in toxic quantities in the investigated pseudogley soil.

  8. Amelioration of acidic soil using various renewable waste resources.

    Science.gov (United States)

    Moon, Deok Hyun; Chang, Yoon-Young; Ok, Yong Sik; Cheong, Kyung Hoon; Koutsospyros, Agamemnon; Park, Jeong-Hun

    2014-01-01

    In this study, improvement of acidic soil with respect to soil pH and exchangeable cations was attempted for sample with an initial pH of approximately 5. Acidic soil was amended with various waste resources in the range of 1 to 5 wt.% including waste oyster shells (WOS), calcined oyster shells (COS), Class C fly ash (FA), and cement kiln dust (CKD) to improve soil pH and exchangeable cations. Upon treatment, the soil pH was monitored for periods up to 3 months. The exchangeable cations were measured after 1 month of curing. After a curing period of 1 month, a maize growth experiment was conducted with selected-treated samples to evaluate the effectiveness of treatment. The treatment results indicate that in order to increase the soil pH to a value of 7, 1 wt.% of WOS, 3 wt.% of FA, and 1 wt.% of CKD are required. In the case of COS, 1 wt.% was more than enough to increase the soil pH value to 7 because of COS's strong alkalinity. Moreover, the soil pH increases after a curing period of 7 days and remains virtually unchanged thereafter up to 1 month of curing. Upon treatment, the summation of cations (Ca, Mg, K, and Na) significantly increased. The growth of maize is superior in the treated samples rather than the untreated one, indicating that the amelioration of acidic soil is beneficial to plant growth, since soil pH was improved and nutrients were replenished.

  9. Metabolism and functions of phosphatides specific fatty acid composition of the red blood cell membranes

    NARCIS (Netherlands)

    Kögl, F.; Gier, J. de; Mulder, I.; Deenen, L.L.M. van

    1960-01-01

    In attempting to establish a specific lipid composition of biological interfaces, the fatty acid composition of the lipid moiety of the red cell membrane of a number of mammals was determined by means of gas-liquid chromatography. A rather constant and characteristic fatty acid pattern proved to occ

  10. Effects of dietary intake of red palm oil on fatty acid composition and ...

    African Journals Online (AJOL)

    Effects of dietary intake of red palm oil on fatty acid composition and lipid profiles in ... Log in or Register to get access to full text downloads. ... and triglycerides as well as accumulation of saturated fatty acids in the liver of the experimental rats.

  11. Red blood cell fatty acid composition and the metabolic syndrome: NHLBI GOLDN study

    Science.gov (United States)

    Different fatty acids may vary in their effect on the metabolic syndrome (MetS). We tested whether fatty acid classes measured in red blood cells (RBC) are associated with the MetS or its components. Included were men (n=497, 49+/-16 y) and women (n=539, 48+/-16 y) from 187 families in the Genetics ...

  12. Metabolism and functions of phosphatides specific fatty acid composition of the red blood cell membranes

    NARCIS (Netherlands)

    Kögl, F.; Gier, J. de; Mulder, I.; Deenen, L.L.M. van

    1960-01-01

    In attempting to establish a specific lipid composition of biological interfaces, the fatty acid composition of the lipid moiety of the red cell membrane of a number of mammals was determined by means of gas-liquid chromatography. A rather constant and characteristic fatty acid pattern proved to occ

  13. Autistic children exhibit decreased levels of essential Fatty acids in red blood cells.

    Science.gov (United States)

    Brigandi, Sarah A; Shao, Hong; Qian, Steven Y; Shen, Yiping; Wu, Bai-Lin; Kang, Jing X

    2015-05-04

    Omega-6 (n-6) and omega-3 (n-3) polyunsaturated fatty acids (PUFA) are essential nutrients for brain development and function. However, whether or not the levels of these fatty acids are altered in individuals with autism remains debatable. In this study, we compared the fatty acid contents between 121 autistic patients and 110 non-autistic, non-developmentally delayed controls, aged 3-17. Analysis of the fatty acid composition of red blood cell (RBC) membrane phospholipids showed that the percentage of total PUFA was lower in autistic patients than in controls; levels of n-6 arachidonic acid (AA) and n-3 docosahexaenoic acid (DHA) were particularly decreased (pautism.

  14. Physical-chemical effects of irrigation with treated wastewater on Dusky Red Latosol soil

    Directory of Open Access Journals (Sweden)

    Vanessa Ribeiro Urbano

    2015-11-01

    Full Text Available The current water crisis underlines the importance of improving water management. The use of effluent from secondary treatment in agriculture can reduce the discharge of effluent into natural bodies and provide nutrients to crops. This study evaluated the physical and chemical properties of a Dusky Red Latosol soil that had been irrigated with treated wastewater. Conducted at the Center of Agricultural Sciences (CCA of Federal University of São Carlos (UFSCar, in Araras/São Paulo/Brazil, 18 undisturbed soil samples were collected and deposited on a constant-head permeameter in order to simulate the irrigation of five growth cycles of lettuce (Lactuca sativa L., organized in five different treatments and one control group. For each treatment 0.58 L, 1.16 L, 1.74 L, 2.32 L, and 2.90 L of treated wastewater and distilled water were applied . The treated wastewater came from a domestic waste treatment plant. After the water filtered through the soil, samples of treated wastewater were collected for analyses of electrical conductivity (EC, sodium adsorption ratio (SAR, turbidity, pH, Na, K, Mg, P and Ca and, in the soil the granulometry, complete fertility, exchangeable sodium percentage (ESP and saturated hydraulic conductivity (Ksat. The Ksat decreased, but did not alter the infiltration of water and nutrients in the soil. The concentration of nutrients in the soil increased, including Na, which raises the need for monitoring soil’s salinity. In conclusion, the application of wastewater did not cause damage to the physical properties of the soil, but resulted in a tendency towards salinization.

  15. Impacts of simulated acid rain on soil enzyme activities in a latosol.

    Science.gov (United States)

    Ling, Da-Jiong; Huang, Qian-Chun; Ouyang, Ying

    2010-11-01

    Acid rain pollution is a serious environmental problem in the world. This study investigated impacts of simulated acid rain (SAR) upon four types of soil enzymes, namely the catalase, acid phosphatase, urease, and amylase, in a latosol. Latosol is an acidic red soil and forms in the tropical rainforest biome. Laboratory experiments were performed by spraying the soil columns with the SAR at pH levels of 2.5, 3.0, 3.5., 4.0, 4.5, 5.0, and 7.0 (control) over a 20-day period. Mixed results were obtained in enzyme activities for different kinds of enzymes under the influences of the SAR. The catalase activities increased rapidly from day 0 to 5, then decreased slightly from day 5 to 15, and finally decreased sharply to the end of the experiments, whereas the acid phosphatase activities decreased rapidly from day 0 to 5, then increased slightly from day 5 to 15, and finally decreased dramatically to the end of the experiments. A decrease in urease activities was observed at all of the SAR pH levels for the entire experimental period, while an increase from day 0 to 5 and then a decrease from day 5 to 20 in amylase activities were observed at all of the SAR pH levels. In general, the catalase, acid phosphatase, and urease activities increased with the SAR pH levels. However, the maximum amylase activity was found at pH 4.0 and decreased as the SAR pH increased from 4.0 to 5.0 or decreased from 4.0 to 2.5. It is apparent that acid rain had adverse environmental impacts on soil enzyme activities in the latosol. Our study further revealed that impacts of the SAR upon soil enzyme activities were in the following order: amylase>catalase>acid phosphatase>urease. These findings provide useful information on better understanding and managing soil biological processes in the nature under the influence of acid rains.

  16. Subcritical Water Extraction of Amino Acids from Atacama Desert Soils

    Science.gov (United States)

    Amashukeli, Xenia; Pelletier, Christine C.; Kirby, James P.; Grunthaner, Frank J.

    2007-01-01

    Amino acids are considered organic molecular indicators in the search for extant and extinct life in the Solar System. Extraction of these molecules from a particulate solid matrix, such as Martian regolith, will be critical to their in situ detection and analysis. The goals of this study were to optimize a laboratory amino acid extraction protocol by quantitatively measuring the yields of extracted amino acids as a function of liquid water temperature and sample extraction time and to compare the results to the standard HCl vapor- phase hydrolysis yields for the same soil samples. Soil samples from the Yungay region of the Atacama Desert ( Martian regolith analog) were collected during a field study in the summer of 2005. The amino acids ( alanine, aspartic acid, glutamic acid, glycine, serine, and valine) chosen for analysis were present in the samples at concentrations of 1 - 70 parts- per- billion. Subcritical water extraction efficiency was examined over the temperature range of 30 - 325 degrees C, at pressures of 17.2 or 20.0 MPa, and for water- sample contact equilibration times of 0 - 30 min. None of the amino acids were extracted in detectable amounts at 30 degrees C ( at 17.2 MPa), suggesting that amino acids are too strongly bound by the soil matrix to be extracted at such a low temperature. Between 150 degrees C and 250 degrees C ( at 17.2 MPa), the extraction efficiencies of glycine, alanine, and valine were observed to increase with increasing water temperature, consistent with higher solubility at higher temperatures, perhaps due to the decreasing dielectric constant of water. Amino acids were not detected in extracts collected at 325 degrees C ( at 20.0 MPa), probably due to amino acid decomposition at this temperature. The optimal subcritical water extraction conditions for these amino acids from Atacama Desert soils were achieved at 200 degrees C, 17.2 MPa, and a water- sample contact equilibration time of 10 min.

  17. Subcritical Water Extraction of Amino Acids from Atacama Desert Soils

    Science.gov (United States)

    Amashukeli, Xenia; Pelletier, Christine C.; Kirby, James P.; Grunthaner, Frank J.

    2007-01-01

    Amino acids are considered organic molecular indicators in the search for extant and extinct life in the Solar System. Extraction of these molecules from a particulate solid matrix, such as Martian regolith, will be critical to their in situ detection and analysis. The goals of this study were to optimize a laboratory amino acid extraction protocol by quantitatively measuring the yields of extracted amino acids as a function of liquid water temperature and sample extraction time and to compare the results to the standard HCl vapor- phase hydrolysis yields for the same soil samples. Soil samples from the Yungay region of the Atacama Desert ( Martian regolith analog) were collected during a field study in the summer of 2005. The amino acids ( alanine, aspartic acid, glutamic acid, glycine, serine, and valine) chosen for analysis were present in the samples at concentrations of 1 - 70 parts- per- billion. Subcritical water extraction efficiency was examined over the temperature range of 30 - 325 degrees C, at pressures of 17.2 or 20.0 MPa, and for water- sample contact equilibration times of 0 - 30 min. None of the amino acids were extracted in detectable amounts at 30 degrees C ( at 17.2 MPa), suggesting that amino acids are too strongly bound by the soil matrix to be extracted at such a low temperature. Between 150 degrees C and 250 degrees C ( at 17.2 MPa), the extraction efficiencies of glycine, alanine, and valine were observed to increase with increasing water temperature, consistent with higher solubility at higher temperatures, perhaps due to the decreasing dielectric constant of water. Amino acids were not detected in extracts collected at 325 degrees C ( at 20.0 MPa), probably due to amino acid decomposition at this temperature. The optimal subcritical water extraction conditions for these amino acids from Atacama Desert soils were achieved at 200 degrees C, 17.2 MPa, and a water- sample contact equilibration time of 10 min.

  18. Effect of humic acid on transformation of soil heavy metals

    Science.gov (United States)

    Wu, Shengzhe; Li, Rui; Peng, Shuyang; Liu, Qiuyong; Zhu, Xi

    2017-06-01

    The pattern of transformation among different fractions of heavy metals in soil draws great attention. This article investigated the effect of humic acid on soil heavy metal under different pH and temperature. The results showed that with the increasing of the concentration of humic acid, the concentration of available Cu, Pb decreased greatly, though the decrease of available Cd was light. Also, pH of soil had certain impact on the concentration of available Cu, Pb, Cd while the influence of environmental temperature was minor. The removal efficiency of contaminated soil was 57.283% (Cu), 2.645% (Cd) and 15.485% (Pb) while it could reach more than 98% in contaminated solution.

  19. [Effects of combined application of biochar and inorganic fertilizers on the available phosphorus content of upland red soil].

    Science.gov (United States)

    Jing, Yan; Chen, Xiao-min; Liu, Zu-xiang; Huang, Qian-ru; LiI, Qiu-xia; Chen, Chen; Lu, Shao-shan

    2013-04-01

    Aiming at the low content of available phosphorus in upland red soil of Southern China, this paper studied the effects of combined application of biochar and inorganic fertilizers on the available phosphorus and organic carbon contents and the pH of this soil. With the combined application of biochar and inorganic fertilizers, the soil physical and chemical properties improved to different degrees. As compared with the control, the soil pH and the soil organic carbon and available phosphorus contents at different growth stages of oil rape after the combined application of biochar and inorganic fertilizers all had an improvement, with the increments at bolting stage, flowering stage, and ripening stage being 16%, 24% and 26%, 23%, 34% and 38%, and 100%, 191% and 317% , respectively. The soil pH and the soil organic carbon and available phosphorus contents were increased with the increasing amount of applied biochar. Under-the application of biochar, the soil available phosphorus had a significant correlation with the soil pH and soil organic carbon content. This study could provide scientific basis to improve the phosphorus deficiency and the physical and chemical properties of upland red soil.

  20. Combined Use of Alkaline Slag and Rapeseed Cake to Ameliorate Soil Acidity in an Acid Tea Garden Soil

    Institute of Scientific and Technical Information of China (English)

    WANG Lei; YANG Xing-Lun; K.RACHEL; WANG Yu; TONG De-Li; YE Mao; JIANG Xin

    2013-01-01

    Rapeseed cake (RC),the residue of rapeseed oil extraction,is effective for improving tea (Camellia sinensis) quality,especially taste and aroma,but it has limited ability to ameliorate strongly acidic soil.In order to improve the liming potential of RC,alkaline slag (AS),the by-product of recovery of sodium carbonate,was incorporated.Combined effects of different levels of RC and AS on ameliorating acidic soil from a tea garden were investigated.Laboratory incubations showed that combined use of AS and RC was an effective method to reduce soil exchangeable acidity and A1 saturation and increase base saturation,but not necessarily for soil pH adjustment.The release of alkalinity from the combined amendments and the mineralization of organic nitrogen increased soil pH initially,but then soil pH decreased due to nitrifications.Various degrees of nitrification were correlated with the interaction of different Ca levels,pH and N contents.When RC was applied at low levels,high Ca levels from AS repressed soil nitrification,resulting in smaller pH fluctuations.In contrast,high AS stimulated soil nitrification,when RC was applied at high levels,and resulted in a large pH decrease.Based on the optimum pH for tea production and quality,high ratios of AS to RC were indicated for soil acidity amelioration,and 8.0 g kg-1 and less than 2.5 g kg-1 were indicated for AS and RC,respectively.Further,field studies are needed to investigate the variables of combined amendments.

  1. Distribution of Exchangeable Calcium,Magnesium and Potassium as Affected by Fertilizer Application to Red Soil

    Institute of Scientific and Technical Information of China (English)

    SHENREN-FANG; ZHAOQI-GUO

    1995-01-01

    A leaching experiment was Carried out with repacked soil columns in laboratory to study the leaching process of a red soil derived from sandstone as affected by various fertilization practices.The treatments were CK(as a control),CaCO3,CaSO4,MgCO3,Ca(H2PO4)2,Urea,KCl,Multiple(a mixture of the above mentioned fertilizers) and KNO3,The fertilizers were added to the bare surface of the soil columns,and then the columns were leached with 120 mL deionized water daily through perstaltic pumps over a period of 92 days,At the end of leaching process,soils were sampled from different depths of the soil profiles ,i.o.,of 92 days,At the end of leaching process,soils were sampled from different depths of the soil profiles,I.e.0-5cm,5-10cm,10-20cm,20-40cm,and 40-60cm,The results showed when applying Ca,Mg,and K to the bare surface of the soil columns,exchangeable Ca2+,Mg2+,and K+ in the upper layer of the soil profile increased correspondingly,with an extent depending mainly on the application rates of Ca,Mg,and K and showing a downward trend,CaCO3,CaSO4,MgCO3,and Ca(H2PO4)2 treatments had scarcely and effect on movement of exchangeable K+,while CaCO3,and CaSO4 treatments singnificantly promoted the downward movement of exchangealble Mg2+ although these two treatments had no obvious effect on leaching losses of Mg,The fact that under Urea treatment,exchangeable Ca2+ and Mg2+,were higher as compared to CK treatment showed urea could prevent leaching of exchangeable Ca2+and Mg2+,the obvious downward movement of exchangeable Ca2+and Mg2+ was noticed in KCl treatment ,In Multiple treatment,the downward movement of exchangeable Ca2+ and Mg2+ was evident,while that of K+ was less evident,Application of KNO3 strongly promoted the downward movement of exchangeable Ca2+and Mg2+ in the soil profile.

  2. Combined Pollution and Pollution Index of Heavy Metals in Red Soil

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    A field experiment was conducted to study the effects of Pb, Cd, Cu, Zn and As coexisting in red soil on growth of rice (Oryza sativa L.), mung bean (Vigna rabiata (Linn.) Wilczek), alfalfa (Medicago sativa L.), slash pine (Pinus elliottii Engelm.) and aspen (Populus L.). Results showed that rice, mung bean and alfalfa were significantly influenced by combined pollution of the heavy metals. The contents of Pb, Cd and As in rice grains greatly exceeded the National Standards for Food Hygiene of China. Heavy metals at a high concentration seriously retarded growth of mung bean and alfalfa, but not so obviously with slash pine and aspen. The composite index is suggested for evaluating the relativity of combined pollution with heavy metals in soil.

  3. A chromosomally based luminescent bioassay for mercury detection in red soil of China

    Energy Technology Data Exchange (ETDEWEB)

    Wei, He [Chinese Academy of Sciences, Nanking (China). State Key Lab. of Soil and Sustainable Agriculture; Nanjing Normal Univ., Nanking (China). College of Life Science; Cheng, Han; Ting, Mao; Zhong, Wen-Hui [Nanjing Normal Univ., Nanking (China). College of Chemistry and Environmental Science; Lin, Xian-Gui [Chinese Academy of Sciences, Nanking (China). State Key Lab. of Soil and Sustainable Agriculture

    2010-07-15

    A luminescent reporter gene system was constructed by fusing the mercury-inducible promoter, P{sub merT}, and its regulatory gene, merR, with a promoterless reporter gene EGFP. A stable and nonantibiotic whole-cell reporter (BMB-ME) was created by introducing the system cassette into the chromosome of Pseudomonas putida strain and then applied it for mercury detection in the red soil of China. Spiked with 10 and 100 {mu}g g{sup -1} Hg{sup 2+} and after 15 and 30 days incubation, soil samples were extracted and evaluated water soluble, bioavailable, organic matter bound, and residual fractions of mercury by both BMB-ME and chemical way. The expression of EGFP was confirmed in soil extraction, and fluorescence intensity was quantified by luminescence spectrometer. The sensor strain BMB-ME appeared to have a detection range similar to that of reversed-phase high-performance liquid chromatography method. The optimal temperature for EGFP expression was 35 C and the lowest detectable concentration of Hg{sup 2+} 200 nM. Cu{sup 2+}, Fe{sup 2+}, Mn{sup 2+}, Sn{sup 2+}, Zn{sup 2+}, Co{sup 2+}, Ag{sup +}, Ba{sup 2+}, Mg{sup 2+}, and Pb{sup 2+} ions at nanomolar level did not interfere with the measurement. These results showed that the BMB-ME constitute an adaptable system for easy sensing of small amounts of mercury in the red soil of China. (orig.)

  4. Effects of Humic Acid and Solution pH on Dispersion of Na—and Ca—Soil Clays

    Institute of Scientific and Technical Information of China (English)

    LANYEQING; HUQIONGYING; 等

    1996-01-01

    Dispersed soil clays have a negative impact on soil structure and contribute to soil erosion and contaminant movement.In this study,two typical soils from the south of China were chosen for investigating roles of pH and humic acid(HA) on dispersion of soil clays.Critical flocculation concentration (CFC) of the soil clay suspension was determined by using light transmission at a wavelength of 600 nm.The results indicated that effects of pH and HA on dispersion of the soil clays were closely related to the type of the major minerals makin up the soil and to the valence of the exchangeable cations as well.At four rates of pH(4,6,8and 10),the CFC for the Na-yellow-brown soil treated with H2O2 was increased from 0.32 to 0.56,6.0 to 14.0,10.0 to 24.6 and 26.0 to 52.0mmol L-1 NaCl,respectively when Na-HA was added at the rate of from 0 to 40mgL-1,With the same Na-HA addition and three pH(6,8and 10)treatments,the CFC for the Na-red soil was incresed from 0.5 to 20.0,1.0 to 40.0 and 6.0 to 141.0mmol L-1 NaCl,respectively.Obviously,pH and HA has greater effects on clay dispersion of the red soil(dominated by 1:1 minerals and oxides) than on that of the yellow-brown soil(dominated by 2:1minerals).However,at three rates of pH(6,8and 10) and with the addition of Ca-HA from 0 to 40mg L-1,the CFC of the Ca-yellow-brown soil and Ca-red soil treated with H2O2 was increased from 0.55 to 0.81,0.75 to 1.28,0.55 to 1.45and 0.038 to 0.266.0.25 to 0.62,0.7to 1.6mmol CaCl2 L-1,respectively.So,Na-soil claye are more sensitive to pH and HA than Ca-soil clays.

  5. Effects of poultry manure on soil biochemical properties in phthalic acid esters contaminated soil.

    Science.gov (United States)

    Gao, Jun; Qin, Xiaojian; Ren, Xuqin; Zhou, Haifeng

    2015-12-01

    This study aimed to evaluate the effects of poultry manure (PM) on soil biological properties in DBP- and DEHP-contaminated soils. An indoor incubation experiment was conducted. Soil microbial biomass C (Cmic), soil enzymatic activities, and microbial phospholipid fatty acid (PLFA) concentrations were measured during incubation period. The results indicated that except alkaline phosphatase activity, DBP and DEHP had negative effects on Cmic, dehydrogenase, urease, protease activities, and contents of total PLFA. However, 5 % PM treatment alleviated the negative effects of PAEs on the above biochemical parameters. In DBP-contaminated soil, 5 % PM amendment even resulted in dehydroenase activity and Cmic content increasing by 17.8 and 11.8 % on the day 15 of incubation, respectively. During the incubation periods, the total PLFA contents decreased maximumly by 17.2 and 11.6 % in DBP- and DEHP-contaminated soils without PM amendments, respectively. Compared with those in uncontaminated soil, the total PLFA contents increased slightly and the value of bacPLFA/fugalPLFA increased significantly in PAE-contaminated soils with 5 % PM amendment. Nevertheless, in both contaminated soils, the effects of 5 % PM amendment on the biochemical parameters were not observed with 10 % PM amendment. In 10 % PM-amended soils, DBP and DEHP had little effect on Cmic, soil enzymatic activities, and microbial community composition. At the end of incubation, the effects of PAEs on these parameters disappeared, irrespective of PM amendment. The application of PM ameliorated the negative effect of PAEs on soil biological environment. However, further work is needed to study the effect of PM on soil microbial gene expression in order to explain the change mechanisms of soil biological properties.

  6. Mineral magnetism to probe into the nature of palaeomagnetic signals of subtropical red soil sequences in southern China

    Science.gov (United States)

    Liu, Caicai; Deng, Chenglong; Liu, Qingsong; Zheng, Longting; Wang, Wei; Xu, Xinming; Huang, Sheng; Yuan, Baoyin

    2010-06-01

    Magnetic polarity stratigraphy has proved to be useful in dating of both marine and terrestrial sedimentary sequences over the world. However, the reliability of magnetostratigraphic results of red soil sequences in subtropical southern China has been found to be variable in different regions. To probe into the capabilities of recording magnetic polarity stratigraphy in the red soils, three red soil sequences have been selected for detailed mineral magnetic, petrographic and/or palaeomagnetic analyses. These include the Xuancheng and Qiliting sequences, which are located in the lower reaches of the Yangtze River and the Damei sequence in the Bose Basin near the Tropic of Cancer. Palaeomagnetic results indicate that the Xuancheng sequence has recorded the Brunhes Chron and the late Matuyama Chron, including a short interval probably representing the Santa Rosa geomagnetic event. The Xuancheng and Qiliting sequences have faithfully recorded the palaeogeomagnetic field behaviour while the Damei sequence has failed. Detailed mineral magnetic and petrographic measurements suggest that four magnetic minerals (magnetite, maghemite, haematite and goethite) are contained in the three studied sequences, but the characteristic remanent magnetization (ChRM) carriers are different. For the Xuancheng and Qiliting samples, the ChRM carriers are magnetite and haematite, which are all of detrital origin. However, the ChRMs of Damei samples are carried by pedogenic haematite with an unblocking temperature (TB) of about 630-640 °C, which has overprinted the primary remanence of the Damei red soil deposits. This pedogenic haematite is mainly produced by chemical weathering, which is commonly intensified by the climate of high temperature and rainfall. It further suggests that climatic conditions have a great effect on the nature of palaeomagnetic signals of the red soil sequences. In addition, the red pigment components in the red soils may be used to indicate the degree of

  7. [Mineralogy and genesis of mixed-layer clay minerals in the Jiujiang net-like red soil].

    Science.gov (United States)

    Yin, Ke; Hong, Han-Lie; Li, Rong-Biao; Han, Wen; Wu, Yu; Gao, Wen-Peng; Jia, Jin-Sheng

    2012-10-01

    Mineralogy and genesis were investigated using X-ray diffraction (XRD), Fourier infrared absorption spectroscopy (FTIR) and high resolution transmission electron microscopy (HRTEM) to understand the mineralogy and its genesis significance of mixed-layer clay minerals in Jiujiang red soil section. XRD and FTIR results show that the net-like red soil sediments are composed of illite, kaolinite, minor smectite and mixed-layer illite-smectite and minor mixed-layer kaolinite-smectite. HRTEM observation indicates that some smectite layers have transformed into kaolinite layers in net-like red soil. Mixed-layer illite-smectite is a transition phase of illite transforming into smectite, and mixed-layer kaolinite-smectite is a transitional product relative to kaolinite and smectite. The occurrence of two mixed-layer clay species suggests that the weathering sequence of clay minerals in net-like red soil traversed from illite to mixed-layer illite-smectite to smectite to mixed-layer kaolinite-smectite to kaolinite, which indicates that net-like red soil formed under a warm and humid climate with strengthening of weathering.

  8. Effect of strong acids on red mud structural and fluoride adsorption properties.

    Science.gov (United States)

    Liang, Wentao; Couperthwaite, Sara J; Kaur, Gurkiran; Yan, Cheng; Johnstone, Dean W; Millar, Graeme J

    2014-06-01

    The removal of fluoride using red mud has been improved by acidifying red mud with hydrochloric, nitric and sulphuric acid. The acidification of red mud causes sodalite and cancrinite phases to dissociate, confirmed by the release of sodium and aluminium into solution as well as the disappearance of sodalite bands and peaks in infrared and X-ray diffraction data. The dissolution of these mineral phases increases the amount of available iron and aluminium oxide/hydroxide sites that are accessible for the adsorption of fluoride. However, concentrated acids have a negative effect on adsorption due to the dissolution of these iron and aluminium oxide/hydroxide sites. The removal of fluoride is dependent on the charge of iron and aluminium oxide/hydroxides on the surface of red mud. Acidifying red mud with hydrochloric, nitric and sulphuric acid resulted in surface sites of the form ≡SOH2(+) and ≡SOH. Optimum removal is obtained when the majority of surface sites are in the form ≡SOH2(+) as the substitution of a fluoride ion does not cause a significant increase in pH. This investigation shows the importance of having a low and consistent pH for the removal of fluoride from aqueous solutions using red mud.

  9. Characterizing the release of different composition of dissolved organic matter in soil under acid rain leaching using three-dimensional excitation-emission matrix spectroscopy.

    Science.gov (United States)

    Liu, Li; Song, Cunyi; Yan, Zengguang; Li, Fasheng

    2009-09-01

    Although excitation-emission matrix spectroscopy (EEMS) has been widely used to characterize dissolved organic matter (DOM), there has no report that EEMS has been used to study the effects of acid rain on DOM and its composition in soil. In this work, we employed three-dimensional EEMS to characterize the compositions of DOM leached by simulated acid rain from red soil. The red soil was subjected to leaching of simulated acid rain of different acidity, and the leached DOM presented five main peaks in its EEMS: peak-A, related to humic acid-like (HA-like) material, at Ex/Em of 310-330/395-420nm; peak-B, related to UV fulvic acid-like (FA-like) material, at Ex/Em of 230-280/400-435nm; peak-C and peak-D, both related to microbial byproduct-like material, at Ex/Em of 250-280/335-355nm and 260-280/290-320nm, respectively; and peak-E, related to simple aromatic proteins, at Ex/Em of 210-240/290-340nm. EEMS analysis results indicated that most DOM could be lost from red soil in the early phase of acid rain leaching. In addition to the effects of the pH of acid rain, the loss of DOM also depended on the properties of its compositions and the solubility of their complexes with aluminum. HA-like and microbial byproduct-like materials could be more easily released from red soil by acid rain at both higher pH (4.5 and 5.6) and lower pH (2.5 and 3) than that at middle pH (3.5). On the contrary, FA-like material lost in a similar manner under the action of different acid rains with pH ranging from 2.5 to 5.6.

  10. Study on the Adsorption Kinetics of Acid Red 3B on Expanded Graphite

    Directory of Open Access Journals (Sweden)

    Xiu-yan Pang

    2008-01-01

    Full Text Available Expanded graphite (EG is a kind of important adsorbent for organic compound such as oil and dyes. We have investigated the adsorption kinetics characteristics of this adsorbent for dye. EG was prepared with 50 mesh crude graphite through chemical oxidation intercalation of potassium permanganate and vitriol, and dye of acid red 3B was used as model sorbate. We have studied the adsorption kinetic models and rate-limiting step of the process. Adsorption rate and activation energy of the adsorption process were calculated. Kinetic studies show that the kinetic data are well described by the pseudo second-order kinetic model. The equilibrium adsorbance increases with the increase of the initial acid red 3B concentration. Initial adsorption rate increases with the increase of the initial dye concentration and temperature. Adsorption process of acid red 3B on EG has small activation energy. Internal diffusion appears to be the rate-limiting step for the adsorption process.

  11. Acetylsalicylic acid and morphology of red blood cells

    Directory of Open Access Journals (Sweden)

    Jacques Natan Grinapel Frydman

    2010-06-01

    Full Text Available This work evaluated the effect of in vitro and in vivo treatment with ASA on the morphology of the red blood cells. Blood samples or Wistar rats were treated with ASA for one hour. Blood samples or animals treated with saline were used as control group. Blood smears were prepared, fixed, stained and the qualitative and quantitative morphology of red blood cells were evaluated under optical microscopy. Data showed that the in vitro treatment for one hour with ASA at higher dose used significantly (pEste trabalho avaliou o efeito do tratamento in vitro e in vivo com AAS na morfologia dos eritrócitos. Amostras de sangue ou ratos Wistar foram tratadas com AAS por uma hora. Amostras sangüíneas ou animais tratados com salina foram utilizados como grupos controle. Distensões de sangue foram preparadas, fixadas, coradas e a análise morfológica qualitativa e quantitativa dos eritrócitos foi realizada em microscópio óptico. Os dados mostraram que o tratamento in vitro por uma hora com AAS na maior dose utilizada modificou significativamente (p<0.05 a relação perímetro/área dos eritrócitos. Não foram obtidas alterações morfológicas com o tratamento in vivo. O uso do AAS em doses altas poderia interferir na forma dos eritrócitos.

  12. Determination of total mercury in aluminium industrial zones and soil contaminated with red mud.

    Science.gov (United States)

    Rasulov, Oqil; Zacharová, Andrea; Schwarz, Marián

    2017-08-01

    This study investigated total mercury contents in areas impacted by aluminium plants in Tajikistan and Slovakia and in one area flooded with red mud in Hungary. We present the first determination of total mercury contents in the near-top soil (0-10 and 10-20 cm) in Tajikistan and the first comparative investigation of Tajikistan-Slovakia-Hungary. The Tajik Aluminium Company (TALCO) is one of the leading producers of primary aluminium in Central Asia. In the past 30 years, the plant has been producing large volumes of industrial waste, resulting in negative impacts on soil, groundwater and air quality of the surrounding region. Mercury concentrations were significant in Slovakia and Hungary, 6 years after the flooding. In studied areas in Slovakia and Hungary, concentrations of total mercury exceeded the threshold limit value (TLV = 0.5 mg Hg kg(-1)). However, in Tajikistan, values were below the TLV (0.006-0.074 mg kg(-1)) and did not significantly vary between depths. Total Hg in Slovakia ranged from 0.057 to 0.668 mg kg(-1) and in Hungary from 0.029 to 1.275 mg kg(-1). However, in the plots near to the red mud reservoir and the flooded area, Hg concentrations were higher in the upper layers than in the lower ones.

  13. Acid-activated biochar increased sulfamethazine retention in soils.

    Science.gov (United States)

    Vithanage, Meththika; Rajapaksha, Anushka Upamali; Zhang, Ming; Thiele-Bruhn, Sören; Lee, Sang Soo; Ok, Yong Sik

    2015-02-01

    Sulfamethazine (SMZ) is an ionizable and highly mobile antibiotic which is frequently found in soil and water environments. We investigated the sorption of SMZ onto soils amended with biochars (BCs) at varying pH and contact time. Invasive plants were pyrolyzed at 700 °C and were further activated with 30 % sulfuric (SBBC) and oxalic (OBBC) acids. The sorption rate of SMZ onto SBBC and OBBC was pronouncedly pH dependent and was decreased significantly when the values of soil pH increased from 3 to 5. Modeled effective sorption coefficients (K D,eff) values indicated excellent sorption on SBBC-treated loamy sand and sandy loam soils for 229 and 183 L/kg, respectively. On the other hand, the low sorption values were determined for OBBC- and BBC700-treated loamy sand and sandy loam soils. Kinetic modeling demonstrated that the pseudo second order model was the best followed by intra-particle diffusion and the Elovich model, indicating that multiple processes govern SMZ sorption. These findings were also supported by sorption edge experiments based on BC characteristics. Chemisorption onto protonated and ligand containing functional groups of the BC surface, and diffusion in macro-, meso-, and micro-pores of the acid-activated BCs are the proposed mechanisms of SMZ retention in soils. Calculated and experimental q e (amount adsorbed per kg of the adsorbent at equilibrium) values were well fitted to the pseudo second order model, and the predicted maximum equilibrium concentration of SBBC for loamy sand soils was 182 mg/kg. Overall, SBBC represents a suitable soil amendment because of its high sorption rate of SMZ in soils.

  14. Differential effects of sugar maple, red oak, and hemlock tannins on carbon and nitrogen cycling in temperate forest soils.

    Science.gov (United States)

    Talbot, Jennifer M; Finzi, Adrien C

    2008-03-01

    Tannins are abundant secondary chemicals in leaf litter that are hypothesized to slow the rate of soil-N cycling by binding protein into recalcitrant polyphenol-protein complexes (PPCs). We studied the effects of tannins purified from sugar maple, red oak, and eastern hemlock leaf litter on microbial activity and N cycling in soils from northern hardwood-conifer forests of the northeastern US. To create ecologically relevant conditions, we applied tannins to soil at a concentration (up to 2 mg g(-1) soil) typical of mineral soil horizons. Sugar maple tannins increased microbial respiration significantly more than red oak or hemlock tannins. The addition of sugar maple tannins also decreased gross N mineralization by 130% and, depending upon the rate of application, decreased net rates of N mineralization by 50-290%. At low concentrations, the decrease in mineralization appeared to be driven by greater microbial-N immobilization, while at higher concentrations the decrease in mineralization was consistent with the formation of recalcitrant PPCs. Low concentrations of red oak and hemlock tannins stimulated microbial respiration only slightly, and did not significantly affect fluxes of inorganic N in the soil. When applied to soils containing elevated levels of protein, red oak and hemlock tannins decreased N mineralization without affecting rates of microbial respiration, suggesting that PPC formation decreased substrate availability for microbial immobilization. Our results indicate that tannins from all three species form recalcitrant PPCs, but that the degree of PPC formation and its attendant effect on soil-N cycling depends on tannin concentration and the pool size of available protein in the soil.

  15. Characteristics of Soluble and Exchangeable Acidity in an Extremely Acidified Acid Sulfate Soil

    Institute of Scientific and Technical Information of China (English)

    C.Lin; M.D.MELVILLE; 等

    1999-01-01

    An extremely acidified acid sulfate soil(ASS) was investigated to characterise its soluble and exchangeable acidity,The results showed that soluble acidity of a sample dtermined by titration with a KOH soulution was much significantly greater than that indicated by pH measured using a pH meter,paricularly for the extremely acidic soil samples,This is because the total soluble acidity of the extremely acidic soil samples was mainly composed of various soluble Al and Fe species,possibly in forms of Al sulfate complexes(e.g.,AlSO4+) and feerous Fe(Fe2+)_,It is therefore suggested not to use pH alone as an indicator of soluble acidity in ASS,particularly for extremely acidic ASS,It is also likely that AlSO4+ actively participated in cation exchange reactions.It appears that the possible involvement of this Al sulfate cation in the cation adsorption has significant effect on increasing the amount of acidity being adsorbed by the soils.

  16. Sustainable Agriculture Evaluation for Red Soil Hill Region of Southeast China

    Institute of Scientific and Technical Information of China (English)

    ZHAO Qi-Guo; XU Meng-Jie

    2004-01-01

    Agricultural sustainability for economic development is important and a complex issue throughout the world; however,it is difficult to synthetically evaluate its use in the policy making process. The objective of this study was to evaluate sustainable agriculture in the red soil hill region of Southeast China through a newly proposed method combining four separate sub-systems: regional population (P), resource (R), environmental (E), and socio-economic (S). This new index system was proposed to appraise synthetically the agricultural sustainability of the red soil hill region from 1988 to 1996 with a two-step method assessing: a) the agricultural sustainability in each province independently and b) the relative sustainability of each province to the whole region. The first step only provided a development trend for each province based on its original situation, while the second step provided additional information on the comparative status of each province in agricultural development to the region as a whole. Higher index scores were found for the economy and resource categories denoting improvement. However, lower scores in the environment category indicated the improvement was achieved at the cost of deteriorating ecological surroundings due to an increasing population that demanded more from the agro-ecosystem and put heavier pressures on it. Results also showed that water and soil losses in this region were the major obstacles encountered in sustainable agriculture development. The assessment results were verified when compared with results from another method. This suggested that the new assessment system was reliable and credible in evaluating agricultural sustainability on a regional scale.

  17. Synthesis and optical properties of pyrrolidinyl peptide nucleic acid carrying a clicked Nile red label

    Directory of Open Access Journals (Sweden)

    Nattawut Yotapan

    2014-09-01

    Full Text Available DNA or its analogues with an environment-sensitive fluorescent label are potentially useful as a probe for studying the structure and dynamics of nucleic acids. In this work, pyrrolidinyl peptide nucleic acid (acpcPNA was labeled at its backbone with Nile red, a solvatochromic benzophenoxazine dye, by means of click chemistry. The optical properties of the Nile red-labeled acpcPNA were investigated by UV–vis and fluorescence spectroscopy in the absence and in the presence of DNA. In contrast to the usual quenching observed in Nile red-labeled DNA, the hybridization with DNA resulted in blue shifting and an enhanced fluorescence regardless of the neighboring bases. More pronounced blue shifts and fluorescence enhancements were observed when the DNA target carried a base insertion in close proximity to the Nile red label. The results indicate that the Nile red label is located in a more hydrophobic environment in acpcPNA–DNA duplexes than in the single-stranded acpcPNA. The different fluorescence properties of the acpcPNA hybrids of complementary DNA and DNA carrying a base insertion are suggestive of different interactions between the Nile red label and the duplexes.

  18. Synthesis and optical properties of pyrrolidinyl peptide nucleic acid carrying a clicked Nile red label.

    Science.gov (United States)

    Yotapan, Nattawut; Charoenpakdee, Chayan; Wathanathavorn, Pawinee; Ditmangklo, Boonsong; Wagenknecht, Hans-Achim; Vilaivan, Tirayut

    2014-01-01

    DNA or its analogues with an environment-sensitive fluorescent label are potentially useful as a probe for studying the structure and dynamics of nucleic acids. In this work, pyrrolidinyl peptide nucleic acid (acpcPNA) was labeled at its backbone with Nile red, a solvatochromic benzophenoxazine dye, by means of click chemistry. The optical properties of the Nile red-labeled acpcPNA were investigated by UV-vis and fluorescence spectroscopy in the absence and in the presence of DNA. In contrast to the usual quenching observed in Nile red-labeled DNA, the hybridization with DNA resulted in blue shifting and an enhanced fluorescence regardless of the neighboring bases. More pronounced blue shifts and fluorescence enhancements were observed when the DNA target carried a base insertion in close proximity to the Nile red label. The results indicate that the Nile red label is located in a more hydrophobic environment in acpcPNA-DNA duplexes than in the single-stranded acpcPNA. The different fluorescence properties of the acpcPNA hybrids of complementary DNA and DNA carrying a base insertion are suggestive of different interactions between the Nile red label and the duplexes.

  19. Soil Studies: Applying Acid-Base Chemistry to Environmental Analysis.

    Science.gov (United States)

    West, Donna M.; Sterling, Donna R.

    2001-01-01

    Laboratory activities for chemistry students focus attention on the use of acid-base chemistry to examine environmental conditions. After using standard laboratory procedures to analyze soil and rainwater samples, students use web-based resources to interpret their findings. Uses CBL probes and graphing calculators to gather and analyze data and…

  20. Soil Studies: Applying Acid-Base Chemistry to Environmental Analysis.

    Science.gov (United States)

    West, Donna M.; Sterling, Donna R.

    2001-01-01

    Laboratory activities for chemistry students focus attention on the use of acid-base chemistry to examine environmental conditions. After using standard laboratory procedures to analyze soil and rainwater samples, students use web-based resources to interpret their findings. Uses CBL probes and graphing calculators to gather and analyze data and…

  1. Release of Soil Nonexchangeable K by Organic Acids

    Institute of Scientific and Technical Information of China (English)

    ZHUYONG-GUAN; LUOJIA-XIAN

    1993-01-01

    The amounts of soil nonexchangeable K extracted with 0.01mL/L oxalic acid and citric acid solutions and that with boiling 1mL/L HNO3 for ten minutes were remarkably significantly correlated with each other,and the amount extracted with the oxalic acid solution was higher than that with the citric acid solution.The soil nonexchangeable K release was comprised of two first-order kinetic processes.The faster one was ascribed to the interlayer K in outer sphere,while the slower one to that in inner sphere.The rate constants of the soil nonexchageable K were significantly correlated with the amounts of nonexchangeable K ex tracted with boiling 1mL/L HNO3 for ten minutes.Study on the fitness of different kinetic equations indicated that the first-order,parabolic diffusion and zero-order equations could all describe the release of soil nonexchangeable K well,but Elovich equation was not suitable to describe it.

  2. Effects of long-term fertilizer on soil fertility and soil enzyme activities in upland red soils%长期施肥对旱地红壤肥力和酶活性的影响

    Institute of Scientific and Technical Information of China (English)

    邵兴华; 徐金仁; 张建忠; 李海峰; 周同林; 张辉

    2011-01-01

    In order to understand the relation between soil enzyme activity and soil chemical propertities in upland red soil under different fertilizer treatments, we conducted a study to determine the effects of pig manure, inorganic fertiliser and combination of pig manure and inorganic NPK on soil chemical and biological properties in a more than 30 a long-term fertilization experiment. The treatments as the following: no fertilization(CK), N, NP, NPK, double NPK, pig manure, NPK+pig manure. The results showed, the total N content had no significant difference between different treatments. The only applied N could significantly improve available N in soil. Soil pH, organic matter, total P and available P in manure fertilization treatments ( NPK+pig manure and pig manure) all increased significantly compared with no fertilization (CK) and mineral fertilization treatmets (N, NP, NPK and double NPK). Except for the highest urease activity was double NPK treatment, the soil invertase, dehydrognease, catalase and acid phosphatase activities were all significantly higher than those in other fertilization treatments. Acid phosphatase, catalase, dehydrognease and urease activities were significant and dramatically significant positively correlated with total N, organic matter and available N. So, manure application or co-application of manure and mineral fertilizers not only increased the soil fertility, but also enhanced significantly soil enzymes activities, thus could improve red soil sustainable productivity.%为了明确不同施肥种类对旱地红壤肥力与酶活性的影响,以30年(1981年至今)长期定位试验地为基础,研究不同施肥处理(CK,N,NP,NPK,2倍NPK,猪粪,NPK+猪粪)旱地红壤玉米田耕层(0~20 cm)土壤酶活性与养分的变化趋势及其相关性.结果表明:1)全N含量各处理间差异不显著,单施N肥显著增加土壤速效N,施有机肥处理(NPK+猪粪,猪粪)土壤的pH值、有机质、全P、速效P均显著增加;2)

  3. Microbiological transformations of phosphorus and sulphur compounds in acid soils

    Directory of Open Access Journals (Sweden)

    Stamenov Dragana

    2012-01-01

    Full Text Available The dynamics of phosphorus and sulphur in soil is closely related to the dynamics of the biological cycle in which microorganisms play a central role. There is not much microbiological activity in acid soils because aerobes are scarce, rhizosphere is restricted to the shallow surface layer, and the biomass of microorganisms decreases with higher acidity. The aim of the research was to investigate the number of microorganisms, which decompose organic and inorganic phosphorus compounds and organic sulphur compounds in calcocambisol, luvisol, and pseudogley. The following parameters were determined in the soil samples: pH in H2O and in 1MKCl; the content of CaCO3 (%; humus content (%, nitrogen content (%; the content of physiologically active phosphorus and potassium (mg P2O5/100g of soil; mg K2O/100g of soil. The number of microorganisms was determined by the method of agar plates on appropriate nutrient media: the number of microorganisms solubilizing phosphates on a medium by Muramcov; the number of microorganisms that decompose organic phosphorus compounds on a medium with lecithin; and the number of microorganisms that transform organic sulphur compounds on a medium by Baar. All three types of soil are acid non-carbonate soils with a low level of available phosphorus and a more favorable amount of potassium, nitrogen, and humus. The largest number of bacteria, which transform organic phosphorus compounds, was found in calcocambisol. The largest number of phosphate solubilizing bacteria was recorded in pseudogley, whereas the largest number of phosphate solubilizing fungi was recorded in calcocambisol. The largest number of bacteria, which transform organic sulphur compounds, was recorded in pseudogley.

  4. Impact of tree species on soil carbon stocks and soil acidity in southern Sweden

    Energy Technology Data Exchange (ETDEWEB)

    Oostra, Swantje [Swedish Univ. of Agricultural Sciences, Alnarp (Sweden). Dept. of Landscape Planning; Majdi, Hooshang [Swedish Univ. of Agricultural Sciences, Uppsala (Sweden). Dept. of Ecology and Environmental Sciences; Olsson, Mats [Swedish Univ. of Agricultural Sciences, Uppsala (Sweden). Dept. of Forest Soils

    2006-10-15

    The impact of tree species on soil carbon stocks and acidity in southern Sweden was studied in a non-replicated plantation with monocultures of 67-year-old ash (Fraxinus excelsior L.), beech (Fagus silvatica L.), elm (Ulmus glabra Huds.), hornbeam (Carpinusbetulus L.), Norway spruce (Picea abies L.) and oak (Quercus robur L.). The site was characterized by a cambisol on glacial till. Volume-determined soil samples were taken from the O-horizon and mineral soil layers to 20 cm. Soil organic carbon (SOC), total nitrogen (TN), pH (H2O), cation-exchange capacity and base saturation at pH 7 and exchangeable calcium, magnesium, potassium and sodium ions were analysed in the soil fraction < 2 mm. Root biomass <5 mm in diameter) and its proportion in the forest floor and mineral soil varied between tree species. There was a vertical gradient under all species, with the highest concentrations of SOC, TN and base cations in the O-horizon and the lowest in the 10-20 cm layer. The tree species differed with respect to SOC, TN and soil acidity in the O-horizon and mineral soil. For SOC and TN, the range in the O-horizon was spruce> hornbeam > oak > beech > ash > elm. The pH in the O-horizon ranged in the order elm > ash > hornbeam > beech > oak > spruce. In the mineral soil, SOC and TN ranged in the order elm > oak > ash = hornbeam > spruce > beech, i.e. partly reversed, and pH ranged in the same order as for the O-horizon. It is suggested that spruce is the best option for fertile sites in southern Sweden if the aim is a high carbon sequestration rate, whereas elm, ash and hornbeam are the best solutions if the aim is a low soil acidification rate.

  5. Betalain, Acid Ascorbic, Phenolic Contents and Antioxidant Properties of Purple, Red, Yellow and White Cactus Pears

    Science.gov (United States)

    Sumaya-Martínez, María Teresa; Cruz-Jaime, Sandra; Madrigal-Santillán, Eduardo; García-Paredes, Juan Diego; Cariño-Cortés, Raquel; Cruz-Cansino, Nelly; Valadez-Vega, Carmen; Martinez-Cardenas, Leonardo; Alanís-García, Ernesto

    2011-01-01

    Commercialization of cactus pears based on their antioxidant properties can generate competitive advantages, and these can turn into business opportunities and the development of new products and a high-value ingredient for the food industry. This work evaluated the antioxidant activities (1,1-diphenyl-2-picrylhydrazyl radical-scavenging, protection against oxidation of a β-carotene-linoleic acid emulsion, and iron (II) chelation), the content of total phenolic compounds, ascorbic acid, betacyanin, betaxanthin and the stability of betacyanin pigments in presence of Cu (II)-dependent hydroxyl radicals (OH•), in 18 cultivars of purple, red, yellow and white cactus pear from six Mexican states. Our results indicated that the antiradical activities from yellow and white cactus pear cultivars were not significantly different (p < 0.05) and were lower than the average antiradical activities in red and purple cultivars. The red cactus pear from the state of Zacatecas showed the highest antioxidant activity. The free radical scavenging activity for red cactus pears was significantly correlated (p < 0.05) to the concentration of total phenolic compounds (R2 = 0.90) and ascorbic acid (R2 = 0.86). All 18 cultivars of cactus pears studied showed significant chelating activity of ferrous ions. The red and purple cactus pears showed a great stability when exposed to OH•. PMID:22072899

  6. Betalain, Acid Ascorbic, Phenolic Contents and Antioxidant Properties of Purple, Red, Yellow and White Cactus Pears

    Directory of Open Access Journals (Sweden)

    Leonardo Martinez-Cardenas

    2011-09-01

    Full Text Available Commercialization of cactus pears based on their antioxidant properties can generate competitive advantages, and these can turn into business opportunities and the development of new products and a high-value ingredient for the food industry. This work evaluated the antioxidant activities (1,1-diphenyl-2-picrylhydrazyl radical-scavenging, protection against oxidation of a β-carotene-linoleic acid emulsion, and iron (II chelation, the content of total phenolic compounds, ascorbic acid, betacyanin, betaxanthin and the stability of betacyanin pigments in presence of Cu (II-dependent hydroxyl radicals (OH•, in 18 cultivars of purple, red, yellow and white cactus pear from six Mexican states. Our results indicated that the antiradical activities from yellow and white cactus pear cultivars were not significantly different (p < 0.05 and were lower than the average antiradical activities in red and purple cultivars. The red cactus pear from the state of Zacatecas showed the highest antioxidant activity. The free radical scavenging activity for red cactus pears was significantly correlated (p < 0.05 to the concentration of total phenolic compounds (R2 = 0.90 and ascorbic acid (R2 = 0.86. All 18 cultivars of cactus pears studied showed significant chelating activity of ferrous ions. The red and purple cactus pears showed a great stability when exposed to OH•.

  7. Enzyme Activities in Perfluorooctanoic Acid (PFOA)-Polluted Soils

    Institute of Scientific and Technical Information of China (English)

    ZHANG Wei; LIN Kuang-Fei; YANG Sha-Sha; ZHANG Meng

    2013-01-01

    Perfluorooctanoic acid (PFOA) is a popular additive of the chemical industry; its effect on activities of important soil enzymes is not well understood.A laboratory incubation experiment was carried out to analyze the PFOA-induced changes in soil urease,catalase,and phosphatase activities.During the entire incubation period,the activities of the three soil enzymes generally declined with increasing PFOA concentration,following certain dose-response relationships.The values of EC10,the contaminant concentration at which the biological activity is inhibited by 10%,of PFOA for the soil enzyme activity calculated from the modeling equation of the respective dose-response curve suggested a sensitivity order of phosphatase > catalase > urease.The effect of PFOA on soil enzyme activities provided a basic understanding of the eco-toxicological effect of PFOA in the environment.Results of this study supported using soil phosphatase as a convenient biomarker for ecological risk assessment of PFOA-polluted soils.

  8. Growth response of Avena sativa in amino-acids-rich soils converted from phenol-contaminated soils by Corynebacterium glutamicum.

    Science.gov (United States)

    Lee, Soo Youn; Kim, Bit-Na; Choi, Yong Woo; Yoo, Kye Sang; Kim, Yang-Hoon; Min, Jiho

    2012-04-01

    The biodegradation of phenol in laboratory-contaminated soil was investigated using the Gram-positive soil bacterium Corynebacterium glutamicum. This study showed that the phenol degradation caused by C. glutamicum was greatly enhanced by the addition of 1% yeast extract. From the toxicity test using Daphnia magna, the soil did not exhibit any hazardous effects after the phenol was removed using C. glutamicum. Additionally, the treatment of the phenolcontaminated soils with C. glutamicum increased various soil amino acid compositions, such as glycine, threonine, isoleucine, alanine, valine, leucine, tyrosine, and phenylalanine. This phenomenon induced an increase in the seed germination rate and the root elongation of Avena sativa (oat). This probably reflects that increased soil amino acid composition due to C. glutamicum treatment strengthens the plant roots. Therefore, the phenol-contaminated soil was effectively converted through increased soil amino acid composition, and additionally, the phenol in the soil environment was biodegraded by C. glutamicum.

  9. Soil CO2 and N2O Emissions in Maize Growing Season Under Different Fertilizer Regimes in an Upland Red Soil Region of South China

    Institute of Scientific and Technical Information of China (English)

    ZHANG Xu-bo; WU Lian-hai; SUN Nan; DING Xue-shan; LI Jian-wei; WANG Bo-ren; LI Dong-chu

    2014-01-01

    Upland red soils have been identiifed as major CO2 and N2O sources induced by human activities such as fertilization. To monitor characteristics of soil surface CO2 and N2O lfuxes in cropland ecosystems after continuous fertilizer applications over decades and to separate the respective contributions of root and heterotrophic respiration to the total soil CO2 and N2O lfuxes, the measurements of soil surface CO2 and N2O lfuxes throughout the maize growing season in 2009 were carried out based on a fertilization experiment (from 1990) through of the maize (Zea mays L.) growing season in red soil in southern China. Five fertilization treatments were chosen from the experiment for study: zero-fertilizer application (CK), nitrogen-phosphorus-potassium (NPK) fertilizer application only, pig manure (M), NPK plus pig manure (NPKM) and NPK with straw (NPKS). Six chambers were installed in each plot. Three of them are in the inter-row soil (NR) and the others are in the soil within the row (R). Each fertilizer treatment received the same amount of N (300kg ha-1 yr-1). Results showed that cumulative soil CO2 lfuxes in NR or R were both following the order: NPKS>M, NPKM>NPK>CK. The contributions of root respiration to soil CO2 lfuxes was 40, 44, 50, 47 and 35%in CK, NPK, NPKM, M and NPKS treatments, respectively, with the mean value of 43%. Cumulative soil N2O lfuxes in NR or R were both following the order: NPKS, NPKM>M>NPK>CK, and soil N2O lfuxes in R were 18, 20 and 30%higher than that in NR in NPKM, M and NPKS treatments, respectively, but with no difference between NR and R in NPK treatment. Furthermore, combine with soil temperature at -5 cm depth and soil moisture (0-20cm) together could explain 55-70% and 42-59% of soil CO2 and N2O emissions with root interference and 62-78%and 44-63% of that without root interference, respectively. In addition, soil CO2 and N2O lfuxes per unit yield in NPKM (0.55 and 0.10kg Ct-1) and M(0.65 and 0.13g Nt-1) treatments were lower than

  10. Sustainable Lang Use in Hilly Red Soil Region of Southeastern China

    Institute of Scientific and Technical Information of China (English)

    ZHANGTAO-LIN; ZHAOQI-GUO; 等

    1995-01-01

    In the present work,an integrated analysis of natural and socio-economic conditions in the hilly red soil region of southeastern China is made by means of a Geographic Information System.Particular emphasis lies on soil degradation and other adverse ecological and environmental effects of the prevalent and irrational land-use systems of mono-and valley-agriculture in the region.Moreover,taking into account the simultaneous existence of enormous potentials and serious constraints and the high diversity and complexity of the biophysical and socio-economic environments,a set of strategies and countermeasures are also proposed for appropriate management of environmental resources,in terms of maintaining harmony between utilization and coservation of the natural environment,including 1) adjustment of the agricultural structure and optimization of ecological patterns of stereo-agriculture;2) improvement and integrated exploitation of the low-yield lands and wastelands;3) ehabilitation and conservation of soil and water resources;and 4) establishment of production bases of tropical and subtropical cash crops and fruits.

  11. Influencing factors on microbubble ozonation treatment of acid red 3R wastewater

    Directory of Open Access Journals (Sweden)

    Yurong YA

    2017-08-01

    Full Text Available The microbubble ozonation was used to treat acid red 3R wastewater in order to investigate the influencing factors on its performance. The effects of ozone dose, initial acid red 3R concentration and activated carbon on the performance of microbubble ozonation treatment of acid red 3R wastewater are investigated. The decolorization rate, TOC removal rate, pH variation and ozone utilization efficiency in the microbubble ozonation treatment are compared under different treatment conditions. The results indicate that when increasing ozone dose or decreasing initial acid red 3R concentration, both decolorization rate and TOC removal rate of acid red 3R wastewater increase, but ozone utilization efficiency decreases. The coal-based activated carbon shows strong catalytic activity for microbubble ozonation, which could enhance the decolorization rate and TOC removal rate of acid red 3R wastewater. The better performance of microbubble ozonation treatment is achieved when the ozone dose is 48.3 mg/min and the initial acid red 3R mass concentration is 100 mg/L. Under these conditions, the decolorization efficiency reaches to 100% after treatment for 30 min, the TOC removal efficiency reaches to 78.0% after treatment for 120 min, the reaction rate constant of TOC removal is 0.015 min-1 and the ozone utilization efficiency is higher than 99%. With addition of the coal-based activated carbon of 5 g/L, the decolorization efficiency reaches to 100% after treatment for 15 min, the TOC removal efficiency reaches to 91.2% after treatment for 120 min and the reaction rate constant of TOC removal increases to 0037 min-1.The accumulation and following degradation of intermediate products of small molecule organic acid happens during treatment process, and as a result, the solution pH decreases initially and then increases. Therefore, the optimization of influencing factors for microbubble ozonation could increase both contaminant removal

  12. Soil knowledge for farmers, farmer knowledge for soil scientists : the case of acid sulphate soils in the Mekong delta, Viet Nam

    NARCIS (Netherlands)

    Mensvoort, van M.E.F.

    1996-01-01


    Half the Mekong delta in Vietnam, i.e. around 2 million hectares, suffers soil related problems due to acid sulphate soils. These soils generate sulphuric acid due to the oxidation of pyrite after aeration. Pyrite is most easily formed in tidal swamps. Human interference through land

  13. Soil knowledge for farmers, farmer knowledge for soil scientists. The case of acid sulphate soils in the Mekong delta, Viet Nam.

    NARCIS (Netherlands)

    Mensvoort, van M.E.F.

    1996-01-01

    Half the Mekong delta in Vietnam, i.e. around 2 million hectares, suffers soil related problems due to acid sulphate soils. These soils generate sulphuric acid due to the oxidation of pyrite after aeration. Pyrite is most easily formed in tidal swamps. Human interference through land drainage is the

  14. Metagenomic Analysis of the Rhizosphere Soil Microbiome with Respect to Phytic Acid Utilization

    OpenAIRE

    Unno, Yusuke; Shinano, Takuro

    2012-01-01

    While phytic acid is a major form of organic phosphate in many soils, plant utilization of phytic acid is normally limited; however, culture trials of Lotus japonicus using experimental field soil that had been managed without phosphate fertilizer for over 90 years showed significant usage of phytic acid applied to soil for growth and flowering and differences in the degree of growth, even in the same culture pot. To understand the key metabolic processes involved in soil phytic acid utilizat...

  15. Microbial diversity and metabolite composition of Belgian red-brown acidic ales.

    Science.gov (United States)

    Snauwaert, Isabel; Roels, Sanne P; Van Nieuwerburg, Filip; Van Landschoot, Anita; De Vuyst, Luc; Vandamme, Peter

    2016-03-16

    Belgian red-brown acidic ales are sour and alcoholic fermented beers, which are produced by mixed-culture fermentation and blending. The brews are aged in oak barrels for about two years, after which mature beer is blended with young, non-aged beer to obtain the end-products. The present study evaluated the microbial community diversity of Belgian red-brown acidic ales at the end of the maturation phase of three subsequent brews of three different breweries. The microbial diversity was compared with the metabolite composition of the brews at the end of the maturation phase. Therefore, mature brew samples were subjected to 454 pyrosequencing of the 16S rRNA gene (bacteria) and the internal transcribed spacer region (yeasts) and a broad range of metabolites was quantified. The most important microbial species present in the Belgian red-brown acidic ales investigated were Pediococcus damnosus, Dekkera bruxellensis, and Acetobacter pasteurianus. In addition, this culture-independent analysis revealed operational taxonomic units that were assigned to an unclassified fungal community member, Candida, and Lactobacillus. The main metabolites present in the brew samples were L-lactic acid, D-lactic acid, and ethanol, whereas acetic acid was produced in lower quantities. The most prevailing aroma compounds were ethyl acetate, isoamyl acetate, ethyl hexanoate, and ethyl octanoate, which might be of impact on the aroma of the end-products. Copyright © 2016 Elsevier B.V. All rights reserved.

  16. Effect of Plant Roots on Penetrability and Anti-Scouri bility of Red Soil Derived from Granite

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    Distribution of plant roots in a red soil derived from granite was investigated to study the effect of plant roots on intensifying soil penetrability and anti-scouribility by the double-cutting-ring and the undisturbed soil-flume methods, respectively. The plant roots system consisting mostly of fibrils, < 1 mm in diameter, was mainly distributed in the upper surface soil 30 cm in depth. It can remarkably increase the penetrability and anti-scouribility of the red soil derived from granite. When the root density was > 0.35 root cm-2, the intensifying effect of roots on both the penetrability and the anti-scouribility could be described by exponent equations, △Ks = 0.0021RD1.4826 (R2 = 0.9313) and △As = 0.0003RD1.8478 (R2 = 0.9619), where △Ks is the value of intensified soil penetrability, △ As the value of intensified soil anti-scouribility and RD the root density, especially in the top soils within 30 cm in depth where plant roots were concentrated.

  17. Soil Components Affecting Phosphate Sorption Parameters of Acid Paddy Soils in Guangdong Province

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    Soil components affecting phosphate sorption parameters were studied using acid paddy soils derived from basalt, granite, sand-shale and the Pearl River Delta sediments, respectively, in Guangdong Province.For each soil, seven 2.50 g subsamples were equilibrated with 50 mL 0.02 mol L-1 (pH=7.0) of KCl containing 0, 5, 10, 15, 25, 50 and 100 ng P kg-1, respectively, in order to derive P sorption parameters (P sorption maximum, P sorption intensity factor and maximum buffer capacity) by Langmuir isotherm equation. It was shown that the main soil components influencing phosphate sorption maximum (Xm) included soil clay, pH,amorphous iron oxide (Feo) and amorphous aluminum oxide (Alo), with their effects in the order of Alo >Feo > pH > clay. Among these components, pH had a negative effect, and the others had a positive effect.Organic matter (OM) was the only soil component influencing P sorption intensity factor (K). The main components influencing maximum phosphate buffer capacity (MBC) consisted of soil clay, OM, pH, Feo and Alo, with their effects in the order of Alo > OM > pH > Feo > clay. Path analysis indicated that among the components with positive effects on maximum phosphate buffer capacity (MBC), the effect was in the order of Alo > Feo > Clay, while among the components with negative effects, OM > pH. OM played an important role in mobilizing phosphate in acid paddy soils mainly through decreasing the sorption intensity of phosphate by soil particles.

  18. Mechanisms for the retention of inorganic N in acidic forest soils of southern China

    Science.gov (United States)

    Zhang, Jin-bo; Cai, Zu-cong; Zhu, Tong-bin; Yang, Wen-yan; Müller, Christoph

    2013-01-01

    The mechanisms underlying the retention of inorganic N in acidic forest soils in southern China are not well understood. Here, we simultaneously quantified the gross N transformation rates of various subtropical acidic forest soils located in southern China (southern soil) and those of temperate forest soils located in northern China (northern soil). We found that acidic southern soils had significantly higher gross rates of N mineralization and significantly higher turnover rates but a much greater capacity for retaining inorganic N than northern soils. The rates of autotrophic nitrification and NH3 volatilization in acidic southern soils were significantly lower due to low soil pH. Meanwhile, the relatively higher rates of NO3− immobilization into organic N in southern soils can counteract the effects of leaching, runoff, and denitrification. Taken together, these processes are responsible for the N enrichment of the humid subtropical forest soils in southern China. PMID:23907561

  19. Ammonia Volatilization from Urea Applied to Acid Paddy Soil in Southern China and Its Control

    Institute of Scientific and Technical Information of China (English)

    CAIGUI-XIN; PENGGUANG-HAO; 等

    1992-01-01

    Results showed that ammonia loss from urea broadcast into floodwater and incorporated into soil at transplanting was as high as 40% of applied N,and the corresponding total nitrogen (N) loss was 56%.Ammonia loss was measured with simplified micrometeorological method (ammonia sampler),and total N loss was concurrently measured using 15N balance technique.The experiment was conducted under strong sunshine conditions on acid paddy soil derived from Quaternary red clay.The ammonia loss in this particular condition was much greater than those obtained from previous studies when urea was also applied to acid paddy soil but under cloudy conditions.It is concluded that the strong sunshine conditions with high temperature and shallow floodwater during the period of present experiment favoured ammonia volatilization.Application of stearyl alcohol on the surface of the floodwater reduced ammonia loss to 23% of applied N.However,the effect of stearyl alcohol was short-lived,probably due to the microbiological decomposition.

  20. Plant adaptation to acid soils: the molecular basis for crop aluminum resistance

    Science.gov (United States)

    Aluminum (Al) toxicity on acid soils is a significant limitation to crop production worldwide, as approximately 50% of the world’s potentially arable soils are acidic. Because acid soils are such an important constraint to agriculture, understanding the mechanisms and genes conferring resistance to ...

  1. Cadmium Release in Contaminated Soils due to Organic Acids

    Institute of Scientific and Technical Information of China (English)

    LIAO Min; XIE Xiao-Mei

    2004-01-01

    There is limited information on the release behavior of heavy metals from natural soils by organic acids. Thus,cadmium release,due to two organic acids (tartrate and citrate) that are common in the rhizosphere,from soils polluted by metal smelters or tailings and soils artificially contaminated by adding Cd were analyzed. The presence of tartrate or citrate at a low concentration (≤6mmol L-1 for tartrate and ≤0.5 mmol L-1 for citrate) inhibited Cd release,whereas the presence of organic acids in high concentrations (≥2 mmol L-1 for citrate and ≥15 mmol L-1 for tartrate)apparently promoted Cd release. Under the same conditions,the Cd release in naturally polluted soils was less than that of artificially contaminated soils. Additionally,as the initial pH rose from 2 to 8 in the presence of citrate,a sequential valley and then peak appeared in the Cd release curve,while in the presence of tartrate the Cd release steadily decreased.In addition,Cd release was clearly enhanced as the electrolyte concentration of KNO3 or KC1 increased in the presence of 2 mmol L-1 tartrate. Moreover,a higher desorption of Cd was shown with the KC1 electrolyte compared to KNO3 for the same concentration levels. This implied that the bioavailability of heavy metals could be promoted with the addition of suitable types and concentrations of organic acids as well as reasonable field conditions.

  2. Adsorption of glyphosate and aminomethylphosphonic acid in soils

    Science.gov (United States)

    Rampazzo, N.; Rampazzo Todorovic, G.; Mentler, A.; Blum, W. E. H.

    2013-03-01

    The results showed that glyphosate is initially adsorbed mostly in the upper 2 cm. It is than transported and adsorbed after few days in deeper soil horizons with concomitant increasing content of its metabolite aminomethylphosphonic acid. Moreover, Fe-oxides seem to be a key parameter for glyphosate and aminomethylphosphonic adsorption in soils. This study confirmed previous studies: the analysis showed lower contents of dithionite-soluble and Fe-oxides for the Chernozem, with consequently lower adsorption of glyphosate and aminomethylphosphonic as compared with the Cambisol and the Stagnosol.

  3. [Effects of simulated acid rain on decomposition of soil organic carbon and crop straw].

    Science.gov (United States)

    Zhu, Xue-Zhu; Huang, Yao; Yang, Xin-Zhong

    2009-02-01

    To evaluate the effects of acid rain on the organic carbon decomposition in different acidity soils, a 40-day incubation test was conducted with the paddy soils of pH 5.48, 6.70 and 8.18. The soils were amended with 0 and 15 g x kg(-1) of rice straw, adjusted to the moisture content of 400 g x kg(-1) air-dried soil by using simulated rain of pH 6.0, 4.5, and 3.0, and incubated at 20 degrees C. The results showed that straw, acid rain, and soil co-affected the CO2 emission from soil system. The amendment of straw increased the soil CO2 emission rate significantly. Acid rain had no significant effects on soil organic carbon decomposition, but significantly affected the straw decomposition in soil. When treated with pH 3.0 acid rain, the amount of decomposed straw over 40-day incubation in acid (pH 5.48) and alkaline (pH 8.18) soils was 8% higher, while that in neutral soil (pH 6.70) was 15% lower, compared to the treatment of pH 6.0 rain. In the treatment of pH 3.0 acid rain, the decomposition rate of soil organic C in acid (pH 5.48) soil was 43% and 50% (P acid and alkaline soils, respectively.

  4. Phenotypic and quantitative relationship of red cell acid phosphatase with haemoglobin, haptoglobin, and G6PD phenotypes.

    Science.gov (United States)

    Saha, N; Patgunarajah, N

    1981-08-01

    The phenotypic and quantitative relationship of red cell acid phosphatase with haemoglobin, haptoglobin, and G6PD phenotypes was investigated in three populations in the Sudan and one population in Nilgiris, India. No significant consistent association of red cell acid phosphatase phenotypes was observed with these polymorphisms. However, there was a lack of acid phosphatase AB in G6PD deficient subjects from Nilgiris. The relative quantitative expression of red cell acid phosphatase genes PA, PB, and PC was 1.0, 1.2, and 1.3, respectively. The red cell acid phosphatase activity was higher (15%) in the presence of raised haemoglobin A2 and in sickle cell anaemia (21%). Those with Hp2 had 18% higher level of acid phosphatase than those with Hp1. G6PD deficient subjects had a lower level of acid phosphatase activity (20%) than those with normal G6PD activity.

  5. Citramalic acid and salicylic acid in sugar beet root exudates solubilize soil phosphorus

    Directory of Open Access Journals (Sweden)

    Karlovsky Petr

    2011-08-01

    Full Text Available Abstract Background In soils with a low phosphorus (P supply, sugar beet is known to intake more P than other species such as maize, wheat, or groundnut. We hypothesized that organic compounds exuded by sugar beet roots solubilize soil P and that this exudation is stimulated by P starvation. Results Root exudates were collected from plants grown in hydroponics under low- and high-P availability. Exudate components were separated by HPLC, ionized by electrospray, and detected by mass spectrometry in the range of mass-to-charge ratio (m/z from 100 to 1000. Eight mass spectrometric signals were enhanced at least 5-fold by low P availability at all harvest times. Among these signals, negative ions with an m/z of 137 and 147 were shown to originate from salicylic acid and citramalic acid. The ability of both compounds to mobilize soil P was demonstrated by incubation of pure substances with Oxisol soil fertilized with calcium phosphate. Conclusions Root exudates of sugar beet contain salicylic acid and citramalic acid, the latter of which has rarely been detected in plants so far. Both metabolites solubilize soil P and their exudation by roots is stimulated by P deficiency. These results provide the first assignment of a biological function to citramalic acid of plant origin.

  6. 红黄壤土壤结构改良剂应用效果研究%Study on Applied Effect of Red-Yellow Soil Conditioner

    Institute of Scientific and Technical Information of China (English)

    陈先茂; 章发根; 邓国强; 关贤交; 唐先干; 陈斌

    2013-01-01

    为探明红黄壤土壤结构改良剂在红壤旱地上应用的改土培肥效果及其不同用量的产量效应,在典型红壤丘陵区选取3个不同试验点,设计不同用量处理并以花生、红薯、烟草为供试作物进行田间试验,2年定位试验的结果表明:在红壤旱地上施用红黄壤土壤结构改良剂可有效调节土壤酸性、改善土壤结构、提高土壤养分及有机质含量,具有较好的改土培肥效果,其中土壤pH值提高了0.15~0.19、土壤容重降低了5~6个百分点、土壤有机质提高了2.2~2.8 g/kg;在花生、红薯、烟草上应用,其适宜施用量分别为1500~2000、2250~3000、1500~1800 kg/hm2,与对照(不施改良剂量)相比分别增产8%~11%、9%~14%、6%~9%,效益明显。%In order to explore the effect of improving soil structure and fertility of Red -Yellow Soil Conditioner ( RYSC) appli-cation in red soil upland and its yield -increasing effect under the condition of different application rates , we carried out peanut , sweet potato and tobacco field tests for the application rate of RYSC at three test points in the representative hilly red soil region . The results of 2-year location tests indicated that the application of RYSC in the red soil upland had favorable effect of improving soil structure and fertility , it could effectively adjust soil acidity , improve soil structure , and increase soil nutrient and organic mat-ter content.After the application of RYSC, the soil pH -value was increased by 0.15~0.19, the bulk density of soil was de-creased by 5~6 percent, and the soil organic matter content was enhanced by 2.2~2.8 g/kg.As for the application of RYSC in peanut, sweet potato and tobacco fields , its suitable application rate was 1500~2000, 2250~3000, 1500~1800 kg/hm2 respec-tively, and the yield was increased by 8%~11%, 9%~14%, 6%~9%respectively in comparison with the control ( without the application of

  7. Characterization of Phytochemicals and Antioxidant Activities of Red Radish Brines during Lactic Acid Fermentation

    Directory of Open Access Journals (Sweden)

    Pu Jing

    2014-07-01

    Full Text Available Red radish (Raphanus L. pickles are popular appetizers or spices in Asian-style cuisine. However, tons of radish brines are generated as wastes from industrial radish pickle production. In this study, we evaluated the dynamic changes in colour properties, phenolics, anthocyanin profiles, phenolic acid composition, flavonoids, and antioxidant properties in radish brines during lactic acid fermentation. The results showed that five flavonoids detected were four anthocyanins and one kaempferol derivative, including pelargonidin-3-digluoside-5-glucoside derivatives acylated with p-coumaric acid, ferulic acid, p-coumaric and manolic acids, or ferulic and malonic acids. Amounts ranged from 15.5–19.3 µg/mL in total monomeric anthocyanins, and kaempferol-3,7-diglycoside (15–30 µg/mL. 4-Hydroxy-benzoic, gentisic, vanillic, syringic, p-coumaric, ferulic, sinapic and salicylic acids were detected in amounts that varied from 70.2–92.2 µg/mL, whereas the total phenolic content was 206–220 µg/mL. The change in colour of the brine was associated with the accumulation of lactic acid and anthocyanins. The ORAC and Fe2+ chelation capacity of radish brines generally decreased, whereas the reducing power measured as FRAP values was increased during the fermentation from day 5 to day 14. This study provided information on the phytochemicals and the antioxidative activities of red radish fermentation waste that might lead to further utilization as nutraceuticals or natural colorants.

  8. [Quantitative input of atmospheric nitrogen to an agro-ecosystem in a typical red soil region].

    Science.gov (United States)

    Cui, Jian; Zhou, Jing; Yang, Hao; Liang, Jia-ni; Liu, Xiao-li

    2009-08-15

    The atmospheric nitrogen (N) deposition flux and dry deposition N velocities (Vd) were estimated using big leaf resistance analogy model by observations of onflow and factors of farmland microclimate, analysis of nitrides from the atmosphere and rain in an agro-ecosystem, a typical red soil region on Experiment Station of Red Earth Ecology, Chinese Academy (Yingtan, Jiangxi) of Sciences in 2005. The results showed that the dry deposition N was 82.63 kg x hm(-2), accounting for 67.94% of the total N, which was 132.6 kg x hm(-2) in the whole year (2005). In N dry deposition progress, NH3-N and NO3- -N were the main settlement for gas and particle, respectively. NH3-N was made up 43.02% to 89.89% (mean value, 71.05%) of the gaseous N deposition while NO3- -N was accounted for 33.67% to 94.54% (mean value, 61.01%) of the particle N deposition. The N wet deposition fluxes were 0.50-8.45 kg x hm(-2) per month and reached the higher value in July and November.

  9. Acid sulfate soils are an environmental hazard in Finland

    Science.gov (United States)

    Pihlaja, Jouni

    2016-04-01

    Acid sulfate soils (ASS) create significant threats to the environment on coastal regions of the Baltic Sea in Finland. The sediments were deposited during the ancient Litorina Sea phase of the Baltic Sea about 7500-4500 years ago. Finland has larger spatial extent of the ASS than any other European country. Mostly based on anthropogenic reasons (cultivation, trenching etc.) ASS deposits are currently being exposed to oxygen which leads to chemical reaction creating sulfuric acid. The acidic waters then dissolve metals form the soil. Acidic surface run off including the metals are then leached into the water bodies weakening the water quality and killing fish or vegetation. In constructed areas acidic waters may corrode building materials. Geological Survey of Finland (GTK) is mapping ASS deposits in Finland. The goal is to map a total of 5 million hectares of the potentially ASS affected region. It has been estimated that the problematic Litorina Sea deposits, which are situated 0-100 m above the recent Baltic Sea shoreline, cover 500 000 hectares area. There are several phases in mapping. The work begins at the office with gathering the existing data, interpreting airborne geophysical data and compiling a field working plan. In the field, quality of the soil is studied and in uncertain cases samples are taken to laboratory analyses. Also electrical conductivity and pH of soil and water are measured in the field. Laboratory methods include multielemental determinations with ICP-OES, analyses of grain size and humus content (LOI), and incubation. So far, approximately 60 % of the potential ASS affected regions in Finland are mapped. Over 15 000 sites have been studied in the field and 4000 laboratory analyses are done. The spatial database presented in the scale of 1: 250 000 can be viewed at the GTK's web pages (http://gtkdata.gtk.fi/hasu/index.html).

  10. Effects of mist acidity and ambient ozone removal on montane red spruce

    Energy Technology Data Exchange (ETDEWEB)

    Vann, D.R. [Pennsylvania Univ., Philadelphia, PA (United States). Dept. of Biology; Strimbeck, D.R.; Johnson, A.H. [Pennsylvania Univ., Philadelphia, PA (United States). Dept. of Geology

    1995-10-01

    The effects of acidic mists and ozone on several biochemical and growth parameters in mature montane red spruce were examined. Branch-size environmental chambers were used to introduce mists of controlled composition and to protect selected branches from ambient ozone and acidic mists. Mists of distilled water increased the end-of-season pigment concentration and shoot length of enclosed branches relative to ambient or artificial mists. Needle and twig weights and starch concentrations were not significantly altered by the acidic mist treatments. Removal of ambient ozone had no apparent effect on the variables measured. 8 figs., 2 tabs., 39 refs.

  11. Influence of the insecticides acetamiprid and carbofuran on arylamidase and myrosinase activities in the tropical black and red clay soils.

    Science.gov (United States)

    Mohiddin, G Jaffer; Srinivasulu, M; Maddela, N R; Manjunatha, B; Rangaswamy, V; Koch Kaiser, Alma Rosel; Maisincho Asqui, Jessica Cristina; Darwin Rueda, O

    2015-06-01

    The objective of this study was to determine the effects of two insecticides, namely, acetamiprid and carbofuran on the enzymatic activities of arylamidase (as glucose formed from sinigrin) and myrosinase (as β-naphthylamine formed from L-leucine β-naphthylamide) in the black and red clay soils collected from a fallow groundnut (Arachis hypogaea L.) fields in the Anantapur District, Andhra Pradesh, India. The study was realized within the framework of the laboratory experiments in which the acetamiprid and carbofuran were applied to the soils at different doses (1.0, 2.5, 5.0, 7.5, 10.0 kg ha(-1)). Initially, the physicochechemical properties of the soil samples were analyzed. After 10 days of pesticide application, the soil samples were analyzed for the enzyme activities. Acetamiprid and carbofuran stimulated the arylamidase and myrosinase activities at lower concentrations after 10 days incubation. Striking stimulation in soil enzyme activities was noticed at 2.5 kg ha(-1), persists for 20 days in both the soils. Overall, higher concentrations (5.0-10.0 kg ha(-1)) of acetamiprid and carbofuran were toxic or innocuous to the arylamidase and myrosinase activities. Nevertheless, the outcomes of the present study clearly indicate that the use of these insecticides (at field application rates) in the groundnut fields (black and red clay soils) stimulated the enzyme (arylamidase and myrosinase) activities.

  12. Effect of Excess Fertilizer Phosphorus on Some Chemical Properties of Paddy Soil Drived from Red Soil and Its Relation to Rice Growth

    Institute of Scientific and Technical Information of China (English)

    NIWUZHONG; HENIANZU

    1997-01-01

    A filed experiment with an early rice-late rice rotation was carried out on a paddy soil derived from red soil in the southern part of Zhejing Province to elucidate the effect of excess P application on some important characteristics of soil properies and its relation to nutrient status and grain yields of rice crops.The experimental results indicated that adequate fertilizer P(15 kg P hm-2)could increase the content of soil available P at the tillering stage of early rice,the contents of N,P and K in the shoots of early rice at primary growth stages,and the grain yield of early rice by increasing valid ears per hectare and weight per thousand grains,which,was mainly related to the higher contents of reduced,non-reduced and total sugar in the shoot at the heading stage, And early rice supplied with excessive P could not yield more than that applied with adequate, P de to the reduction in the valid grain percentage and weight per thousead grains. In addition,one-time excess P supply at a rate as high as 90 kg P hm-2 could not improve the soil P fertility in case the soil available P content was lower than the initial(3.74mg kg-1 soil) after an early rice-late rice rotaion,and made a decline in the grain yield increased by per kilogram fertilzer P.Thus,one-time excess P supply should not be adopted for soils with a large P fixation capacity like the paddy soils derived from red soils.

  13. Study on Effects of Human Activities on Rehabilitation of Vegetation on Red Soil in Hilly Areas

    Institute of Scientific and Technical Information of China (English)

    Liu Gengling

    2000-01-01

    Based on the two long-term experiments on red soil in hilly areas in the southern part of Hunan Province, a study on rehabilitation of natural vegetation in this area has been carried out.The results showed that when the more frequently vegetation was cut, the less bio-mass and the fewer the species of the vegetation were year by year, especially the growth of xylophyto. For example,in plot 1 (under annual cutting), the bio-mass of vegetation decreased from 90. 2kg/plot to 45. 0kg/polt, the species of the vegetation decreased from 15 to 4, and the proportion of the xylophyta biomass decreased from 17% to 0.9% in 1991. As for imparata cylindrica var. major during the process of restoration of natural vegetation, applying fertilizer made it reproduced excessively, then eliminate. With frequently cutting, the soil fertility was exhausted gradually and the biomass of Imparata cylindrica decreased sharply, especially under the condition of N fertilizer application.

  14. [Effects of applying controlled release fertilizers on N2O emission from a lateritic red soil].

    Science.gov (United States)

    Du, Ya-qin; Zheng, Li-xing; Fan, Xiao-lin

    2011-09-01

    Static closed chamber technique and contrast method were adopted to study the effects of three coated compound fertilizers (N:P2O5:K2O = 19:8.6:10.5, high N; 14.4:14.4:14.4, balanced NPK; and 12.5:9.6:20.2, high K) on the NO2O emission from a lateritic red soil under the condition of no crop planting, taking uncoated compound fertilizers (N:P2O5:K2O = 20:9:11, high N; 15:15:15, balanced NPK; and 13:10:21, high K) as the contrasts. Different formula of fertilizer NPK induced significant difference in the N2O emission. Under the application of uncoated compound fertilizers, the cumulative N2O emission was in the order of balanced NPK > or = high N > high K. Applying coated compound fertilizers decreased the N2O emission significantly, and the emission amount under the application of high N, balanced NPK, and high K was 34.4%, 30.5%, and 89.3% of the corresponding uncoated compound fertilizers, respectively. Comparing with the application of uncoated compound fertilizers, applying coated compound fertilizers also decreased the daily N2O flux significantly, and delayed and shortened the N2O peak, suggesting that coated fertilizers could reduce soil nitrogen loss and the global warming potential induced by N2O emission.

  15. Simple method of isolating humic acids from organic soils

    Science.gov (United States)

    Ahmed, O. H.; Susilawati, K.; Nik Muhamad, A. B.; Khanif, M. Y.

    2009-04-01

    Humic substances particularly humic acids (HA) play a major role in soil conditioning e.g. erosion control, soil cation exchange capacity, complexation of heavy metal ions and pesticides, carbon and nitrogen cycles, plant growth and reduction of ammonia volatilization from urea. Humified substances such as coal, composts, and peat soils have substantial amounts of HA but the isolation of these acids is expensive, laborious, and time consuming. Factors that affect the quality and yield of HA isolated from these materials include extraction, fractionation, and purification periods. This work developed a simple, rapid, and cost effective method of isolating HA from peat soils. There was a quadratic relationship between extraction period and HA yield. Optimum extraction period was estimated at 4 h instead of the usual range of 12 to 48 h. There was no relationship between fractionation period and HA yield. As such 2 h instead of the usual range of 12 to 24 h fractionation period could be considered optimum. Low ash content (5%), remarkable reduction in K, coupled with the fact that organic C, E4/E6, carboxylic COOH, phenolic OH, and total acidity values of the HA were consistent with those reported by other authors suggest that the HA dealt with were free from mineral matter. This was possible because the distilled water used to purify the HA served as Bronsted-Lowry acid during the purification process of the HA. Optimum purification period using distilled waster was 1 h instead of the usual range of 1 and 7 days (uses HF and HCl and dialysis). Humic acids could be isolated from tropical peat soils within 7 h (i.e. 4 h extraction, 2 h fractionation, and 1 h purification) instead of the existing period of 2 and 7 days. This could facilitate the idea of producing organic fertilizers such as ammonium-humate and potassium-humate from humified substances since techniques devised in this study did not alter the true nature of the HA. Besides, the technique is rapid, simple

  16. FATTY ACID COMPOSITION AND PROSTAGLANDIN CONTENT OF THE RED SEAWEED Gracilaria sp. FROM INDONESIA

    Directory of Open Access Journals (Sweden)

    Muhammad Ikbal Illijas

    2012-06-01

    Full Text Available High content of polyunsaturated fatty acids (PUFAs such as arachidonic and eicosapentaenoic acids are typical for the red alga. Analysis of fatty acid composition and prostaglandin content was conducted in the red alga Gracilaria sp. from Indonesia. Total lipid of the alga was extracted with CHCl3-MeOH (2:1, v/v. Analysis of the fatty acids composition was performed on gas chromatography (GC equipped with omega wax column (30 m x 0,32 mm i.d., Supelco, PA, USA and analysis of prostaglandins were carried out by HPLC on ODS column (Mightysil RP-18 GP, 250 mm x 4.6 mm, 5 μm. The content of fatty acids high for were palmitic acid (50% and arachidonic acid (26.9%, whereas prostaglandin E2 was identified and found lower concentration (44.2 μg/gram total lipid.

  17. Transport of humic and fulvic acids in relation to metal mobility in a copper-contaminated acid sandy soil

    NARCIS (Netherlands)

    Weng, L.; Fest, E.P.M.J.; Filius, J.; Temminghoff, E.J.M.; Riemsdijk, van W.H.

    2002-01-01

    The transport of inorganic and organic pollutants in water and soil can be strongly influenced by the mobility of natural dissolved organic matter (DOM). In this paper, the transport of a humic acid (HA) and a fulvic acid (FA) in a copper-contaminated acid sandy soil was studied. The data showed

  18. Persistence of glyphosate and aminomethylphosphonic acid in loess soil under different combinations of temperature, soil moisture and light/darkness

    NARCIS (Netherlands)

    Martins Bento, Celia; Yang, Xiaomei; Gort, Gerrit; Xue, Sha; Dam, van Ruud; Zomer, Paul; Mol, Hans G.J.; Ritsema, Coen J.; Geissen, Violette

    2016-01-01

    The dissipation kinetics of glyphosate and its metabolite aminomethylphosphonic acid (AMPA) were studied in loess soil, under biotic and abiotic conditions, as affected by temperature, soil moisture (SM) and light/darkness. Nonsterile and sterile soil samples were spiked with 16 mg kg− 1

  19. Persistence of glyphosate and aminomethylphosphonic acid in loess soil under different combinations of temperature, soil moisture and light/darkness

    NARCIS (Netherlands)

    Martins Bento, Celia; Yang, Xiaomei; Gort, Gerrit; Xue, Sha; Dam, van Ruud; Zomer, Paul; Mol, Hans G.J.; Ritsema, Coen J.; Geissen, Violette

    2016-01-01

    The dissipation kinetics of glyphosate and its metabolite aminomethylphosphonic acid (AMPA) were studied in loess soil, under biotic and abiotic conditions, as affected by temperature, soil moisture (SM) and light/darkness. Nonsterile and sterile soil samples were spiked with 16 mg kg− 1

  20. [Characteristics of acid red 3R wastewater treatment by ozone microbubbles].

    Science.gov (United States)

    Zhang, Jing; Du, Ya-Wei; Liu, Xiao-Jing; Zhou, Yu-Wen; Liu, Chun; Yang, Jing-Liang; Zhang, Lei

    2015-02-01

    The application of microbubble technology for ozonation wastewater treatment could enhance ozone mass transfer, improve ozonation performance and increase ozone utilization efficiency. The ozone microbubbles were used to treat synthetic acid red 3R wastewater in the present study, and compared to ozone conventional bubbles. The ozone mass transfer and ozonation characteristics of acid red 3R were investigated when ozone microbubbles and ozone conventional bubbles were applied. The results confirmed the enhanced ozone mass transfer using microbubbles. The ozone mass transfer coefficient using microbubbles was 3.6 times higher than that using conventional bubbles under the same conditions. Simultaneously, the ozone decomposition coefficient using microbubbles was 6.2 times higher than that using conventional bubbles, which would be favorable for *OH generation. The ozonation rate and mineralization efficiency of acid red 3R could be improved significantly using ozone microbubbles. A TOC removal efficiency of 78.0% was achieved using ozone microbubbles, which was about 2 times higher than that using ozone conventional bubbles. The ozone utilization efficiency using microbubbles was much higher that using conventional bubbles during ozonation treatment of acid red 3R. The average ozone utilization efficiencies were 97.8% and 69.3% when microbubbles and conventional bubbles were used, respectively. The oxidative ability of ozone microbubbles could be increased by enhancing *OH generation, and as a result, the oxidative reaction of degradation intermediates was accelerated by ozone microbubbles. Especially, the mineralization ability of small organic acid intermediates using ozone microbubbles was about 1.6 times higher than that using ozone conventional bubbles.

  1. Toxicological responses of red-backed salamander (Plethodon cinereus) exposed to aged and amended soils containing lead.

    Science.gov (United States)

    Bazar, Matthew A; Quinn, Michael J; Mozzachio, Kristie; Bleiler, John A; Archer, Christine R; Phillips, Carlton T; Johnson, Mark S

    2010-05-01

    The use of lead in military and civilian small arms projectiles is widely acknowledged to have resulted in high soil lead concentrations at many small arms ranges. These ranges are often adjacent to wildlife habitat or have become habitat when no longer used. To assess the potential toxicity of lead to terrestrial amphibians in contaminated areas, we exposed 100 red-backed salamanders (Plethodon cinereus) to either a control soil or one of four soil treatments amended with lead acetate for 28 days. Analytical mean soil concentrations were 14 (control), 553, 1700, 4700, and 9167 mg Pb/kg soil dry weight. An additional 60 salamanders were also exposed for 28 days to one of six field-collected soil samples from a small arms range and a skeet range. The field soil concentrations ranged from 11 (background) to 16,967 mg Pb/kg soil dry weight. Food consisted of uncontaminated flightless Drosophila melanogaster. Salamander survival was reduced in amended soil treatments of 4700 and 9167 mg/kg by 15% and 80%, respectively. Inappetence was observed at 4700 and 9167 mg/kg and growth decreased in the 9167 mg/kg treatment. Total white blood cells decreased 32% at 4700 mg/kg compared to controls and were 22% lower in the 9167 mg/kg treatment. In contrast, survival was 100% for all field-collected soils with no hematological effects. At 16,967 mg/kg there was evidence of soil avoidance and decreased growth. These data suggest marked differences in toxicity and bioavailability of the lead-amended soil in contrast to the field-collected soil containing lead.

  2. Acid washing and stabilization of an artificial arsenic-contaminated soil.

    Science.gov (United States)

    Tokunaga, Shuzo; Hakuta, Toshikatsu

    2002-01-01

    An acid-washing process was studied on a laboratory scale to extract the bulk of arsenic(V) from a highly contaminated Kuroboku soil (Andosol) so as to minimize the risk of arsenic to human health and the environment. The sorption and desorption behavior of arsenic in the soil suggested the possibility of arsenic leaching under acidic conditions. Artificially contaminated Kuroboku soil (2830 mg As/kg soil) was washed with different concentrations of hydrogen fluoride, phosphoric acid, sulfuric acid, hydrogen chloride, nitric acid, perchloric acid, hydrogen bromide, acetic acid, hydrogen peroxide, 3:1 hydrogen chloride-nitric acid, or 2:1 nitric acid-perchloric acid. Phosphoric acid proved to be most promising as an extractant, attaining 99.9% arsenic extraction at 9.4% acid concentration in 6 h. Sulfuric acid also attained high percentage extraction. The arsenic extraction by these acids reached equilibrium within 2 h. Elovich-type equation best described most of the kinetic data for dissolution of soil components as well as for extraction of arsenic. Dissolution of the soil components could be minimized by ceasing acid washing in 2 h. The acid-washed soil was further stabilized by the addition of lanthanum, cerium, and iron(III) salts or their oxides or hydroxides which form insoluble complex with arsenic. Both salts and oxides of lanthanum and cerium were effective in immobilizing arsenic in the soil attaining less than 0.01 mg/l As in the leaching test.

  3. Effects of Composted and Thermally Dried Sewage Sludges on Soil and Soil Humic Acid Properties

    Institute of Scientific and Technical Information of China (English)

    J.M.FERN(A)NDEZ; N.SENESI; C.PLAZA; G.BRUNETTI; A.POLO

    2009-01-01

    The effect of annual additions of composted sewage sludge (CS) and thermally dried sewage sludge (TS) at 80 t ha-1 on soil chemical properties was investigated for three years in a field experiment under semiarid conditions.Humie acids (HAs) isolated by conventional procedures from CS,TS,and unamended (SO) and sludge amended soils were analysed for elemental (C,H,N,S and O) and acidic functional groups (carboxylic and phenolic) and by ultraviolet-visible,Fourier transform infrared and fluorescence spectroscopies.With respect to CS,TS had similar pH and total P and K contents,larger dry matter,total organic C,total N.and C/N ratio and smaller ash content and electrical conductivity.Amendment with both CS and TS induced a number of modifications in soil properties,including an increase of pH,electrical conductivity,total organic C,total N,and available P.The CS-HA had greater O,total acidity,carboxyl,and phenolic OH group contents and smaller C and H contents than TS-HA.The CS-HA and TS-HA had larger N and S contents,smaller C,O and acidic functional group contents,and lower aromatic polycondensation and humification degrees than SO-HA.Amended soil-HAs showed C,H,N and S contents larger than SO-HA,suggesting that sludge HAs were partially incorporated into soil HAs.These effects were more evident with increasing number of sludge applications.

  4. EFFECTS OF ALKALINE SANDY LOAM ON SULFURIC SOIL ACIDITY AND SULFIDIC SOIL OXIDATION

    Directory of Open Access Journals (Sweden)

    Patrick S. Michael

    2015-08-01

    Full Text Available  In poor soils, addition of alkaline sandy loam containing an adequate proportion of sand, silt and clay would add value by improving the texture, structure and organic matter (OM for general use of the soils. In acid sulfate soils (ASS, addition of alkaline sandy would improve the texture and leach out salts as well as add a sufficient proportion of OM for vegetation establishment. In this study, addition of alkaline sandy loam into sulfuric soil effectively increased the pH, lowered the redox and reduced the sulfate content, the magnitude of the effects dependent on moisture content. Addition of alkaline sandy loam in combination with OM was highly effective than the effects of the lone alkaline sandy loam. When alkaline sandy was added alone or in combination with OM into sulfidic soil, the effects on pH and the redox were similar as in the sulfuric soil but the effect on sulfate content was variable. The effects under aerobic conditions were higher than under anaerobic conditions. The findings of this study have important implications for the general management of ASS where lime availability is a concern and its application is limited.International Journal of Environment Volume-4, Issue-3, June-August 2015Page: 42-54

  5. Acid Release from an Acid Sulfate Soil Sample Under Successive Extractions with Different Extractants

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    An acid sulfate soil sample was successively extracted with deionized water, 1 mol L-1 KCI and 0.000 5 mol L-1 Ca(OH)2 solutions. The results showed that only very small amounts of acidity were extracted by deionized water, possibly through slow jarosite hydrolysis. Acid release through jarosite hydrolysis was greatly enhanced by Ca(OH)2 extraction at the expense of the added OH- being neutralized by the acid released. Successive extraction of the sample with KCI removed the largest amounts of acidity from the sample. However, it is likely that the major form of acidity released by KC1 extraction was exchangeable acidity. The results also show the occurrence of low or non charged A1 and Fe species in water and Ca(OH)2 extracts after first a few extractions. It appears that such a phenomenon was related to a decreasing EC value with increasing number of extractions.

  6. Reclamation of acid sulfate soils using lime-stabilized biosolids.

    Science.gov (United States)

    Orndorff, Zenah W; Daniels, W Lee; Fanning, Delvin S

    2008-01-01

    Excavation of sulfidic materials during construction has resulted in acid rock drainage (ARD) problems throughout Virginia. The most extensive documented uncontrolled disturbance at a single location is Stafford Regional Airport (SRAP) in Stafford, Virginia. Beginning in 1998, over 150 ha of sulfidic Coastal Plain sediments were disturbed, including steeply sloping cut surfaces and spoils placed into fills. Acid sulfate soils developed, and ARD generated on-site degraded metal and concrete structures and heavily damaged water quality with effects noted over 1 km downstream. The site was not recognized as sulfidic until 2001 when surface soil sampling revealed pH values ranging from 1.9 to 5.3 and peroxide potential acidity (PPA) values ranging from 1 to 42 Mg CaCO(3) per 1000 Mg material. In February 2002 a water quality program was established in and around the site to monitor baseline pH, EC, NO(3)-N, NH(4)-N, PO(4)-P, Fe, Al, Mn, and SO(4)-S, and initial pH values as low as 2.9 were noted in on-site receiving streams. In the spring and fall of 2002, the site was treated with variable rates of lime-stabilized biosolids, straw-mulch, and acid- and salt-tolerant legumes and grasses. By October 2002, the site was fully revegetated (> or = 90% living cover) with the exception of a few highly acidic outcrops and seepage areas. Surface soil sampling in 2003, 2004, and 2006 revealed pH values typically > 6.0. Water quality responded quickly to treatment, although short-term NH(4)(+) release occurred. Despite heavy loadings, no significant surface water P losses were observed.

  7. Isolation and identification of lactic acid bacteria from fermented red dragon fruit juices.

    Science.gov (United States)

    Ong, Yien Yien; Tan, Wen Siang; Rosfarizan, Mohamad; Chan, Eng Seng; Tey, Beng Ti

    2012-10-01

    Red dragon fruit or red pitaya is rich in potassium, fiber, and antioxidants. Its nutritional properties and unique flesh color have made it an attractive raw material of various types of food products and beverages including fermented beverages or enzyme drinks. In this study, phenotypic and genotypic methods were used to confirm the identity of lactic acid bacteria (LAB) appeared in fermented red dragon fruit (Hylocereus polyrhizus) beverages. A total of 21 isolates of LAB were isolated and characterized. They belonged to the genus of Enterococcus based on their biochemical characteristics. The isolates can be clustered into two groups by using the randomly amplified polymorphic DNA method. Nucleotide sequencing and restriction fragment length polymorphism of the 16S rRNA region suggested that they were either Enterococcus faecalis or Enterococcus durans. Current research revealed the use of biochemical analyses and molecular approaches to identify the microbial population particularly lactic acid bacteria from fermented red dragon fruit juices. © 2012 Institute of Food Technologists®

  8. Ozonation of azo dyes (Orange II and Acid Red 27) in saline media

    Energy Technology Data Exchange (ETDEWEB)

    Silva, Alessandra C. [Chemical Engineering Program, COPPE, Federal University of Rio de Janeiro, Av. Horacio Macedo, 2030, P.O. Box, 68502, CEP 21941-972, Rio de Janeiro, RJ (Brazil); Pic, Jean Stephane [Institut National des Sciences Appliquees, INSA-GPE-LIPE, Toulouse (France); Sant' Anna, Geraldo L., E-mail: lippel@peq.coppe.ufrj.br [Chemical Engineering Program, COPPE, Federal University of Rio de Janeiro, Av. Horacio Macedo, 2030, P.O. Box, 68502, CEP 21941-972, Rio de Janeiro, RJ (Brazil); Dezotti, Marcia [Chemical Engineering Program, COPPE, Federal University of Rio de Janeiro, Av. Horacio Macedo, 2030, P.O. Box, 68502, CEP 21941-972, Rio de Janeiro, RJ (Brazil)

    2009-09-30

    Ozonation of two azo dyes was investigated in a monitored bench scale bubble column reactor (8.5-L), varying liquid media salt content (0, 1, 40 and 100 g L{sup -1}, NaCl). In experiments with Orange II pH was varied (5, 7.5 and 9) but ozonation of Acid Red 27 was performed at pH 7.5. Ozone self-decomposition rate-constant increased with salt concentration. Color removal was very effective and fast achieved under all experimental conditions. For the two azo dyes tested, more than 98% of color intensity was removed in 30-min ozonation assays. However, only partial mineralization of azo dyes (45%-Orange II; 20%-Acid Red 27) was attained in such experiments. The degree of mineralization (TOC removal) was negatively affected by salt concentration. Biodegradation assays conducted by respirometry revealed the inhibitory effect of dye degradation products formed during ozonation.

  9. Relationships between soil properties and community structure of soil macroinvertebrates in oak-history forests along an acidic deposition gradient

    Energy Technology Data Exchange (ETDEWEB)

    Kuperman, R.G. [Argonne National Lab., IL (United States). Environmental Assessment Div.

    1996-02-01

    Soil macroinvertebrate communities were studied in ecologically analogous oak-hickory forests across a three-state atmospheric pollution gradient in Illinois, Indiana, and Ohio. The goal was to investigate changes in the community structure of soil fauna in study sites receiving different amounts of acidic deposition for several decades and the possible relationships between these changes and physico-chemical properties of soil. The study revealed significant differences in the numbers of soil animals among the three study sites. The sharply differentiated pattern of soil macroinvertebrate fauna seems closely linked to soil chemistry. Significant correlations of the abundance of soil macroinvertebrates with soil parameters suggest that their populations could have been affected by acidic deposition in the region. Abundance of total soil macroinvertebrates decreased with the increased cumulative loading of acidic deposition. Among the groups most sensitive to deposition were: earthworms gastropods, dipteran larvae, termites, and predatory beetles. The results of the study support the hypothesis that chronic long-term acidic deposition could aversely affect the soil decomposer community which could cause lower organic matter turnover rates leading to an increase in soil organic matter content in high deposition sites.

  10. Corrosion Behavior of Copper-Clad Steel Bars with Unclad Two-End Faces for Grounding Grids in the Red Clay Soil

    Science.gov (United States)

    Shao, Yupei; Mu, Miaomiao; Zhang, Bing; Nie, Kaibin; Liao, Qiangqiang

    2017-02-01

    Iron-aluminum oxides in the red soil have a significant impact on the corrosion behavior of the metal for grounding grids. Effects of iron-aluminum oxides on the corrosion behavior of the cross section of copper-clad steel in the red soil have been investigated using electrochemical impedance spectroscopy and Tafel polarization. All the data indicate that the iron-aluminum oxides can promote the corrosion of copper-clad steel in the red soil. The corrosivity of the red soil greatly increases after iron-aluminum oxides are added into the soil. Iron-aluminum oxides promote galvanic corrosion of copper-clad steel and increase the corrosion degree of the center steel layer. The iron-aluminum oxides stimulate corrosion process of copper-clad steel acting as a cathodic depolarizing agent. XRD results further validate that the corrosion products of the copper-clad steel bar mainly consist of Fe3O4 and Cu2O.

  11. Corrosion Behavior of Copper-Clad Steel Bars with Unclad Two-End Faces for Grounding Grids in the Red Clay Soil

    Science.gov (United States)

    Shao, Yupei; Mu, Miaomiao; Zhang, Bing; Nie, Kaibin; Liao, Qiangqiang

    2017-04-01

    Iron-aluminum oxides in the red soil have a significant impact on the corrosion behavior of the metal for grounding grids. Effects of iron-aluminum oxides on the corrosion behavior of the cross section of copper-clad steel in the red soil have been investigated using electrochemical impedance spectroscopy and Tafel polarization. All the data indicate that the iron-aluminum oxides can promote the corrosion of copper-clad steel in the red soil. The corrosivity of the red soil greatly increases after iron-aluminum oxides are added into the soil. Iron-aluminum oxides promote galvanic corrosion of copper-clad steel and increase the corrosion degree of the center steel layer. The iron-aluminum oxides stimulate corrosion process of copper-clad steel acting as a cathodic depolarizing agent. XRD results further validate that the corrosion products of the copper-clad steel bar mainly consist of Fe3O4 and Cu2O.

  12. The effects of applying sewage sludge into Jiangxi red soil on the growth of vegetables and the migration and enrichment

    Directory of Open Access Journals (Sweden)

    Wang Rrong

    2016-09-01

    Full Text Available Jiangxi red soil was used as the tested soil and water spinach (Ipomoea aquatic and Chinese chive (Allium tuberosum were used as the tested vegetables in this study to investigate the effects of different amounts of sewage-sludge application on the growth of vegetables and the migration and enrichment patterns of Cu and Zn in vegetables using the potted method. The results indicated that the application of sewage sludge could improve the properties of red soil and promote vegetable growth. The dry weight of water spinach and Chinese chive reached the maximal levels when treated with the amount of sewage sludge at 4% and 10%, which was 4.38 ± 0.82 g and 1.56 ± 0.31 g, respectively. The dry weights after the application of sewage sludge were all larger than control treatment (CK without sludge application. With increases in the applied amount of sewage sludge, the concentrations of Cu and Zu in red soil continued to increase, and the peak value was not reached. After the two vegetables were planted, the concentrations of Cu and Zn in red soil decreased by different degrees. The degrees of decrease of Zn were generally higher than those of Cu. The enrichment coefficient of water spinach on Cu showed a trend of increase followed by a decrease and reached the peak value of 1.04 ± 0.38 when the applied amount was 4%. The enrichment coefficient of Chinese chive on Cu overall showed a decreasing trend and did not reach the peak value under the treatment levels used in this experiment. The enrichment pattern of Chinese chive on Zn was not obvious, and the differences among all treatment levels were not significant (p < 0.05. However, the enrichment coefficient after the application of sewage sludge was significantly lower than that without the application of sludge.

  13. pH effects of the addition of three biochars to acidic Indonesian mineral soils

    DEFF Research Database (Denmark)

    Martinsen, V; Alling, V; Nurida, N L

    2015-01-01

    Soil acidity may severely reduce crop production. Biochar (BC) may increase soil pH and cation exchange capacity (CEC) but reported effects differ substantially. In a systematic approach, using a standardized protocol on a uniquely large number set of 31 acidic soils, we quantified the effect of ...

  14. Utilisation of coal ash to improve acid soil

    Directory of Open Access Journals (Sweden)

    Shigeru Kato

    2004-09-01

    Full Text Available The study on utilization of coal ash to improve acid soil was carried out in a greenhouse at the Land Development Regional Office 1, Pathum Thani Province, Central Thailand, from January-May 2003. Fly ash mixture (fly ash plus gypsum and lime at the proportion 5:4:1 and clinker ash mixture (clinker ash plus gypsum and lime at the proportion 5:4:1 were used as soil amendments at varying rates i.e., 0, 6.25,12.5, 18.75 and 25 t/ha to improve the soil. The aim of this study was to determine the effect of application of coal ash on acid soil and the growth of a vegetable (Chinese kale. Chinese kale cultivars were planted in a randomized complete block design with three replications. Pak Chong soil series (Ultisols was used as the growth medium. Twenty-day-old seedlings were transplanted in 270 pots (two plants per pot containing acid soil with different treatments of coal ash mixture which were as follows: 1 control, 2 fly ash mixture 6.25 t/ha, 3 fly ash mixture 12.5 t/ha, 4 fly ash mixture 18.75 t/ha, 5 fly ash mixture 25 t/ha, 6 clinker ash mixture 6.25 t/ha, 7 clinker ash mixture 12.5 t/ha, 8 clinker ash mixture 18.75 t/ha and 9 clinker ash mixture 25 t/ha. Chemical fertilizers were applied at the rate of 250 kg/ha using a grade of 15-15-15 of N, P and K, respectively. Plants were harvested 40 days after transplanting. Among the treatments, application of fly ashmixture at a rate of 25t/ha (4t/rai substantially increased soil pH up to 5.7. Fly ash was found more effective than clinker ash in increasing soil pH. The highest yield of Chinese kale was also obtained when fly ash mixture was applied at a rate of 25 t/ha followed by fly ash mixture at 18.75 t/ha and clinker ash mixture at 18.75 t/ha with an average yield per plant of 4.980, 3.743 and 3.447 grams, respectively. It can be concluded that the application of coal ash mixture, either fly- or clinker ash, at 18.75-25 t/ha (3-4 t/rai was the most effective in terms of plant yield. The use of

  15. Influence of tebuconazole and copper hydroxide on phosphatase and urease activities in red sandy loam and black clay soils.

    Science.gov (United States)

    Anuradha, B; Rekhapadmini, A; Rangaswamy, V

    2016-06-01

    The efficacy of two selected fungicides i.e., tebuconazole and coppoer hydroxide, was conducted experiments in laboratory and copper hydroxide on the two specific enzymes phosphatase and urease were determined in two different soil samples (red sandy loam and black clay soils) of groundnut (Arachis hypogaea L.) from cultivated fields of Anantapuramu District, Andhra Pradesh. The activities of the selected soil enzymes were determined by incubating the selected fungicides-treated (1.0, 2.5, 5.0, 7.5 and 10.0 kg ha(-1)) and -untreated groundnut soil samples at 10 day intervals. By determining the effective concentration, the rate of selected enzyme activity was estimated by adding the suitable substrate at 10, 20, 30 and 40 days of soil incubation. Both the enzyme activities were increased up to 5.0 kg ha(-1) level of fungicide in both soil samples significantly at 10 days of soil incubation and further enhanced up to 20 days of incubation. The activity of the phosphatase and urease decreased progressively at 30 and 40 days of incubation. From overall studies, higher concentrations (7.5 and 10.0 kg ha(-1)) of both tebuconazole and copper hydroxide were toxic to phosphatase and urease activities, respectively, in both soil samples.

  16. Rice husk ash as corrective of soil acidity

    Directory of Open Access Journals (Sweden)

    Gláucia Oliveira Islabão

    2014-06-01

    Full Text Available Rice husk ash (RHA is a by-product from the burning of rice husk that can have favorable effects on the soil in terms of acidity correction. The objectives of this study were to determine the effective calcium carbonate equivalent (ECC of RHA under field conditions, and establish technical criteria as a basis for estimating the overall ECC of RHA. The 12 treatments of the experiment consisted of 10 RHA dosages (0, 10, 20, 30, 40, 60, 80, 100, 120, and 140 Mg ha-1 and two references, one of which was an absolute control (AC and the other a plot limed and fertilized according to official recommendations (recommended fertilization - RF. The soil was sampled twice (15 and 210 days after incorporating RHA, in the layers 0.00-0.10 and 0.10-0.20 m, to determine the pH(H2O and base saturation (V%. The ECC and neutralizing value (NV of RHA were also determined. The results showed that RHA neutralizes soil acidity, in a faster reaction than conventional limestone, despite a low ECC (around 3 %.

  17. Effect of aging on the bioavailability and fractionation of arsenic in soils derived from five parent materials in a red soil region of Southern China.

    Science.gov (United States)

    Wang, Yanan; Zeng, Xibai; Lu, Yahai; Su, Shiming; Bai, Lingyu; Li, Lianfang; Wu, Cuixia

    2015-12-01

    The effects of aging time and soil parent materials on the bioavailability and fractionations of arsenic (As) in five red soils were studied. The results indicated that As bioavailability in all soils decreased during aging, especially with a sharp decline occurring in the first 30 days. After aging for 360 days, the highest available As concentration, which accounted for 12.3% of the total, was observed in soils derived from purple sandy shale. While 2.67% was the lowest proportion of the available As in soils derived from quaternary red clay. Furthermore, the best fit of the available As changing with aging time was obtained using the pseudo-second-order model (R(2) = 0.939-0.998, P < 0.05). Notably, Al oxides played a more crucial role (R(2) = 0.89, P<0.05) than did Fe oxides in controlling the rate of As aging. The non-specially and specially absorbed As constituted the primary forms of available As. Copyright © 2015 Elsevier Ltd. All rights reserved.

  18. Elevational Variation in Soil Amino Acid and Inorganic Nitrogen Concentrations in Taibai Mountain, China.

    Directory of Open Access Journals (Sweden)

    Xiaochuang Cao

    Full Text Available Amino acids are important sources of soil organic nitrogen (N, which is essential for plant nutrition, but detailed information about which amino acids predominant and whether amino acid composition varies with elevation is lacking. In this study, we hypothesized that the concentrations of amino acids in soil would increase and their composition would vary along the elevational gradient of Taibai Mountain, as plant-derived organic matter accumulated and N mineralization and microbial immobilization of amino acids slowed with reduced soil temperature. Results showed that the concentrations of soil extractable total N, extractable organic N and amino acids significantly increased with elevation due to the accumulation of soil organic matter and the greater N content. Soil extractable organic N concentration was significantly greater than that of the extractable inorganic N (NO3--N + NH4+-N. On average, soil adsorbed amino acid concentration was approximately 5-fold greater than that of the free amino acids, which indicates that adsorbed amino acids extracted with the strong salt solution likely represent a potential source for the replenishment of free amino acids. We found no appreciable evidence to suggest that amino acids with simple molecular structure were dominant at low elevations, whereas amino acids with high molecular weight and complex aromatic structure dominated the high elevations. Across the elevational gradient, the amino acid pool was dominated by alanine, aspartic acid, glycine, glutamic acid, histidine, serine and threonine. These seven amino acids accounted for approximately 68.9% of the total hydrolyzable amino acid pool. The proportions of isoleucine, tyrosine and methionine varied with elevation, while soil major amino acid composition (including alanine, arginine, aspartic acid, glycine, histidine, leucine, phenylalanine, serine, threonine and valine did not vary appreciably with elevation (p>0.10. The compositional

  19. Valuable biomolecules from nine North Atlantic red macroalgae: Amino acids, fatty acids, carotenoids, minerals and metals

    DEFF Research Database (Denmark)

    Razi Parjikolaei, Behnaz; Bruhn, Annette; Eybye, Karin Loft

    2016-01-01

    , glutamic acid, and arginine, respectively. The amino acid score of the nine algae varied from 44% to 92%, the most commonly first limiting amino acid being histidine. Lutein, β-carotene, and zeaxanthin were the identified carotenoids. Contents of all macro and trace minerals, with the exception...

  20. Valuable biomolecules from nine North Atlantic red macroalgae: Amino acids, fatty acids, carotenoids, minerals and metals

    DEFF Research Database (Denmark)

    Razi Parjikolaei, Behnaz; Bruhn, Annette; Eybye, Karin Loft

    2016-01-01

    , glutamic acid, and arginine, respectively. The amino acid score of the nine algae varied from 44% to 92%, the most commonly first limiting amino acid being histidine. Lutein, β-carotene, and zeaxanthin were the identified carotenoids. Contents of all macro and trace minerals, with the exception...

  1. Degradation of reactive dyes by ozonation and oxalic acid-assimilating bacteria isolated from soil.

    Science.gov (United States)

    Kurosumi, Akihiro; Kaneko, Erika; Nakamura, Yoshitoshi

    2008-07-01

    Ozonation and treatment of wastewaters with oxalic acid-assimilating bacterium was attempted for the complete degradation of reactive dyes. Oxalic acid-assimilating bacterium, Pandoraea sp. strain EBR-01, was newly isolated from soil under bamboo grove and was identified to be a member of the genus Pandoraea by physicochemical and biochemical tests including 16S rDNA sequence analysis. The bacterium was grown optimally at pH 7 and temperature of 30 degrees C under the laboratory conditions. Reactive Red 120 (RR120), Reactive Green 19 (RG19), Reactive Black 5 (RB5) and Remazol Brilliant Blue R (RBBR) were used in degradation experiments. At the initial reactive dye concentrations of 500 mg/l and the ozonation time of 80 min, it was confirmed that 75-90 mg/l oxalic acid was generated from reactive dyes by ozonation. Microbial treatment using EBR-01 greatly decreased the amount of oxalic acid in the mixture after 48 h, but it was not removed completely. TOC/TOC(0) of reactive dye solutions was also decreased to 80-90% and 20-40% by ozonation and microbial treatment using EBR-01, respectively. The study confirmed that consecutive treatments by ozone and microorganisms are efficient methods to mineralize reactive dyes.

  2. Influence of ameliorating soil acidity with dolomite on the priming of soil C content and CO2 emission.

    Science.gov (United States)

    Shaaban, Muhammad; Wu, Lei; Peng, Qi-An; van Zwieten, Lukas; Chhajro, Muhammad Afzal; Wu, Yupeng; Lin, Shan; Ahmed, Muhammad Mahmood; Khalid, Muhammad Salman; Abid, Muhammad; Hu, Ronggui

    2017-02-21

    Lime or dolomite is commonly implemented to ameliorate soil acidity. However, the impact of dolomite on CO2 emissions from acidic soils is largely unknown. A 53-day laboratory study was carried out to investigate CO2 emissions by applying dolomite to an acidic Acrisol (rice-rapeseed rotation [RR soil]) and a Ferralsol (rice-fallow/flooded rotation [RF soil]). Dolomite was dosed at 0, 0.5, and 1.5 g 100 g(-1) soil, herein referred to as CK, L, and H, respectively. The soil pH(H2O) increased from 5.25 to 7.03 and 7.62 in L and H treatments of the RR soil and from 5.52 to 7.27 and 7.77 in L and H treatments of the RF soil, respectively. Dolomite application significantly (p ≤ 0.001) increased CO2 emissions in both RR and RF soils, with higher emissions in H as compared to L dose of dolomite. The cumulative CO2 emissions with H dose of dolomite were greater 136% in the RR soil and 149% in the RF soil as compared to CK, respectively. Dissolved organic carbon (DOC) and microbial biomass carbon (MBC) increased and reached at 193 and 431 mg kg(-1) in the RR soil and 244 and 481 mg kg(-1) in the RF soil by H treatments. The NH4(-)-N and NO3(-)-N were also increased by dolomite application. The increase in C and N contents stimulated microbial activities and therefore higher respiration in dolomite-treated soil as compared to untreated. The results suggest that CO2 release in dolomite-treated soils was due to the priming of soil C content rather than chemical reactions.

  3. COMPARISON OF FATTY ACID PROFILES OF MALE AND FEMALE GIANT RED SHRIMPS (Aristaeomorpha foliacea RISSO, 1827) OBTAINED FROM MEDITERRANEAN SEA

    OpenAIRE

    İ.A. Olgunoglu; E. Artar; M. Gocer

    2015-01-01

    This study was carried out to detect the concentration of fatty acid in female and male specimens of commercially important giant red shrimp (Aristaeomorpha foliacea) obtained from (including 20 male shrimps and also 20 female shrimp) Mediterranean Sea. In fatty acid composition, the saturated fatty acid fraction was dominant, followed by polyunsaturated fatty acid and monounsaturated fatty acid for both sexes. The analyses indicated that PUFAs, and the MUFAs content were higher in female shr...

  4. PRINCIPAL COMPONENT ANALYSIS OF FACTORS DETERMINING PHOSPHATE ROCK DISSOLUTION ON ACID SOILS

    Directory of Open Access Journals (Sweden)

    Yusdar Hilman

    2016-10-01

    Full Text Available Many of the agricultural soils in Indonesia are acidic and low in both total and available phosphorus which severely limits their potential for crops production. These problems can be corrected by application of chemical fertilizers. However, these fertilizers are expensive, and cheaper alternatives such as phosphate rock (PR have been considered. Several soil factors may influence the dissolution of PR in soils, including both chemical and physical properties. The study aimed to identify PR dissolution factors and evaluate their relative magnitude. The experiment was conducted in Soil Chemical Laboratory, Universiti Putra Malaysia and Indonesian Center for Agricultural Land Resources Research and Development from January to April 2002. The principal component analysis (PCA was used to characterize acid soils in an incubation system into a number of factors that may affect PR dissolution. Three major factors selected were soil texture, soil acidity, and fertilization. Using the scores of individual factors as independent variables, stepwise regression analysis was performed to derive a PR dissolution function. The factors influencing PR dissolution in order of importance were soil texture, soil acidity, then fertilization. Soil texture factors including clay content and organic C, and soil acidity factor such as P retention capacity interacted positively with P dissolution and promoted PR dissolution effectively. Soil texture factors, such as sand and silt content, soil acidity factors such as pH, and exchangeable Ca decreased PR dissolution.

  5. EDTA and HCl leaching of calcareous and acidic soils polluted with potentially toxic metals: remediation efficiency and soil impact.

    Science.gov (United States)

    Udovic, Metka; Lestan, Domen

    2012-07-01

    The environmental risk of potentially toxic metals (PTMs) in soil can be diminished by their removal. Among the available remediation techniques, soil leaching with various solutions is one of the most effective but data about the impact on soil chemical and biological properties are still scarce. We studied the effect of two common leaching agents, hydrochloric acid (HCl) and a chelating agent (EDTA) on Pb, Zn, Cd removal and accessibility and on physico-chemical and biological properties in one calcareous, pH neutral soil and one non-calcareous acidic soil. EDTA was a more efficient leachant compared to HCl: up to 133-times lower chelant concentration was needed for the same percentage (35%) of Pb removal. EDTA and HCl concentrations with similar PTM removal efficiency decreased PTM accessibility in both soils but had different impacts on soil properties. As expected, HCl significantly dissolved carbonates from calcareous soil, while EDTA leaching increased the pH of the acidic soil. Enzyme activity assays showed that leaching with HCl had a distinctly negative impact on soil microbial and enzyme activity, while leaching with EDTA had less impact. Our results emphasize the importance of considering the ecological impact of remediation processes on soil in addition to the capacity for PTM removal. Copyright © 2012 Elsevier Ltd. All rights reserved.

  6. Effect of ascorbic acid (vitamin C) on the ESR spectra of the red and black hair: pheomelanin free radicals are not always present in red hair.

    Science.gov (United States)

    Chikvaidze, Eduard; Topeshashvili, Maia

    2015-12-01

    Increased incidence of melanoma in the population with red hair is conditioned by synthesis of pheomelanin pigments in the skin and their phototoxic properties. The recent research has shown that free radicals of pheomelanin are produced not only by the influence of UV irradiation, but also in UV-independent pathways of oxidative stress. It has been ascertained, that the color of the hair is not always determinant of the amount of pheolemanin radicals in red hair. Therefore, in order to evaluate the risk of melanoma in different individuals, it is necessary to define the amount of free radicals of pheomelanin in red hair using ESR spectroscopy method. Besides, it is very important to find effective antioxidant, capable of neutralizing free radicals of pheomelanin. It was proved that ascorbic acid neutralizes free radicals of pheomelanin very effectively. The main goal of our research was to define the presumably optimal concentration of ascorbic acid as an antioxidant and study the kinetics of the influence of this concentration on red and black hair. It has been found out, that ascorbic acid influences the free radicals of red and black hair, and its appropriate optimal concentration is 10 mM. The obtained results can be considered in dermatology and cosmetology.

  7. Study of changes organic acids in red wines during malolactic fermentation

    Directory of Open Access Journals (Sweden)

    Jindřiška Kučerová

    2011-01-01

    Full Text Available The aim of this contribution is to be able to describe the movement of organic acids in red wine during malolactic fermentation. Wines from Znojmo wine region were represented by varieties of Svatovavřinecké (Saint Laurent, Rulandské modré (Pinot Noir, Zweigeltrebe, Frankovka (Lemberger and Dornfelder. The grapes went through the same way of wine making and after completion of alcoholic fermentation were inoculated with pure culture of lactic acid bacteria Oenococcus oeni. Samples were taken for chemical analysis during biodegradation of acids within the range of 2 to 4 days and they were measured using a device WineScan FT 120. Chemical analysis detected changes in the concentrations of the following parameters: total acidity, lactic, malic, tartaric and citric acids. The total content of acids statistically significantly (P = 0.05 differed only between samples of Svatovavřinecké T 66 and Zweigeltrebe T 2.The differences of average mass concentrations of lactic, malic and citric acids were not statistically relevant. Nevertheless, statistically relevant difference in the concentration of tartaric acid from all other wines was detected in a sample of SV T 66 which also reached the highest average value (5.18 g/l.

  8. Atmospheric inorganic nitrogen deposition to a typical red soil forestland in southeastern China.

    Science.gov (United States)

    Fan, Jian-Ling; Hu, Zheng-Yi; Wang, Ti-Jian; Zhou, Jing; Wu, Cong-Yang-Hui; Xia, Xu

    2009-12-01

    A 2-year monitoring study was conducted to estimate nitrogen deposition to a typical red soil forestland in southeastern China. The dry deposition velocities (V(d)) were estimated using big leaf resistance analogy model. Atmospheric nitrogen dry deposition was estimated by combing V(d) and nitrogen compounds concentrations, and the wet deposition was calculated via rainfall and nitrogen concentrations in rainwater. The total inorganic nitrogen deposition was 83.7 kg ha(-1) a(-1) in 2004 and 81.3 kg ha(-1) a(-1) in 2005, respectively. The dry deposition contributed 78.6% to total nitrogen deposition, in which ammonia was the predominant contributor that accounted for 86.1%. Reduced nitrogen compounds were the predominant contributors, accounting for 78.3% of total nitrogen deposition. The results suggested that atmospheric inorganic nitrogen could be attributed to intensive agricultural practices such as excessive nitrogen fertilization and livestock production. Therefore, impacts of atmospheric nitrogen originated from agriculture practices on nearby forest ecosystems should be evaluated.

  9. Atmospheric Sulfur Deposition for a Red Soil Broadleaf Forest in Southern China

    Institute of Scientific and Technical Information of China (English)

    XU Cheng-Kai; HU Zheng-Yi; CAI Zu-Cong; WANG Ti-Jian; HE Yuan-Qiu; CAO Zhi-Hong

    2004-01-01

    A two-year study in a typical red soil region of Southern China was conducted to determine 1) the dry deposition velocity (Vd) for SO2 and particulate SO2 4- above a broadleaf forest, and 2) atmospheric sulfur fluxes so as to estimate the contribution of various fractions in the total. Using a resistance model based on continuous hourly meteorological data, atmospheric dry sulfur deposition in a forest was estimated according to Vd and concentrations of both atmospheric SO2 and particulate SO24-. Meanwhile, wet S deposition was estimated based on rainfall and sulfate concentrations in the rainwater. Results showed that about 99% of the dry sulfur deposition flux in the forest resulted from SO2 dry deposition.In addition, the observed dry S deposition was greater in 2002 than in 2000 because of a higher average concentration of SO2 in 2002 than in 2000 and not because of the average dry deposition velocity which was lower for SO2 in 2002. Also,dry SO2 deposition was the dominant fraction of deposited atmospheric sulfur in forests, contributing over 69% of the total annual sulfur deposition. Thus, dry SO2 deposition should be considered when estimating sulfur balance in forest ecological systems.

  10. Levels of red blood cell fatty acids in patients with psychosis, their unaffected siblings, and healthy controls

    NARCIS (Netherlands)

    S. Medema (Suzanne); L.P.C.M. Mocking (Remco); M. Koëter (Maarten); F.M. Vaz (Frédéric M.); C. Meijer (Carin); L. Haan (Lieuwe); N.J.M. De Van Beveren (Nico J. M.); R. Kahn; L. de Haan (Lieuwe); J. Van Os (Jim); D. Wiersma (Durk); R. Bruggeman (Richard); W. Cahn (Wiepke); I. Myin-Germeys (Inez)

    2016-01-01

    textabstractBackground: Two recent meta- Analyses showed decreased red blood cell (RBC) polyunsaturated fatty acids (FA) in schizophrenia and related disorders. However, both these meta- Analyses report considerable heterogeneity, probably related to differences in patient samples between studies. H

  11. Controls of Soluble Al in Experimental Acid Sulfate Conditions and Acid Sulfate Soils

    Institute of Scientific and Technical Information of China (English)

    LINCHUXIA; M.D.MELVILLE

    1997-01-01

    The controls of soluble Al concentration were examined in three situations of acid sulfate conditions:1) experimental acid sulfate conditions by addition of varying amounts of Al(OH)3(gibbsite) into a sequence of H2SO4 solutions;2)experimental acid sulfate conditions by addition of the same sequence of H2SO4 solutions into two non-cid sulfacte soil samples with known amounts of acid oxalate extractable Al; and 3) actual acid sulfate soil conditions.The experiment using gibbsite as an Al-bearing mineral showed that increase in the concentration of H2SO4 solution increased the soluble Al concentration,accompanied by a decrease i the solution pH, Increasing amount of gibbsite added to the H2SO4 solutions also increased soluble Al concentration,but resulted in an increase in solution pH.Within the H2SO4 concentration range of 0.0005-0.5mol L-1 and the Al(OH)3 range of 0.01-0.5g(in 25 mL of H2SO4 solutions),the input of H2SO4 had the major control on soluble Al Concentration and pH .The availability of Al(OH)3,however,was responsible for the spread fo the various sample points,with a tendency that the samples containing more gibbsite had a higher soluble Al concentration than those containing less gibbsite at equivalent pH levels.The experimental results from treatment of soil samples with H2SO4 solutions and the analytical results of acid sulfate soils also showed the similar trend.

  12. Transport of two naphthoic acids and salicylic acid in soil: experimental study and empirical modeling.

    Science.gov (United States)

    Hanna, K; Lassabatere, L; Bechet, B

    2012-09-15

    In contrast to the parent compounds, the mechanisms responsible for the transport of natural metabolites of polycyclic aromatic hydrocarbons (PAH) in contaminated soils have been scarcely investigated. In this study, the sorption of three aromatic acids (1-naphthoic acid (NA), 1-hydroxy-2-naphthoic acid (HNA) and salicylic acid (SA)) was examined on soil, in a batch equilibrium single-system, with varying pH and acid concentrations. Continuous flow experiments were also carried out under steady-state water flow. The adsorption behavior of naphthoic and benzoic acids was affected by ligand functionality and molecular structure. All modeling options (equilibrium, chemical nonequilibrium, i.e. chemical kinetics, physical nonequilibrium, i.e. surface sites in the immobile water fraction, and both chemical and physical nonequilibrium) were tested in order to describe the breakthrough behavior of organic compounds in homogeneously packed soil columns. Tracer experiments showed a small fractionation of flow into mobile and immobile compartments, and the related hydrodynamic parameters were used for the modeling of reactive transport. In all cases, the isotherm parameters obtained from column tests differed from those derived from the batch experiments. The best accurate modeling was obtained considering nonequilibrium for the three organic compounds. Both chemical and physical nonequilibrium led to appropriate modeling for HNA and NA, while chemical nonequilibrium was the sole option for SA. SA sorption occurs mainly in mobile water and results from the concomitancy of instantaneous and kinetically limited sites. For all organic compounds, retention is contact condition dependent and differs between batch and column experiments. Such results show that preponderant mechanisms are solute dependent and kinetically limited, which has important implications for the fate and transport of carboxylated aromatic compounds in contaminated soils. Copyright © 2012 Elsevier Ltd. All

  13. Influences of humic acid and fulvic acid on horizontal leaching behavior of anthracene in soil barriers.

    Science.gov (United States)

    Yu, Sheng; Li, Bang-Yu; Chen, Yi-Hu

    2015-12-01

    The influences of humic acid (HA) and fulvic acid (FA) on horizontal leaching behaviors of anthracene in barriers were investigated. Soil colloids (≤1 μm) were of concern because of their abilities of colloid-facilitated transport for hydrophobic organic compounds with soluble and insoluble organic matters. Through freely out of the barriers in the presence of soil colloids with FA added, the higher concentrations of anthracene were from 320 μg L(-1) (D1 and D3) to 390 μg L(-1) (D2 and D4) with 1 to 20 cm in length. The contents of anthracene were distributed evenly at 25 ng g(-1) dry weight (DW) (D1 and D3) and 11 ng g(-1) DW (D2 and D4) in barriers. Therefore, anthracene leaching behaviors were mainly induced by soil colloids with soluble organic matters. The insoluble organic matters would facilitate anthracene onto soil colloids and enhance the movement in and through porous media of soil matrix.

  14. Modification of red mud by acid treatment and its application for CO removal.

    Science.gov (United States)

    Sushil, Snigdha; Batra, Vidya S

    2012-02-15

    Activated red mud (ARM) samples were tested for carbon monoxide (CO) oxidation in the temperature range of 100-500°C. Conversion of >90% was obtained for temperatures above 400°C for all samples. In order to study the effect of hydroxylated phases of iron oxide in red mud on the removal of CO, 'as-received' red mud (RM) and acid digested and re-precipitated red mud (TRM) were also tested under similar conditions. It was found that TRM was more effective in removal of CO with the 50% conversion temperature (T50) 80°C lower than the ARM samples. The samples before and after reaction were characterized by inductively coupled plasma-optical emission spectroscopy (ICP-OES), BET N(2) adsorption, X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), electron microscopy (SEM and TEM) and temperature programmed reduction (TPR). It was observed that TRM had iron in an amorphous form which then converted to iron oxide after heating. The higher activity of TRM was due to its higher surface area and presence of hydroxylated phase of iron oxide.

  15. Effects of simulated acid rain on soil fauna community composition and their ecological niches.

    Science.gov (United States)

    Wei, Hui; Liu, Wen; Zhang, Jiaen; Qin, Zhong

    2017-01-01

    Acid rain is one of the severest environmental issues globally. Relative to other global changes (e.g., warming, elevated atmospheric [CO2], and nitrogen deposition), however, acid rain has received less attention than its due. Soil fauna play important roles in multiple ecological processes, but how soil fauna community responds to acid rain remains less studied. This microcosm experiment was conducted using latosol with simulated acid rain (SAR) manipulations to observe potential changes in soil fauna community under acid rain stress. Four pH levels, i.e., pH 2.5, 3.5, 4.5, and 5.5, and a neutral control of pH 7.0 were set according to the current pH condition and acidification trend of precipitation in southern China. As expected, we observed that the SAR treatments induced changes in soil fauna community composition and their ecological niches in the tested soil; the treatment effects tended to increase as acidity increased. This could be attributable to the environmental stresses (such as acidity, porosity and oxygen supply) induced by the SAR treatments. In addition to direct acidity effect, we propose that potential changes in permeability and movability of water and oxygen in soils induced by acid rain could also give rise to the observed shifts in soil fauna community composition. These are most likely indirect pathways of acid rain to affect belowground community. Moreover, we found that nematodes, the dominating soil fauna group in this study, moved downwards to mitigate the stress of acid rain. This is probably detrimental to soil fauna in the long term, due to the relatively severer soil conditions in the deep than surface soil layer. Our results suggest that acid rain could change soil fauna community and the vertical distribution of soil fauna groups, consequently changing the underground ecosystem functions such as organic matter decomposition and greenhouse gas emissions.

  16. The determination of titratable acidity and total tannins in red wine

    Directory of Open Access Journals (Sweden)

    Rajković Miloš B.

    2009-01-01

    Full Text Available Titration acidity and content of total tannins in mass-market red wines are analyzed in this paper. The content of total acids in wine, expressed through wine acid, was analyzed by potentiometric titration on 7.00 pH value. According to titratable acidity in analyzed wines, all wines (only with analyzed parameters according to Regulations about wine quality. The analysis of differential potentiometric curves shows that these curves can give the answer to the question if non organic substances, amino groups and phenols are present in wine in large quantity, as they are always present in wine. However it doesn't give the clear answer which substances are present in analyzed samples. The answer to this question can be received only by the method of ionic chromatography. The content of total tannins shows short time of storage in wine cellars so wine wasn't stored long enough, i.e. they are commercial wines made for mass market production and consumption. Although they have less content of total tannin materials of given values, wine taste gives the correlation with other polyphenol materials that only give odour, aroma and 'bouquet' to wine. The relative error of mean value is very low which indicates the reproduction of results and reliability of the method of determination of total tannins in red wine.

  17. Fatty acids in female’s gonads of the Red Sea fish Rhabdosargus sarba during the spawning season

    OpenAIRE

    Suhaila Qari; Samia Moharram; Safaa Alowaidi

    2014-01-01

    Objective: To determine the fatty acids profiles in female fish, Rhabdosargus sarba (R. sarba) from the Red Sea during the spawning season. Methods: Monthly individual R. sarba were obtained from Bangalah market in Jeddah, Red Sea and transported to the laboratory in ice aquarium. The total length, standard length and weight were measured, fishes were dissected. Ovaries were removed, weighed and 10 mL of concentrated hydrochloric acid were added to 10 g of the ovary in a conica...

  18. Declining acidic deposition begins reversal of forest-soil acidification in the northeastern U.S

    Science.gov (United States)

    Gregory B. Lawrence; Paul W. Hazlett; Ivan J. Fernandez; Rock Ouimet; Scott W. Bailey; Walter C. Shortle; Kevin T. Smith; Michael R. Antidormi

    2015-01-01

    Decreasing trends in acidic deposition levels over the past several decades have led to partial chemical recovery of surface waters. However, depletion of soil Ca from acidic deposition has slowed surface water recovery and led to the impairment of both aquatic and terrestrial ecosystems. Nevertheless, documentation of acidic deposition effects on soils has been...

  19. Lead binding to soil fulvic and humic acids: NICA-Donnan modeling and XAFS spectroscopy

    NARCIS (Netherlands)

    Xiong, J.; Koopal, L.K.; Tan, W.; Fang, L.; Wang, W.; Zhao, W.; Liu, T.; Zhang, J.; Weng, L.

    2013-01-01

    Binding of lead (Pb) to soil fulvic acid (JGFA), soil humic acids (JGHA, JLHA), and lignite-based humic acid (PAHA) was investigated through binding isotherms and XAFS. Pb binding to humic substances (HS) increased with increasing pH and decreasing ionic strength. The NICA-Donnan model described Pb

  20. THE STABILIZATION SYSTEM OF SOIL ACIDITY WHEN GROWING TOMATOES IN A GREENHOUSE

    Directory of Open Access Journals (Sweden)

    Tsokur D. S.

    2013-11-01

    Full Text Available The article presents: the stabilization system of soil acidity, which allows subsoil irrigation tomato plants catholyte to compensate the negative effects of acidic fertilizer, and additionally to prevent plant diseases anolyte solution; transfer function of the stabilization system of soil acidity and the results of its tests

  1. Betalain, Acid ascorbic, phenolic contents and antioxidant properties of purple, red, yellow and white cactus pears.

    Science.gov (United States)

    Sumaya-Martínez, María Teresa; Cruz-Jaime, Sandra; Madrigal-Santillán, Eduardo; García-Paredes, Juan Diego; Cariño-Cortés, Raquel; Cruz-Cansino, Nelly; Valadez-Vega, Carmen; Martinez-Cardenas, Leonardo; Alanís-García, Ernesto

    2011-01-01

    Commercialization of cactus pears based on their antioxidant properties can generate competitive advantages, and these can turn into business opportunities and the development of new products and a high-value ingredient for the food industry. This work evaluated the antioxidant activities (1,1-diphenyl-2-picrylhydrazyl radical-scavenging, protection against oxidation of a β-carotene-linoleic acid emulsion, and iron (II) chelation), the content of total phenolic compounds, ascorbic acid, betacyanin, betaxanthin and the stability of betacyanin pigments in presence of Cu (II)-dependent hydroxyl radicals (OH•), in 18 cultivars of purple, red, yellow and white cactus pear from six Mexican states. Our results indicated that the antiradical activities from yellow and white cactus pear cultivars were not significantly different (p cactus pear from the state of Zacatecas showed the highest antioxidant activity. The free radical scavenging activity for red cactus pears was significantly correlated (p cactus pears studied showed significant chelating activity of ferrous ions. The red and purple cactus pears showed a great stability when exposed to OH•.

  2. Regional-scale assessment of soil salinity in the Red River Valley using multi-year MODIS EVI and NDVI.

    Science.gov (United States)

    Lobell, D B; Lesch, S M; Corwin, D L; Ulmer, M G; Anderson, K A; Potts, D J; Doolittle, J A; Matos, M R; Baltes, M J

    2010-01-01

    The ability to inventory and map soil salinity at regional scales remains a significant challenge to scientists concerned with the salinization of agricultural soils throughout the world. Previous attempts to use satellite or aerial imagery to assess soil salinity have found limited success in part because of the inability of methods to isolate the effects of soil salinity on vegetative growth from other factors. This study evaluated the use of Moderate Resolution Imaging Spectroradiometer (MODIS) imagery in conjunction with directed soil sampling to assess and map soil salinity at a regional scale (i.e., 10-10(5) km(2)) in a parsimonious manner. Correlations with three soil salinity ground truth datasets differing in scale were made in Kittson County within the Red River Valley (RRV) of North Dakota and Minnesota, an area where soil salinity assessment is a top priority for the Natural Resource Conservation Service (NRCS). Multi-year MODIS imagery was used to mitigate the influence of temporally dynamic factors such as weather, pests, disease, and management influences. The average of the MODIS enhanced vegetation index (EVI) for a 7-yr period exhibited a strong relationship with soil salinity in all three datasets, and outperformed the normalized difference vegetation index (NDVI). One-third to one-half of the spatial variability in soil salinity could be captured by measuring average MODIS EVI and whether the land qualified for the Conservation Reserve Program (a USDA program that sets aside marginally productive land based on conservation principles). The approach has the practical simplicity to allow broad application in areas where limited resources are available for salinity assessment.

  3. Red Blood Cell Fatty Acids and Incident Diabetes Mellitus in the Women's Health Initiative Memory Study.

    Directory of Open Access Journals (Sweden)

    William S Harris

    Full Text Available The relations between dietary and/or circulating levels of fatty acids and the development of type 2 diabetes is unclear. Protective associations with the marine omega-3 fatty acids and linoleic acid, and with a marker of fatty acid desaturase activity delta-5 desaturase (D5D ratio have been reported, as have adverse relations with saturated fatty acids and D6D ratio.To determine the associations between red blood cell (RBC fatty acid distributions and incident type 2 diabetes.Prospective observational cohort study nested in the Women's Health Initiative Memory Study.General population.Postmenopausal women.Self-reported incident type 2 diabetes.There were 703 new cases of type 2 diabetes over 11 years of follow up among 6379 postmenopausal women. In the fully adjusted models, baseline RBC D5D ratio was inversely associated with incident type 2 diabetes [Hazard Ratio (HR 0.88, 95% confidence interval (CI 0.81-0.95 per 1 SD increase. Similarly, baseline RBC D6D ratio and palmitic acid were directly associated with incident type 2 diabetes (HR 1.14, 95% CI 1.04-1.25; and HR 1.24, 95% CI 1.14-1.35, respectively. None of these relations were materially altered by excluding incident cases in the first two years of follow-up. There were no significant relations with eicosapentaenoic, docosahexaenoic or linoleic acids.Whether altered fatty acid desaturase activities or palmitic acid levels are causally related to the development of type 2 diabetes cannot be determined from this study, but our findings suggest that proportions of certain fatty acids in RBC membranes are associated with risk for type 2 diabetes.

  4. Organic Acids Regulation of Chemical-Microbial Phosphorus Transformations in Soils.

    Science.gov (United States)

    Menezes-Blackburn, Daniel; Paredes, Cecilia; Zhang, Hao; Giles, Courtney D; Darch, Tegan; Stutter, Marc; George, Timothy S; Shand, Charles; Lumsdon, David; Cooper, Patricia; Wendler, Renate; Brown, Lawrie; Blackwell, Martin; Wearing, Catherine; Haygarth, Philip M

    2016-11-01

    We have used an integrated approach to study the mobility of inorganic phosphorus (P) from soil solid phase as well as the microbial biomass P and respiration at increasing doses of citric and oxalic acid in two different soils with contrasting agronomic P status. Citric or oxalic acids significantly increased soil solution P concentrations for doses over 2 mmol kg(-1). However, low organic acid doses (soils, treatment with the tribasic citric acid led to a greater increase in soil solution P than the dibasic oxalic acid, likely due to the rapid degrading of oxalic acids in soils. After equilibration of soils with citric or oxalic acids, the adsorbed-to-solution distribution coefficient (Kd) and desorption rate constants (k-1) decreased whereas an increase in the response time of solution P equilibration (Tc) was observed. The extent of this effect was shown to be both soil and organic acid specific. Our results illustrate the critical thresholds of organic acid concentration necessary to mobilize sorbed and precipitated P, bringing new insight on how the exudation of organic acids regulate chemical-microbial soil phosphorus transformations.

  5. Remote Sensing Observations of Snow and Soil Moisture for Snowmelt Flood Predictions in the Red River of the North Basin

    Science.gov (United States)

    Tuttle, S. E.; Jacobs, J. M.; Vuyovich, C.; Cho, E.; Restrepo, P. J.; Jia, X.; Cosh, M. H.; Deweese, M. M.; Connelly, B.; Buan, S.

    2015-12-01

    The northward-flowing Red River of the North Basin (RRB), located in eastern North Dakota and western Minnesota, is vulnerable to frequent floods due to its flat terrain and low permeability soil. A vast majority of floods in the basin occur during the snowmelt season, when the winter snowpack thaws and spring rains fall onto saturated soils. This causes the Red River to spill over shallow banks and across the floodplain. The region has sparse in situ observations of snow and soil moisture, making flood prediction in the RRB difficult. Remote sensing data can help to capture magnitude, timing, and spatial distribution of watershed scale snow, soil moisture, and snowmelt parameters in the RRB, which will allow for better characterization of the watershed's hydrologic state. This research examines snow water equivalent (SWE; from the AMSR-E, AMSR2, and SSM/I satellite instruments), soil moisture (from AMSR-E, SMOS, and SMAP), and snow covered area (SCA; from MODIS), along with modeled SWE and snow depth from NOAA's National Operational Hydrologic Remote Sensing Center (NOHRSC) SNOw Data Assimilation System (SNODAS). These data are compared with observations from local and federal snow surveys, NOHRSC Airborne Gamma Radiation Snow Survey Program flights, NOAA National Climate Data Center (NCDC) cooperative network sites, Natural Resource Conservation Service (NRCS) Soil Climate Analysis Network (SCAN) sites, and the North Central River Forecast Center's (NCRFC) model states, in order to determine data quality as well as strengths and weaknesses of satellite observations for RRB flood forecasting. Future analyses will include evaluation of freeze/thaw state information from the Soil Moisture Active-Passive (SMAP) satellite, and explore the potential for flood forecasting improvement by updating state variables of the NOAA National Weather Service (NWS) operational forecasting models with remotely sensed fields.

  6. An Experimental Method to Quantify Extractable Amino Acids in Soils from Southeast China

    Institute of Scientific and Technical Information of China (English)

    CHEN Xian-you; WU Liang-huan; CAO Xiao-chuang; Sarkar Animesh; ZHU Yuan-hong

    2013-01-01

    The extraction and comparison of soil amino acids using different extractants (deionized water, K2SO4, Na2SO4, NaCl, KCl) were reported. Results showed that 0.5 mol L-1 K2SO4 with a 5 times extraction was a better method to assess the concentration of extractable amino acids in soils. The total amino acids extracted from soil planted for tea were similar to the total inorganic nitrogen. While they extracted from vegetable soil and paddy soil were much lower than the total inorganic nitrogen.

  7. Light and acid dual-responsive organogel formation based on m-methyl red derivative.

    Science.gov (United States)

    Cao, Xinhua; Gao, Aiping; Lv, Haiting; Wu, Yan; Wang, Xiuxiu; Fan, Yang

    2013-12-07

    A new gelator 1 that included m-methyl red was synthesized and fully characterized. It was found that the organogel of 1 was stable in DMSO even if the organogel was stimulated by acid or light. The organogel was thoroughly characterized using various microscopic techniques including field-emission scanning electron microscopy (FESEM), X-ray diffraction (XRD), UV-vis and Fourier transform infrared (FTIR) spectra. The organogel exhibited tunable structures and optical properties under different stimulation. The regular nanoring structure was turned into microspheres after the organogel in DMSO was stimulated at 254 nm light or acid. At the same time, the color of molecule 1 in gel state and solution state was all changed after stimulation by light or acid. The hydrogen bonding and π-π stacking were found to be the main driving forces for gel formation. This dual-responsive gel held promise for soft materials application in upscale smart responsive materials.

  8. Genotoxicity studies in vitro and in vivo on carminic acid (natural red 4).

    Science.gov (United States)

    Loprieno, G; Boncristiani, G; Loprieno, N

    1992-09-01

    The potential genotoxic activity of carminic acid (CAS no. 1260-17-9; EINECS no. 215-023-3; C.I. no. 75410), a component of natural red colouring products (cochineal: CAS no. 1343-78-8; EINECS no. 215-680-6; C.I. no. 75470), used in food, cosmetics and drugs, has been evaluated by means of a series of short-term tests in vitro and in vivo, namely Salmonella reverse mutation, chromosome aberrations and sister chromatid exchanges in vitro on Chinese hamster ovary cells, and the mouse micronucleus test. All studies have produced negative results. The data obtained strongly support the non-mutagenic/non-carcinogenic activity of this compound. Genotoxicity data previously obtained for carminic acid, concerning the induction of a series of other genetic endpoints in different test systems, have also been considered, as have recent findings that indicate lack of carcinogenic activity in the cochineal preparation containing 29.8% carminic acid.

  9. Enhanced biodegradation of anthracene in acidic soil by inoculated Burkholderia sp. VUN10013.

    Science.gov (United States)

    Somtrakoon, Khanitta; Suanjit, Sudarat; Pokethitiyook, Prayad; Kruatrachue, Maleeya; Lee, Hung; Upatham, Suchart

    2008-08-01

    The ability of Burkholderia sp. VUN10013 to degrade anthracene in microcosms of two acidic Thai soils was studied. The addition of Burkholderia sp. VUN10013 (initial concentration of 10(5) cells g(-1) dry soil) to autoclaved soil collected from the Plew District, Chanthaburi Province, Thailand, supplemented with anthracene (50 mg kg(-1) dry soil) resulted in complete degradation of the added anthracene within 20 days. In contrast, under the same test conditions but using autoclaved soil collected from the Kitchagude District, Chanthaburi Province, Thailand, only approximately 46.3% of the added anthracene was degraded after 60 days of incubation. In nonautoclaved soils, without adding the VUN10013 inocula, 22.8 and 19.1% of the anthracene in Plew and Kitchagude soils, respectively, were degraded by indigenous bacteria after 60 days. In nonautoclaved soil inoculated with Burkholderia sp. VUN10013, the rate and extent of anthracene degradation were considerably better than those seen in autoclaved soils or in uninoculated nonautoclaved soils in that only 8.2 and 9.1% of anthracene remained in nonautoclaved Plew and Kitchagude soils, respectively, after 10 days of incubation. The results showed that the indigenous microorganisms in the pristine acidic soils have limited ability to degrade anthracene. Inoculation with the anthracene-degrading Burkholderia sp. VUN10013 significantly enhanced anthracene degradation in such acidic soils. The indigenous microorganisms greatly assisted the VUN10013 inoculum in anthracene degradation, especially in the more acidic Kitchagude soil.

  10. Effect of some soil amendments on soil properties and plant growth in Southern Thailand acid upland soil

    Directory of Open Access Journals (Sweden)

    Onthong, C.

    2007-01-01

    Full Text Available One of the major factors limiting plant growth is acid soil. In general lime is used for soil amendment in acid soil. However, It has been reported that gypsum or phosphogypsum can be used for ameliorating soilacidity. Pot experiment was conducted to study the effects of lime, phosphogypsum and kieserite on soil properties and plant growth in Kho Hong soil series (coarse loamy, kaolinitic,isohyperthermic, TypicKandiudults which was considered as acid upland soil (pH 5.07. Sweet corn variety INSEE 2 was used as the test crop. The experiment was a completely randomized design with 4 replications and 19 treatments asfollow : unamended, application of hydrated lime and dolomite to raise soil pH at 5.5, application of hydrated lime and dolomite combined with phosphogypsum at the rate that can supply calcium 0.25, 0.50,0.75 and 1 time of both limes, application of hydrated lime and dolomite combined with kieserite at the rate 0.25, 0.50,0.75 and 1 times of sulfur requirement for corn (40 kg S ha-1. The result showed that shoot and root dry weights of corn were increased when lime materials, phosphogypsum and kieserite were applied and the drymatter weights were increased according to the increasing of phosphogypsum and kieserite. The maximum shoot dry weight (18.98 g pot-1 was obtained when 1 times of kieserite was supplied with dolomite and wassignificantly (P<0.01 higher than those of the unamended treatment, only hydrated lime and dolomite treatments, which had dry weights of 12.64, 15.18 and 15.67 g pot-1 respectively. Phosphorus and K uptakewere not significantly different in all treatments and the lowest uptake of N, Ca, Mg and S was obtained in the unamended treatment. The maximum uptake of N (512.10 mg pot-1 was found when 0.5 times ofphosphogypsum was applied together with dolomite. Calcium and Mg uptake was likely to increase according to the increasing rate of soil amendment application. Highest uptake of Ca (42.51 mg pot-1 was obtainedwhen

  11. Isotopically exchangeable Al in coastal lowland acid sulfate soils

    Energy Technology Data Exchange (ETDEWEB)

    Yvanes-Giuliani, Yliane A.M. [UNSW Water Research Centre, School of Civil and Environmental Engineering, UNSW Australia, Sydney, NSW 2052 (Australia); Centre Européen de Recherche et d' Enseignement des Géosciences de l' Environnement, Aix-Marseille Université, Aix en Provence (France); Fink, D. [Centre Européen de Recherche et d' Enseignement des Géosciences de l' Environnement, Aix-Marseille Université, Aix en Provence (France); Rose, J. [Institute for Environmental Research, Australian Nuclear Science and Technology Organisation, Locked Bag 2001, Kirrawee DC, NSW 2232 (Australia); Waite, T. David [UNSW Water Research Centre, School of Civil and Environmental Engineering, UNSW Australia, Sydney, NSW 2052 (Australia); Collins, Richard N., E-mail: richard.collins@unsw.edu.au [UNSW Water Research Centre, School of Civil and Environmental Engineering, UNSW Australia, Sydney, NSW 2052 (Australia)

    2016-01-15

    Periodic discharges of high concentrations of aluminium (Al) causing fish kills and other adverse effects occur worldwide in waterways affected by coastal lowland acid sulfate soils (CLASS). The exchangeability — a metal's ability to readily transfer between the soil solid- and solution-phases — of Al in these soils is therefore of particular importance as it has implications for metal transport, plant availability and toxicity to living organisms. In the present study, the concentrations of isotopically exchangeable Al (E values) were measured in 27 CLASS and compared with common salt extractions (i.e. KCl and CuCl{sub 2}) used to estimate exchangeable soil pools of Al. E values of Al were high in the soils, ranging from 357 to 3040 mg·kg{sup −1}. Exchangeable concentrations estimated using 1 M KCl were consistently lower than measured E values, although a reasonable correlation was obtained between the two values (E = 1.68 × Al{sub KCl}, r{sup 2} = 0.66, n = 25). The addition of a 0.2 M CuCl{sub 2} extraction step improved the 1:1 agreement between extractable and isotopically exchangeable Al concentrations, but lead to significant mobilisation of non-isotopically exchangeable Al in surficial ‘organic-rich’ CLASS having E values < 1000 mg·kg{sup −1}. It was concluded that currently used (i.e. 1 M KCl) methodology severely underestimates exchangeable Al and total actual acidity values in CLASS and should be corrected by a factor similar to the one determined here. - Highlights: • Isotopically exchangeable Al was compared to 1 M KCl or 0.2 M CuCl{sub 2} extractable Al. • 1 M KCl always underestimated isotopically exchangeable Al concentrations. • 0.2 M CuCl{sub 2} mobilised non-isotopically exchangeable Al • 1 M KCl values require correction of ~ 1.7 to reflect exchangeable Al concentrations.

  12. Extraction of amino acids from soils and sediments with superheated water

    Science.gov (United States)

    Cheng, C. N.; Ponnamperuma, C.

    1974-01-01

    A method of extraction for amino acids from soils and sediments involving superheated water has been investigated. About 75-97 per cent of the amino acids contained in four soils of a soil profile from Illinois were extracted by this method. Deep penetration of water into soil aggregates and partial hydrolysis of peptide bonds during this extraction by water at high temperature are likely mechanisms responsible for the release of amino acids from samples. This extraction method does not require subsequent desalting treatments when analyses are carried out with an ion-exchange amino acid analyzer.

  13. Effects of Bahia Grass Cover and Mulch on Runoff and Sediment Yield of Sloping Red Soil in Southern China

    Institute of Scientific and Technical Information of China (English)

    LI Xin-Hu; ZHANG Zhan-Yu; YANG Jie; ZHANG Guo-Hua; WANG Bin

    2011-01-01

    Rainfall, runoff (surface runoff, interflow and groundwater runoff) and soil loss from 5 m × 15 m plots were recorded for 5 years (2001-2005) in an experiment with three treatments (cover, mulch and bare ground) on sloping red soil in southern China. Surface runoff and erosion from the Bahia grass (Paspalum notatum Flugge) cover plot (A) and mulch plot (B) during the 5 years were low,despite the occurrence of potentially erosive rains. In contrast, the bare plot (C) had both the highest surface runoff coefficient and the highest sediment yield. There were significant differences in interflow and surface runoff and no significant difference in groundwater runoff among plots. The runoff coefficients and duration of interflow and groundwater runoff were in the order plot B > plot A > plot C. Effects of Bahia grass cover were excellent, indicating that the use of Bahia grass cover can be a simple and feasible practice for soil and water conservation on sloping red soil in the region.

  14. Response of Red-Backed Salamanders (Plethodon Cinereus to Changes in Hemlock Forest Soil Driven by Invasive Hemlock Woolly Adelgid (Adelges Tsugae

    Directory of Open Access Journals (Sweden)

    Alison Ochs

    2017-01-01

    Full Text Available Hemlock forests of the northeastern United States are declining due to the invasive hemlock woolly adelgid (HWA (Adelges tsugae. Hardwood species replace these forests, which affects soil properties that may influence other communities, such as red-backed salamanders (red-backs (Plethodon cinereus. This study examined the effects of HWA invasion on soil properties and how this affects red-backs at the Hemlock Removal Experiment at Harvard Forest, which consists of eight 0.8 ha plots treated with girdling to simulate HWA invasion, logging to simulate common management practices, or hemlock- or hardwood-dominated controls. Coverboard surveys were used to determine the relative abundance of red-backs between plots during June and July 2014 and soil cores were collected from which the bulk density, moisture, pH, temperature, leaf litter, and carbon-nitrogen ratio were measured. Ordination provided a soil quality index based on temperature, pH, and carbon-to-nitrogen ratio, which was significantly different between plot treatments (p < 0.05 and showed a significant negative correlation with the red-back relative abundance (p < 0.05. The findings support the hypothesis that red-backs are affected by soil quality, which is affected by plot treatment and thus HWA invasion. Further studies should explore how salamanders react in the long term towards changing environments and consider the use of red-backs as indicator species.

  15. [Effects of different long-term fertilization on the activities of enzymes related to carbon, nitrogen, and phosphorus cycles in a red soil].

    Science.gov (United States)

    Fan, Miao-zhen; Yin, Chang; Fan, Fen-liang; Song, A-lin; Wang, Bo-ren; Li, Dong-chu; Liang, Yong-chao

    2015-03-01

    Using a microplate fluorimetric assay method, five fertilization treatments, i.e. no-fertilizer control (CK) , sole application of nitrogen (N), balanced application of nitrogen, phosphorus, and potassium fertilizer (NPK), application of pig manure (M), and combination of pig manure with balanced chemical fertilizer (MNPK) were selected to investigate the effects of different long-term fertilization regimes on the activity of five enzymes (β-1, 4-glucosidase, βG; cellobiohydrolase, CBH; β-1, 4-xylosidase, βX; β-1, 4-N-acetylglucosaminidase, NAG; acid phosphatase, AP) in a red soil sampled from Qiyang, Hunnan Province. The results showed that compared with CK treatment, N treatment had no impact on βG, βX, CBH, and NAG activities but reduced AP activity, while NPK, M and MNPK treatments increased the activities of all the five enzymes. Correlation analysis indicated that all the five enzyme activities were positively correlated with the content of nitrate (r=0.465-0.733) , the content of available phosphorus (r=0.612-0.947) , soil respiration (r=0.781-0.949) and crop yield (r=0.735-0.960), while βG, CBH and AP were positively correlated with pH (r= 0.707-0.809), only AP was significantly correlated with dissolvable organic carbon (r = -0.480). These results suggested that the activities of the measured enzymes could be used as indicators of red soil fertility under different fertilization regimes, but the five enzymes tested provided limited information on the degree of acidification induced by application of mineral nitrogen.

  16. Detailed predictive mapping of acid sulfate soil occurrence using electromagnetic induction data

    DEFF Research Database (Denmark)

    Beucher, Amélie; Boman, A; Mattbäck, S

    Acid sulfate soils are often called the nastiest soils in the world (Dent & Pons 1995). Releasing a toxic combination of acidity and metals into the recipient watercourses and estuaries, these soils represent a crucial environmental problem. Moreover, these soils can have a considerable economic...... impact through the resulting corrosion of concrete and steel infrastructures, or their poor geotechnical qualities. Therefore, mapping acid sulfate soil occurrence constitutes a key step to target the strategic areas for subsequent environmental risk management and mitigation. Conventional mapping (i.......e. soil sampling and subsequent pH measurements) has typically been used for acid sulfate soils. Nonetheless, spatial modelling techniques have recently been assessed, demonstrating promising results at catchment or regional extent (Beucher et al. 2014, 2015). Furthermore, electromagnetic induction data...

  17. [Occurrence relationship between iron minerals and clay minerals in net-like red soils: evidence from X-ray diffraction].

    Science.gov (United States)

    Yin, Ke; Hong, Han-Lie; Han, Weni; Ma, Yu-Bo; Li, Rong-Biao

    2013-04-01

    The high purity of clay minerals is a key factor to reconstruct the palaeoclimate in clay mineralogy, however, the existence of iron minerals (such as goethite and hematite) and organics lead to the intergrowth of clay minerals and other minerals, producing other mineral impurities in enriched clay minerals. Although the removal of organics in soil sediments has been fully investigated, the occurrence state of iron minerals remains controversial, hindering the preparation of high-purity clay minerals. Therefore, the occurrence relationship of iron minerals and clay minerals in Jiujiang net-like red soils of the middle to lower reaches of the Yangtze River was investigated using the sequential separation method, which provided some implications for the removal of iron minerals in soil sediments. The results indicated that goethite and hematite were mostly absorbed on the surface of hydroxy-interlayered smectite and illite in the form of films, and the rest were absorbed by kaolinite.

  18. Autistic Children Exhibit Decreased Levels of Essential Fatty Acids in Red Blood Cells

    Directory of Open Access Journals (Sweden)

    Sarah A. Brigandi

    2015-05-01

    Full Text Available Omega-6 (n-6 and omega-3 (n-3 polyunsaturated fatty acids (PUFA are essential nutrients for brain development and function. However, whether or not the levels of these fatty acids are altered in individuals with autism remains debatable. In this study, we compared the fatty acid contents between 121 autistic patients and 110 non-autistic, non-developmentally delayed controls, aged 3–17. Analysis of the fatty acid composition of red blood cell (RBC membrane phospholipids showed that the percentage of total PUFA was lower in autistic patients than in controls; levels of n-6 arachidonic acid (AA and n-3 docosahexaenoic acid (DHA were particularly decreased (p < 0.001. In addition, plasma levels of the pro-inflammatory AA metabolite prostaglandin E2 (PGE2 were higher in a subset of the autistic participants (n = 20 compared to controls. Our study demonstrates an alteration in the PUFA profile and increased production of a PUFA-derived metabolite in autistic patients, supporting the hypothesis that abnormal lipid metabolism is implicated in autism.

  19. Toxicological responses of red-backed salamanders (Plethodon cinereus) to subchronic soil exposures of 2,4-dinitrotoluene

    Energy Technology Data Exchange (ETDEWEB)

    Johnson, Mark S. [U.S. Army Center for Health Promotion and Preventive Medicine, Health Effects Research Program, 5158 Blackhawk Road, ATTN: MCHB-TS-THE, Aberdeen Proving Ground, MD 21010-5403 (United States)]. E-mail: mark.s.johnson@us.army.mil; Suski, Jamie [U.S. Army Center for Health Promotion and Preventive Medicine, Health Effects Research Program, 5158 Blackhawk Road, ATTN: MCHB-TS-THE, Aberdeen Proving Ground, MD 21010-5403 (United States); Bazar, Matthew A. [U.S. Army Center for Health Promotion and Preventive Medicine, Health Effects Research Program, 5158 Blackhawk Road, ATTN: MCHB-TS-THE, Aberdeen Proving Ground, MD 21010-5403 (United States)

    2007-06-15

    Dinitrotoluenes are used as propellants and in explosives by the military and as such have been found at relatively high concentrations in the soil. To determine whether concentrations of 2,4-dinitrotoluene (2,4-DNT) in soil are toxic to amphibians, 100 red-backed salamanders (Plethodon cinereus) were exposed to either 1500, 800, 200, 75 or 0 mg 2,4-DNT/kg soil for 28 days and evaluated for indicators of toxicity. Concentrations of 2,4-DNT were less than targets and varied with time. Most salamanders exposed to concentrations exceeding 1050 mg/kg died or were moribund within the first week. Salamanders exposed to soil concentrations exceeding 345 mg/kg lost >6% of their body mass though no mortality occurred. Overt effects included a reduction in feed consumption and an increase in bucco-pharyngeal oscillations in salamanders. These results suggest that only high soil concentrations of 2,4-DNT have the potential to cause overtly toxic effects in terrestrial salamanders. - Exposures of 2,4-dinitrotoluene in soil exceeding 345 mg/kg causes toxicity to P. cinereus.

  20. Selection and breeding for acid-soil tolerance in crops: Upland rice and tropical forages as case studies

    Energy Technology Data Exchange (ETDEWEB)

    Vera, R. (Centro Internacional de Agricultura Tropical, Cali (Colombia)); Zeigler, R.S.; Sarkarung, S. (International Rice Research Institute, Manila (Philippines)); Rao, I.M.

    Soil acidity and associated infertility and mineral toxicities are major constraints to agricultural production in extensive areas of the humid tropics and subtropics. The natural process of soil acidification is often intensified by agricultural practices, particularly nitrogen fertilization, and acid precipitation. This paper briefly discusses the factors contributing to acid-soil infertility, effects on plant growth, and acid-soil treatments in temperate climates particularly liming. However, these treatments are not easily adaptable to tropical regions. However, the development of cultivars adapted to the acid soil complex is a promising alternative. The paper goes on to present several topics related to cultivar development: acid soils of tropical America; identification of germplasm adapted to acid soils; plant adaptation mechanisms for acid soils; improvement of acid-soil adaptation in crops; case study of upland rice by the Centro Internacional de Agricultura Tropical; tropical foages for livestock; and contribution of adapted plants to sustainable production systems. 50 refs., 3 figs., 7 tabs.

  1. Toxicological responses of red-backed salamanders (Plethodon cinereus) to subchronic soil exposures of 2,4,6-trinitrotoluene.

    Science.gov (United States)

    Bazar, Mathew A; Quinn, Michael J; Mozzachio, Kristie; Johnson, Mark S

    2008-06-01

    Since World War I, trinitrotoluene (TNT) has been the most commonly used explosive. Environmental contamination associated with synthesis, manufacture of weapons, and use during training exercises has been extensive, with soil concentrations reaching 145,000 mg/kg. Some of these areas include habitats for amphibian species. Earlier studies have shown that salamanders dermally absorb TNT from soil. To ascertain what soil concentrations of TNT are toxic to amphibians, red-backed salamanders (Plethodon cinereus) were exposed to one of five concentrations of TNT in soil for 28 d and evaluated for indicators of toxicity. A total of 100 salamanders were randomly sorted by weight and assigned to target TNT concentrations in soil of either 3,000, 1,500, 750, 325, or 0 mg/kg dry weight. Food consisted of uncontaminated flightless Drosophila melanogaster. Survival was reduced in salamanders exposed to 1,500 and 3,000 mg/kg by 10 and 55%, respectively. Most mortality/morbidity occurred within the first week of exposure. Salamanders had a reduction in hemoglobin at 750 mg/kg or greater and a reduction in red blood cell concentration at 1,500 mg/kg or greater. Food consumption was affected in salamanders at 750 mg/kg or greater; a reduction in body mass and liver glycogen content also occurred at and above this concentration. Splenic congestion also was observed in salamanders from these groups. These data suggest that soil TNT concentrations of 373 +/- 41.0 mg/kg or greater result in reduced body mass, reduced feed intake, and hematological effects.

  2. Relations between soil surface roughness, tortuosity, tillage treatments, rainfall intensity and soil and water losses from a red yellow latosol

    Directory of Open Access Journals (Sweden)

    Julieta Bramorski

    2012-08-01

    Full Text Available The soil surface roughness increases water retention and infiltration, reduces the runoff volume and speed and influences soil losses by water erosion. Similarly to other parameters, soil roughness is affected by the tillage system and rainfall volume. Based on these assumptions, the main purpose of this study was to evaluate the effect of tillage treatments on soil surface roughness (RR and tortuosity (T and to investigate the relationship with soil and water losses in a series of simulated rainfall events. The field study was carried out at the experimental station of EMBRAPA Southeastern Cattle Research Center in São Carlos (Fazenda Canchim, in São Paulo State, Brazil. Experimental plots of 33 m² were treated with two tillage practices in three replications, consisting of: untilled (no-tillage soil (NTS and conventionally tilled (plowing plus double disking soil (CTS. Three successive simulated rain tests were applied in 24 h intervals. The three tests consisted of a first rain of 30 mm/h, a second of 30 mm/h and a third rain of 70 mm/h. Immediately after tilling and each rain simulation test, the surface roughness was measured, using a laser profile meter. The tillage treatments induced significant changes in soil surface roughness and tortuosity, demonstrating the importance of the tillage system for the physical surface conditions, favoring water retention and infiltration in the soil. The increase in surface roughness by the tillage treatments was considerably greater than its reduction by rain action. The surface roughness and tortuosity had more influence on the soil volume lost by surface runoff than in the conventional treatment. Possibly, other variables influenced soil and water losses from the no-tillage treatments, e.g., soil type, declivity, slope length, among others not analyzed in this study.

  3. Microbial Biomass Carbon Trends in Black and Red Soils Under Single Straw Application: Effect of Straw Placement, Mineral N Addition and Tillage

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    Quantifying trends in soil microbial biomass carbon (SMBC) under contrasting management conditions is important in understanding the dynamics of soil organic matter (SOM) in soils and in ensuring their sustainable use. Against such a background, a 60-day greenhouse simulation experiment was carried out to study the effects of straw placement, mineral N source, and tillage on SMBC dynamics in two contrasting soils, red soil (Ferrasol) and black soil (Acrisol). The treatments included straw addition + buried (T1);straw addition + mineral N (T2); and straw addition + tillage (T3). Straw was either buried in the soil or placed on the surface. Sampling was done every 15 days. Straw placement, addition of external mineral N sources (Urea, 46 % N) and soil type affected SMBC. SMBC levels decreased with exposure durations (15 days, 30 days, 45 days, and 60 days). Rate of SMBC fixation was more in buried straw than in surface placed straw at all sampling dates in both soils. Addition of an external N source significantly increased SMBC level. Soil pH increased in both soil types, with a greater increase in black soil than in red soil. The study could not, however, statistically account for the effect of tillage on SMBC levels because of the limited effect of our tillage method due to the artificial barrier to mechanical interference supplied by the mesh bags,although differences in absolute values were quite evident between treatments T1 and T3.``

  4. Ultrasonic Extraction and TLC Determination of Glyphosate in the Spiked Red Soils

    Directory of Open Access Journals (Sweden)

    Sandra Babić

    2005-09-01

    Full Text Available Pesticides that get into soil bind mostly to its solid phase by physical or chemical processes. In the valley of the Neretva River the use of herbicides, especially of glyphosate is widespread and sometimes uncontrolled. In this work ultrasonic solvent extraction (USE followed by thin-layer chromatography (TLC was applied for determining glyphosate presence in soil. The experiments were conducted with two characterised soil types. The impact of soil composition on extraction efficiency is discussed. Chemical analysis showed that soil 1 contained much more iron and aluminium oxides than soil 2, which was richer in humic substances. Low glyphosate efficiency (ca 44 % in both soils could be attributed either to its binding to iron and aluminium oxides (soil 1, or to chemisorption on humic macromolecules (soil 2.

  5. Effects of organic acids on cadmium and copper sorption and desorption by two calcareous soils.

    Science.gov (United States)

    Najafi, Sarvenaz; Jalali, Mohsen

    2015-09-01

    Low molecular weight organic acids (LMWOAs) present in soil alter equilibrium pH of soil, and consequently, affect heavy metal sorption and desorption on soil constitutes. This study was conducted to investigate the effects of different concentrations (0.1, 1, 2.5, 5, 10, 30, 40, 50, 70, and 100 mM) of citric, malic, and oxalic acids on sorption and desorption of cadmium (Cd) and copper (Cu) in two calcareous soils. Increasing the concentrations of three LMWOAs decreased the equilibrium pH of soil solutions. The results indicated that increase in organic acids concentrations generally reduced Cd and Cu sorption in soils. Increase concentrations of LMWOAs generally promoted Cd and Cu desorption from soils. A valley-like curve was observed for desorption of Cu after the citric acid concentration increment in soil 2. Increasing the concentrations of three LMWOAs caused a marked decrease in Kd(sorp) values of Cd and Cu in soils. In general, citric acid was the most effective organic acid in reducing sorption and increasing desorption of both metals, and oxalic acid had the minimal impact. The results indicated that LMWOAs had a greater impact on Cu sorption and desorption than Cd, which can be attributed to higher stability constants of organic acids complexes with Cu compared to Cd. It can be concluded that by selecting suitable type and concentration of LMWOAs, mobility, and hence, bioavailability of heavy metals can be changed. So, environmental implications concerning heavy metals mobility might be derived from these findings.

  6. ANALYSIS OF PERFLUORINATED CARBOXYLIC ACIDS IN SOILS II: OPTIMIZATION OF CHROMATOGRAPHY AND EXTRACTION

    Science.gov (United States)

    With the objective of detecting and quantitating low concentrations of perfluorinated carboxylic acids (PFCAs), including perfluorinated octanoic acid (PFOA), in soils, we compared the analytical suitability of liquid chromatography columns containing three different stationary p...

  7. ANALYSIS OF PERFLUORINATED CARBOXYLIC ACIDS IN SOILS II: OPTIMIZATION OF CHROMATOGRAPHY AND EXTRACTION

    Science.gov (United States)

    With the objective of detecting and quantitating low concentrations of perfluorinated carboxylic acids (PFCAs), including perfluorinated octanoic acid (PFOA), in soils, we compared the analytical suitability of liquid chromatography columns containing three different stationary p...

  8. Effects of Tannic Acid, Green Tea and Red Wine on hERG Channels Expressed in HEK293 Cells.

    Directory of Open Access Journals (Sweden)

    Xi Chu

    Full Text Available Tannic acid presents in varying concentrations in plant foods, and in relatively high concentrations in green teas and red wines. Human ether-à-go-go-related gene (hERG channels expressed in multiple tissues (e.g. heart, neurons, smooth muscle and cancer cells, and play important roles in modulating cardiac action potential repolarization and tumor cell biology. The present study investigated the effects of tannic acid, green teas and red wines on hERG currents. The effects of tannic acid, teas and red wines on hERG currents stably transfected in HEK293 cells were studied with a perforated patch clamp technique. In this study, we demonstrated that tannic acid inhibited hERG currents with an IC50 of 3.4 μM and ~100% inhibition at higher concentrations, and significantly shifted the voltage dependent activation to more positive potentials (Δ23.2 mV. Remarkably, a 100-fold dilution of multiple types of tea (green tea, oolong tea and black tea or red wine inhibited hERG currents by ~90%, and significantly shifted the voltage dependent activation to more positive potentials (Δ30.8 mV and Δ26.0 mV, respectively. Green tea Lung Ching and red wine inhibited hERG currents, with IC50 of 0.04% and 0.19%, respectively. The effects of tannic acid, teas and red wine on hERG currents were irreversible. These results suggest tannic acid is a novel hERG channel blocker and consequently provide a new mechanistic evidence for understanding the effects of tannic acid. They also revealed the potential pharmacological basis of tea- and red wine-induced biology activities.

  9. Effects of Tannic Acid, Green Tea and Red Wine on hERG Channels Expressed in HEK293 Cells.

    Science.gov (United States)

    Chu, Xi; Guo, Yusong; Xu, Bingyuan; Li, Wenya; Lin, Yue; Sun, Xiaorun; Ding, Chunhua; Zhang, Xuan

    2015-01-01

    Tannic acid presents in varying concentrations in plant foods, and in relatively high concentrations in green teas and red wines. Human ether-à-go-go-related gene (hERG) channels expressed in multiple tissues (e.g. heart, neurons, smooth muscle and cancer cells), and play important roles in modulating cardiac action potential repolarization and tumor cell biology. The present study investigated the effects of tannic acid, green teas and red wines on hERG currents. The effects of tannic acid, teas and red wines on hERG currents stably transfected in HEK293 cells were studied with a perforated patch clamp technique. In this study, we demonstrated that tannic acid inhibited hERG currents with an IC50 of 3.4 μM and ~100% inhibition at higher concentrations, and significantly shifted the voltage dependent activation to more positive potentials (Δ23.2 mV). Remarkably, a 100-fold dilution of multiple types of tea (green tea, oolong tea and black tea) or red wine inhibited hERG currents by ~90%, and significantly shifted the voltage dependent activation to more positive potentials (Δ30.8 mV and Δ26.0 mV, respectively). Green tea Lung Ching and red wine inhibited hERG currents, with IC50 of 0.04% and 0.19%, respectively. The effects of tannic acid, teas and red wine on hERG currents were irreversible. These results suggest tannic acid is a novel hERG channel blocker and consequently provide a new mechanistic evidence for understanding the effects of tannic acid. They also revealed the potential pharmacological basis of tea- and red wine-induced biology activities.

  10. Liquid Swine Manure Can Kill Verticillium dahliae Microsclerotia in Soil by Volatile Fatty Acid, Nitrous Acid, and Ammonia Toxicity.

    Science.gov (United States)

    Conn, Kenneth L; Tenuta, Mario; Lazarovits, George

    2005-01-01

    ABSTRACT In previous studies, liquid swine manure (LSM) was sometimes shown to reduce Verticillium wilt of potato caused by Verticillium dahliae. We also observed that microsclerotia of this fungus died within 1 day, or between 3 and 6 weeks, after addition of LSM to some acid soils and within 1 week in some alkaline soils. In this study, we demonstrated that a volatile fatty acid (VFA) mixture with an identical concentration of VFAs as that found in an effective LSM reduced germination in an acid soil (pH 5.1) to the same extent as the LSM after 1 day of exposure. Germination was reduced by 45, 75, and 90% in the 10, 20, and 40% ([wt/wt] soil moisture) treatments, respectively, with the latter being equivalent to an application of 80 hl/ha. Addition to this acid soil of 19 LSMs (30% [wt/wt] soil moisture) collected from different producers resulted in complete kill of microsclerotia with 12 manures. Effective manures had a total concentration of nonionized forms of VFAs in soil solution of 2.7 mM or higher. In some acid soils (pH 5.8), addition of LSM (40% [wt/wt] soil moisture) did not kill microsclerotia until 3 to 6 weeks later. Here, a reduction in viability of microsclerotia was attributed to the accumulation of 0.06 mM nitrous acid in the soil solution at 4 weeks. When an LSM was added (40% [wt/wt] soil moisture) to an alkaline soil (pH 7.9) where VFAs are not toxic, microsclerotia germination was reduced by 80% after 1 week. Here the pH increased to 8.9 and the concentration of ammonia reached 30 mM in the soil solution. An ammonium chloride solution having an equivalent concentration of ammonium as the manure was shown to have the same spectrum of toxicity as the manure in assays ranging from pH 7 to 9, both in solutions and above the solutions. At pH 9, the concentration of ammonia reached 18 mM and 100% mortality of microsclerotia occurred. Thus, in acid soils, LSM can kill microsclerotia of V. dahliae by VFA and/or nitrous acid toxicity and in alkaline

  11. Metagenomic analysis of the rhizosphere soil microbiome with respect to phytic acid utilization.

    Science.gov (United States)

    Unno, Yusuke; Shinano, Takuro

    2013-01-01

    While phytic acid is a major form of organic phosphate in many soils, plant utilization of phytic acid is normally limited; however, culture trials of Lotus japonicus using experimental field soil that had been managed without phosphate fertilizer for over 90 years showed significant usage of phytic acid applied to soil for growth and flowering and differences in the degree of growth, even in the same culture pot. To understand the key metabolic processes involved in soil phytic acid utilization, we analyzed rhizosphere soil microbial communities using molecular ecological approaches. Although molecular fingerprint analysis revealed changes in the rhizosphere soil microbial communities from bulk soil microbial community, no clear relationship between the microbiome composition and flowering status that might be related to phytic acid utilization of L. japonicus could be determined. However, metagenomic analysis revealed changes in the relative abundance of the classes Bacteroidetes, Betaproteobacteria, Chlorobi, Dehalococcoidetes and Methanobacteria, which include strains that potentially promote plant growth and phytic acid utilization, and some gene clusters relating to phytic acid utilization, such as alkaline phosphatase and citrate synthase, with the phytic acid utilization status of the plant. This study highlights phylogenetic and metabolic features of the microbial community of the L. japonicus rhizosphere and provides a basic understanding of how rhizosphere microbial communities affect the phytic acid status in soil.

  12. Biogenic arsenic volatilisation from an acidic wetland soil

    Science.gov (United States)

    Ilgen, Gunter; Huang, Jen-How; Lu, Shipeng; Tian, Liyan; Alewell, Christine

    2014-05-01

    Biogenic arsenic (As) volatilisation was budgeted at 26000 t yr-1as the largest input of the global As release into the atmosphere, thereby playing an important role in the biogeochemical cycle of As in the surface environment. In order to quantify As volatilisation from wetland soils and to elucidate the geochemical and microbiological factors governing As volatilisation, a series of incubations with an acidic wetland soil collected in NE-Bavaria in Germany were performed at 15oC for 4 months with addition of NaN3, arsenite (As(III)), FeCl3, NaSO4 and NaOAc with N2 and air in the headspace. Speciation of gaseous As in the headspace using GC-ICP-MS/ ESI-MS coupling showed the predominance of either arsine (AsH3) or trimethylarsine ((CH3)3As) in all treatments during the time course of incubation. Monomethylarsine ((CH3)AsH2) and dimethylarsine ((CH3)2AsH) could be only detected in trace amounts. Arsenic speciation in porewater with HPLC-ICP-MS revealed the predominance of As(III) and methylated As was never detectable. Arsenic volatilisation summed to 2.3 ng As (88% as AsH3) in the control incubations, which accounted for ~0.25 % of the total As storage in the wetland soil. Treatments with 10 mM NaN3 resulted in emission of only 0.03 ng As. In contrast, addition of 10 mM NaOAc stimulated microbial activities in wetland soils and subsequently rose As volatilisation to 8.5 ng As. It could be therefore concluded that As volatilisation from the wetland soils was mainly biological. Spiking 67 μM As(III) increased 10 times of As volatilisation and the proportion of methylated arsines increased to 66%, which is supposed to be caused by the largely enhanced As availability in porewater for microbes (480 ppb, ~65 times higher than those in the controls). Adding 10 mM FeCl3 stimulated microbial Fe(III) reducing activities but suppressed other microbial activities by lowering soil pH from 5 to 3.6, decreasing consequently As volatilisation to 0.3 ng As. The much lower redox

  13. [Effects of Low-Molecular-Weight Organic Acids on the Speciation of Pb in Purple Soil and Soil Solution].

    Science.gov (United States)

    Liu, Jiang; Jiang, Tao; Huang, Rong; Zhang, Jin-zhong; Chen, Hong

    2016-04-15

    Lead (Pb) in purple soil was selected as the research target, using one-step extraction method with 0.01 mol · L⁻¹ sodium nitrate as the background electrolyte to study the release effect of citric acid (CA), tartaric acid (TA) and acetic acid (AC) with different concentrations. Sequential extraction and geochemical model (Visual Minteq v3.0) were applied to analyze and predict the speciation of Pb in soil solid phase and soil solution phase. Then the ebvironmental implications and risks of low-molecule weight organic acid (LMWOA) on soil Pb were analyzed. The results indicated that all three types of LMWOA increased the desorption capacity of Pb in purple soil, and the effect followed the descending order of CA > TA > AC. After the action of LMWOAs, the exchangeable Pb increased; the carbonate-bound Pb and Fe-Mn oxide bound Pb dropped in soil solid phase. Organic bound Pb was the main speciation in soil solution phase, accounting for 45.16%-75.05%. The following speciation of Pb in soil solution was free Pb, accounting for 22.71%-50.25%. For CA and TA treatments, free Pb ions and inorganic bound Pb in soil solution increased with increasing LMWOAs concentration, while organic bound Pb suffered a decrease in this process. An opposite trend for AC treatment was observed compared with CA and TA treatments. Overall, LMWOAs boosted the bioavailability of Pb in purple soil and had a potential risk to contaminate underground water. Among the three LMWOAs in this study, CA had the largest potential to activate soil Pb.

  14. Conversion of red-algae Gracilaria verrucosa to sugars, levulinic acid and 5-hydroxymethylfurfural.

    Science.gov (United States)

    Jeong, Gwi-Taek; Ra, Chae Hun; Hong, Yong-Ki; Kim, Joong Kyun; Kong, In-Soo; Kim, Sung-Koo; Park, Don-Hee

    2015-02-01

    This study employed a statistical methodology to investigate the optimization of conversion conditions and evaluate the reciprocal interaction of reaction factors related to the process of red-algae Gracilaria verrucosa conversion to sugars (glucose, galactose), levulinic acid and 5-hydroxymethylfurfural (5-HMF) by acidic hydrolysis. Overall, the conditions optimized for glucose formation included a higher catalyst concentration than did those for galactose, and these conditions for galactose were similar to those for 5-HMF. Levulinic acid production, meanwhile, was optimized at a higher reaction temperature, a higher catalyst concentration, and a longer reaction time than was glucose, galactose or 5-HMF production. By this approach, the optimal yields (and reaction conditions) for glucose, galactose, levulinic acid, and 5-HMF were as follows: glucose 5.29 g/L (8.46 wt%) (reaction temperature 160 °C, catalyst concentration 1.92%, reaction time 20 min), galactose 18.38 g/L (29.4 wt%) (160 °C, 1.03%, 20 min), levulinic acid 14.65 g/L (18.64 wt%) (180.9 °C, 2.85%, 50 min), and 5-HMF 3.74 g/L (5.98 wt%) (160.5 °C, 1%, 20 min).

  15. Solvent-extractable lipids in an acid andic forest soil; variations with dept and season

    NARCIS (Netherlands)

    Naafs, Derck Ferdinand Werner; Bergen, P.F. van; Boogert, S.J.; Leeuw, J.W. de

    2004-01-01

    Total lipid extracts from an acid andic soil profile located on Madeira Island (Portugal) were analysed using gas chromatography (GC) and GC–mass spectrometry (GC/MS). The profile was covered mainly by grass. Bulk soil characteristics determined included soil pH (H2O) ranging from 4.5 to 4.0 and TOC

  16. Field evidence of cadmium phytoavailability decreased effectively by rape straw and/or red mud with zinc sulphate in a Cd-contaminated calcareous soil.

    Science.gov (United States)

    Li, Bo; Yang, Junxing; Wei, Dongpu; Chen, Shibao; Li, Jumei; Ma, Yibing

    2014-01-01

    To reduce Cd phytoavailability in calcareous soils, the effects of soil amendments of red mud, rape straw, and corn straw in combination with zinc fertilization on Cd extractability and phytoavailability to spinach, tomato, Chinese cabbage and radish were investigated in a calcareous soil with added Cd at 1.5 mg kg-1. The results showed that water soluble and exchangeable Cd in soils was significantly decreased by the amendments themselves from 26% to 70%, which resulted in marked decrease by approximately from 34% to 77% in Cd concentration in vegetables. The amendments plus Zn fertilization further decreased the Cd concentration in vegetables. Also cruciferous rape straw was more effective than gramineous corn straw. In all treatments, rape straw plus red mud combined with Zn fertilization was most effective in decreasing Cd phytoavailability in soils, and it is potential to be an efficient and cost-effective measure to ensure food safety for vegetable production in mildly Cd-contaminated calcareous soils.

  17. Detailed predictive mapping of acid sulfate soil occurrence using electromagnetic induction data

    DEFF Research Database (Denmark)

    Beucher, Amélie; Boman, A; Mattbäck, S

    Acid sulfate soils are often called the nastiest soils in the world (Dent & Pons, 1995). Releasing a toxic combination of acidity and metals into the recipient watercourses and estuaries, these soils represent a crucial environmental problem. Moreover, these soils can have a considerable economic...... occurrence. Different machine learning approaches will be assessed over a field located in western Finland, using soil observations and various environmental predictors (Quaternary geology maps, EM data collected from a DUALEM proximal sensor, and remote sensing data, such as airborne gamma-radiometric data...

  18. Reduced nitrogen leaching by intercropping maize with red fescue on sandy soils in North Europe

    DEFF Research Database (Denmark)

    Manevski, Kiril; Børgesen, Christen Duus; Andersen, Mathias Neumann

    2015-01-01

    Aim To study maize (Zea mays L.) growth and soil nitrogen (N) dynamics in monocrop and intercropped systems in a North European climate and soil conditions with the support of a simulation model. Methods Field data for 3 years at two sites/soil types in Denmark and three main factors: (i) cropping...

  19. Toxicological responses of red-backed salamanders (Plethodon cinereus) to subchronic soil exposures of 2,4-dinitrotoluene.

    Science.gov (United States)

    Johnson, Mark S; Suski, Jamie; Bazar, Matthew A

    2007-06-01

    Dinitrotoluenes are used as propellants and in explosives by the military and as such have been found at relatively high concentrations in the soil. To determine whether concentrations of 2,4-dinitrotoluene (2,4-DNT) in soil are toxic to amphibians, 100 red-backed salamanders (Plethodon cinereus) were exposed to either 1500, 800, 200, 75 or 0mg 2,4-DNT/kg soil for 28 days and evaluated for indicators of toxicity. Concentrations of 2,4-DNT were less than targets and varied with time. Most salamanders exposed to concentrations exceeding 1050 mg/kg died or were moribund within the first week. Salamanders exposed to soil concentrations exceeding 345 mg/kg lost >6% of their body mass though no mortality occurred. Overt effects included a reduction in feed consumption and an increase in bucco-pharyngeal oscillations in salamanders. These results suggest that only high soil concentrations of 2,4-DNT have the potential to cause overtly toxic effects in terrestrial salamanders.

  20. Biosurfactant from red ash trees enhances the bioremediation of PAH contaminated soil at a former gasworks site.

    Science.gov (United States)

    Blyth, Warren; Shahsavari, Esmaeil; Morrison, Paul D; Ball, Andrew S

    2015-10-01

    Polycyclic aromatic hydrocarbons (PAHs) are persistent contaminants that accumulate in soil, sludge and on vegetation and are produced through activities such as coal burning, wood combustion and in the use of transport vehicles. Naturally occurring surfactants have been known to enhance PAH-removal from soil by improving PAH solubilization thereby increasing PAH-microbe interactions. The aim of this research was to determine if a biosurfactant derived from the leaves of the Australian red ash (Alphitonia excelsa) would enhance bioremediation of a heavily PAH-contaminated soil and to determine how the microbial community was affected. Results of GC-MS analysis show that the extracted biosurfactant was significantly more efficient than the control in regards to the degradation of total 16 US EPA priority PAHs (78.7% degradation compared to 62.0%) and total petroleum hydrocarbons (TPH) (92.9% degradation compared to 44.3%). Furthermore the quantification of bacterial genes by qPCR analysis showed that there was an increase in the number of gene copies associated with Gram positive PAH-degrading bacteria. The results suggest a commercial potential for the use of the Australian red ash tree as a source of biosurfactant for use in the accelerated degradation of hydrocarbons.

  1. Plant-associated fluorescent Pseudomonas from red lateritic soil: Beneficial characteristics and their impact on lettuce growth.

    Science.gov (United States)

    Maroniche, Guillermo A; Rubio, Esteban J; Consiglio, Adrián; Perticari, Alejandro

    2016-11-25

    Fluorescent Pseudomonas are ubiquitous soil bacteria that usually establish mutualistic associations with plants, promoting their growth and health by several mechanisms. This makes them interesting candidates for the development of crop bio-inoculants. In this work, we isolated phosphate-solubilizing fluorescent Pseudomonas from the rhizosphere and inner tissues of different plant species growing in red soil from Misiones, Argentina. Seven isolates displaying strong phosphate solubilization were selected for further studies. Molecular identification by rpoD genotyping indicated that they belong to different species within the P. fluorescens and P. putida phylogenetic groups. Screening for in vitro traits such as phosphate solubilization, growth regulators synthesis or degradation, motility and antagonism against phytopathogens or other bacteria, revealed a unique profile of characteristics for each strain. Their plant growth-promoting potential was assayed using lettuce as a model for inoculation under controlled and greenhouse conditions. Five of the strains increased the growth of lettuce plants. Overall, the strongest lettuce growth promoter under both conditions was strain ZME4, isolated from inner tissues of maize. No clear association between lettuce growth promotion and in vitro beneficial traits was detected. In conclusion, several phosphate solubilizing pseudomonads from red soil were isolated that display a rich array of plant growth promotion traits, thus showing a potential for the development of new inoculants.

  2. Relationship of soil qualities to maize growth under increasing phosphorus supply in acid soils of southern Cameroon

    Institute of Scientific and Technical Information of China (English)

    TCHIENKOUA; M.JEMO; R.NJOMGANG; C.NOLTE; N.SANGINGA; J.TAKOW

    2008-01-01

    A large array of soil properties influences plant growth response to phosphorus (P) fertilizer input in acid soils.We carried out a pot experiment using three contrasted acid soils from southern Cameroon with the following main objectives:i) to assess the main soil causal factors of different maize (Zea mays L.) growth response to applied P and ii) to statistically model soil quality variation across soil types as well as their relationships to dry matter production.The soils used are classified as Typic Kandiudox (TKO),Rhodic Kandiudult (RKU),and Typic Kandiudult (TKU).Analysis of variance,regression,and principal component analyses were used for data analysis and interpretation.Shoot dry matter yield (DMY) was significantly affected by soil type and P rate with no significant interaction.Predicted maximum attainable DMY was lowest in the TKO (26.2 g pot-1) as compared to 35.6 and 36.7 g pot-1 for the RKU and TKU,respectively.Properties that positively influenced DMY were the levels of inorganic NaHCO3-extractable P,individual basic cations (Ca,Mg,and K),and pH.Their effects contrasted with those of exchangeable A1 and C/N ratio,which significantly depressed DMY.Principal component analysis yielded similar results,identifying 4 orthogonal components,which accounted for 84.7% of the total system variance (TSV).Principal component 1 was identified as soil nutrient deficiency explaining 35.9% of TSV.This soil quality varied significantly among the studied soils,emerging as the only soil quality which significantly (P < 0.05) correlated with maize growth.The 2nd,3rd,and 4th components were identified as soil organic matter contents,texture,and HCl-extractable P,respectively.

  3. Characteristics of biomass ashes from different materials and their ameliorative effects on acid soils.

    Science.gov (United States)

    Shi, Renyong; Li, Jiuyu; Jiang, Jun; Mehmood, Khalid; Liu, Yuan; Xu, Renkou; Qian, Wei

    2017-05-01

    The chemical characteristics, element contents, mineral compositions, and the ameliorative effects on acid soils of five biomass ashes from different materials were analyzed. The chemical properties of the ashes varied depending on the source biomass material. An increase in the concrete shuttering contents in the biomass materials led to higher alkalinity, and higher Ca and Mg levels in biomass ashes, which made them particularly good at ameliorating effects on soil acidity. However, heavy metal contents, such as Cr, Cu, and Zn in the ashes, were relatively high. The incorporation of all ashes increased soil pH, exchangeable base cations, and available phosphorus, but decreased soil exchangeable acidity. The application of the ashes from biomass materials with a high concrete shuttering content increased the soil available heavy metal contents. Therefore, the biomass ashes from wood and crop residues with low concrete contents were the better acid soil amendments. Copyright © 2016. Published by Elsevier B.V.

  4. Impact of acid atmosphere deposition on soils : field monitoring and aluminum chemistry

    NARCIS (Netherlands)

    Mulder, J.

    1988-01-01

    The effect of acid atmospheric deposition on concentrations and transfer of major solutes in acid, sandy soils was studied. Emphasis was given to mobilization and transport of potentially toxic aluminum. Data on solute concentrations and fluxes in meteoric water as well as soil solutions

  5. Impact of acid atmospheric deposition on soils: Field monitoring and aluminium chemistry.

    NARCIS (Netherlands)

    Mulder, J.

    1988-01-01

    The effect of acid atmospheric deposition on concentrations and transfer of major solutes in acid, sandy soils was studied. Emphasis was given to mobilization and transport of potentially toxic aluminum. Data on solute concentrations and fluxes in meteoric water as well as soil solutions were obtain

  6. Effect of root derived organic acids on the activation of nutrients in the rhizosphere soil

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    Four types of soils, including brown coniferous forest soil, dark brown soil, black soil, and black calic soil, sampled from three different places in northeast China were used in this test. The functions of two root-derived organic acids and water were simulated and compared in the activation of mineral nutrients from the rhizosphere soil. The results showed that the organic acids could activate the nutrients and the activated degree of the nutrient elements highly depended on the amount and types of the organic acid excreted and on the physiochemical and biochemical properties of the soil tested. The activation effect of the citric acid was obviously higher than that of malic acid in extracting Fe, Mn, Cu, and Zn for all the tested soil types. However, the activation efficiencies of P, K, Ca, and Mg extracting by the citric acid were not much higher, sometimes even lower, than those by malic acid. The solution concentration of all elements increased with increase of amount of the citric acid added.

  7. Mapping potential acid sulfate soils in Denmark using legacy data and LiDAR-based derivatives

    DEFF Research Database (Denmark)

    Beucher, Amélie; Adhikari, Kabindra; Breuning-Madsen, H.

    2017-01-01

    Leaching large amounts of acidity and metals into recipient watercourses and estuaries, acid sulfate (a.s.) soils constitute a substantial environmental issue worldwide. Mapping of these soils enables measures to be taken to prevent pollution in high risk areas. In Denmark, legislation prohibits...

  8. Influence of Soil Humic and Fulvic Acid on the Activity and Stability of Lysozyme and Urease

    NARCIS (Netherlands)

    Li, Yan; Tan, WenFeng; Koopal, Luuk K.; Wang, MingXia; Liu, Fan; Norde, Willem

    2013-01-01

    Humic substances (HS), including humic acids (HA) and fulvic acids (FA), are important components of soil systems. HS form strong complexes with oppositely charged proteins, which will lead to changes in the enzyme activity. The effect of soil HS on the activity and stability of two enzymes was inve

  9. Influence of soil humic and fulvic acid on the activity and stability of lysozyme and urease

    NARCIS (Netherlands)

    Li, Y.; Tan, W.; Koopal, L.K.; Wang, M.; Liu, Fan; Norde, W.

    2013-01-01

    Humic substances (HS), including humic acids (HA) and fulvic acids (FA), are important components of soil systems. HS form strong complexes with oppositely charged proteins, which will lead to changes in the enzyme activity. The effect of soil HS on the activity and stability of two enzymes was inve

  10. Phosphorus in Finnish soils in the 1900s with particular reference to the acid ammonium acetate soil test

    Directory of Open Access Journals (Sweden)

    I. SAARELA

    2008-12-01

    Full Text Available Comprehensive research into phosphorus (P in soils and crops began in Finland in the early 1900s. The average amount of total P in the ploughed topsoil layer of mineral soils was about two tonnes per hectare in the 1930s, before the abundant use of fertilisers. The main chemical fractions of P in mineral soils were organic matter, primary apatite and secondary complexes of the hydrous oxides of Al and Fe. Of the smaller amounts of P in light peat soils, as much as 80% was present in stable organic compounds. Field experiments showed that the native P reserves of Finnish soils are poorly available to plants, and that P fertilisers are inefficiently utilised because of the strong fixation of applied phosphate in soils. In evaluations before the late 1950s, all simple chemical tests appeared to be rather unreliable indicators of the supply of P from soils to plants, but later research has shown that the results were impaired by errors implicit in the research materials. Some soil test P values (STPobtained from old samples stored for more than ten years evidently were too high, particularly for organic soils, and many of the soils studied were strongly acidic and therefore biologically less fertile than the chemical P tests indicated. The acid ammonium acetate method (pH 4.65 was introduced in the early 1950s and has since been used in routine soil testing in Finland, not only for P but for all macronutrients except N. In later evaluations of different methods used for estimating the requirement of P fertilisation, the acid ammonium acetate method has proven equal or superior to any other simple chemical method.;

  11. Isolation and Fatty Acid Profile of Selected Microalgae Strains from the Red Sea for Biofuel Production

    Directory of Open Access Journals (Sweden)

    Khalid M. Abu-Salah

    2013-05-01

    Full Text Available The isolation of lipid-rich autochthonous strains of microalgae is a crucial stage for the development of a microalgae-based biofuel production plant, as these microalgae already have the necessary adaptations to withstand competition, predation and the temperatures observed at each production site. This is particularly important in extreme climates such as in Saudi Arabia. Resorting to fluorescence activated cell sorting (FACS we screened for and isolated several microalgal strains from samples collected from the Red Sea. Relying on the fluorescence of BODIPY 505/515 (4,4-difluoro-1,3,5,7-tetramethyl-4-bora-3a,4a-diazasindacene and growth performance, four promising candidates were identified and the total lipid content and fatty acid profile was assessed for biofuels production. Selected isolates were classified as chlorophytes, belonging to three different genera: Picochlorum, Nannochloris and Desmochloris. The lipid contents were assessed microscopically by means of BODIPY 505/515-associated fluorescence to detect intracellular lipid bodies, which revealed several lipid drops in all selected strains. This result was confirmed by lipid gravimetric determination, which demonstrated that all strains under study presented inner cell lipid contents ranging from 20% to 25% of the biomass dry weight. Furthermore, the fatty acid methyl esters profile of all strains seems ideal for biodiesel production due to a low degree of polyunsaturated fatty acid methyl esters and high amount of palmitic and oleic acids.

  12. Aliphatic, cyclic, and aromatic organic acids, vitamins, and carbohydrates in soil: a review.

    Science.gov (United States)

    Vranova, Valerie; Rejsek, Klement; Formanek, Pavel

    2013-11-10

    Organic acids, vitamins, and carbohydrates represent important organic compounds in soil. Aliphatic, cyclic, and aromatic organic acids play important roles in rhizosphere ecology, pedogenesis, food-web interactions, and decontamination of sites polluted by heavy metals and organic pollutants. Carbohydrates in soils can be used to estimate changes of soil organic matter due to management practices, whereas vitamins may play an important role in soil biological and biochemical processes. The aim of this work is to review current knowledge on aliphatic, cyclic, and aromatic organic acids, vitamins, and carbohydrates in soil and to identify directions for future research. Assessments of organic acids (aliphatic, cyclic, and aromatic) and carbohydrates, including their behaviour, have been reported in many works. However, knowledge on the occurrence and behaviour of D-enantiomers of organic acids, which may be abundant in soil, is currently lacking. Also, identification of the impact and mechanisms of environmental factors, such as soil water content, on carbohydrate status within soil organic matter remains to be determined. Finally, the occurrence of vitamins in soil and their role in biological and biochemical soil processes represent an important direction for future research.

  13. Classification of acid sulphate soils of Finland according to Soil taxonomy and the FAO/Unesco legend

    Directory of Open Access Journals (Sweden)

    M. YLI-HALLA

    2008-12-01

    Full Text Available In order to place acid sulphate soils (a.s. soils of Finland in an international context, five pedons from cultivated a.s. soils from Liminka, Ylistaro and Laitila on the western coast of Finland were analyzed and classified according to Soil Taxonomy and the revised legend of the FAO/Unesco Soil Map of the World. Three of the pedons (Liminka 1 and 2, Laitila 1 had sulfuric horizons within 50 cm of soil surface and qualify as Typic Sulfaquepts. One pedon (Ylistaro had a sulfuric horizon at the depth of 100-150 cm and was classified as a Sulfic Cryaquept. The fifth pedon (Laitila 2 did not have either a sulfuric horizon or sulfidic materials, but it had a pH

  14. The potential application of red mud and soil mixture as additive to the surface layer of a landfill cover system.

    Science.gov (United States)

    Ujaczki, Éva; Feigl, Viktória; Molnár, Mónika; Vaszita, Emese; Uzinger, Nikolett; Erdélyi, Attila; Gruiz, Katalin

    2016-06-01

    Red mud, the by-product of aluminum production, has been regarded as a problematic residue all over the world. Its storage involves risks as evidenced by the Ajka red mud spill, an accident in Hungary where the slurry broke free, flooding the surrounding areas. As an immediate remediation measure more than 5cm thick red mud layer was removed from the flooded soil surface. The removed red mud and soil mixture (RMSM) was transferred into the reservoirs for storage. In this paper the application of RMSM is evaluated in a field study aiming at re-utilizing waste, decreasing cost of waste disposal and providing a value-added product. The purpose was to investigate the applicability of RMSM as surface layer component of landfill cover systems. The field study was carried out in two steps: in lysimeters and in field plots. The RMSM was mixed at ratios ranging between 0 and 50% w/w with low quality subsoil (LQS) originally used as surface layer of an interim landfill cover. The characteristics of the LQS+RMSM mixtures compared to the subsoil (LQS) and the RMSM were determined by physical-chemical, biological and ecotoxicological methods. The addition of RMSM to the subsoil (LQS) at up to 20% did not result any ecotoxic effect, but it increased the water holding capacity. In addition, the microbial substrate utilization became about triple of subsoil (LQS) after 10months. According to our results the RMSM mixed into subsoil (LQS) at 20% w/w dose may be applied as surface layer of landfill cover systems.

  15. Soil and Rhizosphere Associated Fungi in Gray Mangroves (Avicennia marina from the Red Sea — A Metagenomic Approach

    Directory of Open Access Journals (Sweden)

    Marta Filipa Simões

    2015-10-01

    Full Text Available Covering a quarter of the world’s tropical coastlines and being one of the most threatened ecosystems, mangroves are among the major sources of terrestrial organic matter to oceans and harbor a wide microbial diversity. In order to protect, restore, and better understand these ecosystems, researchers have extensively studied their microbiology, yet few surveys have focused on their fungal communities. Our lack of knowledge is even more pronounced for specific fungal populations, such as the ones associated with the rhizosphere. Likewise, the Red Sea gray mangroves (Avicennia marina remain poorly characterized, and understanding of their fungal communities still relies on cultivation-dependent methods. In this study, we analyzed metagenomic datasets from gray mangrove rhizosphere and bulk soil samples collected in the Red Sea coast, to obtain a snapshot of their fungal communities. Our data indicated that Ascomycota was the dominant phylum (76%–85%, while Basidiomycota was less abundant (14%–24%, yet present in higher numbers than usually reported for such environments. Fungal communities were more stable within the rhizosphere than within the bulk soil, both at class and genus level. This finding is consistent with the intrinsic patchiness in soil sediments and with the selection of specific microbial communities by plant roots. Our study indicates the presence of several species on this mycobiome that were not previously reported as mangrove-associated. In particular, we detected representatives of several commercially-used fungi, e.g., producers of secreted cellulases and anaerobic producers of cellulosomes. These results represent additional insights into the fungal community of the gray mangroves of the Red Sea, and show that they are significantly richer than previously reported.

  16. Soil and Rhizosphere Associated Fungi in Grey Mangroves (Avicennia marina) from the Red Sea - A Metagenomic Approach

    KAUST Repository

    Simões, Marta Filipa

    2015-11-05

    Covering a quarter of the world’s tropical coastlines and being one of the most threatened ecosystems, mangroves are among the major sources of terrestrial organic matter to oceans and harbor a wide microbial diversity. In order to protect, restore, and better understand these ecosystems, researchers have extensively studied their microbiology, yet few surveys have focused on their fungal communities. Our lack of knowledge is even more pronounced for specific fungal populations, such as the ones associated with the rhizosphere. Likewise, the Red Sea grey mangroves (Avicennia marina) remain poorly characterized, and understanding of their fungal communities still relies on cultivation-dependent methods. In this study, we analyzed metagenomic datasets from grey mangrove rhizosphere and bulk soil samples collected in the Red Sea coast, to obtain a snapshot of their fungal communities. Our data indicated that Ascomycota was the dominant phylum (76%–85%), while Basidiomycota was less abundant (14%–24%), yet present in higher numbers than usually reported for such environments. Fungal communities were more stable within the rhizosphere than within the bulk soil, both at class and genus level. This finding is consistent with the intrinsic patchiness in soil sediments and with the selection of specific microbial communities by plant roots. Our study indicates the presence of several species on this mycobiome that were not previously reported as mangrove-associated. In particular, we detected representatives of several commercially-used fungi, e.g., producers of secreted cellulases and anaerobic producers of cellulosomes. These results represent additional insights into the fungal community of the grey mangroves of the Red Sea, and show that they are significantly richer than previously reported.

  17. Soil and Rhizosphere Associated Fungi in Gray Mangroves (Avicennia marina) from the Red Sea--A Metagenomic Approach.

    Science.gov (United States)

    Simões, Marta Filipa; Antunes, André; Ottoni, Cristiane A; Amini, Mohammad Shoaib; Alam, Intikhab; Alzubaidy, Hanin; Mokhtar, Noor-Azlin; Archer, John A C; Bajic, Vladimir B

    2015-10-01

    Covering a quarter of the world's tropical coastlines and being one of the most threatened ecosystems, mangroves are among the major sources of terrestrial organic matter to oceans and harbor a wide microbial diversity. In order to protect, restore, and better understand these ecosystems, researchers have extensively studied their microbiology, yet few surveys have focused on their fungal communities. Our lack of knowledge is even more pronounced for specific fungal populations, such as the ones associated with the rhizosphere. Likewise, the Red Sea gray mangroves (Avicennia marina) remain poorly characterized, and understanding of their fungal communities still relies on cultivation-dependent methods. In this study, we analyzed metagenomic datasets from gray mangrove rhizosphere and bulk soil samples collected in the Red Sea coast, to obtain a snapshot of their fungal communities. Our data indicated that Ascomycota was the dominant phylum (76%-85%), while Basidiomycota was less abundant (14%-24%), yet present in higher numbers than usually reported for such environments. Fungal communities were more stable within the rhizosphere than within the bulk soil, both at class and genus level. This finding is consistent with the intrinsic patchiness in soil sediments and with the selection of specific microbial communities by plant roots. Our study indicates the presence of several species on this mycobiome that were not previously reported as mangrove-associated. In particular, we detected representatives of several commercially-used fungi, e.g., producers of secreted cellulases and anaerobic producers of cellulosomes. These results represent additional insights into the fungal community of the gray mangroves of the Red Sea, and show that they are significantly richer than previously reported.

  18. Soil and Rhizosphere Associated Fungi in Gray Mangroves (Avicennia marina) from the Red Sea-A Metagenomic Approach

    Institute of Scientific and Technical Information of China (English)

    Marta Filipa Simoes; Andre Antunes; Cristiane A Ottoni; Mohammad Shoaib Amini; Intikhab Alam; Hanin Alzubaidy; Noor-Azlin Mokhtar; John AC Archer; Vladimir B Bajic

    2015-01-01

    Covering a quarter of the world’s tropical coastlines and being one of the most threat-ened ecosystems, mangroves are among the major sources of terrestrial organic matter to oceans and harbor a wide microbial diversity. In order to protect, restore, and better understand these ecosystems, researchers have extensively studied their microbiology, yet few surveys have focused on their fungal communities. Our lack of knowledge is even more pronounced for specific fungal populations, such as the ones associated with the rhizosphere. Likewise, the Red Sea gray man-groves (Avicennia marina) remain poorly characterized, and understanding of their fungal commu-nities still relies on cultivation-dependent methods. In this study, we analyzed metagenomic datasets from gray mangrove rhizosphere and bulk soil samples collected in the Red Sea coast, to obtain a snapshot of their fungal communities. Our data indicated that Ascomycota was the dominant phylum (76%–85%), while Basidiomycota was less abundant (14%–24%), yet present in higher numbers than usually reported for such environments. Fungal communities were more stable within the rhizosphere than within the bulk soil, both at class and genus level. This finding is consistent with the intrinsic patchiness in soil sediments and with the selection of specific microbial communities by plant roots. Our study indicates the presence of several species on this mycobiome that were not previously reported as mangrove-associated. In particular, we detected representatives of several commercially-used fungi, e.g., producers of secreted cellulases and anaerobic producers of cellulosomes. These results represent additional insights into the fungal community of the gray mangroves of the Red Sea, and show that they are significantly richer than previously reported.

  19. Recovery of rare earth elements from the sulfothermophilic red alga Galdieria sulphuraria using aqueous acid.

    Science.gov (United States)

    Minoda, Ayumi; Sawada, Hitomi; Suzuki, Sonoe; Miyashita, Shin-ichi; Inagaki, Kazumi; Yamamoto, Takaiku; Tsuzuki, Mikio

    2015-02-01

    The demand for rare earth elements has increased dramatically in recent years because of their numerous industrial applications, and considerable research efforts have consequently been directed toward recycling these materials. The accumulation of metals in microorganisms is a low-cost and environmentally friendly method for the recovery of metals present in the environment at low levels. Numerous metals, including rare earth elements, can be readily dissolved in aqueous acid, but the efficiency of metal biosorption is usually decreased under the acidic conditions. In this report, we have investigated the use of the sulfothermophilic red alga Galdieria sulphuraria for the recovery of metals, with particular emphasis on the recovery of rare earth metals. Of the five different growth conditions investigated where G. sulphuraria could undergo an adaptation process, Nd(III), Dy(III), and Cu(II) were efficiently recovered from a solution containing a mixture of different metals under semi-anaerobic heterotrophic condition at a pH of 2.5. G. sulphuraria also recovered Nd(III), Dy(III), La(III), and Cu(II) with greater than 90% efficiency at a concentration of 0.5 ppm. The efficiency remained unchanged at pH values in the range of 1.5-2.5. Furthermore, at pH values in the range of 1.0-1.5, the lanthanoid ions were collected much more efficiently into the cell fractions than Cu(II) and therefore successfully separated from the Cu(II) dissolved in the aqueous acid. Microscope observation of the cells using alizarin red suggested that the metals were accumulating inside of the cells. Experiments using dead cells suggested that this phenomenon was a biological process involving specific activities within the cells.

  20. [Eco-hydrological characteristics and soil and water conservation effect of citrus plantation on slope red soil of Jiangxi Province, China].

    Science.gov (United States)

    Yang, Jie; Guo, Xiao-Min; Song, Yue-Jun; Xiao, Sheng-Sheng; Niu, De-Kui

    2012-02-01

    A 9-year observation was conducted at the experimental plots in the Citrus reticulata plantation in Jiangxi Provincial Eco-Technology Park to study the eco-hydrological characteristics and soil conservation benefits of the plantation on slope red soil. Seven treatments were designed and monitored over nine years. The average flow and the rate of sediment for the seven treatments were reduced by 78.5% and 77.2%, respectively. The reduction rates were the highest in treatments band coverage of Paspalum natatu, whole coverage of P. natatu, and level terrace with grass on ridge, with the values of 94.8%, 94.3% and 92.5%, respectively, followed by in treatment intercropping Glycine max (66.0%) and Raphanus sativus (77.5%), with horizontal planting being better than vertical planting, and the lowest in treatment without understory vegetation (33.1%). The observations on the precipitation redistribution of 43 rainfall events with a mean precipitation of 20.07 mm in 2009-2010 showed that the throughfall, stemflow, and canopy interception were 9.15, 4.72 and 6.20 mm, accounting for 44.7%, 25.7% and 29.6% of the precipitation, respectively. The throughfall and stemflow tended to increase with increasing precipitation. There was a significant liner negative correlation between the canopy interception rate and the precipitation when the rainfall was less than 10 mm, but no significant correlation when the rainfall was greater than 10 mm. The water holding rate of C. reticulata litters was logarithmically correlated with water soaking time, and the maximum water holding rate was 326%. It was considered that rational allocation of understory vegetation played an important role in the soil and water conservation of citrus orchard on slope red soil.

  1. Heart Rate is Associated with Red Blood Cell Fatty Acid Concentration: the GOCADAN Study

    Science.gov (United States)

    Ebbesson, Sven O.E.; Devereux, Richard B.; Cole, Shelley; Ebbesson, Lars O.E.; Fabsitz, Richard R.; Haack, Karin; Harris, William S.; Howard, Wm. James; Laston, Sandra; Lopez-Alvarenga, Juan Carlos; MacCluer, Jean W.; Okin, Peter M.; Tejero, M. Elizabeth; Voruganti, V. Saroja; Wenger, Charlotte R.; Howard, Barbara V.; Comuzzie, Anthony G.

    2010-01-01

    Background Consumption of omega-3 fatty acids (FAs) is associated with a reduction in deaths from coronary heart disease, arrhythmia, and sudden death. Although these FAs were originally thought to be anti-atherosclerotic, recent evidence suggests that their benefits are related to reducing risk for ventricular arrhythmia, and that this may be mediated by a slowed heart rate (HR). Methods The study was conducted in Alaskan Eskimos participating in the Genetics of Coronary Artery Disease in Alaska Natives (GOCADAN) Study, a population experiencing a dietary shift from unsaturated to saturated fats. We compared HR with red blood cell (RBC) FA content in 316 men and 391 women ages 35–74 years. Results Multivariate linear regression analyses of individual FAs with HR as the dependent variable and specific FAs as covariates revealed negative associations between HR and docosahexaenoic acid (DHA; 22:6n-3; p= 0.004) and eicosapentaenoic acid (EPA; 20:5n-3; p=0.009) and positive associations between HR and palmitoleic acid (16:1n-7; p=0.021), eicosenoic acid (20:1n9; p=0.007), and dihomo-gamma-linolenic acid (DGLA; 20:3n-6; p=0.021). Factor analysis revealed that the omega-3 FAs were negatively associated with HR (p=0.003), while a cluster of other, non-omega-3 unsaturated FAs (16:1, 20:1, and 20:3) was positively associated. Conclusions Marine omega 3 FAs are associated with lower HR, whereas palmitoleic and DGLA, previously identified as associated with saturated FA consumption and directly related to cardiovascular mortality, are associated with higher HR. These relations may at least partially explain the relations between omega-3 FAs, ventricular arrhythmia, and sudden death. PMID:20569715

  2. Wheat-Exuded Organic Acids Influence Zinc Release from Calcareous Soils

    Institute of Scientific and Technical Information of China (English)

    M. A. MAQSOOD; S. HUSSAIN; T. AZIZ; M. ASHRAF

    2011-01-01

    Rhizosphere drives plant uptake of sparingly soluble soil zinc (Zn).An investigation with three experiments was conducted to study organic acid exudation by two contrasting wheat genotypes (Sehar-06 and Vatan),Zn fractious in 10 different calcareous soils from Punjab,Pakistan,and release of different soil Zn fractions by organic acids.The two genotypes differed significantly in biomass production and Zn accumulation under deficient and optimum Zn levels in nutrient solution.At a deficient Zn level,Sehar-06 released more maleic acid in the rhizosphere than Vatan.Ten soils used in the present study had very different physicochemical properties; their total Zn and Zn distribution among different fractions varied significantly.Zinc release behaviour was determined by extracting the soils with 0.005 mol L-1 citric acid or maleic acid.The parabolic diffusion model best described Zn release as a function of time.Parabolic diffusion model fitting indicated more maleic acid-driven than citric acid-driven soil Zn mobility from different fractions.Cumulative Zn release in six consecutive extractions during 24 h ranged from 1.85 to 13.58 mg kg-1 using maleic acid and from 0.37 to 11.84 mg kg-1 using citric acid.In the selected calcareous soils,the results of stepwise linear regression indicated significant release of Fe-Mn oxide-bounded soil Zn by maleic acid and its availability to the Zn-efficient genotype.Hence,release of maleic acid by plants roots played an important role in phytoavailability of Zn from calcareous soils.

  3. Extraction of rare earth elements from a contaminated cropland soil using nitric acid, citric acid, and EDTA.

    Science.gov (United States)

    Tang, Hailong; Shuai, Weitao; Wang, Xiaojing; Liu, Yangsheng

    2017-08-01

    Rare earth elements (REEs) contamination to the surrounding soil has increased the concerns of health risk to the local residents. Soil washing was first attempted in our study to remediate REEs-contaminated cropland soil using nitric acid, citric acid, and ethylene diamine tetraacetic acid (EDTA) for soil decontamination and possible recovery of REEs. The extraction time, washing agent concentration, and pH value of the washing solution were optimized. The sequential extraction analysis proposed by Tessier was adopted to study the speciation changes of the REEs before and after soil washing. The extract containing citric acid was dried to obtain solid for the X-ray fluorescence (XRF) analysis. The results revealed that the optimal extraction time was 72 h, and the REEs extraction efficiency increased as the agent concentration increased from 0.01 to 0.1 mol/L. EDTA was efficient to extract REEs over a wide range of pH values, while citric acid was around pH 6.0. Under optimized conditions, the average extraction efficiencies of the major REEs in the contaminated soil were 70.96%, 64.38%, and 62.12% by EDTA, nitric acid, and citric acid, respectively. The sequential extraction analyses revealed that most soil-bounded REEs were mobilized or extracted except for those in the residual fraction. Under a comprehensive consideration of the extraction efficiency and the environmental impact, citric acid was recommended as the most suitable agent for extraction of the REEs from the contaminated cropland soils. The XRF analysis revealed that Mn, Al, Si, Pb, Fe, and REEs were the major elements in the extract indicating a possibile recovery of the REEs.

  4. Dissolution of Aluminum in Variably Charged Soils as Affected by Low-Molecular-Weight Organic Acids

    Institute of Scientific and Technical Information of China (English)

    LI Jiu-Yu; XU Ren-Kou; JI Guo-Liang

    2005-01-01

    Low-molecular-weight (LMW) organic acids exist widely in soils and play an important role in soil processes such as mineral weathering, nutrient mobilization and Al detoxification. In this research, a batch experiment was conducted to examine the effects of LMW organic acids on dissolution of aluminum in two variably charged soils, an Ultisol and an Oxisol. The results showed that the LMW organic acids enhanced the dissolution of Al in the two investigated soils in the following order: citric > oxalic > malonic > malic > tartaric > salicylic > lactic > maleic. This was generally in agreement with the magnitude of the stability constants for the Al-organic complexes. The effects of LMW organic acids on Al dissolution were greater in the Ultisol than in the Oxisol as compared to their controls. Also, the accelerating effects of citric and oxalic acids on dissolution of Al increased with an increase in pH, while the effects of lactic and salicylic acids decreased. Additionally, when the organic acid concentration was less than 0.2 mmol L-1, the dissolution of Al changed little with increase in acid concentration. However, when the organic acid concentration was greater than 0.2 mmol L-1,the dissolution of Al increased with increase in acid concentration. In addition to the acid first dissociation constant and stability constant of Al-organic complexes, the promoting effects of LMW organic acids on dissolution of Al were also related to their sorption-desorption equilibrium in the soils.

  5. Sustainable Soil Washing: Shredded Card Filtration of Potentially Toxic Elements after Leaching from Soil Using Organic Acid Solutions.

    Directory of Open Access Journals (Sweden)

    Christopher Ash

    Full Text Available Shredded card (SC was assessed for use as a sorbent of potentially toxic elements (PTE carried from contaminated soil in various leachates (oxalic acid, formic acid, CaCl2, water. We further assessed SC for retention of PTE, using acidified water (pH 3.4. Vertical columns and a peristaltic pump were used to leach PTE from soils (O and A/B horizons before passing through SC. Sorption onto SC was studied by comparing leachates, and by monitoring total PTE contents on SC before and after leaching. SC buffers against acidic soil conditions that promote metals solubility; considerable increases in solution pH (+4.49 were observed. Greatest differences in solution PTE content after leaching with/without SC occurred for Pb. In oxalic acid, As, Cd, Pb showed a high level of sorption (25, 15, and 58x more of the respective PTE in leachates without SC. In formic acid, Pb sorption was highly efficient (219x more Pb in leachate without SC. In water, only Pb showed high sorption (191x more Pb in leachate without SC. In desorption experiments, release of PTE from SC varied according to the source of PTE (organic/mineral soil, and type of solvent used. Arsenic was the PTE most readily leached in desorption experiments. Low As sorption from water was followed by fast release (70% As released from SC. A high rate of Cd sorption from organic acid solutions was followed by strong retention (~12% Cd desorption. SC also retained Pb after sorption from water, with subsequent losses of ≤8.5% of total bound Pb. The proposed use of this material is for the filtration of PTE from extract solution following soil washing. Low-molecular-mass organic acids offer a less destructive, biodegradable alternative to strong inorganic acids for soil washing.

  6. Low—Molecular—Weight Aliphatic Acids in Soils Inculbated with Plant Residues Under Different Moisture Conditions

    Institute of Scientific and Technical Information of China (English)

    SHENALIN; LIXUEYUAN; 等

    1997-01-01

    Iucubation experiments were conducted to investigate the dynamics of low-molecular-weight aliphatic acids i two andosols with and without plant materials.Results showed that amount of low-molecular-weight aliphatic acids in soils alone varied considerably with water regime under which the soil was incubated,duration of incubation and soil organic matter content,ranging from 257-860μmol kg-1 soil,of which 19%-33% was in free state.Incorporation of plant matrials increased greatly both the amount and unmber of members of low-molecular-weight aliphatic acids,and also the proportion of low-molecular-weght aliphatic acids occurred in free state ,Generally,among these ,aliphatic acids detected,acetic,propionic,glyoxalic and formic acids were predominant.

  7. Interactions of chrysotile and crocidolite asbestos with red blood cell membranes. Chrysotile binds to sialic acid.

    Science.gov (United States)

    Brody, A R; George, G; Hill, L H

    1983-10-01

    Chrysotile and crocidolite are commonly used forms of asbestos. Hemolysis has been widely used as a test of membrane injury, and it has been shown previously that chrysotile causes rapid breakdown of red blood cells (RBCs), whereas crocidolite is only weakly hemolytic. A reasonable hypothesis set forth to explain the cytotoxic effects of chrysotile maintains that positively charged chrysotile fibers bind to negatively charged sialic acid residues on RBC membranes causing clustering of membrane proteins and increased cell permeability to Na and K ions. Our studies presented here provide two lines of evidence in direct support of this hypothesis. (a) Morphologic--Ultrastructural techniques showed that both chrysotile and crocidolite asbestos bind to and distort more than 85% of RBCs treated for 15 minutes. The distorting effects of chrysotile, but not crocidolite, were almost totally ablated by pretreating the cells with neuraminidase. In addition, gold-conjugated wheat germ agglutinin was used to label the distribution of sialic acid groups on RBC membranes. Pretreatment of the RBCs with chrysotile, but not crocidolite, reduced the number of gold-conjugated wheat germ agglutinin-labeled sites to less than 30% of the control level. (b) Biochemical--The thiobarbituric acid assay was used to determine the percentage of sialic acid that remained with the cell pellet after neuraminidase and/or asbestos treatment. Asbestos treatment alone caused no release of sialic acid from the cells. Neuraminidase treatment for 3.5 hours removed more than 80% of the sialic acid from cell surfaces. Chrysotile, but not crocidolite, asbestos prevented neuraminidase-mediated removal of sialic acid from RBCs. In addition, x-ray energy spectrometry of freeze-dried cells showed that RBCs distorted by chrysotile, but not by crocidolite, exhibited significant alterations in intracellular Na:K ratios. The morphologic and biochemical data strongly support the hypothesis that chrysotile asbestos

  8. Characterization of the coal derived humic acids from Mukah, Sarawak as soil conditioner

    Directory of Open Access Journals (Sweden)

    Fong Sim Siong

    2006-01-01

    Full Text Available In Malaysia, abundant coal resources were found in Sarawak and Sabah. The utilization of coal resources, to date, is emphasized on the energy productions. The non-energy utilization as soil conditioner is unexplored. Therefore, this study attempted to characterize the coal humic acids extracted from Mukah coal and to evaluate its properties as soil conditioner. The coal humic acids from the regenerated sample were also assessed. The results revealed that different extractants and concentrations influenced the properties of humic acids. The extraction with KOH at 0.5 mol L-1 produced humic acids with low ash content and high acidic functional groups, which are substantial as soil conditioner. However, the yield was low. Regeneration of coal sample with 10% nitric acids improved the yield to an average of 83.45%. The acidic functional groups of nitrohumic acids were improved with the ash content remained at a low level.

  9. Effects of organic acids on Cd adsorption and desorption by two anthropic soils

    Institute of Scientific and Technical Information of China (English)

    Jingui WANG; Jialong LV; Yaolong FU

    2013-01-01

    The objective of this experiment was to study the effects of malic, tartaric, oxalic, and citric acid on the adsorption and desorption characteristics of Cd by two typical anthropic soils (lou soil and irrigation-silted soil) in North-west China. Cadmium adsorption and desorption were studied under a range of temperatures (25℃, 30℃, 35℃, 40℃), organic acid concentrations (0.5-5.0 mmol·L-1), and pH values (2-8). The results showed that the Cd adsorption capacity of the lou soil was significantly greater than that of the irrigation-silted soil. Generally, Cd adsorption increased as the temperature increased. In the presence of NaNO3, the adsorption of Cd was endothermic with △H values of 31.365 kJ·mo1-1 for lou soil and 28.278 kJ·mol-1 for irrigation-silted soil. The endothermic reaction indicated that H bonds were the main driving force for Cd adsorption in both soils. However, different concentrations of organic acids showed various influences on the two soils. In the presence of citric acid, chemical adsorption and van der Waals interactions were the main driving forces for Cd adsorption rather than H bonds. Although the types of organic acids and soil properties were different, the effects of the organic acids on the adsorption and desorption of Cd were similar in the two soils. The adsorption percentage of Cd generally decreased as organic acid concentrations increased. In contrast, the adsorption percentage increased as the pH of the initial solution increased. The exception was that adsorption percentage of Cd increased slightly as oxalic acid concentrations increased. In contrast, the desorption percentage of Cd increased with increasing concentrations of organic acids but decreased as the initial solution pH increased.

  10. Identifying sources of acidity and spatial distribution of acid sulfate soils in the Anglesea River catchment, southern Australia

    Science.gov (United States)

    Wong, Vanessa; Yau, Chin; Kennedy, David

    2015-04-01

    Globally, coastal and estuarine floodplains are frequently underlain by sulfidic sediments. When exposed to oxygen, sulfidic sediments oxidise to form acid sulfate soils, adversely impacting on floodplain health and adjacent aquatic ecoystems. In eastern Australia, our understanding of the formation of these coastal and estuarine floodplains, and hence, spatial distribution of acid sulfate soils, is relatively well established. These soils have largely formed as a result of sedimentation of coastal river valleys approximately 6000 years BP when sea levels were one to two metres higher. However, our understanding of the evolution of estuarine systems and acid sulfate soil formation, and hence, distribution, in southern Australia remains limited. The Anglesea River, in southern Australia, is subjected to frequent episodes of poor water quality and low pH resulting in closure of the river and, in extreme cases, large fish kill events. This region is heavily reliant on tourism and host to a number of iconic features, including the Great Ocean Road and Twelve Apostles. Poor water quality has been linked to acid leakage from mining activities and Tertiary-aged coal seams, peat swamps and acid sulfate soils in the region. However, our understanding of the sources of acidity and distribution of acid sulfate soils in this region remains poor. In this study, four sites on the Anglesea River floodplain were sampled, representative of the main vegetation communities. Peat swamps and intertidal marshes were both significant sources of acidity on the floodplain in the lower catchment. However, acid neutralising capacity provided by carbonate sands suggests that there are additional sources of acidity higher in the catchment. This pilot study has highlighted the complexity in the links between the floodplain, upper catchment and waterways with further research required to understand these links for targeted acid management strategies.

  11. DESERT PAVEMENTS AND SOILS ON BASALTIC PYROCLASTIC DEPOSITS AT LATHROP WELLS AND RED CONE VOLCANOES, SOUTHERN NEVADA ABSTRACT

    Energy Technology Data Exchange (ETDEWEB)

    G.A. Valentine; C.D. Harrington

    2005-08-26

    Formation of desert pavement and accretionary soils are intimately linked in arid environments such as the Mojave Desert. Well-sorted fallout scoria lapilli at Lathrop Wells (75-80 ky) and Red Cone ({approx}1 Ma) volcanoes (southern Nevada) formed an excellent starting material for pavement, allowing infiltration of eolian silt and fine sand that first clogs the pore space of underlying tephra and then aggrades and develops vesicular A (Av) horizons. Variations in original pyroclast sizes provide insight into minimum and maximum clast sizes that promote pavement and soil formation: pavement becomes ineffective when clasts can saltate under the strongest winds, while clasts larger than coarse lapilli are unable to form an interlocking pavement that promotes silt accumulation (necessary for Av development). Contrary to predictions that all pavements above altitudes of {approx}400 m would have been ''reset'' in their development after late Pleistocene vegetation advances (about 15 ka), the soils and pavements show clear differences in maturity between the two volcanoes. This indicates that either the pavements/soils develop slowly over many 10,000's of years and then are very stable, or that, if they are disrupted by vegetation advances, subsequent pavements are reestablished with successively more mature characteristics.

  12. DESERT PAVEMENTS AND SOILS ON BASALTIC PYROCLASTIC DEPOSITS AT LATHROP WELLS AND RED CONE VOLCANOES, SOUTHERN NEVADA

    Energy Technology Data Exchange (ETDEWEB)

    G.A. Valentine; C.D. Harrington

    2005-08-10

    Formation of desert pavement and accretionary soils are intimately linked in arid environments such as the Mojave Desert. Well-sorted fallout scoria lapilli at Lathrop Wells (75-80 ky) and Red Cone ({approx}1 Ma) volcanoes (southern Nevada) formed an excellent starting material for pavement, allowing infiltration of eolian silt and fine sand that first clogs the pore space of underlying tephra and then aggrades and develops vesicular A (Av) horizons. Variations in original pyroclast sizes provide insight into minimum and maximum clast sizes that promote pavement and soil formation: pavement becomes ineffective when clasts can saltate under the strongest winds, while clasts larger than coarse lapilli are unable to form an interlocking pavement that promotes silt accumulation (necessary for Av development). Contrary to predictions that all pavements above altitudes of {approx}400 m would have been ''reset'' in their development after late Pleistocene vegetation advances (about 15 ka), the soils and pavements show clear differences in maturity between the two volcanoes. This indicates that either the pavement soils develop slowly over many 10,000's of years and then are very stable, or that, if they are disrupted by vegetation advances, subsequent pavements are reestablished with successively more mature characteristics.

  13. Solid components and acid buffering capacity of soils in South China

    Institute of Scientific and Technical Information of China (English)

    1998-01-01

    The effects of soil solid components on soil sensitivityto acid deposition were studied in this paper by sequentialextraction method. A multiple regression equation of soilsensitivity was set up on the basis of stepwise regressionanalysis. The results showed that organic matter expressed dualeffects that were decided by soil original pH value andexchangeable cation composition on acid buffering reactions. Thehydrolysis of activated oxides was a very important protonbuffering reaction when in low pH situation. The crystalline oxidesalso played a role in the buffering reactions, but the role wasrestricted by the rate of activation of oxides. Meanwhile, theresults by stepwise analysis showed that factors that hadsignificant effect on soil acid buffering capacity were content ofmontmorillite, soil original pH value, Alo, Mno and CEC indecreasing order. Finally, sixteen soils were classified into fourtypes of sensitive with single index cluster and multiple fuzzy cluster analysis respectively.

  14. Impact of acid atmospheric deposition on soils: Field monitoring and aluminium chemistry.

    OpenAIRE

    1988-01-01

    The effect of acid atmospheric deposition on concentrations and transfer of major solutes in acid, sandy soils was studied. Emphasis was given to mobilization and transport of potentially toxic aluminum. Data on solute concentrations and fluxes in meteoric water as well as soil solutions were obtained from intensive monitoring programmes conducted at a number of sites in northwestern Europe and North-America. Specific hypotheses were tested in laboratory experiments.Atmospheric acid inputs do...

  15. Emission of nitrous acid from soil and biological soil crusts as a major source of atmospheric HONO on Cyprus

    Science.gov (United States)

    Meusel, Hannah; Tamm, Alexandra; Wu, Dianming; Kuhn, Uwe; Leifke, Anna-Lena; Weber, Bettina; Su, Hang; Lelieveld, Jos; Hoffmann, Thorsten; Pöschl, Ulrich; Cheng, Yafang

    2017-04-01

    Elucidation of the sources and atmospheric chemistry of nitrous acid (HONO) is highly relevant, as HONO is an important precursor of OH radicals. Up to 30% of the OH budget are formed by photolysis of HONO, whereas major fractions of HONO measured in the field derive from yet unidentified sources. Heterogeneous conversion of nitrogen dioxide (NO2) to HONO on a variety of surfaces (soot, humic acid aerosol) is assumed to be a major HONO source (Stemmler et al., 2007, Ammann et al., 1998). In rural regions, however, NO2 concentrations were found to be too low to explain observed HONO concentrations, as e.g., in the case of a recent field study on the Mediterranean island of Cyprus (Meusel et al., 2016). In this study a good correlation between missing sources of HONO and nitrogen oxide (NO) was found indicating a common origin of both reactive nitrogen compounds. Simultaneous emission of HONO and NO from soil was reported earlier (Oswald et al., 2013), and enhanced emission rates were found when soil was covered by biological soil crusts in arid and semi-arid ecosystems (Weber et al., 2015). In the present study we measured HONO and NO emissions of 43 soil and soil crust samples from Cyprus during full wetting and drying cycles under controlled laboratory conditions by means of a dynamic chamber system. The observed range of HONO and NO emissions was in agreement with earlier studies, but unlike the study of Weber et al. (2015), we found highest emission from bare soil, followed by soil covered by light and dark cyanobacteria-dominated biological soil crusts. Emission rates correlated well with the nitrite and nitrate contents of soil and biological soil crust samples, and higher nutrient contents of bare soil samples, as compared to the previous biological soil crust study, explain the higher bare soil emissions. Integrating the emission rates of bare soil and the different types of biological soil crusts, based on their local relative abundance, the calculated

  16. Bioaccumulation of perfluoroalkyl acids by earthworms (Eisenia fetida) exposed to contaminated soils.

    Science.gov (United States)

    Rich, Courtney D; Blaine, Andrea C; Hundal, Lakhwinder; Higgins, Christopher P

    2015-01-20

    The presence of perfluoroalkyl acids (PFAAs) in biosolids-amended and aqueous film-forming foam (AFFF)-impacted soils results in two potential pathways for movement of these environmental contaminants into terrestrial foodwebs. Uptake of PFAAs by earthworms (Eisenia fetida) exposed to unspiked soils with varying levels of PFAAs (a control soil, an industrially impacted biosolids-amended soil, a municipal biosolids-amended soil, and two AFFF-impacted soils) was measured. Standard 28 day exposure experiments were conducted in each soil, and measurements taken at additional time points in the municipal soil were used to model the kinetics of uptake. Uptake and elimination rates and modeling suggested that steady state bioaccumulation was reached within 28 days of exposure for all PFAAs. The highest concentrations in the earthworms were for perfluorooctane sulfonate (PFOS) in the AFFF-impacted Soil A (2160 ng/g) and perfluorododecanoate (PFDoA) in the industrially impacted soil (737 ng/g). Wet-weight (ww) and organic carbon (OC)-based biota soil accumulation factors (BSAFs) for the earthworms were calculated after 28 days of exposure for all five soils. The highest BSAF in the industrially impacted soil was for PFDoA (0.42 goc/gww,worm). Bioaccumulation factors (BAFs, dry-weight-basis, dw) were also calculated at 28 days for each of the soils. With the exception of the control soil and perfluorodecanoate (PFDA) in the industrially impacted soil, all BAF values were above unity, with the highest being for perfluorohexanesulfonate (PFHxS) in the AFFF-impacted Soil A (139 gdw,soil/gdw,worm). BSAFs and BAFs increased with increasing chain length for the perfluorocarboxylates (PFCAs) and decreased with increasing chain length for the perfluoroalkyl sulfonates (PFSAs). The results indicate that PFAA bioaccumulation into earthworms depends on soil concentrations, soil characteristics, analyte, and duration of exposure, and that accumulation into earthworms may be a potential

  17. Study of morphology, chemical, and amino acid composition of red deer meat

    Directory of Open Access Journals (Sweden)

    Eleonora Okuskhanova

    2017-06-01

    Full Text Available Aim: The aim of this study was to evaluate red deer (maral meat quality based on chemical composition, pH, water-binding capacity (WBC, and amino acid content. Materials and Methods: Maral meat surface morphology measurements were obtained by scanning electron microscopy. Active acidity (pH was determined by potentiometry. Samples were analyzed for WBC by exudation of moisture to a filter paper by the application of pressure. Chemical composition (moisture, protein, fat, and ash fractions was obtained by drying at 150°C and by extraction, using ethylic ether, and ashing at 500-600°C. The amino acid composition was obtained by liquid chromatography. Results: Maral meat, with a pH of 5.85 and an average moisture content of 76.82%, was found to be low in fat (2.26%. Its protein content was 18.71% while its ash content was 2.21%. The amino acid composition showed that lysine (9.85 g/100 g, threonine (5.38 g/100 g, and valine (5.84 g/100 g predominated in maral meat, while phenylalanine (4.08 g/100 g, methionine (3.29 g/100 g, and tryptophan (0.94 g/100 g were relatively low in maral meat compared to other meats. The average WBC was found to be 65.82% and WBC was found to inversely correlate with moisture content. Conclusion: Low-fat content, high mineral content, and balanced amino-acid composition qualify maral meat as a worthy dietary and functional food.

  18. Kinetic Modelling for Flavonoid Recovery from Red Grape (Vitis vinifera Pomace with Aqueous Lactic Acid

    Directory of Open Access Journals (Sweden)

    Katerina Tzima

    2014-12-01

    Full Text Available This study was undertaken with the aim of establishing a correlation between the extraction yield in total flavonoids from red grape pomace and the extraction temperature, using 0.5% (w/v aqueous lactic acid as the solvent system. Extraction of flavonoids was found to obey second-order kinetics, and on such a basis, the yield in total flavonoids at saturation could be very effectively determined and correlated with temperature using non-linear regression. The results indicated that the extraction yield at saturation is highly correlated with temperature, following a quadratic function. The extract obtained at 40 °C had an optimal predicted total flavonoid yield of 13.27 mg rutin equivalents per gram of dry weight, and it was further analyzed by liquid chromatography-mass spectrometry to characterize its major constituents. The polyphenols detected were flavanols, flavonols and an anthocyanin. The outcome of this study outlined that temperatures above 40 °C are rather unfavorable for flavonoid extraction from red grape pomace, as suggested by the model established through kinetics.

  19. Acidic mist reduces foliar membrane-associated calcium and impairs stomatal responsiveness in red spruce

    Energy Technology Data Exchange (ETDEWEB)

    Borer, C. H.; DeHayes, D. H. [University of Vermont, Rubinstein School of Environment and Natural Resources, Burlington, VT (United States); Schaberg, P. G. [USDA Forest Service, Northeastern Research Station, South Burlington, VT (United States)

    2005-06-01

    The possibility of impairment of stomatal responsiveness due to acidic mist-induced depletion of foliar membrane calcium (mCa) was investigated by exposing red spruce seedlings to either pH 3.0 or pH 5.0 mist treatments for one growing season. Foliar nutrition was assessed following each treatment, and declines in stomatal conductance and net photosynthesis were measured on current year shoots following stem excision. Seedlings subjected to pH 3.0 acidic mist treatment had reduced mCa, and exhibited impaired stomatal function, including a smaller maximum aperture, slower closure, increased lag time between stomatal closure and photosynthetic decline following experimental water stress, relative to seedling treated with pH 5.0 acidic mist. The evidence supports the hypothesis that anthropogenetically caused depletion of mCa may disrupt physiological processes that depend on foliar Ca, in the process reducing the plants ability to respond adaptively to environmental stresses. 69 refs., 1 tab., 1 fig.

  20. Red blood cells (RBCs), epoxyeicosatrienoic acids (EETs) and adenosine triphosphate (ATP).

    Science.gov (United States)

    Jiang, Houli; Anderson, Gail D; McGiff, John C

    2010-01-01

    In addition to serving as carriers of O(2), red blood cells (RBCs) regulate vascular resistance and the distribution of microvascular perfusion by liberating adenosine triphosphate (ATP) and epoxyeicosatrienoic acids (EETs) upon exposure to a low O(2) environment. Therefore, RBCs act as sensors that respond to low pO(2) by releasing millimolar amounts of ATP, a signaling molecule, and lipid mediators (EETs). The release of EETs occurs by a mechanism that is activated by ATP stimulation of P2X(7) receptors coupled to ATP transporters, which should greatly amplify the circulatory response to ATP. RBCs are reservoirs of EETs and the primary sources of plasma EETs, which are esterified to the phospholipids of lipoproteins. Levels of free EETs in plasma are low, about 3% of circulating EETs. RBC EETs are produced by direct oxidation of arachidonic acid (AA) esterified to glycerophospholipids and the monooxygenase-like activity of hemoglobin. On release, EETs affect vascular tone, produce profibrinolysis and dampen inflammation. A soluble epoxide hydrolase (sEH) regulates the concentrations of RBC and vascular EETs by metabolizing both cis- and trans-EETs to form dihydroxyeicosatrienoic acids (DHETs). The function and pathophysiological roles of trans-EETs and erythro-DHETs has yet to be integrated into a physiological and pathophysiological context.

  1. Investigation of adsorption and inhibitive effect of acid red GRE (183 dye on the corrosion of carbon steel in hydrochloric acid media

    Directory of Open Access Journals (Sweden)

    M. Abd El-raouf

    2015-09-01

    Full Text Available The adsorption and corrosion inhibitive effect of acid red GRE (183 dye on carbon steel alloy in 1 M HCl solutions was studied using various techniques. Results of weight loss, Tafel polarization measurements and electrochemical impedance spectroscopy (EIS techniques show that this compound has fairly good inhibiting properties for steel corrosion in acidic bath; with efficiency around 96% at a concentration of 50 ppm. The inhibition is of a mixed anodic–cathodic nature. Factors affecting the corrosion process have been calculated and discussed. Acid red GRE (183 dye was shown to be an inhibitor in the acidic corrosion. Inhibition efficiency increased with acid red GRE (183 dye concentration but decreased with rise in temperature, corrosion inhibition is attributed to the adsorption of acid red GRE (183 dye on the carbon steel surface via a physical adsorption mechanism. Langmuir isotherm is found to provide an accurate description of the adsorption behavior of the investigated azo compound. The nature of the protective film was investigated using SEM and EDX techniques.

  2. Role of amino acid metabolites in the formation of soil organic matter

    DEFF Research Database (Denmark)

    Sørensen, Lasse Holst

    1972-01-01

    Carbon-14 labelled cellulose or glucose were added to a medium loam and two sandy soils. The soils were incubated at 20°C for about 6 yr under laboratory conditions. Six to 12 per cent of the labelled carbon added to the soils was transformed into metabolites hydrolysable to amino acids during...... as incubation proceeded. Twenty-six to 30 per cent of the total labelled carbon remaining in the soils after 6 yr of incubation was located in amino acids when the labelled carbon was added as cellulose, compared to 43 per cent when the labelled carbon was added as glucose. The amounts of amino acid metabolites...... extracted by sodium hydroxide or by the chelating ion-exchange resin Dowex A-1 decreased during the period of incubation. The unlabelled soil carbon as a whole was more extractable by the resin treatment than the labelled. Sixteen protein amino acids and two amino sugars were detected in hydrolysates...

  3. Alleviating aluminium toxicity on an acid sulphate soils in Peninsular Malaysia with application of calcium silicate

    Science.gov (United States)

    Elisa, A. A.; Ninomiya, S.; Shamshuddin, J.; Roslan, I.

    2015-10-01

    A study was conducted to alleviate Al toxicity of an acid sulphate soils collected from paddy cultivation area in Kedah, Peninsular Malaysia. For this purpose, the collected acid sulphate soils were treated with calcium silicate. The treated soils were incubated for 120 days in submerged condition in a glasshouse. Subsamples were collected every 30 days throughout the incubation period. Soil pH and exchangeable Al showed positive effect; soil pH increased from 2.9 to 3.5, meanwhile exchangeable Al was reduced from 4.26 to 0.82 cmolc kg-1, which was well below the critical Al toxicity level for rice growth of 2 cmolc kg-1. It was noted that the dissolution of calcium silicate (CaSiO3) supplied substantial amount of Ca2+ and H4SiO42- ions into the soil, noted with increment in Si (silicate) content from 21.21 to 40 mg kg-1 at day 30 and reduction of exchangeable Al at day 90 from 4.26 to below 2 cmolc kg-1. During the first 60 days of incubation, Si content was positively correlated with soil pH, while the exchangeable Al was negatively correlated with Si content. It is believed that the silicate anions released by calcium silicate were active in neutralizing H+ ions that governs the high acidity (pH 2.90) of the acid sulphate soils. This scenario shows positive effect of calcium silicate to reduce soil acidity, therefore creates a favourable soil condition for good rice growth during its vegetative phase (30 days). Thus, application of calcium silicate to alleviate Al toxicity of acid sulphate soils for rice cultivation is a good soil amendment.

  4. Effects of acidic and neutral biochars on properties and cadmium retention of soils.

    Science.gov (United States)

    Qi, Fangjie; Dong, Zhaomin; Lamb, Dane; Naidu, Ravi; Bolan, Nanthi S; Ok, Yong Sik; Liu, Cuixia; Khan, Naser; Johir, M A H; Semple, Kirk T

    2017-08-01

    In this study, an acidic biochar and a neutral biochar were applied at 5 wt% into two soils for an 11-month incubation experiment. One Ferrosol soil (Ba) was slightly acidic with low organic matter and the other Dermosol soil (Mt) was slightly alkaline with high organic matter. The acidic (pH = 3.25) wood shaving (WS) biochar had no marked impact on nutrient levels, cation exchange capacity (CEC), pH and acid neutralization capacity (ANC) of either soil. By contrast, the neutral (pH = 7.00) chicken litter (CL) biochar significantly increased major soluble nutrients, pH, ANC of soil Ba. In terms of C storage, 87.9% and 69.5% WS biochar-C can be sequestrated as TOC by soil Ba and Mt, respectively, whereas only 24.0% of CL biochar-C stored in soil Ba and negligible amount in Mt as TOC. Biochars did not have significant effects on soil sorption capacity and sorption reversibility except that CL biochar increased sorption of soil Ba by around 25.4% and decreased desorption by around 50.0%. Overall, the studied acidic C rich WS biochar held little agricultural or remedial values but was favourable for C sequestration. The neutral mineral rich CL biochar may provide short-term agricultural benefit and certain sorption capacities of lower sorption capacity soils, but may be unlikely to result in heightened C sequestration in soils. This is the first study comprehensively examining functions of acidic and neutral biochars for their benefits as a soil amendment and suggests the importance of pre-testing biochars for target purposes prior to their large scale production. Copyright © 2017 Elsevier Ltd. All rights reserved.

  5. Synthesis and Site-Specific Incorporation of Red-Shifted Azobenzene Amino Acids into Proteins.

    Science.gov (United States)

    John, Alford A; Ramil, Carlo P; Tian, Yulin; Cheng, Gang; Lin, Qing

    2015-12-18

    A series of red-shifted azobenzene amino acids were synthesized in moderate-to-excellent yields via a two-step procedure in which tyrosine derivatives were first oxidized to the corresponding quinonoidal spirolactones followed by ceric ammonium nitrate-catalyzed azo formation with the substituted phenylhydrazines. The resulting azobenzene-alanine derivatives exhibited efficient trans/cis photoswitching upon irradiation with a blue (448 nm) or green (530 nm) LED light. Moreover, nine superfolder green fluorescent protein (sfGFP) mutants carrying the azobenzene-alanine analogues were expressed in E. coli in good yields via amber codon suppression with an orthogonal tRNA/PylRS pair, and one of the mutants showed durable photoswitching with the LED light.

  6. Pathophysiological changes associated with dietary melamine and cyanuric acid toxicity in red tilapia.

    Science.gov (United States)

    Phromkunthong, W; Choochuay, P; Kiron, V; Nuntapong, N; Boonyaratpalin, M

    2015-02-01

    This study examined the adverse effects of feed-delivered melamine (MEL) and cyanuric acid (CYA) in red tilapia. Diet 1 (without MEL and CYA), diets 2-4 (with MEL and CYA at 2.5, 5 and 7.5 g kg(-1) diet, respectively) and diets 5 and 6 (with either MEL or CYA at 10 g kg(-1) diet) were examined. MEL alone lowered both growth and FCR (P tilapia. Protein efficiency ratio and apparent net utilization of fish on diets 2-6 were poor (P 5 g kg(-1) diet induced the activity of catalase in liver and the activity of glutathione peroxidase in liver and kidneys. Therefore, these adulterants should not be included in fish feeds.

  7. Nature of Soil Acidity in Relation to Properties and Lime Requirement of Some Inceptisols

    Institute of Scientific and Technical Information of China (English)

    A. K. DOLUI; S. BHATTACHARJEE

    2003-01-01

    Some Inceptisols representing the Singla catchment area in Karimgaunge district of Assam, India, were studied for lime requirement as influenced by the nature of soil acidity. The electrostatically bonded (EB)-H+ and EB-Al3+ acidities constituted 33 and 67 percent of exchangeable acidity while EB-H+, EB-Al3+,exchangeable and pH-dependent acidities comprised 6, 14, 20 and 80 percent of total potential acidity. The pH-dependent acidity made a major contribution towards the total potential acidity (67%~84%). Grand mean of lime requirement determined by the laboratory incubation method and estimated by the methods of New Woodruff, Woodruff and Peech as expressed in MgCaCO3 ha-1 was in the order: Woodruff (15.6) > New Woodruff (14.9) > Peech (5.1) > incubation (5.0). Correlations analysis among different forms of acidity and lime requirement methods with selected soil properties showed that pH in three media, namely water, 1 mol L-1 KCl and 0.01 mol L-1 CaCl2, had a significant negative correlation with different forms of acidity and lime requirement methods. Exchangeable Fe and Al showed significant positive correlations with EB-Al3+ acidity, exchangeable acidity, pH-dependent acidity and total potential acidity, and also lime requirement methods. Extractable Al showed positive correlations with different forms of acidity except EB-H+ and EB-Al3+ acidities. The lime requirement by different methods depended upon the extractable aluminium.Significant positive correlations existed between lime requirements and different forms of acidity of the soils except EB-H+ acidity and incubation method. The nature of soil acidity was mostly pH-dependent. Statistically, the Woodruff method did slightly better than the New Woodruff, incubation and Peech methods at estimating lime requirement and hence the Woodruff procedure may be recommended for routine soil testing because of its speed and simplicity.

  8. Molecular and microscopic insights into the persistence of soil organic matter in a red pine rhizosphere

    Science.gov (United States)

    Microbially-derived carbon inputs to soils play an important role in stabilization of soil organic matter (SOM), but detailed knowledge of basic mechanisms of carbon (C) cycling, such as stabilization of organic C compounds originating from rhizodeposition, is lacking. This study aimed to investigat...

  9. Vegetable production after flooded rice improves soil properties in the Red River Delta, Vietnam

    NARCIS (Netherlands)

    Everaarts, A.P.; Neeteson, J.J.; Pham Thi Thu, H.; Struik, P.C.

    2015-01-01

    Vegetable production in South East Asia often is in rotation with °ooded rice. The puddling of the soil with flooded rice production may result in unfavourable soil conditions for the subsequent production of dry land crops. To establish whether permanent vegetable production results in favourable s

  10. Characterizing the Soil Ecology of Red Raspberry Produced under Different Production Regimes

    Science.gov (United States)

    Soil and rhizosphere ecology play important roles in plant health and development. Using culture-independent microbial community profiling, we investigated the effects of fertilizer (composted dairy solids + mustard seed meal) on fungal communities in soil and endophytic in a raspberry production sy...

  11. Utilization of maize cob biochar and rice husk charcoal as soil amendments for improving acid soil fertility and productivity

    Directory of Open Access Journals (Sweden)

    Nurhidayati

    2014-10-01

    Full Text Available The decline in soil fertility in agricultural land is a major problem that causes a decrease in the production of food crops. One of the causes of the decline in soil fertility is declining soil pH that caused the decline in the availability of nutrients in the soil. This study aimed to assess the influence of alternative liming materials derived from maize cob biochar and rice husk charcoal compared to conventional lime to improve soil pH, soil nutrient availability and maize production. The experiment used a factorial complete randomized design which consisting of two factors. The first factor is the type of soil amendment which consists of three levels (calcite lime, rice husk charcoal and cob maize biochar. The second factor is the application rates of the soil amendment consisted of three levels (3, 6 and 9 t/ha and one control treatment (without soil amendment. The results of this study showed that the application of various soil amendment increased soil pH, which the pH increase of the lime application was relatively more stable over time compared to biochar and husk charcoal. The average of the soil pH increased for each soil amendment by 23% (lime, 20% (rice husk charcoal and 23% (biochar as compared with control. The increase in soil pH can increase the availability of soil N, P and K. The greatest influence of soil pH on nutrient availability was shown by the relationship between soil pH and K nutrient availability with R2 = 0.712, while for the N by R2 = 0.462 and for the P by R2 = 0.245. The relationship between the availability of N and maize yield showed a linear equation. While the relationship between the availability of P and K with the maize yield showed a quadratic equation. The highest maize yield was found in the application of biochar and rice husk charcoal with a dose of 6-9 t/ha. The results of this study suggested that biochar and husk charcoal could be used as an alternative liming material in improving acid soil

  12. Red- and blue-shifted hydrogen bonds in the cis-trans noncyclic formic acid dimer.

    Science.gov (United States)

    Zhou, Pan-Pan; Qiu, Wen-Yuan

    2009-08-01

    The cis-trans noncyclic formic acid dimer was studied by means of MP2 method with 6-31G(d,p), 6-31+G(d,p) and 6-311+G(d,p) basis sets. It exhibits simultaneously red-shifted O-H...O and blue-shifted C-H...O hydrogen bonds. AIM and NBO analyses are performed at the MP2/6-31+G(d,p) level to explore their properties and origins. AIM analysis provides the evidence that the O-H bond becomes weaker and the C-H bond becomes stronger upon the hydrogen bond formations. Intermolecular and intramolecular hyperconjugations have important influence on the electron densities in the X-H (X = O, C) sigma bonding orbital and its sigma* antibonding orbital. The electron densities in the two orbitals are closely connected with the X-H (X = O, C) bond length, and they are used to quantitatively estimate the bond length variation. The larger amount of charge transfer in the red-shifted O-H...O hydrogen bond is due to its favorable H...O electron channel, whereas the H...O electron channel in the blue-shifted C-H...O hydrogen bond is weaker. Structural reorganization effects shorten the C-H bond by approximately 30% when compared to the C-H bond contraction upon the dimerization. Strikingly, it leads to a small elongation and a slight red shift of the O-H bond. Both rehybridization and repolarization result in the X-H (X = O, C) bond contraction, but their effects on the O-H bond do not hold a dominant position. The hydrogen-bonding processes go through the electrostatic attractions, van der Waals interactions, charge-transfer interactions, hydrogen-bonding interactions and electrostatic repulsions. Electrostatic attractions are of great importance on the origin of the red-shifted O-H...O hydrogen bond, especially the strong H(delta+)...O(delta-) attraction. For the blue-shifted C-H...O hydrogen bond, the considerable nucleus-nucleus repulsion between H and O atoms caused by the strong electrostatic attraction between C and O atoms is a possible reason for the C-H bond contraction and

  13. The effect of acidity on the distribution and symbiotic efficiency of rhizobia in Lithuanian soils

    Science.gov (United States)

    Lapinskas, E. B.

    2007-04-01

    The distribution and symbiotic efficiency of nodule bacteria Rhizobium leguminosarum_bv. trifolii F., Sinorhizobium meliloti D., Rhizobium galegae L., and Rhizobium leguminosarum bv. viciae F. in Lithuanian soils as dependent on the soil acidity were studied in the long-term field, pot, and laboratory experiments. The critical and optimal pH values controlling the distribution of rhizobia and the symbiotic nitrogen fixation were determined for every bacterial species. The relationship was found between the soil pH and the nitrogen-fixing capacity of rhizobia. A positive effect of liming of acid soils in combination with inoculation of legumes on the efficiency of symbiotic nitrogen fixation was demonstrated.

  14. Hydraulic conductivity study of compacted clay soils used as landfill liners for an acidic waste.

    Science.gov (United States)

    Hamdi, Noureddine; Srasra, Ezzeddine

    2013-01-01

    Three natural clayey soils from Tunisia were studied to assess their suitability for use as a liner for an acid waste disposal site. An investigation of the effect of the mineral composition and mechanical compaction on the hydraulic conductivity and fluoride and phosphate removal of three different soils is presented. The hydraulic conductivity of these three natural soils are 8.5 × 10(-10), 2.08 × 10(-9) and 6.8 × 10(-10)m/s for soil-1, soil-2 and soil-3, respectively. Soil specimens were compacted under various compaction strains in order to obtain three wet densities (1850, 1950 and 2050 kg/m(3)). In this condition, the hydraulic conductivity (k) was reduced with increasing density of sample for all soils. The test results of hydraulic conductivity at long-term (>200 days) using acidic waste solution (pH=2.7, charged with fluoride and phosphate ions) shows a decrease in k with time only for natural soil-1 and soil-2. However, the specimens of soil-2 compressed to the two highest densities (1950 and 2050 kg/m(3)) are cracked after 60 and 20 days, respectively, of hydraulic conductivity testing. This damage is the result of a continued increase in the internal stress due to the swelling and to the effect of aggressive wastewater. The analysis of anions shows that the retention of fluoride is higher compared to phosphate and soil-1 has the highest sorption capacity.

  15. Adsorption behavior of herbicide butachlor on typical soils in China and humic acids from the soil samples.

    Science.gov (United States)

    Xu, Duanping; Xu, Zhonghou; Zhu, Shuquan; Cao, Yunzhe; Wang, Yu; Du, Xiaoming; Gu, Qingbao; Li, Fasheng

    2005-05-01

    Three kinds of soils in China, krasnozem, fluvo-aquic soil, and phaeozem, as well as the humic acids (HAs) isolated from them, were used to adsorb the herbicide butachlor from water. Under the experimental conditions, the adsorption amount of butachlor on soils was positively correlated with the content of soil organic matter. HAs extracted from different kinds of soils had different adsorption capacity for the tested herbicide, which was positively correlated with their content of carbonyls. The adsorption mechanism was studied using Fourier transform infrared spectroscopy and cross-polarization with magic angle spinning 13C nuclear magnetic resonance (CP-MAS 13C NMR) techniques. It was showed that the adsorption mainly took place on the C=O, phenolic and alcoholic O-H groups of HAs. It was also confirmed that the adsorption mechanism was hydrogen bonds formation between the above groups of HAs and butachlor molecules.

  16. The effect of plowing under green manure on the soil microorganism and fertility in tobacco cultivation red soil%绿肥翻压对烟地红壤微生物及土壤养分的影响

    Institute of Scientific and Technical Information of China (English)

    陈晓波; 官会林; 郭云周; 洪丽芳; 任石所; 曹卫东

    2011-01-01

    To explore the biological mechanisms of the green manure to improve fertility of tobacco cultivation red soil, the effects of purple green manure plowing and wheat stubble plowing on microorganisms, soil enzyme activity and nutrient content of tobacco cultivation red soil were studied with the control of fallow land. The results showed that: bacteria, actinomy-cetes, soil enzyme activity, soil organic matter and nutrient content of green manure treated soil were higher than those of wheat stubble treated land and those of fallow land, changes in differences were significant (p <0.05) or highly significant (p <0. 01) , and fungi of wheat stuble were higher than those. Green manure plowing land , wheat stubble plowing land and fallow land to compare; soil bacteria in Yuezhou test area were increased 1.74 × 10 6 , 2. 61 × 10 6 cfu · g-1, actinomy-cetes increased 1. 35 × 10 4, 0.65 × 10 4 cfu · g-1. Soil urease increased 1.50, 1.68 mg · g-1, acid phosphatase increased 2. 90, 3. 09 mg · g-1, catalase increased 1.20, 2. 54 Ml · g-1, polyphenol oxidase enzyme increased 1.91, 7. 58 mg ? Kg-1, soil organic matter increased 16. 36, 26. 22 g · kg-1, soil available N increased 42. 52, 54.31 mg- kg-1, soil a-vaikble P increased 6.22, 7. 57 mg · kg-1, soil bacteria in Jinning test area increased 2. 52 × 10 6, 3.95 × l0 6 cfu ? G-1 , actinomycetes increased 1.17 × 10 4, 1. 62 × 10 4 cfu · g-1, soil urease increased 1. 77 , 2. 00 mg · g-1, acid phosphatase increased 1. 13, 1. 24 mg · g-1, catalase increased 1.45, 2.19 Ml · g-1, polyphenol oxidase increased 4. 81, 11. 34 mg · kg-1, soil organic matter increased 10.18, 19.43 g · kg-1, soil available N increased 41. 34, 54. 43 mg · kg-1, soil available P increased 4.79, 5. 86 mg · kg-1.%为探讨绿肥对烟地红壤改良培肥的生物机制,试验以冬闲地为对照,研究了紫花苕绿肥翻压及麦茬翻压对烟地红壤微生物、土壤酶活性及养分含量的影响.结果表明,绿肥翻

  17. Application of Modified Red Mud for Adsorption of Acid Orange 7 (AO7 Dye from Aqueous Solution: Isotherms, Kinetics Studies

    Directory of Open Access Journals (Sweden)

    Mohammad Ali Zazouli

    2015-09-01

    Full Text Available Application of modified red mud for adsorption of Acid Orang 7 (AO7 dye from aqueous solution: Isotherms, Kinetics studies Abstract: Backgroud: Existence of color is one of the problems of industrial effluent such as textile industries. The dyes can be removed by various methods. Therefore, the aim of this study is evaluation of adsorption rate of acid orange (AO7 from aqueous solution by activated red mud. Material and method: This is an empirical lab study. Red mud was used as an absorbent to remove of acid orange 7 dye. The effect of various parameters on performance of absorbent was investigated and the isotherms and kinetics of adsorption was determined. The dye concentration was measured in wavelength of 452 nm by spectrophotometer. Results: The results showed that red mud surface area is 30 m2/g. The results showed that dye removal was highest at a solution pH 3 and a powder dose of 12 g/L. The AO7 removal percentage decreased from %98 to %55 at 60 min contact time when the concentration of dye was increased from 10 mg/L to 100 mg/L. The equilibrium data is best fitted on Langmuir isotherm and the adsorption kinetic model follows pseudo-second model. conclusion: The results of this study showed that red mud is able to adsorption of dye and can be used as effective and inexpensive absorbent to treat of textile effluent.

  18. Soil organic matter and soil acidity in Mangrove areas in the river Paraiba Estuary, Cabedelo, Paraiba, Brazil

    Directory of Open Access Journals (Sweden)

    Renata Wilma Vasconcelos

    2014-08-01

    Full Text Available Mangrove ecosystems are of great environmental significance, because of their fragility and role in feeding and breeding various animal species. In northeastern Brazil, the disorderly occupation of estuarine areas and the urban sprawl have led to a considerable loss of the original area occupied by mangroves. In the municipality of Cabedelo, State of Paraíba, there are about 4,900 ha of remnant mangrove areas in the estuarine complex of the Paraíba River. However, information about the attributes of mangrove soils at this location is quite scarce. The aim of this study was to quantify the soil organic matter and soil acidity in mangroves located in the estuary of the Paraíba River, State of Paraíba, Brazil, in order to increase the database of soil attributes in this region. The study area is in local influence of the Restinga de Cabedelo National Forest (Flona, an environmental conservation unit of the Chico Mendes Institute for Biodiversity Conservation. For the choice of sampling points, we considered an area that receives direct influence of the eviction of domestic and industrial effluents. The soil of the study area is an “Organossolo Háplico” in Brazilian Soil Classification (Histosol, and was sampled at four point sites: one upstream of the effluent discharge (P1, one in the watercourse receiving effluent water (P2, one downstream of the effluent discharge (P3 and another near Flona (P4, at 0-20 and 20-40 cm, in four replications in time (28/08/2012 in the morning and afternoon, and 21/01/2013 in the morning and afternoon. Potential acidity, pH and soil organic matter (SOM were determined. No significant differences were detected in the potential acidity of the four collection sites, which ranged from 0.38 to 0.45 cmolc dm-3. Soil pH was greatest at point P4 (7.0 and lowest at point P1 (5.8. The SOM was highest at point P1 (86.4 % and lowest at P2 (77.9 %. The attributes related to soil acidity were not sensitive to indicate

  19. Supplementing predictive mapping of acid sulfate soil occurrence with Vis-NIR spectroscopy

    DEFF Research Database (Denmark)

    Beucher, Amélie; Peng, Yi; Knadel, Maria

    . Recently, a digital soil mapping approach was assessed to create a predictive map for potential acid sulfate soil occurrence in the wetlands of Jutland (c. 6500 km2; Beucher et al., 2016). An Artificial Neural Networks method was applied using 8000 soil observations and 16 environmental variables...... occurrence in the Skjern River catchment (c. 2500 km2). Different machine learning approaches will be assessed using soil and environmental data, together with laboratory Vis-NIR spectral data available for the study area. Absorbance values (400–2500 nm) were measured for 600 soil samples with a DS2500...

  20. Effect of Simulated Acid Rain on Potential Carbon and Nitrogen Mineralization in Forest Soils

    Institute of Scientific and Technical Information of China (English)

    OUYANG Xue-Jun; ZHOU Guo-Yi; HUANG Zhong-Liang; LIU Ju-Xiu; ZHANG De-Qiang; LI Jiong

    2008-01-01

    Acid rain is a serious environmental problem worldwide. In this study, a pot experiment using forest soils planted with the seedlings of four woody species was performed with weekly treatments of pH 4.40, 4.00, 3.52, and 3.05 simulated acid rain (SAR) for 42 months compared to a control of pH 5.00 lake water. The cumulative amounts of C and N mineralization in the five treated soils were determined after incubation at 25 ℃ for 65 d to examine the effects of SAR treatments.For all five treatments, cumulative CO2-C production ranged from 20.24 to 27.81 mg kg-1 dry soil, net production of available N from 17.37 to 48.95 mg kg-1 dry soil, and net production of NO-3-N from 9.09 to 46.23 mg kg-1 dry soil. SAR treatments generally enhanced the emission of CO2-C from the soils; however, SAR with pH 3.05 inhibited the emission.SAR treatments decreased the net production of available N and NO3-N. The cumulative CH4 and N2O productions from the soils increased with increasing amount of simulated acid rain. The cumulative CO2-C production and the net production of available N of the soil under Acmena acuminatissima were significantly higher (P≤0.05) than those under Schima superba and Cryptocarya concinna. The mineralization of soil organic C was related to the contents of soil organic C and N, but was not related to soil pH. However, the overall effect of acid rain on the storage of soil organic matter and the cycling of important nutrients depended on the amount of acid deposition and the types of forests.

  1. Influence of sugarcane bagasse-derived biochar application on nitrate leaching in calcaric dark red soil.

    Science.gov (United States)

    Kameyama, K; Miyamoto, T; Shiono, T; Shinogi, Y

    2012-01-01

    Application of biochar has been suggested to improve water- and fertilizer-retaining capacity of agricultural soil. The objective of this study was to evaluate the effects of bagasse charcoal (sugarcane [ L.] bagasse-derived biochar) on nitrate (NO) leaching from Shimajiri Maji soil, which has low water- and fertilizer-retaining capacity. The nitrate adsorption properties of bagasse charcoal formed at five pyrolysis temperatures (400-800° C) were investigated to select the most suitable bagasse charcoal for NO adsorption. Nitrate was able to adsorb onto the bagasse charcoal formed at pyrolysis temperatures of 700 to 800° C. Nitrate adsorption by bagasse charcoal (formed at 800° C) that passed through a 2-mm sieve was in a state of nonequilibrium even at 20 h after the addition of 20 mg N L KNO solution. Measurements suggested that the saturated and unsaturated hydraulic conductivity of bagasse charcoal (800° C)-amended soils are affected by changes in soil tortuosity and porosity and the presence of meso- and micropores in the bagasse charcoal, which did not contribute to soil water transfer. In NO leaching studies using bagasse charcoal (800° C)-amended soils with different charcoal contents (0-10% [w/w]), the maximum concentration of NO in effluents from bagasse charcoal-amended soil columns was approximately 5% less than that from a nonamended soil column because of NO adsorption by bagasse charcoal (800° C). We conclude that application of bagasse charcoal (800°C) to the soil will increase the residence time of NO in the root zone of crops and provide greater opportunity for crops to absorb NO.

  2. Uranium Leaching from Contaminated Soil Utilizing Rhamnolipid, EDTA, and Citric Acid

    Directory of Open Access Journals (Sweden)

    Sara Asselin

    2014-01-01

    Full Text Available Biosurfactants have recently gained attention as “green” agents that can be used to enhance the remediation of heavy metals and some organic matter in contaminated soils. The overall objective of this paper was to investigate rhamnolipid, a microbial produced biosurfactant, and its ability to leach uranium present in contaminated soil from an abandoned mine site. Soil samples were collected from two locations in northern Arizona: Cameron (site of open pit mining and Leupp (control—no mining. The approach taken was to first determine the total uranium content in each soil using a hydrofluoric acid digestion, then comparing the amount of metal removed by rhamnolipid to other chelating agents EDTA and citric acid, and finally determining the amount of soluble metal in the soil matrix using a sequential extraction. Results suggested a complex system for metal removal from soil utilizing rhamnolipid. It was determined that rhamnolipid at a concentration of 150 μM was as effective as EDTA but not as effective as citric acid for the removal of soluble uranium. However, the rhamnolipid was only slightly better at removing uranium from the mining soil compared to a purified water control. Overall, this study demonstrated that rhamnolipid ability to remove uranium from contaminated soil is comparable to EDTA and to a lesser extent citric acid, but, for the soils investigated, it is not significantly better than a simple water wash.

  3. Effects of dicyandiamide and dolomite application on N2O emission from an acidic soil.

    Science.gov (United States)

    Shaaban, Muhammad; Wu, Yupeng; Peng, Qi-an; Lin, Shan; Mo, Yongliang; Wu, Lei; Hu, Ronggui; Zhou, Wei

    2016-04-01

    Soil acidification is a major problem for sustainable agriculture since it limits productivity of several crops. Liming is usually adopted to ameliorate soil acidity that can trigger soil processes such as nitrification, denitrification, and loss of nitrogen (N) as nitrous oxide (N2O) emissions. The loss of N following liming of acidic soils can be controlled by nitrification inhibitors (such as dicyandiamide). However, effects of nitrification inhibitors following liming of acidic soils are not well understood so far. Here, we conducted a laboratory study using an acidic soil to examine the effects of dolomite and dicyandiamide (DCD) application on N2O emissions. Three levels of DCD (0, 10, and 20 mg kg(-1); DCD0, DCD10, and DCD20, respectively) were applied to the acidic soil under two levels of dolomite (0 and 1 g kg(-1)) which were further treated with two levels of N fertilizer (0 and 200 mg N kg(-1)). Results showed that N2O emissions were highest at low soil pH levels in fertilizer-treated soil without application of DCD and dolomite. Application of DCD and dolomite significantly (P ≤ 0.001) reduced N2O emissions through decreasing rates of NH4 (+)-N oxidation and increasing soil pH, respectively. Total N2O emissions were reduced by 44 and 13% in DCD20 and dolomite alone treatments, respectively, while DCD20 + dolomite reduced N2O emissions by 54% when compared with DCD0 treatment. The present study suggests that application of DCD and dolomite to acidic soils can mitigate N2O emissions.

  4. Effects of Inorganic-organic Incorporation on Productivity and Soil Fertility of Rice Cropping System in Red Soil Area of China

    Institute of Scientific and Technical Information of China (English)

    ZHOU Wei-jun; WANG Kai-rong; ZHANG Guan-yuan; XIE Xiao-li

    2002-01-01

    Results from ten-year (1990- 1999) field experiments indicated that the productivity and the soil fertility of rice cropping system were significantly influenced by the fertilization system adopted in red soil area of China. Contrasting with no-fertilizer treatment (CK), yield-increase rate of organic matter cycling,chemical NPK and inorganic-organic fertilizer incorporation treatments were 56.5%, 62.5% and 80.7%, respectively. In the case of optimum fertilization system, the largest contribution of inorganic fertilizer to the yield was 38.5% while that of inorganic-organic fertilizer incorporation was 44.7 %. The content of soil organic matter changed in tendency from decrease to equilibrium with heightened the extent of N, P and K incorporation while that of inorganic-organic fertilizer incorporation could be enhanced further. After N, P and K entered into the rice cropping system and maintained organic matter cycling in the system, the pools of total N, P and K could be strengthened.

  5. ANALYSIS OF PERFLUORINATED CARBOXYLIC ACIDS IN SOILS: DETECTION AND QUANTITATION ISSUES AT LOW CONCENTRATIONS

    Science.gov (United States)

    Methods were developed for the extraction from soil, identification, confirmation and quantitation by LC/MS/MS of trace levels of perfluorinated octanoic acid (PFOA), perfluorinated nonanoic acid (PFNA) and perfluorinated decanoic acid (PFDA). Whereas PFOA, PFNA and PFDA all can...