WorldWideScience

Sample records for human-induced soil degradation

  1. Global Assessment of Human-induced Soil Degradation (GLASOD)

    NARCIS (Netherlands)

    Oldeman, L.R.; Hakkeling, R.T.A.; Sombroek, W.G.; Batjes, N.H.

    2014-01-01

    The GLASOD project (1987-1990) has produced a world map of human-induced soil degradation. Data were complied in cooperation with a large number of soil scientists throughout the world, using uniform Guidelines and international correlation. The status of soil degradation was mapped within loosely

  2. Human induced impacts on soil organic carbon in southwest Iceland

    Science.gov (United States)

    Gísladóttir, Guðrún; Erlendsson, Egill; Lal, Rattan

    2013-04-01

    The Icelandic environment has been strongly influenced by natural processes during the Holocene. Since settlement in AD 874, the introduction of grazing animals and other land use has drastically affected the natural environment. This includes the diminishing of vegetative cover, which has led to soil exposure and accelerated erosion over large areas, especially when in conjunction with harsh climate. This has specifically impacted processes and properties of volcanic soils (Andosols), which are subject to accelerated erosion by wind and water. While approximately 46% of the land surface in Iceland has sustained continuous vegetation cover, large areas have lost some or all of their soil cover formed during the postglacial era. Elsewhere, remaining soils have sparse or no vegetation cover, thus impairing soil carbon (C) sequestration. Among their multifunctional roles, soils support plant growth, increase soil biotic activity, enhance nutrient storage and strengthen the cycling of water and nutrients. In contrast, soil degradation by accelerated erosion and other processes impairs soil quality, reduces soil structure and depletes the soil organic matter (SOM) pool. Depletion of the SOM pool has also global implications because the terrestrial C pool is the third largest pool and strongly impacts the global C cycle. Erosional-depositional processes may deplete soil organic C (SOC) by erosion and increase by deposition. Some SOC-enriched sediments are redistributed over the landscape, while others are deposited in depression sites and transported into aquatic ecosystems. SOC decomposition processes are severely constrained in some environmental settings and any SOC buried under anaerobic conditions is protected against decomposition. Yet, the impact of the SOC transported by erosional processes and redistributed over the landscape is not fully understood because the variability in its turnover characteristics has not been widely studied. Thus, the fate of C

  3. Human-induced environmental degradation during Anthropocene in Turkey

    Science.gov (United States)

    Efe, Recep; Curebal, Isa; Soykan, Abdullah; Sönmez, Suleyman

    2015-04-01

    affected by humans (Sanderson et al., 2002; Braje&Erlandson, 2014). The area left in its natural state corresponds to only 15%. Due to population increase, agricultural areas shrinked, forests were destroyed, and pastures declined in size. More chemical fertilizers and agricultural pesticides were used in order to obtain more products. A greater number of machines were employed in agriculture, which led to a rise in the number of products. The human pressure on the environment in Anatolia dates back to thousands of years. Nomadic peoples on these lands have settled in the last 200 years due to settlement policies (Cürebal et al., 2015). This process saw the establishment of villages in higher and inclined areas as a result of the effects of the nomadic culture of Turkomans and other people in Anatolia. Forests in the inclined areas around these villages were destroyed and turned into agricultural areas. Machines, fertilizers, and pesticides were utilized in agricultural activities in order to produce more crops. This transformation led to an increased erosion effect, deterioration of soil, agricultural and environmental pollution (Chin et al., 2013; Hoang et al., 2014; Matteo et al., 2014). The change caused by industrialization gained ground in the 1950s in Turkey. In particular, migration from rural areas to cities gaining pace after the World War II brought about an increased human pressure in and around big cities. Areas around the cities became centers of attraction for many people. Plains around settlement areas were opened to settlement, and most industrial facilities were established there. As a consequence, first class agricultural areas were lost. Settlements and industrial areas generated large amounts of solid and liquid waste. Uncontrolled discharge of liquid waste and intensely stored solid waste caused the physical and chemical pollution of rivers, lakes, and seas to increase in Turkey and other parts of the world (Andersson et al., 2006; Steffen et al

  4. Soil degradation in Pakistan

    International Nuclear Information System (INIS)

    Khan, M.R.

    2005-01-01

    This paper diagnoses the issues involved behind the current state, usage, interactions and linkages in the soils in Pakistan. The condition of soils is deteriorating due to developmental and environmental factors such as soil degradation, water pollution, fauna degeneration etc. Issues, problems and constraints faced in the management and usage of soils are diagnosed at different levels in the ecosystems predominant in Pakistan. The research questions propose effective solutions, types of instruments, methods or processes to resolve the issues within the various areas or ecosystems in the most sustainable and effective manner [23]. Biological solutions and methods can be applied at the sub-system level by private individuals or communities at a lower cost, and at a more localized level than engineering methods. Engineering methods may be suited for interventions at a system level rather than at a sub-system level; but even at this level they will be complementary with biological methods. (author)

  5. Degradation of thiram in soil

    International Nuclear Information System (INIS)

    Raghu, K.; Murthy, N.B.K.; Kumarsamy, R.

    1975-01-01

    Determination of the residual 35 S labelled tetramethylthiuram disulfide showed that the fungicide persisted longer in sterilized than in unsterilized soil, while the chloroform extractable radioactivity decreased, the water extractable radioactivity increased with increase in time. However, in sterilized soil the water extractable radioactivity remained more or less constant. Degradation of the fungicide was further demonstrated by the release of C 35 S 2 from soil treated with labelled thiram. Dimethylamine was found to be one of the degradation products. A bacterium isolated from thiram-enriched soil could degrade the fungicide in shake culture. The degradation pathways of thiram in sterilized and unsterilized soils are discussed. (author)

  6. Meteoric 10Be as a tool to investigate human induced soil fluxes: a conceptual model

    Science.gov (United States)

    Campforts, Benjamin; Govers, Gerard; Vanacker, Veerle; De Vente, Joris; Boix-Fayos, Carolina; Minella, Jean; Baken, Stijn; Smolders, Erik

    2014-05-01

    The use of meteoric 10Be as a tool to understand long term landscape behavior is becoming increasingly popular. Due its high residence time, meteoric 10Be allows in principle to investigate in situ erosion rates over time scales exceeding the period studied with classical approaches such as 137Cs. The use of meteoric 10Be strongly contributes to the traditional interpretation of sedimentary archives which cannot be unequivocally coupled to sediment production and could provide biased information over longer time scales (Sadler, 1981). So far, meteoric 10Be has successfully been used in geochemical fingerprinting of sediments, to date soil profiles, to assess soil residence times and to quantify downslope soil fluxes using accumulated 10Be inventories along a hill slope. However, less attention is given to the potential use of the tracer to directly asses human induced changes in soil fluxes through deforestation, cultivation and reforestation. A good understanding of the processes governing the distribution of meteoric 10Be both within the soil profile and at landscape scale is essential before meteoric 10Be can be successfully applied to assess human impact. We developed a spatially explicit 2D-model (Be2D) in order to gain insight in meteoric 10Be movement along a hillslope that is subject to human disturbance. Be2D integrates both horizontal soil fluxes and vertical meteoric 10Be movement throughout the soil prolife. Horizontal soil fluxes are predicted using (i) well studied geomorphical laws for natural erosion and soil formation as well as (ii) human accelerated water and tillage erosion. Vertical movement of meteoric 10Be throughout the soil profile is implemented by inserting depth dependent retardation calculated using experimentally determined partition coefficients (Kd). The model was applied to different environments such as (i) the Belgian loess belt, characterized by aeolian deposits enriched in inherited meteoric 10Be, (ii) highly degraded and stony

  7. Aggregate stability and soil degradation in the tropics

    International Nuclear Information System (INIS)

    Mbagwu, J.S.C.

    2004-01-01

    Aggregate stability is a measure of the structural stability of soils. Factors that influence aggregate stability are important in evaluating the ease with which soils erode by water and/or wind, the potential of soils to crust and/or seal, soil permeability, quasi-steady state infiltration rates and seedling emergence and in predicting the capacity of soils to sustain long-term crop production. Aggregate stability of soils can be measured by the wet-sieving or raindrop techniques. A reduction in soil aggregate stability implies an increase in soil degradation. Hence aggregate stability and soil degradation are interwoven. The measures used can either be preventive or remedial. Preventive practices minimize the chances of soil degradation occurring or the magnitude or severity of the damage when the degradation manifests. These include in Nigeria, (i) manuring and mulching, (ii) planted fallows and cover crops, (iii) sustainable farming systems, (iv) adequate rotations, (v) home gardens or compound farms, (vi) alley cropping and related agro forestry systems, and (vii) chemical fertilizers which are mainly remedial measures. Because of alterations in soil properties that affect particular land uses, soils may degrade for one crop (maize rather sorghum). As long as some land use is possible soil degradation is not always an absolute concept. Decline in agricultural productivity should be evaluated in terms of inputs such as fertilizer use, water management and tillage methods. We can alleviate some types of soil degradation by use of micronutrients, inorganic fertilizers and organic residues. Soil that responds to management practices cannot be said to be degraded. Since crop growth depends on weather, degraded soils may be more sensitive to harsh weather (e.g. drought, temperature) than undegraded soils. A soil is degraded if its productivity falls below the economic threshold even under favourable weather conditions or with judicious inputs. All human-induced

  8. Restoring Soil Quality to Mitigate Soil Degradation

    Directory of Open Access Journals (Sweden)

    Rattan Lal

    2015-05-01

    Full Text Available Feeding the world population, 7.3 billion in 2015 and projected to increase to 9.5 billion by 2050, necessitates an increase in agricultural production of ~70% between 2005 and 2050. Soil degradation, characterized by decline in quality and decrease in ecosystem goods and services, is a major constraint to achieving the required increase in agricultural production. Soil is a non-renewable resource on human time scales with its vulnerability to degradation depending on complex interactions between processes, factors and causes occurring at a range of spatial and temporal scales. Among the major soil degradation processes are accelerated erosion, depletion of the soil organic carbon (SOC pool and loss in biodiversity, loss of soil fertility and elemental imbalance, acidification and salinization. Soil degradation trends can be reversed by conversion to a restorative land use and adoption of recommended management practices. The strategy is to minimize soil erosion, create positive SOC and N budgets, enhance activity and species diversity of soil biota (micro, meso, and macro, and improve structural stability and pore geometry. Improving soil quality (i.e., increasing SOC pool, improving soil structure, enhancing soil fertility can reduce risks of soil degradation (physical, chemical, biological and ecological while improving the environment. Increasing the SOC pool to above the critical level (10 to 15 g/kg is essential to set-in-motion the restorative trends. Site-specific techniques of restoring soil quality include conservation agriculture, integrated nutrient management, continuous vegetative cover such as residue mulch and cover cropping, and controlled grazing at appropriate stocking rates. The strategy is to produce “more from less” by reducing losses and increasing soil, water, and nutrient use efficiency.

  9. Soil Degradation in India: Challenges and Potential Solutions

    Directory of Open Access Journals (Sweden)

    Ranjan Bhattacharyya

    2015-03-01

    Full Text Available Soil degradation in India is estimated to be occurring on 147 million hectares (Mha of land, including 94 Mha from water erosion, 16 Mha from acidification, 14 Mha from flooding, 9 Mha from wind erosion, 6 Mha from salinity, and 7 Mha from a combination of factors. This is extremely serious because India supports 18% of the world’s human population and 15% of the world’s livestock population, but has only 2.4% of the world’s land area. Despite its low proportional land area, India ranks second worldwide in farm output. Agriculture, forestry, and fisheries account for 17% of the gross domestic product and employs about 50% of the total workforce of the country. Causes of soil degradation are both natural and human-induced. Natural causes include earthquakes, tsunamis, droughts, avalanches, landslides, volcanic eruptions, floods, tornadoes, and wildfires. Human-induced soil degradation results from land clearing and deforestation, inappropriate agricultural practices, improper management of industrial effluents and wastes, over-grazing, careless management of forests, surface mining, urban sprawl, and commercial/industrial development. Inappropriate agricultural practices include excessive tillage and use of heavy machinery, excessive and unbalanced use of inorganic fertilizers, poor irrigation and water management techniques, pesticide overuse, inadequate crop residue and/or organic carbon inputs, and poor crop cycle planning. Some underlying social causes of soil degradation in India are land shortage, decline in per capita land availability, economic pressure on land, land tenancy, poverty, and population increase. In this review of land degradation in India, we summarize (1 the main causes of soil degradation in different agro-climatic regions; (2 research results documenting both soil degradation and soil health improvement in various agricultural systems; and (3 potential solutions to improve soil health in different regions using a

  10. Hotspots of human-induced biomass productivity decline and their social-ecological types toward supporting national policy and local studies on combating land degradation

    Science.gov (United States)

    Vu, Quyet Manh; Le, Quang Bao; Vlek, Paul L. G.

    2014-10-01

    Identification and social-ecological characterization of areas that experience high levels of persistent productivity decline are essential for planning appropriate management measures. Although land degradation is mainly induced by human actions, the phenomenon is concurrently influenced by global climate changes that need to be taken into account in land degradation assessments. This study aims to delineate the geographic hotspots of human-induced land degradation in the country and classify the social-ecological characterizations of each specific degradation hotspot type. The research entailed a long-term time-series (1982-2006) of Normalized Difference Vegetation Index to specify the extents of areas with significant biomass decline or increase in Vietnam. Annual rainfall and temperature time-series were then used to separate areas of human-induced biomass productivity decline from those driven by climate dynamics. Next, spatial cluster analyses identified social-ecological types of degradation for guiding further investigations at regional and local scales. The results show that about 19% of the national land mass experienced persistent declines in biomass productivity over the last 25 years. Most of the degraded areas are found in the Southeast and Mekong River Delta (17,984 km2), Northwest Mountains (14,336 km2), and Central Highlands (13,504 km2). We identified six and five social-ecological types of degradation hotspots in agricultural and forested zones, respectively. Constraints in soil nutrient availability and nutrient retention capability are widely spreading in all degradation hotspot types. These hotspot types are different from each other in social and ecological conditions, suggesting that region-specific strategies are needed for the formulation of land degradation combating policy.

  11. Tributyltin induces mitochondrial fission through Mfn1 degradation in human induced pluripotent stem cells.

    Science.gov (United States)

    Yamada, Shigeru; Asanagi, Miki; Hirata, Naoya; Itagaki, Hiroshi; Sekino, Yuko; Kanda, Yasunari

    2016-08-01

    Organotin compounds, such as tributyltin (TBT), are well-known endocrine disruptors. TBT is also known to cause various forms of cytotoxicity, including neurotoxicity and immunotoxicity. However, TBT toxicity has not been identified in normal stem cells. In the present study, we examined the effects of TBT on cell growth in human induced pluripotent stem cells (iPSCs). We found that exposure to nanomolar concentrations of TBT decreased intracellular ATP levels and inhibited cell viability in iPSCs. Because TBT suppressed energy production, which is a critical function of the mitochondria, we further assessed the effects of TBT on mitochondrial dynamics. Staining with MitoTracker revealed that nanomolar concentrations of TBT induced mitochondrial fragmentation. TBT also reduced the expression of mitochondrial fusion protein mitofusin 1 (Mfn1), and this effect was abolished by knockdown of the E3 ubiquitin ligase membrane-associated RING-CH 5 (MARCH5), suggesting that nanomolar concentrations of TBT could induce mitochondrial dysfunction via MARCH5-mediated Mfn1 degradation in iPSCs. Thus, mitochondrial function in normal stem cells could be used to assess cytotoxicity associated with metal exposure. Copyright © 2016 Elsevier Ltd. All rights reserved.

  12. Soil physical land degradation processes

    Science.gov (United States)

    Horn, Rainer

    2017-04-01

    According to the European Soil Framework Directive (2006) soil compaction is besides water and wind erosion one of the main physical reasons and threats of soil degradation. It is estimated, that 32% of the subsoils in Europe are highly degraded and 18% moderately vulnerable to compaction. The problem is not limited to crop land or forest areas (especially because of non-site adjusted harvesting machines) but is also prevalent in rangelands and grassland, and even in so called natural non-disturbed systems. The main reasons for an intense increase in compacted agricultural or forested regions are the still increasing masses of the machines as well the increased frequency of wheeling under non favorable site conditions. Shear and vibration induced soil deformation enhances the deterioration of soil properties especially if the soil water content is very high and the internal soil strength very low. The same is true for animal trampling in combination with overgrazing of moist to wet pastures which subsequently causes a denser (i.e. reduced proportion of coarse pores with smaller continuity) but still structured soil horizons and will finally end in a compacted platy structure. In combination with high water content and shearing due to trampling therefore results in a complete muddy homogeneous soil with no structure at all. (Krümmelbein et al. 2013) Site managements of arable, forestry or horticulture soils requires a sufficiently rigid pore system which guarantees water, gas and heat exchange, nutrient transport and adsorption as well as an optimal rootability in order to avoid subsoil compaction. Such pore system also guarantees a sufficient microbial activity and composition in order to also decompose the plant etc. debris. It is therefore essential that well structured horizons dominate in soils with at best subangular blocky structure or in the top A- horizons a crumbly structure due to biological activity. In contrast defines the formation of a platy

  13. Soil and geomorphological parameters to characterize natural environmental and human induced changes within the Guadarrama Range (Central Spain)

    Science.gov (United States)

    Schmid, Thomas; Inclán-Cuartas, Rosa M.; Santolaria-Canales, Edmundo; Saa, Antonio; Rodríguez-Rastrero, Manuel; Tanarro-Garcia, Luis M.; Luque, Esperanza; Pelayo, Marta; Ubeda, Jose; Tarquis, Ana; Diaz-Puente, Javier; De Marcos, Javier; Rodriguez-Alonso, Javier; Hernandez, Carlos; Palacios, David; Gallardo-Díaz, Juan; Fidel González-Rouco, J.

    2016-04-01

    to determine the physical and chemical soil properties. The parent material is gneiss andassociated deposits and, as a result, soils are acid. The soils have a low to medium organic matter content and are non-saline. They are moderately to well drained soils and have no or slight evidence of erosion. The soil within the high mountain area has clear evidence of frost heave that has a vertical displacement of the surface in the centimeter range. The stations within the lowland and mid mountain areas represent the most degraded sites as a result of the livestock keeping, whereas the high mountain area is mainly influenced by natural environmental conditions. These soil and geomorphological parameters will constitute a basis for site characterization in future studies regarding soil degradation; determining the interaction between soil, vegetation and atmosphere with respect to human induced activities (e.g. atmospheric contamination and effects of fires); determining the nitrogen and carbon cycles; and the influence of heavy metal contaminants in the soils.

  14. Human-Induced Vegetation Degradation in a Semi-Arid Rangeland

    Science.gov (United States)

    Jackson, Hasan

    Current assessments of anthropogenic land degradation and its impact on vegetation at regional scales are prone to large uncertainties due to the lack of an objective, transferable, spatially and temporally explicit measure of land degradation. These uncertainties have resulted in contradictory estimates of degradation extent and severity and the role of human activities. The uncertainties limit the ability to assess the effects on the biophysical environment and effectiveness of past, current, and future policies of land use. The overall objective of the dissertation is to assess degradation in a semi-arid region at a regional scale where the process of anthropogenic land degradation is evident. Net primary productivity (NPP) is used as the primary indicator to measure degradation. It is hypothesized that land degradation resulting from human factors on the landscape irreversibly reduces NPP below the potential set by environmental conditions. It is also hypothesized that resulting reductions in NPP are distinguishable from natural, spatial and temporal, variability in NPP. The specific goals of the dissertation are to (1) identify the extent and severity of degradation using productivity as the primary surrogate, (2) compare the degradation of productivity to other known mechanisms of degradation, and (3) relate the expression of degradation to components of vegetation and varying environmental conditions. This dissertation employed the Local NPP Scaling (LNS) approach to identify patterns of anthropogenic degradation of NPP in the Burdekin Dry Tropics (BDT) region of Queensland (14 million hectares), Australia from 2000 to 2013. The method started with land classification based on the environmental factors presumed to control NPP to group pixels having similar potential NPP. Then, satellite remotely sensing data were used to compare actual NPP with its potential. The difference, in units of mass of carbon fixed in NPP per unit area per monitoring interval and

  15. Soil Resources Degradation and Conservation Techniques Adopted ...

    African Journals Online (AJOL)

    Soil degradation is increasingly regarded as a major constraint to food production in the tropics. This problem is primarily caused by soil erosion, which particularly damages the soil surfaces. It is therefore the objectives of this paper to study the types of erosion in Gusau area as well as its effects on selected soil properties ...

  16. Differentiating climate- and human-induced drivers of grassland degradation in the Liao River Basin, China.

    Science.gov (United States)

    He, Chunyang; Tian, Jie; Gao, Bin; Zhao, Yuanyuan

    2015-01-01

    Quantitatively distinguishing grassland degradation due to climatic variations from that due to human activities is of great significance to effectively governing degraded grassland and realizing sustainable utilization. The objective of this study was to differentiate these two types of drivers in the Liao River Basin during 1999-2009 using the residual trend (RESTREND) method and to evaluate the applicability of the method in semiarid and semihumid regions. The relationship between the normalized difference vegetation index (NDVI) and each climatic factor was first determined. Then, the primary driver of grassland degradation was identified by calculating the change trend of the normalized residuals between the observed and the predicted NDVI assuming that climate change was the only driver. We found that the RESTREND method can be used to quantitatively and effectively differentiate climate and human drivers of grassland degradation. We also found that the grassland degradation in the Liao River Basin was driven by both natural processes and human activities. The driving factors of grassland degradation varied greatly across the study area, which included regions having different precipitation and altitude. The degradation in the Horqin Sandy Land, with lower altitude, was driven mainly by human activities, whereas that in the Kungl Prairie, with higher altitude and lower precipitation, was caused primarily by climate change. Therefore, the drivers of degradation and local conditions should be considered in an appropriate strategy for grassland management to promote the sustainability of grasslands in the Liao River Basin.

  17. Soil degradation effect on biological activity in Mediterranean calcareous soils

    Science.gov (United States)

    Roca-Pérez, L.; Alcover-Sáez, S.; Mormeneo, S.; Boluda, R.

    2009-04-01

    Soil degradation processes include erosion, organic matter decline, compaction, salinization, landslides, contamination, sealing and biodiversity decline. In the Mediterranean region the climatological and lithological conditions, together with relief on the landscape and anthropological activity are responsible for increasing desertification process. It is therefore considered to be extreme importance to be able to measure soil degradation quantitatively. We studied soil characteristics, microbiological and biochemical parameters in different calcareous soil sequences from Valencia Community (Easter Spain), in an attempt to assess the suitability of the parameters measured to reflect the state of soil degradation and the possibility of using the parameters to assess microbiological decline and soil quality. For this purpose, forest, scrubland and agricultural soil in three soil sequences were sampled in different areas. Several sensors of the soil biochemistry and microbiology related with total organic carbon, microbial biomass carbon, soil respiration, microorganism number and enzyme activities were determined. The results show that, except microorganism number, these parameters are good indicators of a soil biological activity and soil quality. The best enzymatic activities to use like indicators were phosphatases, esterases, amino-peptidases. Thus, the enzymes test can be used as indicators of soil degradation when this degradation is related with organic matter losses. There was a statistically significant difference in cumulative O2 uptake and extracellular enzymes among the soils with different degree of degradation. We would like to thank Spanish government-MICINN for funding and support (MICINN, project CGL2006-09776).

  18. Human induced prehistoric and historical soil erosion and landscape development in Southwestern USA

    Science.gov (United States)

    Dotterweich, Markus; Ivester, Andrew H.; Hanson, Paul R.; Daniel, Larsen; Dye, David H.; Foster, Thomas H., II

    2015-04-01

    gathered data will be used to i) compare the spatial extent of prehistoric and historic erosion and the short-term and long-term pedological and geomorphological effects of subtle soil erosion against extreme events, ii) assess the feedback-mechanisms of soil erosion on soil fertility and measurable land use changes in prehistorical and historical times, and (iii) estimate the long term effects of soil erosion and sediment deposition on archaeological features. The outcome will provide a decisive step forward to gather new qualitative and quantitative information on soil erosion during the Native American land use period to be able to achieve a better understanding of the long-term human induced landscape evolution in the uplands of the Southeastern USA and deliver data for a better predicting of landscape evolution to future climatic shifts in precipitation regimes.

  19. Degradation kinetics of ptaquiloside in soil and soil solution

    DEFF Research Database (Denmark)

    Ovesen, Rikke Gleerup; Rasmussen, Lars Holm; Hansen, Hans Christian Bruun

    2008-01-01

    and soil solutions in sandy and clayey soils subjected to high natural PTA loads from bracken stands. Degradation kinetics in moist soil could be fitted with the sum of a fast and a slow first-order reaction; the fast reaction contributed 20 to 50% of the total degradation of PTA. The fast reaction...... was similar in all horizons, with the rate constant k1F ranging between 0.23 and 1.5/h. The slow degradation, with the rate constant k1S ranging between 0.00067 and 0.029/h, was more than twice as fast in topsoils compared to subsoils, which is attributable to higher microbial activity in topsoils....... Experiments with sterile controls confirmed that nonmicrobial degradation processes constituted more than 90% of the fast degradation and 50% of the slow degradation. The lower nonmicrobial degradation rate observed in the clayey compared with the sandy soil is attributed to a stabilizing effect of PTA...

  20. Degradation kinetics of ptaquiloside in soil and soil solution.

    Science.gov (United States)

    Ovesen, Rikke Gleerup; Rasmussen, Lars Holm; Hansen, Hans Christian Bruun

    2008-02-01

    Ptaquiloside (PTA) is a carcinogenic norsesquiterpene glycoside produced in bracken (Pteridium aquilinum (L.) Kuhn), a widespread, aggressive weed. Transfer of PTA to soil and soil solution eventually may contaminate groundwater and surface water. Degradation rates of PTA were quantified in soil and soil solutions in sandy and clayey soils subjected to high natural PTA loads from bracken stands. Degradation kinetics in moist soil could be fitted with the sum of a fast and a slow first-order reaction; the fast reaction contributed 20 to 50% of the total degradation of PTA. The fast reaction was similar in all horizons, with the rate constant k(1F) ranging between 0.23 and 1.5/h. The slow degradation, with the rate constant k(1S) ranging between 0.00067 and 0.029/ h, was more than twice as fast in topsoils compared to subsoils, which is attributable to higher microbial activity in topsoils. Experiments with sterile controls confirmed that nonmicrobial degradation processes constituted more than 90% of the fast degradation and 50% of the slow degradation. The lower nonmicrobial degradation rate observed in the clayey compared with the sandy soil is attributed to a stabilizing effect of PTA by clay silicates. Ptaquiloside appeared to be stable in all soil solutions, in which no degradation was observed within a period of 28 d, in strong contrast to previous studies of hydrolysis rates in artificial aqueous electrolytes. The present study predicts that the risk of PTA leaching is controlled mainly by the residence time of pore water in soil, soil microbial activity, and content of organic matter and clay silicates.

  1. Degradation of chlorpyrifos in tropical rice soils.

    Science.gov (United States)

    Das, Subhasis; Adhya, Tapan K

    2015-04-01

    Chlorpyrifos [O,O-diethyl O-(3,5,6-trichloro-2-pyridinol) phosphorothioate] is used worldwide as an agricultural insecticide against a broad spectrum of insect pests of economically important crops including rice, and soil application to control termites. The insecticide mostly undergoes hydrolysis to diethyl thiophosphoric acid (DETP) and 3,5,6-trichloro-2-pyridinol (TCP), and negligible amounts of other intermediate products. In a laboratory-cum-greenhouse study, chlorpyrifos, applied at a rate of 10 mg kg(-1) soil to five tropical rice soils of wide physico-chemical variability, degraded with a half-life ranging from 27.07 to 3.82 days. TCP was the major metabolite under both non-flooded and flooded conditions. Chlorpyrifos degradation had significant negative relationship with electrical conductivity (EC), cation exchange capacity (CEC), clay and sand contents of the soils under non-flooded conditions. Results indicate that degradation of chlorpyrifos was accelerated with increase in its application frequency, across the representative rice soils. Management regimes including moisture content and presence or absence of rice plants also influenced the process. Biotic factors also play an important role in the degradation of chlorpyrifos as demonstrated by its convincing degradation in mineral salts medium inoculated with non-sterile soil suspension. Copyright © 2015 Elsevier Ltd. All rights reserved.

  2. Soil-ecological risks for soil degradation estimation

    Science.gov (United States)

    Trifonova, Tatiana; Shirkin, Leonid; Kust, German; Andreeva, Olga

    2016-04-01

    Soil degradation includes the processes of soil properties and quality worsening, primarily from the point of view of their productivity and decrease of ecosystem services quality. Complete soil cover destruction and/or functioning termination of soil forms of organic life are considered as extreme stages of soil degradation, and for the fragile ecosystems they are normally considered in the network of their desertification, land degradation and droughts /DLDD/ concept. Block-model of ecotoxic effects, generating soil and ecosystem degradation, has been developed as a result of the long-term field and laboratory research of sod-podzol soils, contaminated with waste, containing heavy metals. The model highlights soil degradation mechanisms, caused by direct and indirect impact of ecotoxicants on "phytocenosis- soil" system and their combination, frequently causing synergistic effect. The sequence of occurring changes here can be formalized as a theory of change (succession of interrelated events). Several stages are distinguished here - from heavy metals leaching (releasing) in waste and their migration downward the soil profile to phytoproductivity decrease and certain phytocenosis composition changes. Phytoproductivity decrease leads to the reduction of cellulose content introduced into the soil. The described feedback mechanism acts as a factor of sod-podzolic soil self-purification and stability. It has been shown, that using phytomass productivity index, integrally reflecting the worsening of soil properties complex, it is possible to solve the problems dealing with the dose-reflecting reactions creation and determination of critical levels of load for phytocenosis and corresponding soil-ecological risks. Soil-ecological risk in "phytocenosis- soil" system means probable negative changes and the loss of some ecosystem functions during the transformation process of dead organic substance energy for the new biomass composition. Soil-ecological risks estimation is

  3. Prolyl hydroxylation regulates protein degradation, synthesis, and splicing in human induced pluripotent stem cell-derived cardiomyocytes.

    Science.gov (United States)

    Stoehr, Andrea; Yang, Yanqin; Patel, Sajni; Evangelista, Alicia M; Aponte, Angel; Wang, Guanghui; Liu, Poching; Boylston, Jennifer; Kloner, Philip H; Lin, Yongshun; Gucek, Marjan; Zhu, Jun; Murphy, Elizabeth

    2016-06-01

    Protein hydroxylases are oxygen- and α-ketoglutarate-dependent enzymes that catalyse hydroxylation of amino acids such as proline, thus linking oxygen and metabolism to enzymatic activity. Prolyl hydroxylation is a dynamic post-translational modification that regulates protein stability and protein-protein interactions; however, the extent of this modification is largely uncharacterized. The goals of this study are to investigate the biological consequences of prolyl hydroxylation and to identify new targets that undergo prolyl hydroxylation in human cardiomyocytes. We used human induced pluripotent stem cell-derived cardiomyocytes in combination with pulse-chase amino acid labelling and proteomics to analyse the effects of prolyl hydroxylation on protein degradation and synthesis. We identified 167 proteins that exhibit differences in degradation with inhibition of prolyl hydroxylation by dimethyloxalylglycine (DMOG); 164 were stabilized. Proteins involved in RNA splicing such as serine/arginine-rich splicing factor 2 (SRSF2) and splicing factor and proline- and glutamine-rich (SFPQ) were stabilized with DMOG. DMOG also decreased protein translation of cytoskeletal and sarcomeric proteins such as α-cardiac actin. We searched the mass spectrometry data for proline hydroxylation and identified 134 high confidence peptides mapping to 78 unique proteins. We identified SRSF2, SFPQ, α-cardiac actin, and cardiac titin as prolyl hydroxylated. We identified 29 prolyl hydroxylated proteins that showed a significant difference in either protein degradation or synthesis. Additionally, we performed next-generation RNA sequencing and showed that the observed decrease in protein synthesis was not due to changes in mRNA levels. Because RNA splicing factors were prolyl hydroxylated, we investigated splicing ± inhibition of prolyl hydroxylation and detected 369 alternative splicing events, with a preponderance of exon skipping. This study provides the first extensive

  4. SOIL DEGRADATION PROCESSES FROM POLLUTION

    Directory of Open Access Journals (Sweden)

    Popov Leonid

    2012-06-01

    Full Text Available Investigations found HCH and DDT residuals in bottom sediments from several reservoirs and lakes as well as the main rivers, Nistru and Prut (concentrations ranged between 0.2 and 15.8 ppb. The concentration of PCBs in the topsoil collected beneath the capacitors battery at the Vulcănesti substation reached a level of 7100 ppm which is exceeding the MAC by five orders of magnitude (!. With no exception, allowable concentrations of PCBs in soil were exceeded also on the territory of other investigated substations, with peaks registered at the Briceni substation (2545 ppm and the Orhei substation (1959 ppm.

  5. Soil degradation in Sub-Saharan Africa

    NARCIS (Netherlands)

    Hartemink, A.E.; Keulen, van H.

    2005-01-01

    Soil degradation in Sub-Sahara Africa has been much debated in the past decades. Although there are many different views, at the extremes there are those who are of the opinion that the problem is very serious and the main cause for the poverty and food crises and those that are convinced that it is

  6. 14C tebuconazole degradation in Colombian soils.

    Science.gov (United States)

    Mosquera, C S; Martínez, M J; Guerrero, J A

    2010-01-01

    Tebuconazole is a fungicide used on onion crops (Allium Fistulosum L) in Colombia. Persistence of pesticides in soils is characterized by the half-life (DT50), which is influenced by their chemical structure, the physical and chemical properties of the soil and the previous soil history. Based on its structural and chemical properties, tebuconazole should be expected to be relatively persistent in soils. Laboratory incubation studies were conducted to evaluate persistence and bond residues of 14C tebuconazole in three soils, two inceptisol (I) and one histosol (H). Textural classifications were: loam (101), loamy sand (102) and loam (H03), respectively. Data obtained followed a first-order degradation kinetics (R2 > or = 0.899) with DT50 values between 158 and 198 days. The production of 14CO2 from the 14C-ring-labelled test chemicals was very low and increased slightly during 63 days in all cases. The methanol extractable 14C-residues were higher than aqueous ones and both decreased over incubation time for the three soils. The formation of bound 14C-residues increased with time and final values were 11.3; 5.55 and 7.87% for 101, 102 and H03 respectively. Soil 101 showed the lowest mineralization rate and the highest bound residues formation, which might be explained by the clay fraction content. In contrast, an inverse behavior was found for soils 102 and H03, these results might be explained by the higher soil organic carbon content.

  7. A method to detect soil carbon degradation during soil erosion

    OpenAIRE

    F. Conen; M. Schaub; C. Alewell

    2009-01-01

    Soil erosion has been discussed intensively but controversial both as a significant source or a significant sink of atmospheric carbon possibly explaining the gap in the global carbon budget. One of the major points of discussion has been whether or not carbon is degraded and mineralized to CO2 during detachment, transport and deposition of soil material. By combining the caesium-137 (137Cs) approach (quantification of erosion rates) with stable c...

  8. Indicators and degradation mechanisam of loess soil

    Directory of Open Access Journals (Sweden)

    Gajić Grozdana

    2016-01-01

    Full Text Available Studies that are presented in this paper were carried out to define the formation criteria of loess soil degradation. Erosion stability analysis of this soil type will be carried out on the basis of its physical and mechanical characteristics. To describe the established relationships between the individual parameters of loess soil, the study uses mathematical model, that is based on experimentally obtained results of soils’ physical and mechanical characteristics, From the presented results of geotechnical tests, mathematical models and functional relations between water regime and loess soils’ resistant characteristics; indicators of internal erosion were defined as well as the mechanism of this process. Effects of the practical application of found results are also analyzed in this paper.

  9. Microbial degradation of metalaxyl in soil

    Energy Technology Data Exchange (ETDEWEB)

    Musumeci, M.R.; Ruegg, E.F. (Instituto Biologico, Sao Paulo (Brazil). Centro de Radioisotopos)

    1984-10-01

    The behaviour of the fungicide metalaxyl in purple latosol soil was investigated using a ring - /sup 14/C labelled compound under laboratory conditions. In nonsterile soil samples under aerobic conditions, metalaxyl was degraded into two metabolites. After 60 days, 60% of the radiocarbon on TLC plates corresponded to the parent fungicide, 22% to its metabolite N-(2-methoxyacetyl)-N-(2,6-xylyl)-DL-alanine, and 2.7% to a second and unidentified metabolite. The U.V. absorbance value of metalaxyl decreased after seven days incubation with a soil microorganisms suspension. Incubation of /sup 14/C-metalaxyl for 50 days with a bacterium or a fungus isolated from that suspension resulted in metalaxyl gradual disappearance from the medium, but not metabolites were detected during this period.

  10. North American Soil Degradation: Processes, Practices, and Mitigating Strategies

    Directory of Open Access Journals (Sweden)

    R. L. Baumhardt

    2015-03-01

    Full Text Available Soil can be degraded by several natural or human-mediated processes, including wind, water, or tillage erosion, and formation of undesirable physical, chemical, or biological properties due to industrialization or use of inappropriate farming practices. Soil degradation occurs whenever these processes supersede natural soil regeneration and, generally, reflects unsustainable resource management that is global in scope and compromises world food security. In North America, soil degradation preceded the catastrophic wind erosion associated with the dust bowl during the 1930s, but that event provided the impetus to improve management of soils degraded by both wind and water erosion. Chemical degradation due to site specific industrial processing and mine spoil contamination began to be addressed during the latter half of the 20th century primarily through point-source water quality concerns, but soil chemical degradation and contamination of surface and subsurface water due to on-farm non-point pesticide and nutrient management practices generally remains unresolved. Remediation or prevention of soil degradation requires integrated management solutions that, for agricultural soils, include using cover crops or crop residue management to reduce raindrop impact, maintain higher infiltration rates, increase soil water storage, and ultimately increase crop production. By increasing plant biomass, and potentially soil organic carbon (SOC concentrations, soil degradation can be mitigated by stabilizing soil aggregates, improving soil structure, enhancing air and water exchange, increasing nutrient cycling, and promoting greater soil biological activity.

  11. Degradation of aldrin im samples of 'cerrado' Brazilian soils

    International Nuclear Information System (INIS)

    Musumeci, M.R.; Ruegg, E.F.

    1981-01-01

    14 C-aldrin degradation was studied in the laboratory, in samples of 'cerrado' Brazilian soils, during a period of 240 days. Recovery of radiocarbon decreased with time, although radiocarbon was not incorporated to the soil organic matter as show by soil combustion. In both soils 14 C-aldrin degraded to dieldrin and another compound that showed caracteristics of a hydrosoluble derivative of aldrin 14 C-aldrin was more persistent in sandy soil but amendment of this soil with nutrients or fertilizers did not enhanced aldrin degradation in this soil. (Author) [pt

  12. Agrogenic degradation of soils in Krasnoyarsk forest-steppe

    Science.gov (United States)

    Shpedt, A. A.; Trubnikov, Yu. N.; Zharinova, N. Yu.

    2017-10-01

    Agrogenic degradation of soils in Krasnoyarsk forest-steppe was investigated. Paleocryogenic microtopography of microlows and microhighs in this area predetermined the formation of paragenetic soil series and variegated soil cover. Specific paleogeographic conditions, thin humus horizons and soil profiles, and long-term agricultural use of the land resulted in the formation of soils unstable to degradation processes and subjected to active wind and water erosion. Intensive mechanical soil disturbances during tillage and long-term incorporation of the underlying Late Pleistocene (Sartan) calcareous silty and clay loams into the upper soil horizons during tillage adversely affected the soil properties. We determined the contents of total and labile humus and easily decomposable organic matter and evaluated the degree of soil exhaustion. It was concluded that in the case of ignorance of the norms of land use and soil conservation practices, intense soil degradation would continue leading to complete destruction of the soil cover within large areas.

  13. Monitor Soil Degradation or Triage for Soil Security? An Australian Challenge

    Directory of Open Access Journals (Sweden)

    Andrea Koch

    2015-04-01

    Full Text Available The Australian National Soil Research, Development and Extension Strategy identifies soil security as a foundation for the current and future productivity and profitability of Australian agriculture. Current agricultural production is attenuated by soil degradation. Future production is highly dependent on the condition of Australian soils. Soil degradation in Australia is dominated in its areal extent by soil erosion. We reiterate the use of soil erosion as a reliable indicator of soil condition/quality and a practical measure of soil degradation. We describe three key phases of soil degradation since European settlement, and show a clear link between inappropriate agricultural practices and the resultant soil degradation. We demonstrate that modern agricultural practices have had a marked effect on reducing erosion. Current advances in agricultural soil management could lead to further stabilization and slowing of soil degradation in addition to improving productivity. However, policy complacency towards soil degradation, combined with future climate projections of increased rainfall intensity but decreased volumes, warmer temperatures and increased time in drought may once again accelerate soil degradation and susceptibility to erosion and thus limit the ability of agriculture to advance without further improving soil management practices. Monitoring soil degradation may indicate land degradation, but we contend that monitoring will not lead to soil security. We propose the adoption of a triaging approach to soil degradation using the soil security framework, to prioritise treatment plans that engage science and agriculture to develop practices that simultaneously increase productivity and improve soil condition. This will provide a public policy platform for efficient allocation of public and private resources to secure Australia’s soil resource.

  14. Organic contaminants in soil : desorption kinetics and microbial degradation

    NARCIS (Netherlands)

    Schlebaum, W.

    1999-01-01

    The availability of organic contaminants in soils or sediments for microbial degradation or removal by physical means (e.g.) soil washing or soil venting) depends on the desorption kinetics of these contaminants from the soil matrix. When the organic contaminants desorb very slow from the

  15. Soil Degradation Processes; Procesos de Degradacion del Suelo

    Energy Technology Data Exchange (ETDEWEB)

    Nunez Crespi, S; Perez Martinez, M; Cuesta Santianes, M J; Cabrera Jimenez, J A

    2007-12-28

    In the European communication entitled Towards a Thematic Strategy for Soil Protection, eight main threats to soil were identified: contamination, erosion, loss of organic matter, compaction, salinization; hydro-geological risks, soil sealing, and decline in biodiversity. The main purpose of this report is to provide the current state of knowledge of the soil degradation processes both, in the European Community scale and, particularly, in the Spanish territory. Furthermore, the main research project information related to soil degradation processes is also included, identifying the main actors involved in soil scientific research and development. (Author) 66 refs.

  16. Physical soil degradation in the Netherlands

    NARCIS (Netherlands)

    Boels, D.; Havinga, L.

    1980-01-01

    Soils used in agriculture are subjected to a wide variety of human activities. Soil tillage and soil impravement operations may loose the soil, while soil wetting due to rainfall, and farming operations as sowing, spraying, weed control and harvesting but also grazing cattle may compact the soil.

  17. Degradation of glass in the soil

    Energy Technology Data Exchange (ETDEWEB)

    Romich, H.; Gerlach, S.; Mottner, P. [Fraunhofer-Institut fur Silicatforschung (ISC), Wertheim-Bronnbach (Germany)

    2004-07-01

    Full text of publication follows: Glass has been produced and used in Europe for over 2000 years. Glass objects from the Roman period onwards have been excavated during the last centuries. In general, Roman glass is chemically quite stable, and often the only sign of chemical alteration is an iridescent surface, caused by the leaching of cations, which leads to the formation of a hydrated silica-rich layer. Medieval potash glasses are much less durable, and their surfaces are often found deeply leached, sometimes to a point that no unaltered glass remains. These surfaces may be coherent, though fragile, or they are laminar, with no cohesion between the layers at all. In this study an analytical examination of a series of fragments of archaeological glass retrieved from different sites near Cologne and Stuttgart (Germany) has been carried out. Samples of corroded glasses were analysed by optical microscopy and SEM/EDX (surface and cross sections) in order to obtain information about the chemical composition of the bulk glass and the weathered layers. Since the environmental parameters have constantly varied for archaeological objects, mechanistic studies have to rely on laboratory experiments under controlled conditions. For an extensive exposure programme standardised soil or natural garden earth was used, for which the pH was modified. Several corrosion sensitive potash-lime silicate glasses have been designed to study the effect of glass composition. A model glass consisting of SiO{sub 2} (54.2), CaO (28.8) and K{sub 2}O (17.0 weight-%) mostly lead to the formation of a crust on the leached layer, with a total thickness of 100 micrometer (for soil with pH 7 to 8, 12 months exposure). Model glasses also containing Al, Mg and P have built up preferably laminated structures (total thickness up to 200 micrometer). This presentation will give an overview about the variety of degradation phenomena observed on originals and compare the results with controlled laboratory

  18. BioDegradation of Refined Petroleum Hydrocarbons in Soil | Obire ...

    African Journals Online (AJOL)

    Carbon-dioxide production and hydrocarbon degradation of refined petroleum hydrocarbon in soils treated with 5% gasoline, kerosene and diesel oil were investigated. Soil for study was bulked from around a car park in Port Harcourt. Soil samples were collected at weekly intervals for four weeks and subsequently at ...

  19. The Influence of Cattle Wastes on Degraded Savanna Soils of ...

    African Journals Online (AJOL)

    This paper examines the effects of cattle wastes on degraded savanna soils of Kwara State, Nigeria. A total of 40 soil samples were systematically collected from five quadrats of 12m x 12m. In 4 identified cattle sheds and 1 in adjacent fallow land (control field) on the same soil, climatic type and ecological zone. Standard ...

  20. Monitoring of Gasoline-ethanol Degradation In Undisturbed Soil

    Science.gov (United States)

    Österreicher-Cunha, P.; Nunes, C. M. F.; Vargas, E. A.; Guimarães, J. R. D.; Costa, A.

    Environmental contamination problems are greatly emphasised nowadays because of the direct threat they represent for human health. Traditional remediation methods fre- quently present low efficiency and high costs; therefore, biological treatment is being considered as an accessible and efficient alternative for soil and water remediation. Bioventing, commonly used to remediate petroleum hydrocarbon spills, stimulates the degradation capacity of indigenous microorganisms by providing better subsur- face oxygenation. In Brazil, gasoline and ethanol are mixed (78:22 v/v); some authors indicate that despite gasoline high degradability, its degradation in subsurface is hin- dered by the presence of much more rapidly degrading ethanol. Contaminant distribu- tion and degradation in the subsurface can be monitored by several physical, chemical and microbiological methodologies. This study aims to evaluate and follow the degra- dation of a gasoline-ethanol mixture in a residual undisturbed tropical soil from Rio de Janeiro. Bioventing was used to enhance microbial degradation. Shifts in bacte- rial culturable populations due to contamination and treatment effects were followed by conventional microbiology methods. Ground Penetrating Radar (GPR) measure- ments, which consist of the emission of electro-magnetic waves into the soil, yield a visualisation of contaminant degradation because of changes in soil conductivity due to microbial action on the pollutants. Chemical analyses will measure contaminant residue in soil. Our results disclosed contamination impact as well as bioventing stim- ulation on soil culturable heterotrophic bacterial populations. This multidisciplinary approach allows for a wider evaluation of processes occurring in soil.

  1. Bio stimulation for the Enhanced Degradation of Herbicides in Soil

    International Nuclear Information System (INIS)

    Kanissery, R.G; Sims, G.K

    2011-01-01

    Cleanup of herbicide-contaminated soils has been a dire environmental concern since the advent of industrial era. Although microorganisms are excellent degraders of herbicide compounds in the soil, some reparation may need to be brought about, in order to stimulate them to degrade the herbicide at a faster rate in a confined time frame. Bio stimulation through the appropriate utilization of organic amendments and nutrients can accelerate the degradation of herbicides in the soil. However, effective use of bio stimulants requires thorough comprehension of the global redox cycle during the microbial degradation of the herbicide molecules in the soil. In this paper, we present the prospects of using bio stimulation as a powerful remediation strategy for the rapid cleanup of herbicide-polluted soils.

  2. Enantioselective degradation and enantiomerization of indoxacarb in soil.

    Science.gov (United States)

    Sun, Dali; Pang, Junxiao; Qiu, Jing; Li, Li; Liu, Chenglan; Jiao, Bining

    2013-11-27

    In this study, the enantioselective degradation and enantiomerizaton of indoxacarb were investigated in two soils under nonsterilized and sterilized conditions using a chiral OD-RH column on a reversed-phase HPLC. Under nonsterilized conditions, the degradation of indoxacarb in two soils was enantioselective. In acidic soil, the half-lives of R-(-)- and S-(+)-indoxacarb were 10.43 and 14.00 days, respectively. Acidic soil was preferential to the degradation of R-(-)-indoxacarb. In alkaline soil, the half-lives of R-(-)- and S-(+)-indoxacarb were 12.14 and 4.88 days, respectively. S-(+)-Indoxacarb was preferentially degraded. Under sterilized conditions, approximately 5-10% of the initial concentration degraded after 75 days of incubation in acidic soil, whereas in alkaline soil, approximately half of the initial concentration degraded due to chemical hydrolysis under alkaline conditions. Enantiomerization was also discovered in acidic and alkaline soils. The results showed that mutual transformation existed between two enantiomers and that S-(+)-indoxacarb had a significantly higher inversion rate to R-(-)-indoxacarb than its antipode.

  3. Degradation of tetraethyllead in leaded gasoline contaminated and uncontaminated soils

    International Nuclear Information System (INIS)

    Ou, L.; Jing, W.; Thomas, J.; Mulroy, P.

    1995-01-01

    For over 50 years, since its introduction in 1923 by General Motors, tetraethyllead (TEL) was the major antiknock agent used in leaded gasoline. Since the middle of 1970, use of leaded gasoline in automobiles was gradually phased out. The main objective of this study is to determine the degradation rates and metabolites of TEL in gasoline contaminated and uncontaminated soils. TEL in uncontaminated soils disappeared rapidly. Ionic triethyllead (TREL) was the major organolead metabolite in these soils, with ionic diethyllead (DEL) being the minor product. Nonsterile soils, but not autoclaved soils, had limited capacity to mineralize 14 C-TEL to 14 CO 2 , H 2 0, and Pb 2+ . Unlike TEL in uncontaminated soils, petroleum hydrocarbons protected TEL in leaded gasoline contaminated soils from being degraded. Both disappearance and mineralization rates of TEL in leaded gasoline contaminated soils decreased with the increase in gasoline concentration. It appears that TEL in leaded gasoline contaminated soils is relatively stable until the level of petroleum hydrocarbons falls below a critical value. TEL is then rapidly degraded. Hydrocarbon degrading microorganisms may be involved, to some extent, in the degradation of TEL

  4. Degradation of N-nitrosodimethylamine (NDMA) in landscape soils.

    Science.gov (United States)

    Yang, W C; Gan, J; Liu, W P; Green, R

    2005-01-01

    N-nitrosodimethylamine (NDMA), a potential carcinogen, was commonly found in treated wastewater as a by-product of chlorination. As treated water is increasingly used for landscape irrigation, there is an imperative need to understand the leaching risk for NDMA in landscape soils. In this study, adsorption and incubation experiments were conducted using landscape soils planted with turfgrass, ground cover, and trees. Adsorption of NDMA was negligibly weak (K(d) NDMA has a high potential for moving with percolating water in these soils. Degradation of NDMA occurred at different rates among these soils. At 21 degrees C, the half-life (t(1/2)) of NDMA was 4.1 d for the ground cover soil, 5.6 d for the turfgrass soil, and 22.5 d for the tree soil. The persistence was substantially prolonged after autoclaving or when incubated at 10 degrees C. The rate of degradation was not significantly affected by the initial NDMA concentration or addition of organic and inorganic nutrient sources. The relative persistence was inversely correlated with soil organic matter content, soil microbial biomass, and soil dehydrogenase activity, suggesting the importance of microorganisms in NDMA degradation in these soils. These results suggest that the behavior of NDMA depends closely on the vegetation cover in a landscape system, and prolonged persistence and increased leaching may be expected in soils with sparse vegetation due to low organic matter content and limited microbial activity.

  5. DEGRADATION AND MIGRATION OF VINCLOZOLIN IN SAND AND SOIL

    Science.gov (United States)

    The migration of the dicarboximide fungicide vinclozolin and its principal degradation products through porous media was experimentally determined by simulating pesticide applications to a 23-30 mesh Ottawa sand and a North Carolina Piedmont, aquic hapludult soil in laboratory ...

  6. Mobility and degradation of 14C-trifluralin in soil

    International Nuclear Information System (INIS)

    Zheng Lin; Wang Fujun

    1993-01-01

    Under laboratory condition, the adsorption, mobility and degradation of 14 C-trifluralin in soil were studied by using radioactive isotopic tracer. The results show that the adsorption of trifluralin in soil is quite strong. The rates of adsorption in soil are 73.89 ∼ 90.66%. The adsorption is significantly affected by the organic matter content of soil. It leaches rather low in Grassy-marsh land black soil containing plentiful organic matter and higher clay content, but quite higher in sand, and is more easily to move down. Under anaerobic condition, degradation of trifluralin in soil is faster. It is derogated by 60.2 ∼ 60.4% in soil extractive state within 30 days, and by 90.0 ∼ 94.7% within 60 days. Its main metabolites are the compounds with R f 0.06, 0.15 and 0.42 respectively

  7. Nanoscale zerovalent iron-mediated degradation of DDT in soil.

    Science.gov (United States)

    Han, Yuling; Shi, Nan; Wang, Huifang; Pan, Xiong; Fang, Hua; Yu, Yunlong

    2016-04-01

    Nanoscale zerovalent iron (nZVI)-mediated degradation of 1,1,1-trichloro-2,2-bis(p-chlorophenyl)ethane (DDT) was investigated in a spiked soil under different conditions (iron sources, iron dosage, soil moisture, temperature, and soil types) and DDT-contaminated field. The degradation efficiency of p,p'-DDT by nZVI and nZVI coated with sodium oleate (SO-nZVI) was much higher than that by nZVI coated with polyimide (PI-nZVI). The rapid degradation of p,p'-DDT by nZVI only occurred in flooded soil. The degradation half-life of p,p'-DDT decreased significantly from 58.3 to 27.6 h with nZVI dosage from 0.5 to 2.0% and from 46.5 to 32.0 h with temperature from 15 to 35 °C. The degradation efficiency of p,p'-DDT by nZVI differed in Jinhua (JH), Jiaxing (JX), Xiaoshan (XS), Huajiachi (HJC), and Heilongjiang (HLJ) soils. A good correlation was found between the degradation half-life of p,p'-DDT and multiple soil properties. The probable nZVI-mediated degradation pathway of p,p'-DDT in soil was proposed as DDT → DDD/DDE → DDNS → DDOH based on the metabolites identified by GC-MS. The in situ degradation efficiency of residual DDTs in a contaminated field was profoundly enhanced by the addition of nZVI as compared to the control. It is concluded that nZVI might be an efficient agent for the remediation of DDT-contaminated soil under anaerobic environment.

  8. Factors mediating the restoration of structurally degraded soils

    DEFF Research Database (Denmark)

    Arthur, Emmanuel; Moldrup, Per; Schjønning, Per

    with the ability of soils to perform these functions. The present study examines the roles of clay mineralogy, native organic matter, and exogenous organic material on the restoration of structurally degraded soils. Totally seven soils from Denmark and Ghana - five soils dominated by illites, one kaolinitic soil...... the incubation period, structural stability estimated as the amount of water-dispersible clay decreased with prevailing moisture content, and native organic matter. Also, microbial activity significantly increased with addition of exogenous organic matter. At the end of incubation, there was significant...... macroaggregation, decreased bulk density, and increased equivalent pore diameter and tortuosity (derived from measurements of soil-gas diffusivity and soil-air permeability) for all soils. Although aggregate friability was not affected by clay type, aggregate workability was highest for the kaolinitic soil...

  9. Biocide Runoff from Building Facades: Degradation Kinetics in Soil.

    Science.gov (United States)

    Bollmann, Ulla E; Fernández-Calviño, David; Brandt, Kristian K; Storgaard, Morten S; Sanderson, Hans; Bester, Kai

    2017-04-04

    Biocides are common additives in building materials. In-can and film preservatives in polymer-resin render and paint, as well as wood preservatives are used to protect facade materials from microbial spoilage. Biocides leach from the facade material with driving rain, leading to highly polluted runoff water (up to several mg L -1 biocides) being infiltrated into the soil surrounding houses. In the present study the degradation rates in soil of 11 biocides used for the protection of building materials were determined in laboratory microcosms. The results show that some biocides are degraded rapidly in soil (e.g., isothiazolinones: T 1/2 soils; thus, rainfall events control how often new input to the soil occurs. Time intervals between rainfall events in Northern Europe are shorter than degradation half-lives even for many rapidly degraded biocides. Consequently, residues of some biocides are likely to be continuously present due to repeated input and most biocides can be considered as "pseudo-persistent"-contaminants in this context. This was verified by (sub)urban soil screening, where concentrations of up to 0.1 μg g -1 were detected for parent compounds as well as terbutryn degradation products in soils below biocide treated facades.

  10. Naphthalene and pyrene degradation in contaminated soil as a ...

    African Journals Online (AJOL)

    The effect of soil particle size distribution and percent organic matter on the degradation rate of naphthalene and pyrene in a water medium of 7.05 ml/min at 27 ± 2oC in a soil reactor was studied. Analysis of the pattern of disappearance of these polycyclic aromatic hydrocarbons (PAHs) using various particle sizes showed ...

  11. Organic Matter Dynamics in Soils Regenerating from Degraded ...

    African Journals Online (AJOL)

    The area of secondary forest (SF) regenerating from degraded abandoned rubber (Hevea brasiliensis) plantation is increasing in the rainforest zone of south southern Nigeria; however, the build-up of soil organic matter following abandonment is not well understood. This study examined the build-up of soil organic matter in ...

  12. Chiral separation and enantioselective degradation of vinclozolin in soils.

    Science.gov (United States)

    Liu, Hui; Liu, Donghui; Shen, Zhigang; Sun, Mingjing; Zhou, Zhiqiang; Wang, Peng

    2014-03-01

    Vinclozolin is a chiral fungicide with potential environmental problems. The chiral separation of the enantiomers and enantioselective degradation in soil were investigated in this work. The enantiomers were separated by high-performance liquid chromatography (HPLC) on Chiralpak IA, IB, and AZ-H chiral columns under normal phase and the influence of the mobile phase composition on the separation was also studied. Complete resolutions were obtained on all three chiral columns under optimized conditions with the same elution order of (+)/(-). The residual analysis of the enantiomers in soil was conducted using accelerate solvent extraction followed by HPLC determination. The recoveries of the enantiomers ranged from 85.7-105.7% with relative standard deviation (SD) of 0.12-3.83%, and the limit of detection (LOD) of the method was 0.013 µg/g. The results showed that the degradations of vinclozolin enantiomers in the soils followed first-order kinetics. Preferential degradation of the (-)-enantiomer was observed only in one soil with the largest |ES| value of 0.047, and no obvious enantioselective degradation was observed in other soils. It was found that the persistence of vinclozolin in soil was related to pH values based on the half-lives. The two enantiomers disappeared about 8 times faster in basic soils than that in neutral or acidic soils. © 2014 Wiley Periodicals, Inc.

  13. Carbazole degradation in the soil microcosm by tropical bacterial strains

    Directory of Open Access Journals (Sweden)

    Lateef B. Salam

    2015-01-01

    Full Text Available In a previous study, three bacterial strains isolated from tropical hydrocarbon-contaminated soils and phylogenetically identified as Achromobacter sp. strain SL1, Pseudomonassp. strain SL4 and Microbacterium esteraromaticum strain SL6 displayed angular dioxygenation and mineralization of carbazole in batch cultures. In this study, the ability of these isolates to survive and enhance carbazole degradation in soil were tested in field-moist microcosms. Strain SL4 had the highest survival rate (1.8 x 107 cfu/g after 30 days of incubation in sterilized soil, while there was a decrease in population density in native (unsterilized soil when compared with the initial population. Gas chromatographic analysis after 30 days of incubation showed that in sterilized soil amended with carbazole (100 mg/kg, 66.96, 82.15 and 68.54% were degraded by strains SL1, SL4 and SL6, respectively, with rates of degradation of 0.093, 0.114 and 0.095 mg kg−1 h−1. The combination of the three isolates as inoculum in sterilized soil degraded 87.13% carbazole at a rate of 0.121 mg kg−1 h−1. In native soil amended with carbazole (100 mg/kg, 91.64, 87.29 and 89.13% were degraded by strains SL1, SL4 and SL6 after 30 days of incubation, with rates of degradation of 0.127, 0.121 and 0.124 mg kg−1h−1, respectively. This study successfully established the survivability (> 106 cfu/g detected after 30 days and carbazole-degrading ability of these bacterial strains in soil, and highlights the potential of these isolates as seed for the bioremediation of carbazole-impacted environments.

  14. Microbial degradation of sulfentrazone in a Brazilian rhodic hapludox soil

    Directory of Open Access Journals (Sweden)

    Camila O. Martinez

    2010-03-01

    Full Text Available Sulfentrazone is amongst the most widely used herbicides for treating the main crops in the State of São Paulo, Brazil, but few studies are available on the biotransformation of this compound in Brazilian soils. Soil samples of Rhodic Hapludox soil were supplemented with sulfentrazone (0.7 µg active ingredient (a.i. g-1 soil and maintained at 27ºC. The soil moisture content was corrected to 30, 70 or 100 % water holding capacity (WHC and maintained constant until the end of the experimental period. Herbicide-free soil samples were used as controls. Another experiment was carried out using soil samples maintained at a constant moisture content of 70% WHC, supplemented or otherwise with the herbicide, and submitted to different temperatures of 15, 30 and 40º C. In both experiments, aliquots were removed after various incubation periods for the quantitative analysis of sulfentrazone residues by gas chromatography. Herbicide-degrading microorganisms were isolated and identified. After 120 days a significant effect on herbicide degradation was observed for the factor of temperature, degradation being higher at 30 and 40º C. A half-life of 91.6 days was estimated at 27º C and 70 % WHC. The soil moisture content did not significantly affect sulfentrazone degradation and the microorganisms identified as potential sulfentrazone degraders were Nocardia brasiliensis and Penicillium sp. The present study enhanced the prospects for future studies on the bio-prospecting for microbial populations related to the degradation of sulfentrazone, and may also contribute to the development of strategies for the bioremediation of sulfentrazone-polluted soils.

  15. Chemical Degradation of PCBs in Alaskan Soils

    Science.gov (United States)

    2011-04-01

    concentrations in a contaminated feed soil from a Superfund site from 28.2 ppm to 0.043 ppm. This process sprays the contaminated soils with diesel ...modified Fenton’s chemistry. In Proceedings of Battelle Bioremediation Conference. Payne, J., F. Boelsing, A. Habekost, G. Hirschfeld, and V. Birke

  16. Method of degrading pollutants in soil

    Science.gov (United States)

    Hazen, Terry C.; Lopez-De-Victoria, Geralyne

    1994-01-01

    A method and system for enhancing the motility of microorganisms by placing an effective amount of chlorinated hydrocarbons, preferably chlorinated alkenes, and most preferably trichloroethylene in spaced relation to the microbes so that the surprisingly strong, monomodal, chemotactic response of the chlorinated hydrocarbon on subsurface microbes can draw the microbes away from or towards and into a substance, as desired. In remediation of groundwater pollution, for example, TCE can be injected into the plume to increase the population of microbes at the plume whereby the plume can be more quickly degraded. A TCE-degrading microbe, such as Welchia alkenophilia, can be used to degrade the TCE following the degradation of the original pollutant.

  17. Method of degrading pollutants in soil

    Science.gov (United States)

    Hazen, T.C.; Lopez-De-Victoria, G.

    1994-07-05

    Disclosed are a method and system for enhancing the motility of microorganisms. This is accomplished by placing an effective amount of chlorinated hydrocarbons, preferably chlorinated alkenes, and most preferably trichloroethylene in spaced relation to the microbes so that the surprisingly strong, monomodal, chemotactic response of the chlorinated hydrocarbon on subsurface microbes can draw the microbes away from or towards and into a substance, as desired. In remediation of groundwater pollution, for example, TCE can be injected into the plume to increase the population of microbes at the plume whereby the plume can be more quickly degraded. A TCE-degrading microbe, such as Welchia alkenophilia, can be used to degrade the TCE following the degradation of the original pollutant. 5 figures.

  18. Reducing Nutrient Losses with Directed Fertilization of Degraded Soils

    Science.gov (United States)

    Menzies, E.; Walter, M. T.; Schneider, R.

    2016-12-01

    Degraded soils around the world are stunting agricultural productivity in places where people need it the most. In China, hundreds of years of agriculture and human activity have turned large swaths of productive grasslands into expanses of sandy soils where nothing can grow. Returning soils such as these to healthy productive landscapes is crucial to the livelihoods of rural families and to feeding the expanding population of China and the world at large. Buried wood chips can be used to improve the soils' water holding capacity but additional nutrient inputs are crucial to support plant growth and completely restore degraded soils in China and elsewhere. Improperly applied fertilizer can cause large fluxes of soluble nutrients such as nitrogen (N) and phosphorus (P) to pollute groundwater, and reach surface water bodies causing harmful algal blooms or eutrophication. Similarly, fertilization can create increases in nutrient losses in the form of greenhouse gases (GHGs). It is imperative that nutrient additions to this system be done in a way that fosters restoration and a return to productivity, but minimizes nutrient losses to adjacent surface water bodies and the atmosphere. The primary objective of this study is to characterize soluble and gaseous N and P losses from degraded sandy soils with wood chip and fertilizer amendments in order to identify optimal fertilization methods, frequencies, and quantities for soil restoration. A laboratory soil column study is currently underway to begin examining these questions results of this study will be presented at the Fall Meeting.

  19. Study on degradation of dimefuron in soil by nuclear technique

    International Nuclear Information System (INIS)

    Pakkong, P.; Vadeilai, J.

    1996-01-01

    Study on degradation of herbicide dimefuron in soil by using bio meter flask experiment was conducted under laboratory condition, 14 C-dimefuron was applied to three conditions of sterile soil normal and bio fertilizer added soil. Every month 14 CO 2 was collected from 1 N KOH in bio meter flask with in eight months period. Carbon-14 activity was analyzed by liquid scintillation counter. The result of dimefuron degradation as 14 CO 2 in sterile normal and bio fertilizer added soil were 0.96 percent 6.31 percent and 9.36 percent. It can be concluded that increasing in dimefuron degradation rate was involved by micro-organism activity. After eight month extracted and bounded residue of dimefuron in soil were analysed. Radioassay show that extracted and bounded residue were 58.62 and 29.58 percent in sterile soil 45.73 and 41.91 percent in normal soil 45.28 and 36.3 percent in bio fertilizer added soil

  20. Degradation of a chiral nonylphenol isomer in two agricultural soils

    International Nuclear Information System (INIS)

    Zhang Haifeng; Spiteller, Michael; Guenther, Klaus; Boehmler, Gabriele; Zuehlke, Sebastian

    2009-01-01

    The degradation of a chiral nonylphenol isomer, 4-(1-ethyl-1,4-dimethylpentyl)phenol (NP 112 ), in two agricultural soils from Monheim and Dortmund, Germany has been studied. The degradation of NP 112 and the formation of a nitro-nonylphenol metabolite were determined by means of GC-MS analysis. The degradation followed bi-exponential order kinetics, with half-life of less than 5 days in both soils. The nitro-metabolite was found at different concentration levels in the two soils. The nitro-metabolite of NP 112 was more persistent than its parent compound. After 150 days about 13% of the initially applied NP 112 remained in the Monheim soil as its nitro-metabolite. Results of the E-screen assay revealed that the nitro-NP 112 has oestrogenic potency of 85% of that of NP 112 . Furthermore, the results of chiral GC-MS analysis revealed that no chiral degradation of NP 112 occurred in this study. - The degradation of a chiral nonylphenol isomer in agricultural soils followed bi-exponential order kinetics resulting in a more persistent nitro-metabolite.

  1. Degradation and toxicity of phenyltin compounds in soil

    International Nuclear Information System (INIS)

    Paton, G.I.; Cheewasedtham, W.; Marr, I.L.; Dawson, J.J.C.

    2006-01-01

    Although the fate of organotins has been widely studied in the marine environment, fewer studies have considered their impact in terrestrial systems. The degradation and toxicity of triphenyltin in autoclaved, autoclaved-reinoculated and non-sterilised soil was studied in a 231 day incubation experiment following a single application. Degradation and toxicity of phenyltin compounds in soil was monitored using both chemical and microbial (lux-based bacterial biosensors) methods. Degradation was significantly slower in the sterile soil when compared to non-sterilised soils. In the non-sterilised treatment, the half-life of triphenyltin was 27 and 33 days at amendments of 10 and 20 mg Sn kg -1 , respectively. As initial triphenyltin degradation occurred, there was a commensurate increase in toxicity, reflecting the fact that metabolites produced may be both more bioavailable and toxic to the target receptor. Over time, the toxicity reduced as degradation proceeded. The toxicity impact on non-target receptors for these compounds may be significant. - Triphenyltin degradative metabolites cause toxic responses to biosensors

  2. Microbial degradation of metalaxyl in soil

    International Nuclear Information System (INIS)

    Musumeci, M.R.; Ruegg, E.F.

    1984-01-01

    The behaviour of the fungicide metalaxyl in purple latosol soil was investigated using a ring - 14 C labelled compound under laboratory conditions. In nonsterile soil samples under aerobic conditions, metalaxyl was degrated into two metabolites. After 60 days, 60% of the radiocarbon on TLC plates corresponded to the parent fungicide, 22% to its metabolite N-(2-methoxyacetyl)-N-(2,6-xylyl)-DL-alanine, and 2.7% to a second and unidentified metabolite. The U.V. absorbance value of metalaxyl decreased after seven days incubation with a soil microorganisms suspension. Incubation of 14 C-metalaxyl for 50 days with a bacterium or a fungus isolated from that suspension resulted in metalaxyl gradual disappearance from the medium, but not metabolites were detected during this period. (Author) [pt

  3. Degradation of 14C-glyphosate in compost amended soils.

    Science.gov (United States)

    Alexa, E; Bragea, M; Sumalan, R; Negrea, M; Lazureanu, A

    2009-01-01

    Glyphosate (N-phosphonomethyl-glycine), the active ingredient in several herbicide formulations, is a non-selective, post-emergent herbicide used in a variety of crop and non-crop situations. Glyphosate is a non-volatile herbicide that is relatively immobile in soil. Its degradation is due to microbiological processes and most laboratory studies have been conducted with 14C-glyphosate with the rate of 14CO2 evolution being used as an indication of herbicide breakdown. In this paper we have studied the glyphosate degradation in compost amendment soils using Scientilator Liquid TRIATHLER and Glyphosate-phosphonomethyl-14C-labeled with specific activity 2,2mCi/mmol. Four types of soils have been taken under study: Black Chernozem, Vertisol, Gleysol and Phaeozem with different characteristics. For the each type of soil have been realized four experimental variants (glyphosate blind sample with 1,5 ppm, concentration, autoclaved soil, soil with glyphosate and addition of compost in field concentration of 40 t/ha, respectively 60 t/ha. The mineralization curves of 14CO2 accumulated were compared during of 40 days. All the mineralization curves for the soils exhibited same patterns, with only two phases, the initial rapid phase of degradation, for about 20 days, attributed to microbial action on the free glyphosate and the second slow phase, when the curves attained plateaus. Compost applied with different concentrations to Vertisol and Black Chernozem did not appear to stimulate the microbial degradation of glyphosate. In Gleysol and Phaeozem with lower humus content, the mineralization curve of 14C indicate the increase degradation capacity, expressed as accumulated 14CO2 as % total 14C, with the increase of compost concentration.

  4. Adsorption and degradation of five selected antibiotics in agricultural soil.

    Science.gov (United States)

    Pan, Min; Chu, L M

    2016-03-01

    Large quantities of antibiotics are being added to agricultural fields worldwide through the application of wastewater, manures and biosolids, resulting in antibiotic contamination and elevated environmental risks in terrestrial environments. Most studies on the environmental fate of antibiotics focus on aquatic environments or wastewater treatment plants. Little is known about the behavior of antibiotics at environmentally relevant concentrations in agricultural soil. In this study we evaluated the adsorption and degradation of five different antibiotics (tetracycline, sulfamethazine, norfloxacin, erythromycin, and chloramphenicol) in sterilized and non-sterilized agricultural soils under aerobic and anaerobic conditions. Adsorption was highest for tetracycline (Kd, 1093 L/kg), while that for sulfamethazine was negligible (Kd, 1.365 L/kg). All five antibiotics were susceptible to microbial degradation under aerobic conditions, with half-lives ranging from 2.9 to 43.3 d in non-sterilized soil and 40.8 to 86.6 d in sterilized soil. Degradation occurred at a higher rate under aerobic conditions but was relatively persistent under anaerobic conditions. For all the antibiotics, a higher initial concentration was found to slow down degradation and prolong persistence in soil. The degradation behavior of the antibiotics varied in relation to their physicochemical properties as well as the microbial activities and aeration of the recipient soil. The poor adsorption and relative persistence of sulfamethazine under both aerobic and anaerobic conditions suggest that it may pose a higher risk to groundwater quality. An equation was proposed to predict the fate of antibiotics in soil under different field conditions, and assess their risks to the environment. Copyright © 2015 Elsevier B.V. All rights reserved.

  5. Modelling land degradation in IMAGE 2

    NARCIS (Netherlands)

    Hootsmans RM; Bouwman AF; Leemans R; Kreileman GJJ; MNV

    2001-01-01

    Food security may be threatened by loss of soil productivity as a result of human-induced land degradation. Water erosion is the most important cause of land degradation, and its effects are irreversible. This report describes the IMAGE land degradation model developed for describing current and

  6. Thermal properties of degraded lowland peat-moorsh soils

    Science.gov (United States)

    Gnatowski, Tomasz

    2016-04-01

    Soil thermal properties, i.e.: specific heat capacity (c), thermal conductivity (K), volumetric heat capacity (C) govern the thermal environment and heat transport through the soil. Hence the precise knowledge and accurate predictions of these properties for peaty soils with high amount of organic matter are especially important for the proper forecasting of soil temperature and thus it may lead to a better assessment of the greenhouse gas emissions created by microbiological activity of the peatlands. The objective of the study was to develop the predictive models of the selected thermal parameters of peat-moorsh soils in terms of their potential applicability for forecasting changes of soil temperature in degraded ecosystems of the Middle Biebrza River Valley area. Evaluation of the soil thermal properties was conducted for the parameters: specific heat capacity (c), volumetric heat capacities of the dry and saturated soil (Cdry, Csat) and thermal conductivities of the dry and saturated soil (Kdry, Ksat). The thermal parameters were measured using the dual-needle probe (KD2-Pro) on soil samples collected from seven peaty soils, representing total 24 horizons. The surface layers were characterized by different degrees of advancement of soil degradation dependent on intensiveness of the cultivation practises (peaty and humic moorsh). The underlying soil layers contain peat deposits of different botanical composition (peat-moss, sedge-reed, reed and alder) and varying degrees of decomposition of the organic matter, from H1 to H7 (von Post scale). Based on the research results it has been shown that the specific heat capacity of the soils differs depending on the type of soil (type of moorsh and type of peat). The range of changes varied from 1276 J.kg-1.K-1 in the humic moorsh soil to 1944 J.kg-1.K-1 in the low decomposed sedge-moss peat. It has also been stated that in degraded peat soils with the increasing of the ash content in the soil the value of specific heat

  7. Degradation of tetraethyllead during the degradation of leaded gasoline hydrocarbons in soil

    International Nuclear Information System (INIS)

    Mulroy, P.T.; Ou, L.T.

    1998-01-01

    For over 50 years, leaded gasoline was the only fuel for automobiles, and tetraethyllead (TEL) was the major octane number enhancer used in leaded gasoline. Ample information is available on the fate and remediation of gasoline hydrocarbons in contaminated subsoils and groundwater. However, little is known regarding the fate of TEL in leaded gasoline-contaminated subsoils and groundwater. In soil not contaminated with gasoline, TEL was rapidly degraded and completely disappeared in 14 d. In gasoline-contaminated soil, TEL degradation was slower; after 77 d, 4 to 17% of the applied TEL still remained in the contaminated soil. Disappearance of total petroleum hydrocarbons (TPH) was initially rapid but slowed appreciably after 7 to 14 d. As a result, after 77 d, 33 to 51% of the applied gasoline still remained in soil. The retardation of TEL degradation in leaded gasoline-contaminated soil is due to the presence of gasoline hydrocarbons. As long as gasoline hydrocarbons remain in soil, TEL may also remain in soil, most likely in the gasoline hydrocarbon phase

  8. MAPPING OF SOIL DEGRADATION POTENCY IN PADDY FIELD WONOGIRI, INDONESIA

    Directory of Open Access Journals (Sweden)

    Mujiyo

    2016-06-01

    Full Text Available Sustainability of paddy field becomes the main concern as the media of biomass production, thus it is needed a datum and information about land characteristics to find out its degradation. Mapping of soil degradation potency in paddy field is an identification of initial soil condition to discover the land degradation potency. Mapping was done by overlaying map of soil, slope, rainfall and land use with standard procedures to obtain its value and status of soil degradation potency. Area mapping is an effective land for biomass production (natural forest, mixed farm, savanna, paddy field, shrub and dry field with approximately 43,291.00 hectares (ha in Sidoharjo, Girimarto, Jatipurno, Jatisrono, Jatiroto, Tirtomoyo, Nguntoronadi and Ngadirojo District. The result shows that soil degradation potency (SDP in Districts of Sidoharjo, Girimarto, Jatipurno, Jatisrono, Jatiroto, Tirtomoyo, Nguntoronadi and Ngadirojo are very low, low (DP II 20,702.47 ha (47.82%, moderate (DP III 15,823.80 ha (36,55% and high (DP IV 6,764.73 ha (15.63%. Paddy field covered 22,036.26 ha or about 50.90% of all area as effective biomass production, its SDP considers as low (DP II 16,021.04 ha (37.01% and moderate (DP III 6,015.22 ha (13,89%. Paddy field has a low SDP because it is commonly lies on flat area and conservation method by the farmer is maintaining the paddy bund and terrace. This study needs an advanced study to identify actual SDP through detail verification in the field, and also support by soil sample analysis in the laboratory.

  9. Degradation of ¹³C-labeled pyrene in soil-compost mixtures and fertilized soil.

    Science.gov (United States)

    Adam, Iris K U; Miltner, Anja; Kästner, Matthias

    2015-11-01

    Polycyclic aromatic hydrocarbons (PAH) are toxic pollutants widely distributed in the environment due to natural and anthropogenic processes. In order to mitigate tar oil contaminations with PAH, research on improving bioremediation approaches, which are sometimes inefficient, is needed. However, the knowledge on the fate of PAH-derived carbon and the microbial degraders in particular in compost-supplemented soils is still limited. Here we show the PAH carbon turnover mass balance in microcosms with soil-compost mixtures or in farmyard fertilized soil using [(13)C6]-pyrene as a model PAH. Complete pyrene degradation of 100 mg/kg of soil was observed in all supplemented microcosms within 3 to 5 months, and the residual (13)C was mainly found as carbon converted to microbial biomass. Long-term fertilization of soil with farmyard manure resulted in pyrene removal efficiency similar to compost addition, although with a much longer lag phase, higher mineralization, and lower carbon incorporation into the biomass. Organic amendments either as long-term manure fertilization or as compost amendment thus play a key role in increasing the PAH-degrading potential of the soil microbial community. Phospholipid fatty acid stable isotope probing (PLFA-SIP) was used to trace the carbon within the microbial population and the amount of biomass formed from pyrene degradation. The results demonstrate that complex microbial degrader consortia rather than the expected single key players are responsible for PAH degradation in organic-amended soil.

  10. Organochlorine Pesticides and Degradation Products in Soil around ...

    African Journals Online (AJOL)

    The levels and compositions of organochlorine pesticides and degradation products in soil samples collected from a former formulation plant in Morogoro municipality, Tanzania, were determined. Extraction was performed by pressurized fluid extraction using n-hexane:acetone (75:25) mixture. Clean-up of extracts was ...

  11. Amylase activity of a starch degrading bacteria isolated from soil ...

    African Journals Online (AJOL)

    Starch degrading bacteria are most important for industries such as food, fermentation, textile and paper. Thus isolating and manipulating pure culture from various waste materials has manifold importance for various biotechnology industries. In the present investigation a bacterial strain was isolated from soil sample ...

  12. Land degradation and adoption of soil conservation technologies ...

    African Journals Online (AJOL)

    The study investigates the causes of land degradation, and adoption of soil conservation practices using a two-stage decision making process. The data for the study were collected with the aid of structured questionnaire and analyzed with descriptive analysis, difference regression equation and simultaneous probit model.

  13. Soil Degradation, Policy Intervention and Sustainable Agricultural Growth

    NARCIS (Netherlands)

    Sasmal, J.; Weikard, H.P.

    2013-01-01

    Sustainable agricultural growth in developing countries is jeopardized by soil degradation consequent upon intensive cultivation and use of increasing doses of chemical inputs. To pave the way to sustainable agricultural growth we develop a model that incorporates organic fertilizer into the

  14. Degradation Capability of n-hexadecane Degrading Bacteria from Petroleum Contaminated Soils

    Directory of Open Access Journals (Sweden)

    PENG Huai-li

    2017-05-01

    Full Text Available Samplings were performed in the petroleum contaminated soils of Dongying, Shandong Province of China. Degrading bacteria was isolated through enrichment in a Bushnel-Hass medium, with n-hexadecane as the sole source of carbon and energy. Then the isolated strains were identified by amplification of 16S rDNA gene and sequencing. The strain TZSX2 was selected as the powerful bacteria with stronger degradation ability, which was then identified as Rhodococcus hoagii genera based on the constructing results of the phylogenetic tree. The optimum temperature that allowed both high growth and efficient degradation ratio was in the scope of 28~36 ℃, and gas chromatography results showed that approximately more than 30% of n-hexadecane could be degraded in one week of incubation within the temperature range. Moreover, the strain TZSX2 was able to grow in high concentrations of n-hexadecane. The degradation rate reached 79% when the initial n-hexadecane concentration was 2 mL·L-1,while it still achieved 12% with n-hexadecane concentration of 20 mL·L-1. The optimal pH was 9 that allowed the highest growth and the greatest degradation rate of 91%. Above all, the screened strain TZSX2 showed high capabilities of alkali tolerance with excellent degradation efficiency for even high concentration of n-hexadecane, and thus it would be quite suitable for the remediation of petroleum contaminated soils especially in the extreme environment.

  15. Characterization of climate- and human-induced slope, soil and grassland dynamics in Bavarian landscapes under climate change

    Science.gov (United States)

    Waltl, Peter; Schwindt, Daniel; Völkel, Jörg

    2016-04-01

    Since the Neolithic Revolution the intensification of agriculture has been causing increased erosion in Bavarian landscapes. The correlated sediments often induce the formation of new colluvial and alluvial soils (WRB: Regic Anthrosol and Fluvisol i.a.). The soils themselves are able to absorb, bind, and store considerable amounts of C- and N-compounds. Therefore, they are important reactors regarding climate-relevant greenhouse-gas balances in the atmosphere. Learning about the exact spatial extent and thickness of these soils in representative landscapes, but also about their geneses and processes is essential. It allows for a detailed quantification and understanding of the current and potential properties and characteristics of these soils in their role of greenhouse-gas reactors. Two research locations were elected as representative Bavarian landscapes composed of different lithology and pedo-chemical environments (limestone versus crystalline setting): Rottenbuch is situated at the Ammer River in the Upper Bavarian pre-alpine forelands (Lkr. Weilheim-Schongau). The Otterbach Creek lies at the southwestern foothills of the Bavarian Forest at the Donaurandbruch tectonic line next to Donaustauf (Lkr. Regensburg). Detailed information on the soil horizons and layers within these research areas are accumulated by sounding or burrowing soil profiles and subsequently analyzing the soil samples in the lab. Geophysical methods, such as electrical resistivity tomography (ERT), seismic refraction tomography (SRT), and ground penetrating radar (GPR), allow for the extension of this point-source information into three dimensions. By repeatedly and regularly applying these methods, also temporal changes such as soil hydrology or freeze and thaw cycles can be monitored and their influence on fluxes and exchanges can be taken into account.

  16. Understanding and Enhancing Soil Biological Health: The Solution for Reversing Soil Degradation

    Directory of Open Access Journals (Sweden)

    R. Michael Lehman

    2015-01-01

    Full Text Available Our objective is to provide an optimistic strategy for reversing soil degradation by increasing public and private research efforts to understand the role of soil biology, particularly microbiology, on the health of our world’s soils. We begin by defining soil quality/soil health (which we consider to be interchangeable terms, characterizing healthy soil resources, and relating the significance of soil health to agroecosystems and their functions. We examine how soil biology influences soil health and how biological properties and processes contribute to sustainability of agriculture and ecosystem services. We continue by examining what can be done to manipulate soil biology to: (i increase nutrient availability for production of high yielding, high quality crops; (ii protect crops from pests, pathogens, weeds; and (iii manage other factors limiting production, provision of ecosystem services, and resilience to stresses like droughts. Next we look to the future by asking what needs to be known about soil biology that is not currently recognized or fully understood and how these needs could be addressed using emerging research tools. We conclude, based on our perceptions of how new knowledge regarding soil biology will help make agriculture more sustainable and productive, by recommending research emphases that should receive first priority through enhanced public and private research in order to reverse the trajectory toward global soil degradation.

  17. Combating land degradation: the potential of soil reconversion

    Science.gov (United States)

    Tobias, Silvia; Conen, Franz; Duss, Adrian; Wenzel, Leonore; Buser, Christine; Alewell, Christine

    2017-04-01

    Land degradation is usually not seen as a major problem in industrialised countries, although continuous soil sealing for human settlements and infrastructure entails the loss of agricultural land, landscape fragmentation and the loss of natural habitats. In many European countries, land-take on greenfields is unbowed, while, at the same time, there is a considerable number of unused brownfields, like abandoned rail yards and industrial or military sites. In addition, many new by-pass roads have been constructed to take up the volume of traffic and unburden the towns and villages from traffic emissions, but the old roads are rarely downgraded or reconverted and risk being used as shortcuts. Today the sealed area exceeds the requirements of the current generation and contributes to degraded land with heavily disturbed soil-borne ecosystem services. Soil reconversion, i.e. replacing a sealed surface with soil to restore ecosystem services, could mitigate this unsustainable trend that restricts the options of future generations. This contribution discusses the potential and challenges of soil reconversion to reduce net soil loss. The expanses of brownfield area vary between countries, whereas the rate of new soil sealing is still high in most countries and soil reconversion should be considered more. Our research revealed that the current techniques enable successful restoration of agricultural soils and pioneer habitats on site. However, reconverting single small areas can hardly mitigate landscape fragmentation at a regional scale. The same principle prevails as for soil sealing, but in the inverse way: the benefit of soil reconversion may appear small for single cases, but in the sum soil reconversion might be effective. Today, many brownfield areas stay sealed because of economic and political reasons, or because the potential benefit from restoring ecosystem services at these brownfield sites is not known. We developed a mapping approach to assess the potential

  18. Hydrocarbon degradation potential in reference soils and soils contaminated with jet fuel

    International Nuclear Information System (INIS)

    Lee, R.F.; Hoeppel, R.

    1991-01-01

    Petroleum degradation in surface and subsurface soils is affected by such factors as moisture content, pH, soil type, soil organics, temperature, and oxygen concentrations. In this paper, the authors determine the degradation rates of 14 C-labeled hydrocarbons added to soils collected from a contaminated surface site, contaminated subsurface sites, and a clean reference site. The radiolabeled hydrocarbons used include benzene, toluene, naphthalene, 1-methynaphthalene, phenanthrene, fluorene, anthracene, chrysene, and hexadecane. Microbial degradation rates were based on determination of mineralization rates (production of 14 CO 2 ) of hydrocarbons that were added to soil samples. Since water was added and oxygen was not limiting, the hydrocarbon rates determined are likely to be higher than those occurring in situ. Using radiolabeled hydrocarbons, information can be provided on differences in the degradation rates of various petroleum compounds in different types of soils at a site, on possible production of petroleum metabolites in the soil, and on the importance of anaerobic petroleum degradation and the effects of nutrient, water, and surfactant addition on biodegradation rates

  19. Human induced soil erosion and the implications on crop yield in a small mountainous Mediterranean catchment (SW-Turkey)

    NARCIS (Netherlands)

    Van Loo, Maarten; Dusar, Bert; Verstraeten, Gert; Renssen, Hans; Notebaert, Bastiaan; D'Haen, Koen; Bakker, Johan

    2017-01-01

    Many hillslopes in the limestone dominated Taurus Mountain Range (SW Turkey) are characterized by severely depleted soils, while a significant amount of sediment is being stored in the valley bottoms. The same holds true for the 11.4 km2 endorheic Gravgaz basin in the vicinity of the

  20. Degradation of soil fertility can cancel pollination benefits in sunflower.

    Science.gov (United States)

    Tamburini, Giovanni; Berti, Antonio; Morari, Francesco; Marini, Lorenzo

    2016-02-01

    Pollination and soil fertility are important ecosystem services to agriculture but their relative roles and potential interactions are poorly understood. We explored the combined effects of pollination and soil fertility in sunflower using soils from a trial characterized by different long-term input management in order to recreate plausible levels of soil fertility. Pollinator exclusion was used as a proxy for a highly eroded pollination service. Pollination benefits to yield depended on soil fertility, i.e., insect pollination enhanced seed set and yield only under higher soil fertility indicating that limited nutrient availability may constrain pollination benefits. Our study provides evidence for interactions between above- and belowground ecosystem services, highlighting the crucial role of soil fertility in supporting agricultural production not only directly, but also indirectly through pollination. Management strategies aimed at enhancing pollination services might fail in increasing yield in landscapes characterized by high soil service degradation. Comprehensive knowledge about service interactions is therefore essential for the correct management of ecosystem services in agricultural landscapes.

  1. Evaluation of Bioaugmentation with Entrapped Degrading Cells as a Soil Remediation Technology

    DEFF Research Database (Denmark)

    Owsianiak, Mikolaj; Dechesne, Arnaud; Binning, Philip John

    2010-01-01

    Soil augmentation with microbial degraders immobilized on carriers is evaluated as a potential remediation technology using a mathematical model that includes degradation within spatially distributed carriers and diffusion or advectiondispersion as contaminant mass transfer mechanisms. The total...... degraders have low intrinsic degradation rates and that only limited carrier to soil volume ratios are practically feasible, bioaugmented soils are characterized by low effective degradation ratesandcanbeconsidered fully mixed. A simple exponential model is then sufficient to predict biodegradation...

  2. Diuron degradation by bacteria from soil of sugarcane crops

    Directory of Open Access Journals (Sweden)

    Tassia C. Egea

    2017-12-01

    Full Text Available The isolation of microorganisms from soil impacted by xenobiotic chemicals and exposing them in the laboratory to the contaminant can provide important information about their response to the contaminants. The purpose of this study was to isolate bacteria from soil with historical application of herbicides and to evaluate their potential to degrade diuron. The isolation media contained either glucose or diuron as carbon source. A total of 400 bacteria were isolated, with 68% being Gram-positive and 32% Gram-negative. Most isolates showed potential to degrade between 10 and 30% diuron after five days of cultivation; however Stenotrophomonas acidophila TD4.7 and Bacillus cereus TD4.31 were able to degrade 87% and 68%, respectively. The degradation of diuron resulted in the formation of the metabolites DCPMU, DCPU, DCA, 3,4-CAC, 4-CA, 4-CAC and aniline. Based on these results it was proposed that Pseudomonas aeruginosa TD2.3, Stenotrophomonas acidaminiphila TD4.7, B. cereus TD4.31 and Alcaligenes faecalis TG 4.48, act on 3,4-DCA and 4-CA by alkylation and dealkylation while Micrococcus luteus and Achromobacter sp follow dehalogenation directly to aniline. Growth on aniline as sole carbon source demonstrates the capacity of strains to open the aromatic ring. In conclusion, the results show that the role of microorganisms in the degradation of xenobiotics in the environment depends on their own metabolism and also on their synergistic interactions.

  3. A review of the impacts of degradation threats on soil properties in the UK.

    Science.gov (United States)

    Gregory, A S; Ritz, K; McGrath, S P; Quinton, J N; Goulding, K W T; Jones, R J A; Harris, J A; Bol, R; Wallace, P; Pilgrim, E S; Whitmore, A P

    2015-10-01

    National governments are becoming increasingly aware of the importance of their soil resources and are shaping strategies accordingly. Implicit in any such strategy is that degradation threats and their potential effect on important soil properties and functions are defined and understood. In this paper, we aimed to review the principal degradation threats on important soil properties in the UK, seeking quantitative data where possible. Soil erosion results in the removal of important topsoil and, with it, nutrients, C and porosity. A decline in soil organic matter principally affects soil biological and microbiological properties, but also impacts on soil physical properties because of the link with soil structure. Soil contamination affects soil chemical properties, affecting nutrient availability and degrading microbial properties, whilst soil compaction degrades the soil pore network. Soil sealing removes the link between the soil and most of the 'spheres', significantly affecting hydrological and microbial functions, and soils on re-developed brownfield sites are typically degraded in most soil properties. Having synthesized the literature on the impact on soil properties, we discuss potential subsequent impacts on the important soil functions, including food and fibre production, storage of water and C, support for biodiversity, and protection of cultural and archaeological heritage. Looking forward, we suggest a twin approach of field-based monitoring supported by controlled laboratory experimentation to improve our mechanistic understanding of soils. This would enable us to better predict future impacts of degradation processes, including climate change, on soil properties and functions so that we may manage soil resources sustainably.

  4. Plant species influence on soil C after afforestation of Mediterranean degraded soils

    Science.gov (United States)

    Dominguez, Maria T.; García-Vargas, Carlos; Madejón, Engracia; Marañón, Teodoro

    2015-04-01

    Increasing C sequestration in terrestrial ecosystems is one of the main current environmental challenges to mitigate climate change. Afforestation of degraded and contaminated lands is one of the key strategies to achieve an increase in C sequestration in ecosystems. Plant species differ in their mechanisms of C-fixation, C allocation into different plant organs, and interaction with soil microorganisms, all these factors influencing the dynamics of soil C following the afforestation of degraded soils. In this work we examine the influence of different woody plant species on soil C dynamics in degraded and afforested Mediterranean soils. The soils were former agricultural lands that were polluted by a mining accident and later afforested with different native plant species. We analysed the effect of four of these species (Olea europaea var. sylvestris Brot., Populus alba L., Pistacia lentiscus L. and Retama sphaerocarpa (L.) Boiss.) on different soil C fractions, soil nutrient availability, microbial activity (soil enzyme activities) and soil CO2 fluxes 15 years after the establishment of the plantations. Results suggest that the influence of the planted trees and shrubs is still limited, being more pronounced in the more acidic and nutrient-poor soils. Litter accumulation varied among species, with the highest C accumulated in the litter under the deciduous species (Populus alba L.). No differences were observed in the amount of total soil organic C among the studied species, or in the concentrations of phenols and sugars in the dissolved organic C (DOC), which might have indicated differences in the biodegradability of the DOC. Microbial biomass and activity was highly influenced by soil pH, and plant species had a significant influence on soil pH in the more acidic site. Soil CO2 fluxes were more influenced by the plant species than total soil C content. Our results suggest that changes in total soil C stocks after the afforestation of degraded Mediterranean

  5. Assessing and monitoring soil erosion and land degradation in Malta

    Science.gov (United States)

    Symeonakis, Elias; Brearley, James

    2017-04-01

    The United Nations Convention to Combat Desertification (UNCCD) identifies the Mediterranean as one of the most seriously affected by land degradation and desertification (LDD) regions in the World. LDD is a complex process related with a multitude of biogeographical and socioeconomic parameters and is often assessed using proxies or indicators. One of the most important indicators of LDD is soil erosion. Here, we assess the evolution of soil erosion and LDD in the Mediterranean islands of Malta between 1986 and 2002. Soil erosion is estimated using the Revised Soil Loss Equation (RUSLE). For the assessment of LDD, we employ a modification of the Environmentally Sensitive Area Index (ESAI) methodology with Landsat imagery and ancillary GIS datasets. We incorporate 4 vegetation-related indicators, 3 climate-related, 5 soil-related and 3 socio-economic ones in the final assessment of the evolution of LDD. Results show that there has been an increase in soil erosion rates and in the sensitivity to LDD in the areas of San Pawl il-Bahar and Il-Mizieb most likely due to the transition from agricultural use to Mediterranean shrubs. Also, almost the entire country is flagged as belonging to the 'Fragile' and 'Critical' ESAI classes. It is clear that soil erosion and LDD mitigation measures are necessary, especially in the most critical (i.e. 'C3') areas which occupy 10% of Malta.

  6. DEGRADATION OF QUINTOZENE, PENTACHLOROBENZENE, HEXACHLOROBENZENE AND PENTACHLOROANILINE IN SOIL

    DEFF Research Database (Denmark)

    Beck, Jørgen; Hansen, Knud E.

    1974-01-01

    The disappearance of quintozene (I) and its technical impurities and metabolites pentachlorobenzene (III), hexachlorobenzene (IV) and pentachloroaniline (V) from soil, was studied in laboratory experiments under controlled conditions during a period of about 600 days. The very high persistence...... found, was confirmed by the analysis of 22 samples collected from fields used for potato growing and treated regularly during the foregoing 11 years with commercial formulations of quintozene. In the laboratory experiments, III, V and methylthiopentachlorobenzene (VI) were found to be degradation...

  7. Using the VS-Fast methodology for soil degradation assessment: a case study from Senegal

    NARCIS (Netherlands)

    Sonneveld, B.G.J.S.; McGarry, D.; Ndiaye, D.

    2012-01-01

    Soil degradation threatens sustainable food production and accelerates global warming. Poorer countries, whose agricultural sectors are highly dependent on their natural resource bases, are hit particularly hard by declining soil productivity. Calls for soil-quality monitoring are therefore,

  8. Effect of fertilizer and irradiation sterilization on the degradation of lindane in soil

    International Nuclear Information System (INIS)

    Bennaceur, M.; Ghezal, F.

    1992-10-01

    The effect of fertilizer and sterelization using irradiation were studied on the fate of lindane degradation in two soils under laboratory conditions. Degradation of lindane is higher in organic matter rich soil. Half life of product is respectively about one week and one month for both rich soil and poor soil. Fertilizer used decreases PH of soils and irradiation dose of 1 mrad seems to be insufficient to sterilize completely the soils. Ammonium nitrate stimulates slightly the degradations of lindane in soil (not sterilized) after two months

  9. Degradation of zearalenone and ochratoxin A in three Danish agricultural soils

    DEFF Research Database (Denmark)

    Mortensen, G.K.; Strobel, B.W.; Hansen, H.C.B.

    2006-01-01

    Degradation of two mycotoxins: zearalenone (ZON) produced by species of Fusarium and ochratoxin A (OTA) produced by species of Penicillium were followed in pot experiments using agricultural topsoils from Danish experimental farms: a sandy soil, a sandy clay soil and a gyttja soil with a high...... content of silt. Experiments with unplanted soil and pots planted with barley were included. Soil samples were withdrawn during a period of 225 days and analysed for the content of OTA and ZON. The degradation of both toxins consisted of an initial fast degradation followed by a slower transformation step......, whereas the half-lives for OTA were about 0.2-1 day. The slowest degradation was measured in soil rich in clay. After 225 days, neither OTA nor ZON was detected in any of the soil types. Generally, the degradation of ZON and OTA was faster in planted soil than in unplanted soil, probably due to higher...

  10. Assessment of potential soil degradation on agricultural land in the czech republic.

    Science.gov (United States)

    Šarapatka, Bořivoj; Bednář, Marek

    2015-01-01

    Many attempts have been made worldwide to develop methods to identify the areas most threatened by soil degradation. Some soils in afflicted areas may be irreversibly degraded and thus have very little resilience (the ability to restore themselves). For the purpose of assessing the current state of soil degradation in the Czech Republic (CZ) we have developed an overall indicator of land vulnerability to the threat of soil degradation on the basis of individual factors that contribute to soil degradation and are monitored on a long-term basis in various research worksites in the CZ. Individual degradation factors were divided into two groups: chemical and physical degradation. On the basis of principal component analysis, individual degradation factors were assigned a specific weight of influence. With the use of a GIS, the input factors of degradation were combined to create maps of chemical and physical soil degradation, and consequently a map of overall degradation-threatened soils for the CZ, along with a map of areas differentiated according to the prevailing type of degradation. Results showed that, at present, the most important degradation factor in the CZ is water erosion, followed by loss of organic matter. Statistical analysis showed that approximately 51% of agricultural land is moderately threatened in the CZ. Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.

  11. CARBON FIXING CAPACITY OF AMAZONIAN SOILS IN RELATION TO ITS DEGRADATION CONDITIONS

    Directory of Open Access Journals (Sweden)

    Clara Patricia Peña Venegas

    2015-06-01

    Full Text Available Amazonian deforestation and transformation alert about their effects worldwide. One concern is the increase of the Carbon (C levels emitted. Previous works have estimated the fixed C in Amazon forests without including the C stored in soils. Within soil, the organic carbon molecules are highly sensitive to degradation, affecting the natural capacity of soils to fix and store C. The present study evaluates the impact of degradation in the natural capacity of Amazon soils to fix C. Thirty five farms with different typology were selected in Caquetá department which hold the highest deforestation and soil degradation rates in the Colombian Amazon. Soil samples were taken from natural forest relicts, cropping areas and introduced pastures of the farms, in locations with high, intermediate and low soil degradation. Aerial biomass was estimated in pastures with different level of soil degradation. Changes in the labile C stock were estimated from the soil organic carbon and the microbial biomass using substrate induced respiration. Results showed that the main C pool is in the natural forest relicts and the crops of the farms, independently from the size or type of farm sampled. The hills with higher intervention showed the lowest soil C fixation capacities. The soil C fixation capacity was related with changes in the soil microbial composition where conserved soils store preferentially C as fungal biomass while degraded soils store C as bacterial biomass. These estimations contribute to establish the cost of sustainability and soil degradation in the Colombian Amazon.

  12. Current State and Development of Land Degradation Processes Based on Soil Monitoring in Slovakia

    Directory of Open Access Journals (Sweden)

    Kobza Jozef

    2017-08-01

    Full Text Available Current state and development of land degradation processes based on soil monitoring system in Slovakia is evaluated in this contribution. Soil monitoring system in Slovakia is consistently running since 1993 year in 5-years repetitions. Soil monitoring network in Slovakia is constructed using ecological principle, taking into account all main soil types and subtypes, soil organic matter, climatic regions, emission regions, polluted and non-polluted regions as well as various land use. The result of soil monitoring network is 318 sites on agricultural land in Slovakia. Soil properties are evaluated according to the main threats to soil relating to European Commission recommendation for European soil monitoring performance as follows: soil erosion and compaction, soil acidification, decline in soil organic matter and soil contamination. The most significant change has been determined in physical degradation of soils. The physical degradation was especially manifested in compacted and the eroded soils. It was determined that about 39% of agricultural land is potentially affected by soil erosion in Slovakia. In addition, slight decline in soil organic matter indicates the serious facts on evaluation and extension of soil degradation processes during the last period in Slovakia. Soil contamination is without significant change for the time being. It means the soils contaminated before soil monitoring process this unfavourable state lasts also at present.

  13. Soil organic matter degradation and enzymatic profiles of intertidal and subaqueous soils

    Science.gov (United States)

    Ferronato, Chiara; Marinari, Sara; Bello, Diana; Vianello, Gilmo; Trasar-Cepeda, Carmen; Vittori Antisari, Livia

    2017-04-01

    The interest on intertidal and subaqueous soils has recently arisen because of the climate changes forecasts. The preservation of these habitats represents an important challenge for the future of humanity, because these systems represent an important global C sink since soil organic matter (SOM) on intertidal and subaqueous soils undergoes very slow degradation rates due to oxygen limitation. Publications on SOM cycle in saltmarshes are very scarce because of the difficulties involved on those studies i.e. the interaction of many abiotic and biotic factors (e.g., redox changes, water and bio-turbation processes, etc) and stressors (e.g., salinity and anoxia). However, saltmarshes constitute an unique natural system to observe the influence of anoxic conditions on SOM degradation, because the tide fluctuations on the soil surface allow the formation of provisionally or permanently submerged soils. With the aim to investigate the quality of SOM in subaqueous soils, triplicates of subaqueous soils (SASs), intertidal soils (ITSs) and terrestrial soils (TESs) were collected in the saltmarshes of the Baiona Lagoon (Northern Italy) and classified according to their pedogenetic horizons. The SOM quality on each soil horizon was investigated by quantifying SOM, total and water-soluble organic carbon (TOC, WSC) and microbial biomass carbon (MBC). Given the contribution of soil enzymes to the degradation of SOM, some enzymatic assays were also performed. Thereafter, soil classification and humus morpho-functional classification were used to join together similar soil profiles to facilitate the description and discussion of results. Soils were ranked as Aquent or Wassent Entisols, with an A/AC/C pedosequence. SOM, TOC and MBC were statistically higher in A than in AC and C horizons. Among the A horizons, ITSs were those showing the highest values for these parameters (11% TOC, 1.6 mg kg-1 MBC, 0.9 mg kg-1 WSC). These results, combined with the morpho-functional classification

  14. Identification of soil bacteria able to degrade phenanthrene bound to a hydrophobic sorbent in situ

    International Nuclear Information System (INIS)

    Regonne, Raïssa Kom; Martin, Florence; Mbawala, Augustin; Ngassoum, Martin Benoît; Jouanneau, Yves

    2013-01-01

    Efficient bioremediation of PAH-contaminated sites is limited by the hydrophobic character and poor bioavailability of pollutants. In this study, stable isotope probing (SIP) was implemented to track bacteria that can degrade PAHs adsorbed on hydrophobic sorbents. Temperate and tropical soils were incubated with 13 C-labeled phenanthrene, supplied by spiking or coated onto membranes. Phenanthrene mineralization was faster in microcosms with PAH-coated membranes than in microcosms containing spiked soil. Upon incubation with temperate soil, phenanthrene degraders found in the biofilms that formed on coated membranes were mainly identified as Sphingomonadaceae and Actinobacteria. In the tropical soil, uncultured Rhodocyclaceae dominated degraders bound to membranes. Accordingly, ring-hydroxylating dioxygenase sequences recovered from this soil matched PAH-specific dioxygenase genes recently found in Rhodocyclaceae. Hence, our SIP approach allowed the detection of novel degraders, mostly uncultured, which differ from those detected after soil spiking, but might play a key role in the bioremediation of PAH-polluted soils. -- Highlights: •Soil bacteria with the ability to degrade sorbent-bound PAHs were investigated. •In soil, membrane-bound phenanthrene was readily mineralized. •PAH degraders found in biofilms were different in temperate and tropical soils. •Uncultured Rhodocyclaceae were dominant phenanthrene degraders in the tropical soil. •PAH-specific ring-hydroxylating dioxygenase sequences were identified in soil DNA. -- Bacteria able to degrade PAHs bound to a hydrophobic sorbent were mainly identified as uncultured Rhodocyclaceae and Sphingomonadaceae in polluted soils from tropical and temperate area, respectively

  15. The history of human-induced soil erosion: Geomorphic legacies, early descriptions and research, and the development of soil conservation—A global synopsis

    Science.gov (United States)

    Dotterweich, Markus

    2013-11-01

    This paper presents a global synopsis about the geomorphic evidence of soil erosion in humid and semihumid areas since the beginning of agriculture. Historical documents, starting from ancient records to data from the mid-twentieth century and numerous literature reviews form an extensive assortment of examples that show how soil erosion has been perceived previously by scholars, land surveyors, farmers, land owners, researchers, and policy makers. Examples have been selected from ancient Greek and Roman Times and from central Europe, southern Africa, North America, the Chinese Loess Plateau, Australia, New Zealand, and Easter Island. Furthermore, a comprehensive collection on the development of soil erosion research and soil conservation has been provided, with a particular focus on Germany and the USA. Geomorphic evidence shows that most of the agriculturally used slopes in the Old and New Worlds had already been affected by soil erosion in earlier, prehistoric times. Early descriptions of soil erosion are often very vague. With regard to the Roman Times, geomorphic evidence shows seemingly opposing results, ranging from massive devastation to landscapes remaining stable for centuries. Unfortunately, historical documentation is lacking. In the following centuries, historical records become more frequent and more precise and observations on extreme soil erosion events are prominent. Sometimes they can be clearly linked to geomorphic evidence in the field. The advent of professional soil conservation took place in the late eighteenth century. The first extensive essay on soil conservation known to the Western world was published in Germany in 1815. The rise of professional soil conservation occurred in the late nineteenth and early twentieth centuries. Soil remediation and flood prevention programs were initiated, but the long-term success of these actions remains controversial. In recent years, increasing interest is to recover any traditional knowledge of soil

  16. Reclamation status of a degraded pasture based on soil health indicators.

    OpenAIRE

    SANTOS, C. A. dos; KRAWULSKI, C. C.; BINI, D.; GOULART FILHO, T.; KNOB, A.; MEDINA, C. C.; ANDRADE FILHO, G.; NOGUEIRA, M. A.

    2015-01-01

    Pasture degradation is a concern, especially in susceptible sandy soils for which strategies to recover them must be developed. Microbiological and biochemical soil health indicators are useful in the guindace of soil management practices and sustainable soil use. We assessed the success of threePanicum maximum Jacq. cultivars in the reclamation of a pasture in a sandy Typic Acrudox in the northwest of the state of Paraná, Brazil, based on soil health indicators. On a formerly degraded p...

  17. Soil erosion and degradation in Mediterranean Type Ecosystems. The Soil Erosion and Degradation Research Group (SEDER) approach and findings

    Science.gov (United States)

    Cerdà, Artemi; Keesstra, Saskia; Pulido, Manuel; Jordán, Antonio; Novara, Agata; Giménez-Morera, Antonio; Borja, Manuel Esteban Lucas; Francisco Martínez-Murillo, Juan; Rodrigo-Comino, Jesús; Pereira, Paulo; Nadal-Romero, Estela; Taguas, Tani; Úbeda, Xavier; Brevik, Eric C.; Tarolli, Paolo; Bagarello, Vicenzo; Parras Alcantara, Luis; Muñoz-Rojas, Miriam; Oliva, Marc; di Prima, Simone

    2017-04-01

    The Soil Erosion and Degradation Reseach Group (SEDER) is developing a research program since 2002 to assess the soil erosion and degradation processes at the Canyoles River watershed in Eastern Spain. The research study site was selected as representative of the environmental changes that take place in the Mediterranean: abandonment of the agriculture land in the mountains, forest fire expansion, intensification of the agriculture, impact of the infraesturctures such as rail and road embankments, and soil sealing due to the urban expansion. The research is based on the continuous measurements in the Montesa and El Teularet research stations and the sampling of the soils, topographical measurements and the use of rainfall simulators, minidisk infiltrometers, ring infiltrometers and Water Drop Penetration Time tests. The research is moving from a pure scientific approach to a more socio-economic view, and the stakeholders are being researched from a perception point of view. SEDER is also moving from pure to applied science, with the objective to design new managements that will satisfy the stakeholders and will achieve the sustainability. The research is being carried out in vineyards and orchards as they show extremely high erosion rates. But also we are interested in the impact of forest fires and the road embankments. In all three research topics, SEDER wish to find the sustainable managements. Acknowledgements The research leading to these results has received funding from the European Union Seventh Framework Programme (FP7/2007-2013) under grant agreement n° 603498 (RECARE project) and the CGL2013- 47862-C2-1-R and CGL2016-75178-C2-2-R national research projects. References Bodí, M. B., Martin, D. A., Balfour, V. N., Santín, C., Doerr, S. H., Pereira, P., . . . Mataix-Solera, J. (2014). Corrigendum to "wildland fire ash: Production, composition and eco-hydro-geomorphic effects", earth sci. rev. 130 (2014) [103-127]. Earth-Science Reviews, 138, 503. doi:10

  18. Effect of elevated CO2 on chlorpyriphos degradation and soil microbial activities in tropical rice soil.

    Science.gov (United States)

    Adak, Totan; Munda, Sushmita; Kumar, Upendra; Berliner, J; Pokhare, Somnath S; Jambhulkar, N N; Jena, M

    2016-02-01

    Impact of elevated CO2 on chlorpyriphos degradation, microbial biomass carbon, and enzymatic activities in rice soil was investigated. Rice (variety Naveen, Indica type) was grown under four conditions, namely, chambered control, elevated CO2 (550 ppm), elevated CO2 (700 ppm) in open-top chambers and open field. Chlorpyriphos was sprayed at 500 g a.i. ha(-1) at maximum tillering stage. Chlorpyriphos degraded rapidly from rice soils, and 88.4% of initially applied chlorpyriphos was lost from the rice soil maintained under elevated CO2 (700 ppm) by day 5 of spray, whereas the loss was 80.7% from open field rice soil. Half-life values of chlorpyriphos under different conditions ranged from 2.4 to 1.7 days with minimum half-life recorded with two elevated CO2 treatments. Increased CO2 concentration led to increase in temperature (1.2 to 1.8 °C) that played a critical role in chlorpyriphos persistence. Microbial biomass carbon and soil enzymatic activities specifically, dehydrogenase, fluorescien diacetate hydrolase, urease, acid phosphatase, and alkaline phosphatase responded positively to elevated CO2 concentrations. Generally, the enzyme activities were highly correlated with each other. Irrespective of the level of CO2, short-term negative influence of chlorpyriphos was observed on soil enzymes till day 7 of spray. Knowledge obtained from this study highlights that the elevated CO2 may negatively influence persistence of pesticide but will have positive effects on soil enzyme activities.

  19. Impact of electrochemical treatment of soil washing solution on PAH degradation efficiency and soil respirometry

    International Nuclear Information System (INIS)

    Mousset, Emmanuel; Huguenot, David; Hullebusch, Eric D. van; Oturan, Nihal; Guibaud, Gilles; Esposito, Giovanni; Oturan, Mehmet A.

    2016-01-01

    The remediation of a genuinely PAH-contaminated soil was performed, for the first time, through a new and complete investigation, including PAH extraction followed by advanced oxidation treatment of the washing solution and its recirculation, and an analysis of the impact of the PAH extraction on soil respirometry. The study has been performed on the remediation of genuine PAH-contaminated soil, in the following three steps: (i) PAH extraction with soil washing (SW) techniques, (ii) PAH degradation with an electro-Fenton (EF) process, and (iii) recirculation of the partially oxidized effluent for another SW cycle. The following criteria were monitored during the successive washing cycles: PAH extraction efficiency, PAH oxidation rates and yields, extracting agent recovery, soil microbial activity, and pH of soil. Two representative extracting agents were compared: hydroxypropyl-beta-cyclodextrin (HPCD) and a non-ionic surfactant, Tween"® 80. Six PAH with different numbers of rings were monitored: acenaphthene (ACE), phenanthrene (PHE), fluoranthene (FLA), pyrene (PYR), benzo(a)pyrene (BaP), and benzo(g,h,i)perylene (BghiP). Tween"® 80 showed much better PAH extraction efficiency (after several SW cycles) than HPCD, regardless of the number of washing cycles. Based on successive SW experiments, a new mathematical relation taking into account the soil/water partition coefficient (Kd*) was established, and could predict the amount of each PAH extracted by the surfactant with a good correlation with experimental results (R"2 > 0.975). More HPCD was recovered (89%) than Tween"® 80 (79%), while the monitored pollutants were completely degraded (>99%) after 4 h and 8 h, respectively. Even after being washed with partially oxidized solutions, the Tween"® 80 solutions extracted significantly more PAH than HPCD and promoted better soil microbial activity, with higher oxygen consumption rates. Moreover, neither the oxidation by-products nor the acidic media (p

  20. Effect of elevated CO2 on degradation of azoxystrobin and soil microbial activity in rice soil.

    Science.gov (United States)

    Manna, Suman; Singh, Neera; Singh, V P

    2013-04-01

    An experiment was conducted in open-top chambers (OTC) to study the effect of elevated CO2 (580 ± 20 μmol mol(-1)) on azoxystrobin degradation and soil microbial activities. Results indicated that elevated CO2 did not have any significant effect on the persistence of azoxystrobin in rice-planted soil. The half-life values for the azoxystrobin in rice soils were 20.3 days in control (rice grown at ambient CO2 outdoors), 19.3 days in rice grown under ambient CO2 atmosphere in OTC, and 17.5 days in rice grown under elevated CO2 atmosphere in OTC. Azoxystrobin acid was recovered as the only metabolite of azoxystrobin, but it did not accumulate in the soil/water and was further metabolized. Elevated CO2 enhanced soil microbial biomass (MBC) and alkaline phosphatase activity of soil. Compared with rice grown at ambient CO2 (both outdoors and in OTC), the soil MBC at elevated CO2 increased by twofold. Elevated CO2 did not affect dehydrogenase, fluorescein diacetate, and acid phosphatase activity. Azoxystrobin application to soils, both ambient and elevated CO2, inhibited alkaline phosphates activity, while no effect was observed on other enzymes. Slight increase (1.8-2 °C) in temperature inside OTC did not affect microbial parameters, as similar activities were recorded in rice grown outdoors and in OTC at ambient CO2. Higher MBC in soil at elevated CO2 could be attributed to increased carbon availability in the rhizosphere via plant metabolism and root secretion; however, it did not significantly increase azoxystrobin degradation, suggesting that pesticide degradation was not the result of soil MBC alone. Study suggested that increased CO2 levels following global warming might not adversely affect azoxystrobin degradation. However, global warming is a continuous and cumulative process, therefore, long-term studies are necessary to get more realistic assessment of global warming on fate of pesticide.

  1. Enhanced degradation of metalaxyl in agricultural soils of São Paulo State, Brazil

    Directory of Open Access Journals (Sweden)

    Papini Solange

    2001-01-01

    Full Text Available This work investigated the effect of repeated applications on enhanced degradation of metalaxyl in two different agricultural soils used for cultivation of orange and lemon from Casa Branca and Itapetininga districts of São Paulo State, Brazil. Soil samples were collected from areas repeatedly treated with commercial ridomil 50GR for six successive years, and from other areas never exposed to this fungicide. At the laboratory, soil samples received a 14C-metalaxyl solution and its degradation was studied through radiometric techniques to measure biomineralization and recovery of extractable- and soil-bound products. Enhanced degradation was verified only in one soil, although partial degradation and mineralization of the fungicide were detected in both soils. The different rates and patterns of metalaxyl degradation in the soils were probably due to their different physical, chemical, and biological characteristics.

  2. Microbial functional diversity plays an important role in the degradation of polyhydroxybutyrate (PHB) in soil.

    Science.gov (United States)

    Dey, Samrat; Tribedi, Prosun

    2018-03-01

    Towards bioremediation of recalcitrant materials like synthetic polymer, soil has been recognized as a traditional site for disposal and subsequent degradation as some microorganisms in soil can degrade the polymer in a non-toxic, cost-effective, and environment friendly way. Microbial functional diversity is a constituent of biodiversity that includes wide range of metabolic activities that can influence numerous aspects of ecosystem functioning like ecosystem stability, nutrient availability, ecosystem dynamics, etc. Thus, in the current study, we assumed that microbial functional diversity could play an important role in polymer degradation in soil. To verify this hypothesis, we isolated soil from five different sites of landfill and examined several microbiological parameters wherein we observed a significant variation in heterotrophic microbial count as well as microbial activities among the soil microcosms tested. Multivariate analysis (principle component analysis) based on the carbon sources utilization pattern revealed that soil microcosms showed different metabolic patterns suggesting the variable distribution of microorganisms among the soil microcosms tested. Since microbial functional diversity depends on both microbial richness and evenness, Shannon diversity index was determined to measure microbial richness and Gini coefficient was determined to measure microbial evenness. The tested soil microcosms exhibited variation in both microbial richness and evenness suggesting the considerable difference in microbial functional diversity among the tested microcosms. We then measured polyhydroxybutyrate (PHB) degradation in soil microcosms after desired period of incubation of PHB in soil wherein we found that soil microcosms having higher functional diversity showed enhanced PHB degradation and soil microcosms having lower functional diversity showed reduced PHB degradation. We also noticed that all the tested soil microcosms showed similar pattern in both

  3. Contribution of soil fauna to soil functioning in degraded environments: a multidisciplinary approach

    Science.gov (United States)

    Gargiulo, Laura; Mele, Giacomo; Moradi, Jabbar; Kukla, Jaroslav; Jandová, Kateřina; Frouz, Jan

    2016-04-01

    The restoration of the soil functions is essential for the recovery of highly degraded sites and, consequently, the study of the soil fauna role in the soil development in such environments has great potential from a practical point of view. The soils of the post-mining sites represent unique models for the study of the natural ecological succession because mining creates similar environments characterized by the same substrate, but by different ages according to the year of closure of mines. The aim of this work was to assess the contribution of different species of macrofauna on the evolution of soil structure and on the composition and activity of the microbial community in soil samples subjected to ecological restoration or characterized by spontaneous ecological succession. For this purpose, an experimental test was carried out in two sites characterized by different post-mining conditions: 1) natural succession, 2) reclamation with planting trees. These sites are located in the post-mining area of Sokolov (Czech Republic). For the experimental test repacked soil cores were prepared in laboratory with sieved soil sampled from the two sites. The soil cores were prepared maintaining the sequence of soil horizons present in the field. These samples were inoculated separately with two genera of earthworms (Lumbricus and Aporrectodea) and two of centipedes (Julida and Polydesmus). In particular, based on their body size, were inoculated for each cylinder 2 individuals of millipedes, 1 individual of Lumbricus and 4 individuals of Aporrectodea. For each treatment and for control samples 5 replicates were prepared and all samples were incubated in field for 1 month in the two original sampling sites. After the incubation the samples were removed from the field and transported in laboratory in order to perform the analysis of microbial respiration, of PLFA (phospholipid-derived fatty acids) and ergosterol contents and finally for the characterization of soil structure

  4. Effects of traditional land transactions on soil erosion and land degradation

    OpenAIRE

    Leduka, R.C.

    1998-01-01

    A research report on the effects of traditional land transactions on soil erosion and land degradation in Lesotho. This report focuses on the land transactions in Lesotho and how these transaction affect the growing erosion rates of the soil.

  5. Degradation of dimethyl disulphide in soil with or without biochar amendment.

    Science.gov (United States)

    Han, Dawei; Yan, Dongdong; Cao, Aocheng; Fang, Wensheng; Liu, Pengfei; Li, Yuan; Ouyang, Canbin; Wang, Qiuxia

    2017-09-01

    Dimethyl disulphide (DMDS) is a new and effective alternative to methyl bromide for soil fumigation. The effect of biochar on the fate of DMDS in soil is not fully understood. The objective of this study was to determine the degradation kinetics of DMDS in different soils and evaluate the effect of biochar amendment on DMDS degradation using incubation experiments. The degradation half-life of DMDS was between 1.05 and 6.66 days under non-sterile conditions, and 12.63 to 22.67 days under sterile conditions in five types of soil. Seven out of the eight tested biochar amendments (BC-2 to BC-8) delayed the degradation of DMDS in soil, increasing the half-life of DMDS in Fangshan soil from 1.05 to 1.16-5.87 days following amendment with 1% (w/w) biochar. The degradation rate of DMDS in Fangshan soil accelerated as the amendment rate of BC-1 increased, and decreased as the amendment rate of BC-7 increased. Biodegradation is an important degradation route for DMDS in soil, and DMDS degraded faster in alkaline soil. The effects of biochar amendments on DMDS degradation in soil are determined by complex multiple factors (such as surface area, pH and physicochemical composition), rather than by any single property of biochar. © 2017 Society of Chemical Industry. © 2017 Society of Chemical Industry.

  6. Development of a composite soil degradation assessment index for cocoa agroecosystems in southwestern Nigeria

    Science.gov (United States)

    Adenrele Adeniyi, Sunday; de Clercq, Willem Petrus; van Niekerk, Adriaan

    2017-08-01

    Cocoa agroecosystems are a major land-use type in the tropical rainforest belt of West Africa, reportedly associated with several ecological changes, including soil degradation. This study aims to develop a composite soil degradation assessment index (CSDI) for determining the degradation level of cocoa soils under smallholder agroecosystems of southwestern Nigeria. Plots where natural forests have been converted to cocoa agroecosystems of ages 1-10, 11-40, and 41-80 years, respectively representing young cocoa plantations (YCPs), mature cocoa plantations (MCPs), and senescent cocoa plantations (SCPs), were identified to represent the biological cycle of the cocoa tree. Soil samples were collected at a depth of 0 to 20 cm in each plot and analysed in terms of their physical, chemical, and biological properties. Factor analysis of soil data revealed four major interacting soil degradation processes: decline in soil nutrients, loss of soil organic matter, increase in soil acidity, and the breakdown of soil textural characteristics over time. These processes were represented by eight soil properties (extractable zinc, silt, soil organic matter (SOM), cation exchange capacity (CEC), available phosphorus, total porosity, pH, and clay content). These soil properties were subjected to forward stepwise discriminant analysis (STEPDA), and the result showed that four soil properties (extractable zinc, cation exchange capacity, SOM, and clay content) are the most useful in separating the studied soils into YCP, MCP, and SCP. In this way, we have sufficiently eliminated redundancy in the final selection of soil degradation indicators. Based on these four soil parameters, a CSDI was developed and used to classify selected cocoa soils into three different classes of degradation. The results revealed that 65 % of the selected cocoa farms are moderately degraded, while 18 % have a high degradation status. The numerical value of the CSDI as an objective index of soil degradation

  7. CARBON FIXING CAPACITY OF AMAZONIAN SOILS IN RELATION TO ITS DEGRADATION CONDITIONS

    OpenAIRE

    Clara Patricia Peña Venegas; Edmundo Rafael Mendoza Olmos; Carlos Hernando Rodríguez León; Gladys Inés Cardona Vanegas; Bernardo Eusebio Betancurt Parra; Maolenmarx Tatiana Garzón Gómez

    2015-01-01

    Amazonian deforestation and transformation alert about their effects worldwide. One concern is the increase of the Carbon (C) levels emitted. Previous works have estimated the fixed C in Amazon forests without including the C stored in soils. Within soil, the organic carbon molecules are highly sensitive to degradation, affecting the natural capacity of soils to fix and store C. The present study evaluates the impact of degradation in the natural capacity of Amazon soils to fix C. Thirty five...

  8. Exploration of Hydrocarbon Degrading Bacteria on Soils Contaminated by Crude Oil From South Sumatera

    OpenAIRE

    Napoleon, A; Probowati, D S

    2014-01-01

    The goal of this research was to explore hydrocarbon degrading bacteria on crude oil contaminated soil with potential to degrade hydrocarbon in oil pollutant. The research started by early August 2013 till January 2014. Soil sampling for this research was taken on several places with contaminated soil location such as Benakat, Rimau, and Pengabuan all of it located in South Sumatera. Conclusion from this research Isolates obtained from three (3) sites of contaminated soil and treated using SB...

  9. A laboratory examination of organic matter degradation in a B horizon soil from post-mining reconstructed prime farmland soil

    International Nuclear Information System (INIS)

    Felton, G.K.; Taraba, J.L.

    1994-01-01

    A laboratory study was conducted to assess the effect of reclamation treatment on the aerobic degradation rate of organic matter composed of horse faeces, urine, and straw bedding. It was hypothesized that different physical treatments of soil removed during the mining process would alter the rate of organic matter decomposition. The soils were from the B horizon of reclaimed prime farmland. The B horizon was reconstructed using one of two treatments: soil direct hauled from the mining site to the reconstruction site; soil hauled from a 6-month-old stockpile. The soil that was immediately replaced exhibited organic matter degradation rates similar to a control whereas the stockpiled soil organic matter degradation rates were depressed. This implies that stockpiling adversely affects the microbial population. Prescription limiting, typically done during reclamation, did have the desired effect on pH and did not interfere with organic matter degradation. 15 refs., 1 fig., 4 tabs

  10. Polythene and Plastics-degrading microbes from the mangrove soil

    Directory of Open Access Journals (Sweden)

    K Kathiresan

    2003-09-01

    Full Text Available Biodegradation of polythene bags and plastic cups was analyzed after 2, 4, 6, and 9 months of incubation in the mangrove soil. The biodegradation of polythene bags was significantly higher (up to 4.21% in 9 months than that of plastic cups (up to 0.25% in 9 months. Microbial counts in the degrading materials were recorded up to 79.67 x 10 4 per gram for total heterotrophic bacteria, and up to 55.33 x 10 2 per gram for fungi. The microbial species found associated with the degrading materials were identified as five Gram positive and two Gram negative bacteria, and eight fungal species of Aspergillus. The species that were predominant were Streptococcus, Staphylococcus, Micrococcus (Gram +ve, Moraxella, and Pseudomonas (Gram -ve and two species of fungi (Aspergillus glaucus and A. niger. Efficacy of the microbial species in degradation of plastics and polythene was analyzed in shaker cultures. Among the bacteria, Pseudomonas species degraded 20.54% of polythene and 8.16% of plastics in one-month period. Among the fungal species, Aspergillus glaucus degraded 28.80% of polythene and 7.26% of plastics in one-month period. This work reveals that the mangrove soil is a good source of microbes capable of degrading polythene and plasticsLa biodegradación de las bolsas de polietileno y vasos de plástico fue analizada después de 2, 4, 6 y 9 meses de incubación en suelo de manglar. La biodegradación de las bolsas fue significativamente más alta (hasta 4.21% en 9 meses que los vasos plásticos (hasta 0.25% en 9 meses. Los conteos microbianos en los materiales degradados mostraron hasta 79.67 x 10(4 por gramo para las bacterias heterotroficas totales, y hasta 55.33 x 10² por gramo para los hongos. Se identificó 5 especies microbianas Gram positivas, 2 Gram negativas, y 8 especies de hongos del género Aspergillus en asociación con materiales degradados. Las especies predominantes fueron Streptococcus, Staphylococcus, Micrococcus (Gram +, Moraxella

  11. Dynamic changes in functional gene copy numbers and microbial communities during degradation of pyrene in soils

    International Nuclear Information System (INIS)

    Peng Jingjing; Cai Chao; Qiao Min; Li Hong; Zhu Yongguan

    2010-01-01

    This study investigates the dynamics of pyrene degradation rates, microbial communities, and functional gene copy numbers during the incubation of pyrene-spiked soils. Spiking pyrene to the soil was found to have negligible effects on the bacterial community present. Our results demonstrated that there was a significant difference in nidA gene copy numbers between sampling dates in QZ soil. Mycobacterium 16S rDNA clone libraries showed that more than 90% mycobacteria detected were closely related to fast-growing PAH-degrading Mycobacterium in pyrene-spiked soil, while other sequences related to slow-growing Mycobacterium were only detected in the control soil. It is suggested that nidA gene copy number and fast-growing PAH-degrading Mycobacterium could be used as indicators to predict pyrene contamination and its degradation activity in soils. - nidA gene and fast-growing PAH-degrading Mycobacterium can serve as indicators for pyrene contamination.

  12. Aromatic Hydrocarbons: Degrading Bacteria in the Desert Soil of Kuwait

    International Nuclear Information System (INIS)

    Al-Gounaim, M.; Diab, A.; Al-Hilali, A.; Abu-Shady, A. Sattar

    2005-01-01

    Soil samples of different levels of oil pollutants were collected from Kuwait's Burgan Oil Field, near an oil lake. The samples represented, highly polluted (8.0% w/w), moderately polluted (2.1%-3.4%) and slightly polluted (2.1%-3.4%) and slightly polluted (0.5- 0.8%). The aromatic fractions of the collected samples were in the range of (0.21-2.57g/100g) soil. (GC) analysis of the aromatic fractions of the resolution of the different individual (PAHs) revealed the presence of (16) different (PAHs) resolved from the aromatic fraction of the highly polluted sample (S3). (15), (14) and (13) individual (PAHs) were identified soil samples (S5), (S2) and (S1, S4, S6) respectively. The most frequent (PAH) was indeno (1, 2, 3-c, d) pyrene (22.5%-45.11%) followed chrysene (13.6%-19.48%). Eight carcinogenic (PAHs) were resolved from the aromatic fractions of the polluted samples. Total carcinogenic (PAHs) recorded in this study were in this study were in the range of (11.53) (forS4) - (510.98) (for S3) ppm. The counts of (CFU) of aromatic degraders (AD) were in the range of (3x10) - (110x 10) (CFU/g) soil (with a percent of (2.2%-69.6%)). The results show that, higher counts of (AD) were recorded from a highly polluted sample (S3), followed by the moderately polluted samples; total of (51) bacteria, that gave presumptive positive biodegradation activities, were isolated and identified (45.1%) of them were isolated and identified. (45.1%) of them were isolated from the highly polluted sample (S3). Total of (13) different species were identified of which Micrococcus luteus was more frequent (23.5) followed by Bacillus licheniformis (19.6%) and Bacillus subtilis (11.8%). The three Pseudomonas species collectively were presented by (11.8%). Five different species proved to be of good activities, they are: Bacillus brevis, Bacillus lichenoformis, Pseudomonas aeruginosa, Pseudomonas stutzeri and Pseudomonas flourescens. The ability of five species and their mixture was

  13. [Assessment of soil degradation in regions of nuclear power explosions at Semipalatinsk Nuclear Test Site].

    Science.gov (United States)

    Evseeva, T I; Geras'kin, S A; Maĭstrenko, T A; Belykh, E S

    2011-01-01

    Degree of the soil cover degradation at the "Balapan" and "Experimental field" test sites was assessed based on Allium-test of soil toxicity results and international guidelines on radioactive restriction of solid materials (IAEA, 2004) and environment (Smith, 2005). Soil cover degradation maps of large-scale (1 : 25000) were made. The main part of the area mapped belongs to high-contaminated toxic degraded soil. A relationship between the soil toxicity and the total radionuclide activity concentrations was found to be described by power functions. When the calculated value (equal to 413-415 Bq/kg of air dry soil) increases, the soil becomes toxic for plants. This value is 7.8 times higher than the maximal value for background territories (53 Bq/kg) surrounding SNTS. Russian sanitary and hygienic guidelines (Radiation safety norms, 2009; Sanitary regulations of radioactive waste management, 2003) underestimate the degree of soil radioactive contamination for plants.

  14. Assessment of Soil Degradation in The Northern Part of Nile Delta, Egypt, Using Remote Sensing and Gis Techniques

    International Nuclear Information System (INIS)

    El Nahry, A.H.; Ibraheim, M.M.; El Baroudy, A.A.

    2008-01-01

    The present work aims at monitoring soil degradation process within the last two decades in the northern part of Nile Delta .The investigated area lies between longitudes 31 00 and 31 15 E and latitudes 31 00 and 31 37 N, covering an area of about 344584.01 feddans. Detecting soil degradation and recognizing its various types is a necessity to take the practical measures for combating it as well as conserving and keeping the agricultural soil healthy. Land degradation was assessed by adopting new approach through the integration of GLASOD/ FAa approach and Remote Sensing / GIS techniques .The main types of human induced soil degradation that observed in the studied area are salinity, alkalinity (sodicity), compaction and water logging .On the other hand water erosion because of sea rise is assessed. The obtained data showed that, areas that were affected by compaction increment have been spatially enlarged by 40.9 % and those affected by compaction decrease have been spatially reduced by 22.6 % of the total area, meanwhile areas that have been unchanged were estimated by 36.5% of the total area. The areas that were affected by water logging increase have been spatially enlarged by 52.2 % and those affected by water logging decrease have been spatially reduced by 10.1 % of the total area, meanwhile the areas which have been unchanged were represented by 37.7 % of the total area. Areas that were affected by salinity increase have been spatially enlarged by 31.4 % of the total area and those affected by salinity decrease have been reduced by 43.3 % of the total area. An area represented by 25.2 % of the total area has been unchanged. Alkalinization (sodicity) was expressed by the exchangeable sodium percentage (ESP).Areas that were affected by sodicity increase have been spatially enlarged by 33.7 %, meanwhile those affected by sodicity decrease have been spatially reduced by 33.6 % of the total area. An area represented by 32.6 % of the total area has been unchanged

  15. Identification of soil bacteria able to degrade phenanthrene bound to a hydrophobic sorbent in situ

    Energy Technology Data Exchange (ETDEWEB)

    Regonne, Raïssa Kom [CEA, DSV/iRTSV, Chimie et Biologie des Métaux, 38054, Grenoble cedex 9 (France); Univ. Grenoble Alpes and CNRS, UMR 5249, 38042, Grenoble (France); Laboratoire de Substances Actives et Pollution, ENSAI, Université de Ngaoundéré, BP 455, Ngaoundéré (Cameroon); Martin, Florence [CEA, DSV/iRTSV, Chimie et Biologie des Métaux, 38054, Grenoble cedex 9 (France); Univ. Grenoble Alpes and CNRS, UMR 5249, 38042, Grenoble (France); Mbawala, Augustin [Laboratoire de Microbiologie, ENSAI, Université de Ngaoundéré, BP 455, Ngaoundéré (Cameroon); Ngassoum, Martin Benoît [Laboratoire de Substances Actives et Pollution, ENSAI, Université de Ngaoundéré, BP 455, Ngaoundéré (Cameroon); Jouanneau, Yves [CEA, DSV/iRTSV, Chimie et Biologie des Métaux, 38054, Grenoble cedex 9 (France); Univ. Grenoble Alpes and CNRS, UMR 5249, 38042, Grenoble (France)

    2013-09-15

    Efficient bioremediation of PAH-contaminated sites is limited by the hydrophobic character and poor bioavailability of pollutants. In this study, stable isotope probing (SIP) was implemented to track bacteria that can degrade PAHs adsorbed on hydrophobic sorbents. Temperate and tropical soils were incubated with {sup 13}C-labeled phenanthrene, supplied by spiking or coated onto membranes. Phenanthrene mineralization was faster in microcosms with PAH-coated membranes than in microcosms containing spiked soil. Upon incubation with temperate soil, phenanthrene degraders found in the biofilms that formed on coated membranes were mainly identified as Sphingomonadaceae and Actinobacteria. In the tropical soil, uncultured Rhodocyclaceae dominated degraders bound to membranes. Accordingly, ring-hydroxylating dioxygenase sequences recovered from this soil matched PAH-specific dioxygenase genes recently found in Rhodocyclaceae. Hence, our SIP approach allowed the detection of novel degraders, mostly uncultured, which differ from those detected after soil spiking, but might play a key role in the bioremediation of PAH-polluted soils. -- Highlights: •Soil bacteria with the ability to degrade sorbent-bound PAHs were investigated. •In soil, membrane-bound phenanthrene was readily mineralized. •PAH degraders found in biofilms were different in temperate and tropical soils. •Uncultured Rhodocyclaceae were dominant phenanthrene degraders in the tropical soil. •PAH-specific ring-hydroxylating dioxygenase sequences were identified in soil DNA. -- Bacteria able to degrade PAHs bound to a hydrophobic sorbent were mainly identified as uncultured Rhodocyclaceae and Sphingomonadaceae in polluted soils from tropical and temperate area, respectively.

  16. Management-induced Soil Structure Degradation: Organic Matter Depletion and Tillage

    OpenAIRE

    Kay, B.D.; Munkholm, L.J.

    2004-01-01

    Soil structure is an important element of soil quality since changes in structural characteristics can cause changes in the ability of soil to fulfil different functions and services. Emphasis in this chapter is placed on the role of soil structure in biological productivity of agroecosystems. Combinations of management practices in which the extent of the degradation of soil structure caused by one practice is balanced or exceeded by the extent of regeneration by other practices will help su...

  17. Impact of electrochemical treatment of soil washing solution on PAH degradation efficiency and soil respirometry.

    Science.gov (United States)

    Mousset, Emmanuel; Huguenot, David; van Hullebusch, Eric D; Oturan, Nihal; Guibaud, Gilles; Esposito, Giovanni; Oturan, Mehmet A

    2016-04-01

    The remediation of a genuinely PAH-contaminated soil was performed, for the first time, through a new and complete investigation, including PAH extraction followed by advanced oxidation treatment of the washing solution and its recirculation, and an analysis of the impact of the PAH extraction on soil respirometry. The study has been performed on the remediation of genuine PAH-contaminated soil, in the following three steps: (i) PAH extraction with soil washing (SW) techniques, (ii) PAH degradation with an electro-Fenton (EF) process, and (iii) recirculation of the partially oxidized effluent for another SW cycle. The following criteria were monitored during the successive washing cycles: PAH extraction efficiency, PAH oxidation rates and yields, extracting agent recovery, soil microbial activity, and pH of soil. Two representative extracting agents were compared: hydroxypropyl-beta-cyclodextrin (HPCD) and a non-ionic surfactant, Tween(®) 80. Six PAH with different numbers of rings were monitored: acenaphthene (ACE), phenanthrene (PHE), fluoranthene (FLA), pyrene (PYR), benzo(a)pyrene (BaP), and benzo(g,h,i)perylene (BghiP). Tween(®) 80 showed much better PAH extraction efficiency (after several SW cycles) than HPCD, regardless of the number of washing cycles. Based on successive SW experiments, a new mathematical relation taking into account the soil/water partition coefficient (Kd*) was established, and could predict the amount of each PAH extracted by the surfactant with a good correlation with experimental results (R(2) > 0.975). More HPCD was recovered (89%) than Tween(®) 80 (79%), while the monitored pollutants were completely degraded (>99%) after 4 h and 8 h, respectively. Even after being washed with partially oxidized solutions, the Tween(®) 80 solutions extracted significantly more PAH than HPCD and promoted better soil microbial activity, with higher oxygen consumption rates. Moreover, neither the oxidation by-products nor the acidic media (p

  18. Strains of the soil fungus Mortierella show different degradation potentials for the phenylurea herbicide diuron.

    Science.gov (United States)

    Ellegaard-Jensen, Lea; Aamand, Jens; Kragelund, Birthe B; Johnsen, Anders H; Rosendahl, Søren

    2013-11-01

    Microbial pesticide degradation studies have until now mainly focused on bacteria, although fungi have also been shown to degrade pesticides. In this study we clarify the background for the ability of the common soil fungus Mortierella to degrade the phenylurea herbicide diuron. Diuron degradation potentials of five Mortierella strains were compared, and the role of carbon and nitrogen for the degradation process was investigated. Results showed that the ability to degrade diuron varied greatly among the Mortierella strains tested, and the strains able to degrade diuron were closely related. Degradation of diuron was fastest in carbon and nitrogen rich media while suboptimal nutrient levels restricted degradation, making it unlikely that Mortierella utilize diuron as carbon or nitrogen sources. Degradation kinetics showed that diuron degradation was followed by formation of the metabolites 1-(3,4-dichlorophenyl)-3-methylurea, 1-(3,4-dichlorophenyl)urea and an hitherto unknown metabolite suggested to be 1-(3,4-dichlorophenyl)-3-methylideneurea.

  19. Strains of the soil fungus Mortierella show different degradation potentials for the phenylurea herbicide diuron

    DEFF Research Database (Denmark)

    Ellegaard-Jensen, Lea; Aamand, Jens; Kragelund, Birthe Brandt

    2013-01-01

    Microbial pesticide degradation studies have until now mainly focused on bacteria, although fungi have also been shown to degrade pesticides. In this study we clarify the background for the ability of the common soil fungus Mortierella to degrade the phenylurea herbicide diuron. Diuron degradation...... potentials of five Mortierella strains were compared, and the role of carbon and nitrogen for the degradation process was investigated. Results showed that the ability to degrade diuron varied greatly among the Mortierella strains tested, and the strains able to degrade diuron were closely related....... Degradation of diuron was fastest in carbon and nitrogen rich media while suboptimal nutrient levels restricted degradation, making it unlikely that Mortierella utilize diuron as carbon or nitrogen sources. Degradation kinetics showed that diuron degradation was followed by formation of the metabolites 1...

  20. Effect of Polylactic Acid-Degradable Film Mulch on Soil Temperature and Cotton Yield

    Directory of Open Access Journals (Sweden)

    ZHANG Ni

    2016-03-01

    Full Text Available Concern on biodegradable plastic film is increasing because of pollution problems caused by the plastic films currently used. The objective of this field experiment is to evaluate the effect of two thicknesses of polyactic acid-degradable film on soil temperature and cotton yield. The results showed that small holes appeared in the polyactic acid-degradable film at 17~22 d after it was installed. Burst period appeared about 60 d after installation. Splits were observed in the polyactic acid-degradable film at 130 d after installation. Soil temperatures rose slowly under polyactic acid-degradable film during the cotton seedling stage. Daytime soil temperatures were 0.8℃ and 6.2℃ lower under 18μm and 15μm thick polyactic acid-degradable film than non-degradable plastic film(CK, respectively. Nighttime soil temperatures under the polyactic acid-degradable film were about 1℃ warmer than CK. There was no significant difference in cotton yields between the 18μm polyactic acid degradable film treatment and CK. In contrast, yields in the 15μm degradable plastic film treatment were 8.9% less than that in CK. This study indicated that 18μm polyactic acid degradable plastic film had good degradability and no negative effect on cotton growth. The 18μm polyactic acid degradable plastic film can replace ordinary plastic film in agricultural production.

  1. Heavy metals content in degraded agricultural soils of a mountain region related to soil properties

    Science.gov (United States)

    Navarro-Pedreño, José; Belén Almendro-Candel, María; Gómez, Ignacio; Jordán, Manuel M.; Bech, Jaume; Zorpas, Antonis

    2017-04-01

    Agriculture has been practiced for long time in Mediterranean regions. Intensive agriculture and irrigation have developed mainly in the valleys and coastal areas. In the mountainous areas, dry farming has been practiced for centuries. Soils have been fertilized using mainly organic amendments. Plants extracted nutrients and other elements like heavy metals presented in soils and agricultural practices modified soil properties that could favor the presence of heavy metals. In this work, it has been checked the content of heavy metals in 100 agricultural soils samples of the NorthWest area of the province of Alicante (Spain) which has been long cultivated with cereals and olive trees, and now soils are abandoned and degraded because of the low agricultural yields. European policy has the aim to improve the sustainable agriculture and recover landscapes of mountain regions. So that, it is important to check the state of the soils (Marques et al. 2007). Soils samples (arable layer) were analyzed determining: pH (1:5, w/v, water extract), equivalent calcium carbonate content, organic matter by Walkley-Black method (Nelson and Sommers 1996), micronutrients (Cu, Fe, Mn, Zn) extracted with DTPA (Lindsay and Norvell, 1978) and measured by atomic absorption spectrometry, and total content of metals (Cd, Cr, Ni, Pb) measured in soil samples after microwave acid digestion (Moral et al. 1996), quantifying the content of metals by ICP analysis. The correlation between soil properties and metals. The results indicated that pH and carbonates are the most important properties of these soils correlated with the metals (both micronutrients and heavy metals). The available micronutrients (all of them) are close correlated with the pH and carbonates in soils. Moreover, heavy metals like Pb and Ni are related to available Mn and Zn. Keywords: pH, carbonates, heavy metals, abandoned soils. References: Lindsay,W.L., andW.A. Norvell. 1978. "Development of a DTPA Soil Test for Zinc, Iron

  2. Distribution, typology and assessment of degraded soils Piedmont Plains Zhetysu Ridge, Kazakhstan

    Directory of Open Access Journals (Sweden)

    Maira Kussainova

    2017-04-01

    Full Text Available Identification of land degradation is essential to check the problem and to implement the remedial measures needed. The study area falls under parts of foothill plains Zhetysu Ridge, Kazakhstan, that is an arid region in climate. Recent data on the status of study area refer to the 80s of the last century, and the intensive use of them led to a significant anthropogenic transformation. This study was carried out in 2015-2016 as part of a project aimed to study features and causes of land degradation in foothill plains Zhetysu Ridge, Kazakhstan. Under the conditions of rainfed soil degradation manifests itself in the development of erosion processes, agro depletion of soils, reducing the productivity of agriculture. The use of land for irrigation often accompanied by secondary salinization. In this regard, at present there is need to assess current state of the soil, with the identification of changes in their properties as a result of the impact of various anthropogenic factors and creation of new electronic soil maps and applied the powerful capabilities of advanced remote sensing (RS and geographic information system (GIS techniques to identify the geomorphological units and degradation risk assessment. Satellite imagery in addition to the field and laboratory studies to identify salinity-induced soil degradation was adopted in this study. Morphological, chemical and physical characteristics of soils in degraded sites in foothill plains Zhetysu Ridge, Kazakhstan, were depicted. The main results of a thorough evaluation of soil degradation in foothill plains Zhetysu Ridge, Kazakhstan, are presented. The data revealed that extent of salinity-induced degradation was generally related to some physical properties of soil, uncontrolled livestock grazing and previous soil management practices. These results are useful as the basis for designing soil conservation and restoration programs, as a base line for evaluating the performance of conservation

  3. Soil bacterial diversity in degraded and restored lands of Northeast Brazil.

    Science.gov (United States)

    Araújo, Ademir Sérgio Ferreira; Borges, Clovis Daniel; Tsai, Siu Mui; Cesarz, Simone; Eisenhauer, Nico

    2014-11-01

    Land degradation deteriorates biological productivity and affects environmental, social, and economic sustainability, particularly so in the semi-arid region of Northeast Brazil. Although some studies exist reporting gross measures of soil microbial parameters and processes, limited information is available on how land degradation and restoration strategies influence the diversity and composition of soil microbial communities. In this study we compare the structure and diversity of bacterial communities in degraded and restored lands in Northeast Brazil and determine the soil biological and chemical properties influencing bacterial communities. We found that land degradation decreased the diversity of soil bacteria as indicated by both reduced operational taxonomic unit (OTU) richness and Shannon index. Soils under native vegetation and restoration had significantly higher bacterial richness and diversity than degraded soils. Redundancy analysis revealed that low soil bacterial diversity correlated with a high respiratory quotient, indicating stressed microbial communities. By contrast, soil bacterial communities in restored land positively correlated with high soil P levels. Importantly, however, we found significant differences in the soil bacterial community composition under native vegetation and in restored land, which may indicate differences in their functioning despite equal levels of bacterial diversity.

  4. The degradation of [14C] parathion in two Brazilian soils

    International Nuclear Information System (INIS)

    Andrea, M.M. de; Lord, K.A.; Bromilow, R.H.; Ruegg, E.F.

    1980-01-01

    Loss of [ 14 C] parathion from two Brazilian soils was studied by measuring the parathion which could be extracted by a mixture of hexane and propanol and the 14 CO 2 evolved. Recovery of unchanged parathion decreased faster in the soil richer in organic matter (soil 1) from which more radiocarbon was evolved as CO 2 than from the soil poorerin organic matter (soil 2). Evolution of CO 2 from soil 1 decreased rapidly when the soil dried out but little effect of moisture content was observed in soil 2. Radiocarbon remaining in the soils was assayed by combustion after 234 days and the total recovered in soil 1 was 95.6% and, in soil 2,78.7%, sufficient to give almost complete recovery from both soils. (Author) [pt

  5. Degradation of [14C]isofenphos in soil in the laboratory under different soil pH's, temperatures, and moistures

    International Nuclear Information System (INIS)

    Abou-Assaf, N.; Coats, J.R.

    1987-01-01

    The effects of three soil pH's, three soil temperatures, and three soil moistures on [ 14 C]isofenphos degradation were investigated. All three factors interacted strongly and significantly affected the persistence of isofenphos as well as the formation of the degradation products (p less than 1%). Isofenphos degradation was greatest at the higher temperatures 35 0 C greater than 25 0 C greater than 15 0 C (except under alkaline pH's), medium moisture 25% greater than 30% greater than 15%, and in both alkaline (pH = 8) and acidic soils (pH = 6) compared with neutral soil (pH = 7). Isofenphos oxon formation was greatest at higher temperatures 35 0 C compared with 25 0 C and 15 0 C, in acidic soil greater than neutral soil greater than alkaline soil, and under high moisture (30%) compared with the 15% and 22.5% moistures. The formation of soil-bound residues was greatest at higher temperatures 35 0 C greater than 25 0 C greater than 15 0 C, higher moisture 30% compared with 15% and 22.5%, and in alkaline soil compared with neutral and acidic soils

  6. Relationships between physical-geographical factors and soil degradation on agricultural land.

    Science.gov (United States)

    Bednář, Marek; Šarapatka, Bořivoj

    2018-07-01

    It is a well-known fact that soil degradation is dramatically increasing and currently threatens agricultural soils all around the world. The objective of this study was to reveal the possible connection between soil degradation and seven physical-geographical factors - slope steepness, altitude, elevation differences, rainfall, temperature, soil texture and solar radiation - in the form of threshold values (if these exist), where soil degradation begins and ends. The analysis involved the whole area of the Czech Republic which consists of 13,027 cadasters (78,866 km 2 ). The greatest total degradation threat occurs in areas with slope steepness >7 degrees, average annual temperature 10.54, altitude >766 m a.s.l. Similarly, the results for water erosion, wind erosion, soil compaction, loss of organic matter, acidification and heavy metal contamination were processed. The results enable us to identify the relationships of different levels of threats which could consequently be used in various ways - for classification of threatened areas, for more effective implementation of anti-degradation measures, or purely for a better understanding of the role of physical geographical factors in soil degradation in the Czech Republic, and thus could increase the chances of reducing vulnerability to land degradation not only in the Czech Republic. Copyright © 2018 Elsevier Inc. All rights reserved.

  7. Atrazine and its metabolites degradation in mineral salts medium and soil using an enrichment culture.

    Science.gov (United States)

    Kumar, Anup; Singh, Neera

    2016-03-01

    An atrazine-degrading enrichment culture was used to study degradation of atrazine metabolites viz. hydroxyatrazine, deethylatrazine, and deisopropylatrazine in mineral salts medium. Results suggested that the enrichment culture was able to degrade only hydroxyatrazine, and it was used as the sole source of carbon and nitrogen. Hydroxyatrazine degradation slowed down when sucrose and/or ammonium hydrogen phosphate were supplemented as the additional sources of carbon and nitrogen, respectively. The enrichment culture could degrade high concentrations of atrazine (up to 110 μg/mL) in mineral salts medium, and neutral pH was optimum for atrazine degradation. Further, except in an acidic soil, enrichment culture was able to degrade atrazine in three soil types having different physico-chemical properties. Raising the pH of acidic soil to neutral or alkaline enabled the enrichment culture to degrade atrazine suggesting that acidic pH inhibited atrazine-degrading ability. The study suggested that the enrichment culture can be successfully utilized to achieve complete degradation of atrazine and its persistent metabolite hydroxyatrazine in the contaminated soil and water.

  8. Bioremediation of hydrocarbon degradation in a petroleum-contaminated soil and microbial population and activity determination.

    Science.gov (United States)

    Wu, Manli; Li, Wei; Dick, Warren A; Ye, Xiqiong; Chen, Kaili; Kost, David; Chen, Liming

    2017-02-01

    Bioremediation of hydrocarbon degradation in petroleum-polluted soil is carried out by various microorganisms. However, little information is available for the relationships between hydrocarbon degradation rates in petroleum-contaminated soil and microbial population and activity in laboratory assay. In a microcosm study, degradation rate and efficiency of total petroleum hydrocarbons (TPH), alkanes, and polycyclic aromatic hydrocarbons (PAH) in a petroleum-contaminated soil were determined using an infrared photometer oil content analyzer and a gas chromatography mass spectrometry (GC-MS). Also, the populations of TPH, alkane, and PAH degraders were enumerated by a modified most probable number (MPN) procedure, and the hydrocarbon degrading activities of these degraders were determined by the Biolog (MT2) MicroPlates assay. Results showed linear correlations between the TPH and alkane degradation rates and the population and activity increases of TPH and alkane degraders, but no correlation was observed between the PAH degradation rates and the PAH population and activity increases. Petroleum hydrocarbon degrading microbial population measured by MPN was significantly correlated with metabolic activity in the Biolog assay. The results suggest that the MPN procedure and the Biolog assay are efficient methods for assessing the rates of TPH and alkane, but not PAH, bioremediation in oil-contaminated soil in laboratory. Copyright © 2016 Elsevier Ltd. All rights reserved.

  9. A Modified Soil Quality Index to Assess the Influence of Soil Degradation Processes on Desertification Risk: The Apulia Case

    Directory of Open Access Journals (Sweden)

    Valeria Ancona

    2010-10-01

    Full Text Available Apulia is one of the most prone Italian regions to soil alteration phenomena, due to geographical and climatic conditions and also to human activities’ impact. In this study, in order to investigate regional soil degradation processes, following the “European Directive for Soil Protection”, the ESA’s method has been adopted. It is based on the use of an indicator’s set to assess the desertification risk. This approach simplifies the diagnosis and monitoring of soil degradation processes, defining their status and trend. Special attention has been given to Soil Quality Index (SQI determined by six predisposing indicators (parent material, soil texture, rock fragment, soil depth, drainage and slope grade. The integration in the SQI calculation of two additional soil parameters (organic matter content and soil salinity has been considered particularly significant. In fact, through the evaluation of a so “modified SQI” and the Apulia land use too, it could be possible to assess the role of agriculture management on soil degradation processes, which predisposing regional area to desertification threat. Moreover this approach provides short, but accurate, information thanks to GIS integration, which defines phenomena in detail, offering helpful planning tools.

  10. Methane oxidation and degradation of organic compounds in landfill soil covers

    DEFF Research Database (Denmark)

    Scheutz, Charlotte; Kjeldsen, Peter

    2002-01-01

    High rates of methane oxidation and degradation of the lowed halogenated methanes (TCM and DCM) and HCFCs (HCFC-21 and HCFC-22) were found in an investigation of the oxidation of methane and halogenated organic compunds (HOCs) in landfill gas affected soil. The degradation followed zero-order kin......High rates of methane oxidation and degradation of the lowed halogenated methanes (TCM and DCM) and HCFCs (HCFC-21 and HCFC-22) were found in an investigation of the oxidation of methane and halogenated organic compunds (HOCs) in landfill gas affected soil. The degradation followed zero...

  11. Degradation of soil cyanide by single and mixed cultures of Pseudomonas stutzeri and Bacillus subtilis.

    Science.gov (United States)

    Nwokoro, Ogbonnaya; Dibua, Marie Esther Uju

    2014-03-01

    The aim of this investigation was to study whether certain bacteria could be used for cyanide degradation in soil. The bacteria Pseudomonas stutzeri and Bacillus subtilis were selected based on their good growth in a minimal medium containing 0.8 mg mL-1 potassium cyanide (KCN). In this study we tested their ability to reduce cyanide levels in a medium containing 1.5 mg mL-1 of KCN. Although both microorganisms reduced cyanide levels, Pseudomonas stutzeri was the more effective test organism. Later on, the selected cultures were grown, diluted and their various cell concentrations were used individually and in combination to test their ability of cyanide degradation in soil samples collected around a cassava processing mill. Bacillus subtilis caused degradation of soil cyanide from 0.218 mg g-1 soil immediately with an inoculum concentration of 0.1 (OD600nm) to 0.072 mg g-1 soil after 10 days with an inoculum concentration of 0.6 (OD600nm) implying a 66.9 % reduction. Pseudomonas stutzeri cell concentration of 0.1 (OD600nm) decreased soil cyanide from 0.218 mg g-1 soil initially to 0.061 mg g-1 soil after 10 days with an inoculum concentration of 0.6 (OD600nm) (72 % reduction). The mixed culture of the two bacteria produced the best degradation of soil cyanide from 0.218 mg g-1 soil sample with a combined inoculum concentration of 0.1 (OD600nm) initially to 0.025 mg g-1 soil with a combined inoculum concentration of 0.6 (OD600nm) after 10 days incubation resulting in an 88.5 % degradation of soil cyanide. The analysed bacteria displayed high cyanide degradation potential and may be useful for efficient decontamination of cyanide contaminated sites.

  12. Impact of repeated two-phase olive mill waste application on phosphorus fractionation in a degraded olive grove soil

    International Nuclear Information System (INIS)

    Lopez-Pineiro, A.; Albarran, A.; Flores, S.; Rato, J. M.; Munoz, A.; Cabrera, D.; Pena, D.; Fernandez, S.

    2009-01-01

    Loss of organic matter is one of the main forms of soil degradation in Mediterranean agricultural soils, and external sources of organic matter are required to improve soil properties. the two-phase centrifugation system in the olive-oil extraction industry produces a large amount of olive mill waste sludge (TPOMW) which can be used to add organic C to degraded soils. (Author)

  13. Comparative metagenomic analysis of PAH degradation in soil by a mixed microbial consortium.

    Science.gov (United States)

    Zafra, German; Taylor, Todd D; Absalón, Angel E; Cortés-Espinosa, Diana V

    2016-11-15

    In this study, we used a taxonomic and functional metagenomic approach to analyze some of the effects (e.g. displacement, permanence, disappearance) produced between native microbiota and a previously constructed Polycyclic Aromatic Hydrocarbon (PAH)-degrading microbial consortium during the bioremediation process of a soil polluted with PAHs. Bioaugmentation with a fungal-bacterial consortium and biostimulation of native microbiota using corn stover as texturizer produced appreciable changes in the microbial diversity of polluted soils, shifting native microbial communities in favor of degrading specific populations. Functional metagenomics showed changes in gene abundance suggesting a bias towards aromatic hydrocarbon and intermediary degradation pathways, which greatly favored PAH mineralization. In contrast, pathways favoring the formation of toxic intermediates such as cytochrome P450-mediated reactions were found to be significantly reduced in bioaugmented soils. PAH biodegradation in soil using the microbial consortium was faster and reached higher degradation values (84% after 30 d) as a result of an increased co-metabolic degradation when compared with other mixed microbial consortia. The main differences between inoculated and non-inoculated soils were observed in aromatic ring-hydroxylating dioxygenases, laccase, protocatechuate, salicylate and benzoate-degrading enzyme genes. Based on our results, we propose that several concurrent metabolic pathways are taking place in soils during PAH degradation. Copyright © 2016 Elsevier B.V. All rights reserved.

  14. Degradation of 2,4-DB in Argentinean agricultural soils with high humic matter content.

    Science.gov (United States)

    Cuadrado, Virginia; Merini, Luciano J; Flocco, Cecilia G; Giulietti, Ana M

    2008-01-01

    The dissipation of 4-(2,4-dichlorophenoxy) butyric acid (2,4-DB) in high-humic-matter-containing soils from agricultural fields of the Argentinean Humid Pampa region was studied, employing soil microcosms under different experimental conditions. The added herbicide was dissipated almost completely by soils with and without history of herbicide use by day 28. At 500 ppm, both soils showed the same degradation rates; but at 5-ppm concentration, the chronically exposed soil demonstrated a faster degradation of the herbicide. 2,4-DB addition produced increases in herbicide-degrading bacteria of three and 1.5 orders of magnitude in soils with and without history of herbicide use, respectively, in microcosms with 5 ppm. At 500-ppm concentration, the increase in 2,4-DB degraders was five orders of magnitude after 14 days, independent of the history of herbicide use. No differences were observed in either 2,4-DB degradation rates or in degrader bacteria numbers in the presence and absence of alfalfa plants, in spite of some differential characteristics in patterns of 2,4-DB metabolite accumulation. The main factor affecting 2,4-DB degradation rate would be the history of herbicide use, as a consequence of the adaptation of the indigenous microflora to the presence of herbicides in the field.

  15. Carbon degradation in agricultural soils flooded with seawater after managed coastal realignment

    Science.gov (United States)

    Sjøgaard, Kamilla S.; Treusch, Alexander H.; Valdemarsen, Thomas B.

    2017-09-01

    Permanent flooding of low-lying coastal areas is a growing threat due to climate change and related sea-level rise. An increasingly common solution to protect coastal areas lying below sea level is intentional flooding by "managed coastal realignment". However, the biogeochemical implications of flooding agricultural soils with seawater are still not well understood. We conducted a 1-year mesocosm experiment to investigate microbial carbon degradation processes in soils flooded with seawater. Agricultural soils were sampled on the northern coast of the island Fyn (Denmark) at Gyldensteen Strand, an area that was subsequently flooded in a coastal realignment project. We found rapid carbon degradation to TCO2 1 day after experimental flooding and onwards and microbial sulfate reduction established quickly as an important mineralization pathway. Nevertheless, no free sulfide was observed as it precipitated as Fe-S compounds with Fe acting as a natural buffer, preventing toxic effects of free sulfide in soils flooded with seawater. Organic carbon degradation decreased significantly after 6 months, indicating that most of the soil organic carbon was refractory towards microbial degradation under the anoxic conditions created in the soil after flooding. During the experiment only 6-7 % of the initial soil organic carbon pools were degraded. On this basis we suggest that most of the organic carbon present in coastal soils exposed to flooding through sea-level rise or managed coastal realignment will be permanently preserved.

  16. SOLID-PHASE TREATMENT OF A PENTACHLOROPHENOL- CONTAMINATED SOIL USING LIGNIN-DEGRADING FUNGI

    Science.gov (United States)

    The abilities of three lignin-degrading fungi, Phanerochaete chrysosporium, Phanerochaete sordida, and Trametes hirsuta, to deplete pentachlorophenol (PCP) from soil contaminated with PCP and creosote were evaluated. A total of seven fungal and three control treatments ...

  17. Mitigation of Ricin Contamination in Soils: Sorption and Degradation

    National Research Council Canada - National Science Library

    Zartman, R; Green, C; San Francisco, M; Zak, J; James, W; Boroda, E

    2003-01-01

    .... Soils contain a variety of inorganic minerals, organic matter and microorganisms. Soil inorganic minerals and organic matter are known to effectively sorb a wide variety of compounds, such as pesticides and other potential contaminants...

  18. Effect of charcoal amendment on adsorption, leaching and degradation of isoproturon in soils

    Science.gov (United States)

    Si, Youbin; Wang, Midao; Tian, Chao; Zhou, Jing; Zhou, Dongmei

    2011-04-01

    The effects of charcoal amendment on adsorption, leaching and degradation of the herbicide isoproturon in soils were studied under laboratory conditions. The adsorption data all fitted well with the Freundlich empirical equation. It was found that the adsorption of isoproturon in soils increased with the rate of charcoal amended (correlation coefficient r = 0.957 **, P isoproturon in leachate decreased with the increase of the amount of charcoal addition to soil column, while the retention of isoproturon in soils increased with an increase in the charcoal content of soil samples. Biodegradation was still the most significant mechanism for isoproturon dissipation from soil. Charcoal amendment greatly reduced the biodegradation of isoproturon in soils. The half-lives of isoproturon degradation ( DT50) in soils greatly extended when the rate of added charcoal inceased from 0 to 50 g kg - 1 (for Paddy soil, DT50 values increased from 54.6 to 71.4 days; for Alfisol, DT50 from 16.0 to 136 days; and for Vertisol, DT50 from 15.2 to 107 days). The degradation rate of isoproturon in soils was significantly negatively correlated with the amount of added charcoal. This research suggests that charcoal amendment may be an effective management practice for reducing pesticide leaching and enhancing its persistence in soils.

  19. Changes in Flow and Transport Patterns in Fen Peat as a Result of Soil Degradation

    Science.gov (United States)

    Liu, Haojie; Janssen, Manon; Lennartz, Bernd

    2016-04-01

    The preferential movement of water and transport of substances play an important role in soils and are not yet fully understood especially in degraded peat soils. In this study, we aimed at deducing changes in flow and transport patterns in the course of soil degradation as resulting from peat drainage, using titanium dioxide (TiO2) as a dye tracer. The dye tracer experiments were conducted on columns of eight types of differently degraded peat soils from three sites taken both in vertical and horizontal directions. The titanium dioxide suspension (average particle size of 0.3 μm; 10 g l-1) was applied in a pulse of 40 mm to each soil core. Twenty-four hours after the application of the tracer, cross sections of the soil cores were prepared for photo documentation. In addition, the saturated hydraulic conductivity (Ks) was determined. Preferential flow occurred in all investigated peat types. From the stained soil structural elements, we concluded that undecomposed plant remains are the major preferential flow pathways in less degraded peat. For more strongly degraded peat, bio-pores, such as root and earthworm channels, operated as the major transport domain. Results show that Ks and the effective pore network in less degraded peat soils are anisotropic. With increasing peat degradation, the Ks and cross section of effective pore network decreased. The results also indicate a strong positive relationship between Ks and number of macropores as well as pore continuity. Hence, we conclude that changes in flow and transport pathways as well as Ks with an increasing peat degradation are due to the disintegration of the peat forming plant material and decrement of number and continuity of macropores after drainage.

  20. Sorption, degradation and leaching of pesticides in soils amended with organic matter: A review

    Directory of Open Access Journals (Sweden)

    Fardin Sadegh-Zadeh

    2017-04-01

    Full Text Available The use of pesticides in modern agriculture is unavoidable because they are required to control weeds. Pesticides are poisonous; hence, they are dangerous if misused. Understanding the fate of pesticides will be useful to use them safely. Therefore, contaminations of water and soil resources could be avoided. The fates of pesticides in soils are influenced by their sorption, decomposition and movement. Degradation and leaching of pesticides are control by sorption. Soil organic matter and clay content are main soil constituents that have a high capacity for sorption of pesticides. Addition of organic maters to amend the soils is a usual practice that every year has been done in a huge area of worldwide.  The added organic amendments to the soils affect the fate of pesticides in soils as well. Pesticides fates in different soils are different. The addition of organic matter to soils causes different fates for pesticides as well. It is known from the studies that sorption of non-ionic pesticides by soil in aqueous system is controlled mainly by the organic matter content of the soils. Sorption of pesticides has been reported to increase by amending soils with organic matter. In general, conditions that promote microbial activity enhance the rate of pesticides degradation, and those that inhibit the growth of microorganisms reduce the rate of degradation. Amendment of soils with organic matter may modify leaching of pesticides in soil. Some studies showed that organic matter added to soils reduced pesticides in ground water. Generally, organic amendments induces the restriction of pesticides leaching in soils.

  1. Biogenic volatile organic compounds as a potential stimulator for organic contaminant degradation by soil microorganisms

    International Nuclear Information System (INIS)

    McLoughlin, Emma; Rhodes, Angela H.; Owen, Susan M.; Semple, Kirk T.

    2009-01-01

    The effects of monoterpenes on the degradation of 14 C-2,4-dichlorophenol (DCP) were investigated in soils collected from areas surrounding monoterpene and non-monoterpene-emitting vegetation. Indigenous microorganisms degraded 14 C-2,4-DCP to 14 CO 2 , after 1 d contact time. Degradation was enhanced by prior exposure of the soils to 2,4-DCP for 32 d, increasing extents of mineralisation up to 60%. Monoterpene amendments further enhanced 2,4-DCP degradation, but only following pre-exposure to both 2,4-DCP and monoterpene, with total 2,4-DCP mineralisation extents of up to 71%. Degradation was greatest at the higher monoterpene concentrations (≥1 μg kg -1 ). Total mineralisation extents were similar between concentrations, but higher than the control and the 0.1 μg kg -1 amendment, indicating that increases in monoterpene concentration has a diminishing enhancing effect. We suggest that monoterpenes can stimulate the biodegradation of 2,4-DCP by indigenous soil microorganisms and that monoterpene amendment in soils is an effective strategy for removing organic contaminants. - A amendment of soils with monoterpenes may induce organic contaminant degradation by indigenous soil microorganisms

  2. Wind Erosion Induced Soil Degradation in Northern China: Status, Measures and Perspective

    Directory of Open Access Journals (Sweden)

    Zhongling Guo

    2014-12-01

    Full Text Available Soil degradation is one of the most serious ecological problems in the world. In arid and semi-arid northern China, soil degradation predominantly arises from wind erosion. Trends in soil degradation caused by wind erosion in northern China frequently change with human activities and climatic change. To decrease soil loss by wind erosion and enhance local ecosystems, the Chinese government has been encouraging residents to reduce wind-induced soil degradation through a series of national policies and several ecological projects, such as the Natural Forest Protection Program, the National Action Program to Combat Desertification, the “Three Norths” Shelter Forest System, the Beijing-Tianjin Sand Source Control Engineering Project, and the Grain for Green Project. All these were implemented a number of decades ago, and have thus created many land management practices and control techniques across different landscapes. These measures include conservation tillage, windbreak networks, checkerboard barriers, the Non-Watering and Tube-Protecting Planting Technique, afforestation, grassland enclosures, etc. As a result, the aeolian degradation of land has been controlled in many regions of arid and semiarid northern China. However, the challenge of mitigating and further reversing soil degradation caused by wind erosion still remains.

  3. Monomethylhydrazine degradation and its effect on carbon dioxide evolution and microbial populations in soil

    International Nuclear Information System (INIS)

    Ou, L.T.; Street, J.J.

    1988-01-01

    Monomethylhydrazine (MMH), along with hydrazine and 1,1-dimethylhydrazine are the main components of hydrazine fuels. Information on the fate of MMH in soil and its overall effect on soil microbial activity is not known, though MMH is known to be toxic to a number of soil bacteria. Despite the fact that axenic bacterial cultures are inhibited by the three hydrazines, Ou and Street reported that soil respiration, and total bacterial and fungal populations in soil, were not inhibited by hydrazine at concentrations of 100 μg/g and lower. Even at 500 μg/g, only total bacterial populations in soil were inhibited by the presence of hydrazine. They also reported that hydrazine rapidly disappeared in soil. The authors initiated this study to investigate the effect of MMH on soil microbial activity and on degradation of the chemical in soil

  4. Enhancing crude oil degradation in a sandy soil: Effects of addition ...

    African Journals Online (AJOL)

    This study investigated the effects of the addition of poultry manure alone and in combination with surfactant (Goldcrew or Corexit) and/or alternate carbon substrate (glucose or starch) on crude oil degradation in a sandy soil. With poultry manure alone, optimal crude oil degradation was obtained at a concentration of 4.0% ...

  5. Soil degradation level under particular annual rainfall at Jenawi District– Karanganyar, Indonesia

    Science.gov (United States)

    Herawati, A.; Suntoro; Widijanto, H.; Pusponegoro, I.; Sutopo, N. R.; Mujiyo

    2018-03-01

    The study of the climatic elements such as rainfall is vital for the sustainable development of agriculture at a region. The aims of the study were to evaluate the soil degradation based on the annual rainfall and to determine the key factors which responsible for the soil degradation at in Jenawi Sub-District. The mapping of soil degradation potency is an identification of initial soil condition to discover the potential of the land degradation. The mapping was done by overlaying the map of soil, slope, rainfall and land use with the standard procedures to obtain the value and status of Soil Degradation Potency (SDP). The result showed that SDP in Jenawi District categorized in very low (SDP I) 0.00 ha (0.00%); low (SDP II) 109.01 ha (2.57%); moderate (SDP III) 1,935.92 ha (45.63%); high (SDP IV) 1,959.54 ha (46.19%) and very high (SDP V) 238.08 ha (5.61%). The rainfall is the factor which has the strong correlation with the SDP (r = 0.65, P local soil-land characteristics.

  6. Heavy metals in a degraded soil treated with sludge from water treatment plant

    Directory of Open Access Journals (Sweden)

    Teixeira Sandra Tereza

    2005-01-01

    Full Text Available The application of water treatment sludge (WTS to degraded soil is an alternative for both residue disposal and degraded soil reclaim. This study evaluated effects of the application of water treatment sludge to a Typic Hapludox soil degraded by tin mining in the National Forest of Jamari, State of Rondonia, Brazil, on the content of heavy metals. A completely randomized experimental design with five treatments was used: control (n = 4; chemical control, which received only liming (n = 4; and rates D100, D150 and D200, which corresponded to 100, 150 and 200 mg of N-sludge kg-1 soil (n = 20, respectively. Thirty days after liming, period in which soil moisture was kept at 70% of the retention capacity, soil samples were taken and analyzed for total and extractable Fe, Cu, Mn, Zn, Cd, Pb, Ni, and Cr. The application of WTS increased heavy-metal contents in the degraded soil. Although heavy metals were below their respective critical limits, sludge application onto degraded areas may cause hazardous environmental impact and thus must be monitored.

  7. A Perspective on Water Resources in China. Interactions between Climate Change and Soil Degradation

    Energy Technology Data Exchange (ETDEWEB)

    Tao, Fulu; Lin, Erda [Chinese Academy of Agricultural Sciences, Institute of Agricultural Environment and Sustainable Development, Beijing, 100081 (China); Yokozawa, M.; Hayashi, Y. [National Institute for Agro-Environmental Sciences, 3-1-3 Kannondai, Tsukuba, Ibaraki 305-8604 (Japan)

    2005-01-01

    Water is one of the most critical resources in China. Climate change and soil degradation will be two major, interrelated environmental challenges faced by managers of water resources in coming decades. In this study, we used a water-balance model and updated databases to assess the interacting impacts of climate change and soil degradation on China's future water resources. We plotted the spatial pattern of changes in actual and potential evapotranspiration, soil moisture deficits, and surface runoff across China in the 2020s using a resolution of 0.5{sup o} latitude and longitude under scenarios based on climate change, soil degradation, and a combination of the two. The results showed that climate change would affect the magnitude and spatial pattern of water resources on a national scale. Some regions in central, southwestern, and northeastern China would become more vulnerable to disastrous drought and floods as a result of soil degradation. Under the combined impacts of climate change and soil degradation, soil moisture deficits would increase most in central, western, and southwestern China; surface runoff would increase most in southeastern China. More detailed process-based models are needed to capture feedback mechanisms more effectively.

  8. How far can we prevent further physical soil degradation in the future?

    Science.gov (United States)

    Horn, Rainer

    2017-04-01

    Arable as well as forest soils are exposed to increasing external stresses, which coincide with a further and deeper reaching soil degradation, which may result in an aggravation of hydraulic, gaseous, thermal but also physicochemical and chemical soil functions. The decline coincides with a simultaneous reduction in useable land areas and worsens food production amongst others. Therefore, it is mandatory, that stable soil structure from the surface down to depth prevents soil compaction, sustains water infiltration, reduces rates of soil erosion by water and wind in each case to the minimum possible under the soil, terrain, land use, and climatic conditions in which the soils occur. It improves organic carbon storage in soils and optimizes microbial activity and functions. These benefits coincide with sustainable soil properties and soil management systems, which prevent - deep mechanical stress propagation which can cause irreversible soil deformation, - loss of surface soil layers with coinciding organic and mineral nutrient pool available for microbial processing and plant uptake, - Truncation of soil horizons, or damage on private and public infrastructures (roads, houses) and downstream fields. In order to prevent negative impacts on soils, it is recommended, that A) concerning prevention of soil compaction - stresses applied to soils shall not exceed the mechanical soil stability to maintain the actual functioning of chemical, physical and biological processes and to utilize their resilience (i.e. the elasticity), - land use management strategies have to be related to the actual soil properties in order to optimize plant growth, yield, filtering and buffering of infiltrating water, and carbon sequestration. B) soil erosion by - water, wind, and tillage is counteracted by an adequate surface soil stability including a site specific residue management (e.g. conservation tillage), controlled traffic and harvesting, ecological grassland use strategies (e

  9. Laboratory studies of the degradation of chloropyrifos pesticide in soils supplemented by the fungus Phanerochaete chrysosporium

    International Nuclear Information System (INIS)

    Lopera Mesa, Margarita Maria; Penuela Mesa, Gustavo Antonio; Dominguez Gual, Maria Carolina; Mejia Zapata, Gloria Maria

    2005-01-01

    Degradation of the insecticide chloropyrifos was investigated in sterilized soil samples supplemented by the white rot basidiomycetes Phanerochaete chrysosporium. Degradation rates were measured during 21-day incubation at pesticide concentrations of 0,95, 5,3, and 9,41 μ/g. Phanerochaete chrysosporium showed ability to biodegrade the insecticide in values of 96,3%, 82,4% and 62,2%, respectively, followed by rapid degradation at low initial concentration of chloropyrifos

  10. Strong Impact on the Polycyclic Aromatic Hydrocarbon (PAH)-Degrading Community of a PAH-Polluted Soil but Marginal Effect on PAH Degradation when Priming with Bioremediated Soil Dominated by Mycobacteria

    DEFF Research Database (Denmark)

    Johnsen, Anders R.; Schmidt, Stine; Hybholdt, Trine K.

    2007-01-01

    Bioaugmentation of soil polluted with polycyclic aromatic hydrocarbons (PAHs) is often disappointing because of the low survival rate and low activity of the introduced degrader bacteria. We therefore investigated the possibility of priming PAH degradation in soil by adding 2% of bioremediated soil...... with a high capacity for PAH degradation. The culturable PAH-degrading community of the bioremediated primer soil was dominated by Mycobacterium spp. A microcosm containing pristine soil artificially polluted with PAHs and primed with bioremediated soil showed a fast, 100- to 1,000-fold increase in numbers...... of culturable phenanthrene-, pyrene-, and fluoranthene degraders and a 160-fold increase in copy numbers of the mycobacterial PAH dioxygenase gene pdo1. A nonpolluted microcosm primed with bioremediated soil showed a high rate of survival of the introduced degrader community during the 112 days of incubation...

  11. Effect of dairy manure rate and the stabilization time of amended soils on atrazine degradation.

    Science.gov (United States)

    Aguilera, Paula; Briceño, Gabriela; Candia, Maribel; Mora, Maria de la Luz; Demanet, Rolando; Palma, Graciela

    2009-10-01

    The application rate of liquid cow manure (LCM) in the field and the stabilization time of amended soils before application of pre-plant herbicides are factors that determine their efficiency. This study includes evaluation of residual atrazine (2-chloro-4-ethylamino-6-isopropylamino-1,3,5-triazine) in soil and amended soils with equivalent rate of 100,000; 200,000; and 300,000 L ha(-1) of LCM and the effect of pre-incubation time of amended soils on atrazine degradation. The study was carried out under controlled conditions using an Andisol with previous historical application of atrazine. The respiratory activity and fluorescein diacetate (FDA) studies indicated that the time necessary for stabilization of amended soils is over 20-30 d. During the measurement of respiratory and FDA activity, no significant differences were observed when atrazine was applied. The half-life of atrazine ranged from 5 to 8d and the relative distribution of degradation products seem to be affected by the application of LCM. The pre-incubation time of amended soil and LCM dose would not affect atrazine degradation rate, when the soil has a history of herbicide application. However, repeated applications of LCM in a long period of time could change the soil pH and increase the content of dissolved organic carbon (DOC) which could further contribute to a faster degradation of atrazine. Both effects would reduce the effectiveness of atrazine in weed control.

  12. Degradation and adsorption of tralkoxydim in Chinese soils and water-sediment environments.

    Science.gov (United States)

    Wu, Wen Zhu; Shan, Zheng Jun; Kong, De Yang; He, Jian

    2017-06-01

    Tralkoxydim is a cyclohexanedione herbicide primarily used for gramineous weed control in China. In this paper, we present results of a tralkoxydim laboratory environmental fate study characterizing its degradation, adsorption, and mobility behavior in three different soils and two water-sediment systems (river and lake) in China. Degradation half-life of tralkoxydim in soil under aerobic conditions was 5.1, 7.7, and 7.9 days in Jiangxi red soil, Taihu paddy soil, and Northeast China black soil, respectively. Under anaerobic and flooding conditions, half-life values were 6.2, 15.1, and 19.8 days for the same three soils, respectively. Soil pH was the major factor effecting tralkoxydim degradation. In the aerobic water-sediment experiments, tralkoxydim degraded faster in the river system (total system half-life 43.3 days) than the lake system (total system half-life 99.0 days). Correspondingly, its anaerobic degradation half-life values were 46.2 and 53.3 days for the river and lake systems, respectively. Tralkoxydim adsorption in the three soils was found to follow the empirical Freundlich isotherm. The adsorption coefficient (K d ) was 8.60, 1.00, and 1.57 for Jiangxi red soil, Taihu paddy soil, and Northeast China black soil, respectively. Soil pH was the major factor effecting tralkoxydim adsorption. Adsorption free energy change was less than 40 kJ mol -1 in all three soils, indicating a physical mechanism in the process. Thin-layer chromatography (TLC) tests showed that relative to the solvent transport to 11.5 cm, the travel distance of tralkoxydim was 8-10 cm in the three soils, corresponding Rf values at 0.05, 0.35, and 0.75 for Jiangxi red soil, Taihu paddy soil, and Northeast China black soil, respectively. Results of this work suggest that under alkaline conditions, tralkoxydim adsorption becomes smaller; thus, assessments on its mobility and potential groundwater impact should focus on these soil types.

  13. Degradation of roxarsone in a silt loam soil and its toxicity assessment.

    Science.gov (United States)

    Liang, Tengfang; Ke, Zhengchen; Chen, Qing; Liu, Li; Chen, Guowei

    2014-10-01

    The land application of poultry or swine litter, containing large amounts of roxarsone, causes serious arsenic pollution in soil. Understanding biotransformation process of roxarsone and its potential risks favors proper disposal of roxarsone-contaminated animal litter, yet remains not achieved. We report an experimental study of biotransformation process of roxarsone in a silt loam soil under various soil moisture and temperature conditions, and the toxicity of roxarsone and its products from degradation. Results showed that soil moisture and higher temperature promoted roxarsone degradation, associating with emergent pentavalent arsenic. Analysis of fluorescein diacetate (FDA) hydrolysis activity revealed that roxarsone does not exert acute toxic on soil microbes. With the release of inorganic arsenic, FDA hydrolysis activity was inhibited gradually, as evidenced by ecotoxicological assessment using Photobacterium leiognathi. The results shade new lights on the dynamic roxarsone biotransformation processes in soil, which is important for guiding appropriate disposal of poultry or swine litter in the environment. Copyright © 2014 Elsevier Ltd. All rights reserved.

  14. Enhanced degradation of 14C-HCB in two tropical clay soils using multiple anaerobic–aerobic cycles

    International Nuclear Information System (INIS)

    Orori Kengara, Fredrick; Doerfler, Ulrike; Welzl, Gerhard; Ruth, Bernhard; Munch, Jean Charles; Schroll, Reiner

    2013-01-01

    The aim of the study was to induce and enhance the degradation of hexachlorobenzene (HCB), a highly-chlorinated persistent organic pollutant, in two ecologically different tropical soils: a paddy soil (PS) and a non-paddy soil (FS). The degradation of HCB was enhanced using two anaerobic–aerobic cycles in model laboratory experiments. There was greater degradation of HCB in the PS (half-life of 224 days) relative to the FS (half-life of 286 days). It was further shown that soils amended with compost had higher metabolite concentrations relative to the non-amended soils. In the first cycle, there was little degradation of HCB in both soils. However, in the second cycle, there was enhanced mineralization in the PS under aerobic conditions, with the compost-treated samples showing higher mineralization. There was also extensive volatilization in both soils. The metabolite pattern revealed that the increased mineralization and volatilization was due to the formation of lower chlorinated benzenes. - Highlights: ► Two anaerobic–aerobic cycles enhanced the dissipation of HCB in two tropical soils – a paddy and non-paddy soil. ► The paddy soil was more effective in degrading HCB. ► The non-paddy soil adapted and degraded HCB in the second anaerobic–aerobic cycle. ► An additional carbon source enhanced degradation and mineralisation of HCB in both soils. - Two anaerobic–aerobic cycles enhance the degradation of HCB in two ecologically different tropical clay soils.

  15. Microbial degradation of street dust polycyclic aromatic hydrocarbons in microcosms simulating diffuse pollution of urban soil

    DEFF Research Database (Denmark)

    Johnsen, Anders R; de Lipthay, Julia R; Sørensen, Søren J

    2006-01-01

    Diffuse pollution with polycyclic aromatic hydrocarbons (PAHs) of topsoil in urban regions has caused increasing concerns in recent years. We simulated diffuse pollution of soil in microcosms by spiking sandy topsoil (A-horizon) and coarse, mineral subsoil (C-horizon) with street dust (PM63...... for the persistence and low bioaccessibility of 5- and 6-ring PAHs in diffusely polluted soil.......) isolated from municipal street sweepings from central Copenhagen. The microbial communities adapted to PAH degradation in microcosms spiked with street dust in both A-horizon and C-horizon soils, in spite of low PAH-concentrations. The increased potential for PAH degradation was demonstrated on several...

  16. Evaluation of the potential of pentachlorophenol degradation in soil by pulsed corona discharge plasma from soil characteristics.

    Science.gov (United States)

    Wang, Tie Cheng; Lu, Na; Li, Jie; Wu, Yan

    2010-04-15

    Chlorinated organics are frequently found as harmful soil contaminants and persisted for extended periods of time. A novel approach, named pulsed corona discharge plasma (PCDP), was employed for the degradation of pentachlorophenol (PCP) in soil. Experimental results showed that 87% of PCP could be smoothly removed in 60 min. Increasing pulse voltage, enhancing soil pH, lowering humic acid (HA) in soil and reducing granular size of the soil were found to be favorable for PCP degradation efficiency. Oxidation and physical processes simultaneously contributed to PCP removal in soil and ozone was the main factor in PCDP treatment. C-Cl bonds in PCP were cleaved during PCDP treatment by Fourier transform infrared spectroscopy (FTIR) analysis. The mineralization of PCP was confirmed by total organic carbon (TOC) and dechlorination analyses. The main intermediate products such as tetrachlorocatechol, tetrachlorohydroquinone, acetic acid, formic acid, and oxalic acid were identified by HPLC/MS and ion chromatography. A possible pathway of PCP degradation in soil in such a system was proposed.

  17. Distribution of Anaerobic Hydrocarbon-Degrading Bacteria in Soils from King George Island, Maritime Antarctica.

    Science.gov (United States)

    Sampaio, Dayanna Souza; Almeida, Juliana Rodrigues Barboza; de Jesus, Hugo E; Rosado, Alexandre S; Seldin, Lucy; Jurelevicius, Diogo

    2017-11-01

    Anaerobic diesel fuel Arctic (DFA) degradation has already been demonstrated in Antarctic soils. However, studies comparing the distribution of anaerobic bacterial groups and of anaerobic hydrocarbon-degrading bacteria in Antarctic soils containing different concentrations of DFA are scarce. In this study, functional genes were used to study the diversity and distribution of anaerobic hydrocarbon-degrading bacteria (bamA, assA, and bssA) and of sulfate-reducing bacteria (SRB-apsR) in highly, intermediate, and non-DFA-contaminated soils collected during the summers of 2009, 2010, and 2011 from King George Island, Antarctica. Signatures of bamA genes were detected in all soils analyzed, whereas bssA and assA were found in only 4 of 10 soils. The concentration of DFA was the main factor influencing the distribution of bamA-containing bacteria and of SRB in the analyzed soils, as shown by PCR-DGGE results. bamA sequences related to genes previously described in Desulfuromonas, Lautropia, Magnetospirillum, Sulfuritalea, Rhodovolum, Rhodomicrobium, Azoarcus, Geobacter, Ramlibacter, and Gemmatimonas genera were dominant in King George Island soils. Although DFA modulated the distribution of bamA-hosting bacteria, DFA concentration was not related to bamA abundance in the soils studied here. This result suggests that King George Island soils show functional redundancy for aromatic hydrocarbon degradation. The results obtained in this study support the hypothesis that specialized anaerobic hydrocarbon-degrading bacteria have been selected by hydrocarbon concentrations present in King George Island soils.

  18. Associations of Pseudomonas species and forage grasses enhance degradation of chlorinated benzoic acids in soil

    Energy Technology Data Exchange (ETDEWEB)

    Siciliano, S. D.

    1998-12-01

    Using chlorinated benzoic acid (CBA) as a model compound, this study attempted to show that microorganisms and plants can be used as bioremediation agents to clean up contaminated soil sites in a cost effective and environmentally friendly manner. CBA was used because it is present in soils contaminated with polychlorinated biphenyls (PCBs), or chlorinated pesticides. Sixteen forage grasses were screened in combination with 12 bacterial inoculants for their ability to promote the degradation of CBA in soil. Five associations of plants and bacteria were found to degrade CBA to a greater extent than plants without bacterial inoculants. Bacterial inoculants were shown to stimulate CBA degradation by altering the microbial community present on the root surface and thereby increasing the ability of this community to degrade CBA.

  19. Fate of CL-20 in sandy soils: Degradation products as potential markers of natural attenuation

    International Nuclear Information System (INIS)

    Monteil-Rivera, Fanny; Halasz, Annamaria; Manno, Dominic; Kuperman, Roman G.; Thiboutot, Sonia; Ampleman, Guy; Hawari, Jalal

    2009-01-01

    Hexanitrohexaazaisowurtzitane (CL-20) is an emerging explosive that may replace the currently used explosives such as RDX and HMX, but little is known about its fate in soil. The present study was conducted to determine degradation products of CL-20 in two sandy soils under abiotic and biotic anaerobic conditions. Biotic degradation was prevalent in the slightly acidic VT soil, which contained a greater organic C content, while the slightly alkaline SAC soil favored hydrolysis. CL-20 degradation was accompanied by the formation of formate, glyoxal, nitrite, ammonium, and nitrous oxide. Biotic degradation of CL-20 occurred through the formation of its denitrohydrogenated derivative (m/z 393 Da) while hydrolysis occurred through the formation of a ring cleavage product (m/z 156 Da) that was tentatively identified as CH 2 =N-C(=N-NO 2 )-CH=N-CHO or its isomer N(NO 2 )=CH-CH=N-CO-CH=NH. Due to their chemical specificity, these two intermediates may be considered as markers of in situ attenuation of CL-20 in soil. - Two key intermediates of CL-20 degradation are potential markers of its natural attenuation in soil

  20. Use of mycelia as paths for the isolation of contaminant‐degrading bacteria from soil

    Science.gov (United States)

    Furuno, Shoko; Remer, Rita; Chatzinotas, Antonis; Harms, Hauke; Wick, Lukas Y.

    2012-01-01

    Summary Mycelia of fungi and soil oomycetes have recently been found to act as effective paths boosting bacterial mobility and bioaccessibility of contaminants in vadose environments. In this study, we demonstrate that mycelia can be used for targeted separation and isolation of contaminant‐degrading bacteria from soil. In a ‘proof of concept’ study we developed a novel approach to isolate bacteria from contaminated soil using mycelia of the soil oomycete Pythium ultimum as translocation networks for bacteria and the polycyclic aromatic hydrocarbon naphthalene (NAPH) as selective carbon source. NAPH‐degrading bacterial isolates were affiliated with the genera Xanthomonas, Rhodococcus and Pseudomonas. Except for Rhodococcus the NAPH‐degrading isolates exhibited significant motility as observed in standard swarming and swimming motility assays. All steps of the isolation procedures were followed by cultivation‐independent terminal 16S rRNA gene terminal fragment length polymorphism (T‐RFLP) analysis. Interestingly, a high similarity (63%) between both the cultivable NAPH‐degrading migrant and the cultivable parent soil bacterial community profiles was observed. This suggests that mycelial networks generally confer mobility to native, contaminant‐degrading soil bacteria. Targeted, mycelia‐based dispersal hence may have high potential for the isolation of bacteria with biotechnologically useful properties. PMID:22014110

  1. Degradation of dibutyl phthalate in two contrasting agricultural soils and its long-term effects on soil microbial community.

    Science.gov (United States)

    Cheng, Jinjin; Liu, Yanai; Wan, Qun; Yuan, Li; Yu, Xiangyang

    2018-06-04

    Due to its widespread application and large-scale production, dibutyl phthalate (DBP) has become one of the most frequently identified phthalic acid esters (PAEs) in soils. The fate of DBP and its effects on microbial communities in soils with contrasting properties have seldom been studied. In this study, the degradation of DBP and its long-term effects on the soil microbial community were investigated in aquic cambisols and udic ferrosols. The half-lives of DBP in aquic cambisols and udic ferrosols were found to be 0.286-1.41 days and 0.870-20.4 days, respectively, indicating that DBP was degraded faster in aquic cambisols. In addition, the degradation of DBP in aquic cambisols was less vulnerable to adverse incubation conditions, including high DBP concentration, low temperature and low moisture. These results can be ascribed to the higher microbial abundance and activity in aquic cambisols than in udic ferrosols. During DBP degradation, the toxic metabolite monobutyl phthalate (MBP) was present only transiently and did not accumulate in the two soils. After 60 days of incubation, the degradation-resistant DBP residue concentrations were as high as 1.10 and 1.34 mg/kg, and the relative abundance of 8.51%-12.9% of bacterial genera and 5.59%-6.02% of fungal genera was significantly disturbed by DBP in both test soils. The results from this study highlight the need to comprehensively evaluate the environmental risks of degradation-resistant DBP residues and the impact of DBP contamination on soil microbial functions. Copyright © 2018. Published by Elsevier B.V.

  2. Human-induced geomorphic change across environmental gradients

    Science.gov (United States)

    Vanacker, V.; Molina, A.; Bellin, N.; Christl, M.

    2016-12-01

    Human-induced land cover changes are causing important adverse effects on the ecological services rendered by mountain ecosystems, and the number of case-studies of the impact of humans on soil erosion and sediment yield has mounted rapidly. Anthropogenic disturbance of natural vegetation can profoundly alter the physical, chemical and biological processes within soils. Rapid removal of topsoil during intense farming can result in an imbalance between soil production through chemical weathering and physical soil erosion, with direct implications on nutrient cycling, soil fertility and agricultural production. In this study, we present a conceptual model for assessing human-induced erosion for a wide variety of environmental settings and pose that human-induced geomorphic change cannot be assessed solely based on modern erosion rates as natural or baseline erosion rates can be important in e.g. mountainous terrain. As such, we assess the vulnerability of a given ecosystem to human-induced land cover change by quantifying the change in catchment-wide erosion rates resulting from anthropogenic changes in vegetation cover. Human-induced erosion is here approximated by the ratio of the total specific sediment yield to the natural erosional mass flux, and is dimensionless. The conceptual model is applied to three contrasting environmental settings where data on soil production, physical soil erosion and long-term denudation are available: the tropical Andes, subtropical southern Brazil, and semi-arid Spanish Cordillera. The magnitude of human-induced geomorphic change strongly differs between the three regions. The data suggest that the sensitivity to human-induced erosion is ecosystem dependent, and related to soil erosivity and potential vegetation cover disturbances as a result of human impact. It may therefore be expected that the potential for erosion regulation is larger in well-vegetated ecosystem where strong differences may exist in vegetation cover between

  3. Sorption and desorption of indaziflam degradates in several agricultural soils

    Directory of Open Access Journals (Sweden)

    Diego Gonçalves Alonso

    2016-04-01

    Full Text Available ABSTRACT Processes regulating pesticide fate in the environment are influenced by the physicochemical properties of pesticides and soils. Sorption and desorption are important processes as they regulate the movement of pesticides in soil. Although sorption-desorption is widely studied for herbicides, studies involving their metabolites in soil are scarce. Sorption and desorption of indaziflam metabolites (indaziflam-triazinediamine (FDAT, indaziflam-triazine-indanone (ITI and indaziflam-carboxilic acid (ICA were investigated in six Brazilian (BRA soils and three United States (USA soils with different physicochemical properties. The Freundlich equation described sorption of the metabolites for all soils (R2 > 0.98; 1/n ~ 1. Sorption order (Kf was ITI > ICA > FDAT. Mean values of Kf,oc were 453, 289, and 81 (BRA and 444, 48, and 48 (USA for metabolites ITI, ICA, and FDAT respectively. Desorption was hysteretic for all metabolites in all soils. These results suggest that these metabolites fall in the classification range of mobile to moderately mobile in soils.

  4. SYSTEMIC APPROACH AND ROUGHNESS APPLICATION TO CAUSE EMERGING PROPERTIES IN THE RESTORATION OF DEGRADED SOILS

    Directory of Open Access Journals (Sweden)

    Juarês José Aumond

    2014-09-01

    Full Text Available http://dx.doi.org/10.5902/1980509815737Based on the general systems theory, an ecological model for the restoration of ecosystems has been developed, which soils are highly degraded, and treating the ecosystem as a complex dynamic system, hyper-sensitive to initial conditions of soil preparation. Assuming that degraded ecosystems are sensitive to initial conditions of soil preparation, the technique of roughness was evaluated (relief variations alternating between concave and convex surfaces to trigger over time emergent properties that accelerate the process of ecological restoration. The degraded ecosystems can be understood as organizationally open systems, as a dissipative structure, in which irreversibly matter and energy flow. The main task in ecological restoration in areas that had the soil degraded is to achieve the internalization of matter and energy to induce the system to organizational closure. The roughness, represented by soil micro-topography is an effective technique in the internalization of matter, retaining water, sediment, organic matter, nutrients and seeds. Variations of relief trigger environmental changes over time in a dynamic and heterogeneous way, which influence the interactions between solar radiation, moisture and nutrients, creating different opportunities for plants and animal species. There must be an oriented concentration to flow structures and processes between the degraded ecosystem (system and the environment (neighborhood. In this approach, a particular concentration on the interrelationships between the system and the environment is dedicated. For ecological restoration, whose area is with degraded soil, such as mining and ranching, a new integrative degraded systemic approach is proposed, in which the roughness of the soil might trigger spatial and temporal patterns and emergent environmental properties due to the hyper-sensitivity to initial conditions of the land preparation.

  5. Metagenomic Functional Potential Predicts Degradation Rates of a Model Organophosphorus Xenobiotic in Pesticide Contaminated Soils

    Directory of Open Access Journals (Sweden)

    Thomas C. Jeffries

    2018-02-01

    Full Text Available Chemical contamination of natural and agricultural habitats is an increasing global problem and a major threat to sustainability and human health. Organophosphorus (OP compounds are one major class of contaminant and can undergo microbial degradation, however, no studies have applied system-wide ecogenomic tools to investigate OP degradation or use metagenomics to understand the underlying mechanisms of biodegradation in situ and predict degradation potential. Thus, there is a lack of knowledge regarding the functional genes and genomic potential underpinning degradation and community responses to contamination. Here we address this knowledge gap by performing shotgun sequencing of community DNA from agricultural soils with a history of pesticide usage and profiling shifts in functional genes and microbial taxa abundance. Our results showed two distinct groups of soils defined by differing functional and taxonomic profiles. Degradation assays suggested that these groups corresponded to the organophosphorus degradation potential of soils, with the fastest degrading community being defined by increases in transport and nutrient cycling pathways and enzymes potentially involved in phosphorus metabolism. This was against a backdrop of taxonomic community shifts potentially related to contamination adaptation and reflecting the legacy of exposure. Overall our results highlight the value of using holistic system-wide metagenomic approaches as a tool to predict microbial degradation in the context of the ecology of contaminated habitats.

  6. Amylase activity of a starch degrading bacteria isolated from soil ...

    African Journals Online (AJOL)

    STORAGESEVER

    2008-09-17

    Sep 17, 2008 ... Key words: Amylase, Bacillus, kitchen waste, starch degrading. INTRODUCTION ... several sources such as plant, animal and microbes. (Kathiresan .... Test. Response of the strain. Gram's staining. +. Shape. Bacilli. Motility. +.

  7. Monitoring soil for sustainable development and land degradation neutrality.

    Science.gov (United States)

    Tóth, Gergely; Hermann, Tamás; da Silva, Manuela Ravina; Montanarella, Luca

    2018-01-04

    The adoption of the 17 sustainable development goals (SDGs) listed in the 2030 Agenda for Sustainable Development by the United Nations urged the scientific community to generate information for planning and monitoring socioeconomic development and the underlying environmental compartments. SDGs 2, 3, 6, 11, 13, 14, and 15 have targets which commend direct consideration of soil resources. There are five groups of SDGs and assigned SDG indicators where soil plays a central role. Frameworks of soil-related sustainable development goals and related indicators which can be monitored in current monitoring schemes are proposed.

  8. Delignification and Enhanced Gas Release from Soil Containing Lignocellulose by Treatment with Bacterial Lignin Degraders.

    Science.gov (United States)

    Rashid, Goran M M; Duran-Pena, Maria Jesus; Rahmanpour, Rahman; Sapsford, Devin; Bugg, Timothy D H

    2017-04-10

    The aim of the study was to isolate bacterial lignin-degrading bacteria from municipal solid waste soil, and to investigate whether they could be used to delignify lignocellulose-containing soil, and enhance methane release. A set of 20 bacterial lignin degraders, including 11 new isolates from municipal solid waste soil, were tested for delignification and phenol release in soil containing 1% pine lignocellulose. A group of 7 strains were then tested for enhancement of gas release from soil containing 1% lignocellulose in small-scale column tests. Using an aerobic pre-treatment, aerobic strains such as Pseudomonas putida showed enhanced gas release from the treated sample, but four bacterial isolates showed 5-10 fold enhancement in gas release in an in situ experiment under microanaerobic conditions: Agrobacterium sp., Lysinibacillus sphaericus, Comamonas testosteroni, and Enterobacter sp.. The results show that facultative anaerobic bacterial lignin degraders found in landfill soil can be used for in situ delignification and enhanced gas release in soil containing lignocellulose. The study demonstrates the feasibility of using an in situ bacterial treatment to enhance gas release and resource recovery from landfill soil containing lignocellulosic waste. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

  9. Soil Degradation, Land Scarcity and Food Security: Reviewing a Complex Challenge

    Directory of Open Access Journals (Sweden)

    Tiziano Gomiero

    2016-03-01

    Full Text Available Soil health, along with water supply, is the most valuable resource for humans, as human life depends on the soil’s generosity. Soil degradation, therefore, poses a threat to food security, as it reduces yield, forces farmers to use more inputs, and may eventually lead to soil abandonment. Unfortunately, the importance of preserving soil health appears to be overlooked by policy makers. In this paper, I first briefly introduce the present situation concerning agricultural production, natural resources, soil degradation, land use and the challenge ahead, to show how these issues are strictly interwoven. Then, I define soil degradation and present a review of its typologies and estimates at a global level. I discuss the importance of preserving soil capital, and its relationship to human civilization and food security. Trends concerning the availability of arable agricultural land, different scenarios, and their limitations, are analyzed and discussed. The possible relation between an increase in a country’s GNP, population and future availability of arable land is also analyzed, using the World Bank’s database. I argue that because of the many sources of uncertainty in the data, and the high risks at stake, a precautionary approach should be adopted when drawing scenarios. The paper ends with a discussion on the key role of preserving soil organic matter, and the need to adopt more sustainable agricultural practices. I also argue that both our relation with nature and natural resources and our lifestyle need to be reconsidered.

  10. Degradation of polycyclic aromatic hydrocarbons by microbial consortia enriched from three soils using two different culture media

    International Nuclear Information System (INIS)

    Wu, Manli; Chen, Liming; Tian, Yongqiang; Ding, Yi; Dick, Warren A.

    2013-01-01

    A consortium composed of many different bacterial species is required to efficiently degrade polycyclic aromatic hydrocarbons (PAH) in oil-contaminated soil. We obtained six PAH-degrading microbial consortia from three oil-contaminated soils using two different isolation culture media. Denaturing gradient gel electrophoresis (DGGE) and sequence analyses of amplified 16s rRNA genes confirmed the bacterial community was greatly affected by both the culture medium and the soil from which the consortia were enriched. Three bacterial consortia enriched using malt yeast extract (MYE) medium showed higher degradation rates of PAHs than consortia enriched using Luria broth (LB) medium. Consortia obtained from a soil and then added back to that same soil was more effective in degrading PAHs than adding, to the same soil, consortia isolated from other, unrelated soils. This suggests that inoculum used for bioremediation should be from the same, or very similar nearby soils, as the soil that is actually being bioremediated. -- Highlights: •Six PAH-degrading microbial consortia were isolated from three oil-contaminated soils. •The bacterial community by 16s rRNA genes was affected by culture media and source soil. •Inoculum should be from the same or similar soil as the soil being bioremediated. -- Bioremediation of oil-contaminated soils was most effective when using inoculum of microbial consortia from the same or similar soil as the soil being bioremediated

  11. Insight in the PCB-degrading functional community in long-term contaminated soil under bioremediation

    Energy Technology Data Exchange (ETDEWEB)

    Petric, Ines; Hrsak, Dubravka; Udikovic-Kolic, Nikolina [Ruder Boskovic Inst., Division for Marine and Environmental Research, Zagreb (Croatia); Fingler, Sanja [Inst. for Medical Research and Occupational Health, Zagreb (Croatia); Bru, David; Martin-Laurent, Fabrice [INRA, Univ. der Bourgogne, Soil and Environmental Microbiology, Dijon (France)

    2011-02-15

    A small-scale bioremediation assay was developed in order to get insight into the functioning of a polychlorinated biphenyl (PCB) degrading community during the time course of bioremediation treatment of a contaminated soil. The study was conducted with the aim to better understand the key mechanisms involved in PCB-removal from soils. Materials and methods Two bioremediation strategies were applied in the assay: (a) biostimulation (addition of carvone as inducer of biphenyl pathway, soya lecithin for improving PCB bioavailability, and xylose as supplemental carbon source) and (b) bioaugmentation with selected seed cultures TSZ7 or Rhodococcus sp. Z6 originating from the transformer station soil and showing substantial PCB-degrading activity. Functional PCB-degrading community was investigated by using molecular-based approaches (sequencing, qPCR) targeting bphA and bphC genes, coding key enzymes of the upper biphenyl pathway, in soil DNA extracts. In addition, kinetics of PCBs removal during the bioremediation treatment was determined using gas chromatography mass spectrometry analyses. Results and discussion bphA-based phylogeny revealed that bioremediation affected the structure of the PCB-degrading community in soils, with Rhodococcus-like bacterial populations developing as dominant members. Tracking of this population further indicated that applied bioremediation treatments led to its enrichment within the PCB-degrading community. The abundance of the PCB-degrading community, estimated by quantifying the copy number of bphA and bphC genes, revealed that it represented up to 0.3% of the total bacterial community. All bioremediation treatments were shown to enhance PCB reduction in soils, with approximately 40% of total PCBs being removed during a 1-year period. The faster PCB reduction achieved in bioaugmented soils suggested an important role of the seed cultures in bioremediation processes. Conclusions The PCBs degrading community was modified in response to

  12. Pasture degradation modifies soil organic matter properties and biochemical functioning in Tibetan grasslands

    Science.gov (United States)

    Spielvogel, Sandra; Steingräber, Laura; Schleuß, Per; Kuzyakov, Yakov; Guggenberger, Georg

    2015-04-01

    Kobresia pastures of the Tibetan Plateau represent the world's largest alpine ecosystem. Moderate husbandry on Kobresia pastures is beneficial for the storage of soil organic carbon (OC), nitrogen (N) and other nutrients and prevents erosion by establishment of sedge-turf root mats with high OC allocation rates below ground. However, undisturbed root mats are affected by freezing and thawing processes, which cause initial ice cracks. As a consequence decomposition of root mat layers will be accelerated and current sedentarization programs with concomitant increased grazing intensity may additionally enhance root mat degradation. Finally, cracks are enlarged by water and wind erosion as well as pika activities until bare soil surface areas without root mat horizons occur. The aim of this study was to understand the impact of the root mat layer on soil organic carbon stabilization and microbial functioning depending on soil depths and to predict future changes (OC, N and nutrient losses, soil microbial functioning in SOM transformation) by overgrazing and climate change. We investigated the mineral soil below Kobresia root mats along a false time degradation sequence ranging from stage 1 (intact root mat) to stage 4 (mats with large cracks and bare soil patches). Vertical gradients of δ13C values, neutral sugar, cutin and suberin contents as well as microbial biomass estimated by total phospholipid fatty acid (PLFA), microbial community composition (PLFA profiles) and activities of six extracellular enzymes involved in the C, N, and P cycle were assessed. Soil OC and N contents as well as C/N ratios indicate an increasing illuviation of topsoil material into the subsoil with advancing root mat degradation. This was confirmed by more negative δ13C values as well as significantly (p ≤ 0.05) increasing contributions of cutin derived hydroxy fatty acids to OC in the subsoils from degradation stages 1 to 4. PLFA profiles were surprisingly similar in the subsoils of

  13. Comparative study of the selective degradations of two enantiomers in the racemate and an enriched concentration of indoxacarb in soils.

    Science.gov (United States)

    Zhang, Yu-Ping; Hu, De-Yu; Ling, Hu-Rong; Zhong, Lei; Huang, An-Xiang; Zhang, Kan-Kan; Song, Bao-An

    2014-09-17

    In this study, selective degradations of the two enantiomers of indoxacarb in the concentrate (2.33S/1R) and racemate (1S/1R) are examined. The absolute configurations of indoxacarb enantiomers were determined using X-ray diffraction. The results showed that in two alkaline soils, the S-(+)-indoxacarb was preferentially degraded in both the concentrate and racemate. In one acid soil, the two enantiomers degraded no-selectivity. In another acid soil and one neutral soil, the R-(-)-indoxacarb was preferentially degraded in both the concentrate and racemate. Indoxacarb enantiomers were configurationally stable in the five soils, and no interconversion was observed during the incubation. Because no significant difference in degradation was observed after samples were sterilized, the observed enantioselectivity may be attributed primarily to microbial activity in soils. The results indicate that the selective degradation behavior was the same for both formulations that were tested.

  14. Assessment of environmental degradation of soil and groundwater ...

    African Journals Online (AJOL)

    Guest

    Comparisons of means with pristine locations in previous studies were ... South, East and West sectors. ... geology of the Benin West Moat-Ekenwan gully area, the soil ... present work and those of Akujieze (2004) and Akujieze and Oteze.

  15. Pathogenic prion protein is degraded by a manganese oxide mineral found in soils

    Science.gov (United States)

    Russo, F.; Johnson, C.J.; McKenzie, D.; Aiken, Judd M.; Pedersen, J.A.

    2009-01-01

    Prions, the aetiological agents of transmissible spongiform encephalopathies, exhibit extreme resistance to degradation. Soil can retain prion infectivity in the environment for years. Reactive soil components may, however, contribute to the inactivation of prions in soil. Members of the birnessite family of manganese oxides (MnO2) rank among the strongest natural oxidants in soils. Here, we report the abiotic degradation of pathogenic prion protein (PrPTSE) by a synthetic analogue of naturally occurring birnessite minerals. Aqueous MnO2 suspensions degraded the PrPTSE as evidenced by decreased immunoreactivity and diminished ability to seed protein misfolding cyclic amplification reactions. Birnessite-mediated PrPTSE degradation increased as a solution's pH decreased, consistent with the pH-dependence of the redox potential of MnO2. Exposure to 5.6 mg MnO2 ml-1 (PrPTSE:MnO2=1 : 110) decreased PrPTSE levels by ???4 orders of magnitude. Manganese oxides may contribute to prion degradation in soil environments rich in these minerals. ?? 2009 SGM.

  16. Degradation of biodegradable plastic mulch films in soil environment by phylloplane fungi isolated from gramineous plants.

    Science.gov (United States)

    Koitabashi, Motoo; Noguchi, Masako T; Sameshima-Yamashita, Yuka; Hiradate, Syuntaro; Suzuki, Ken; Yoshida, Shigenobu; Watanabe, Takashi; Shinozaki, Yukiko; Tsushima, Seiya; Kitamoto, Hiroko K

    2012-08-02

    To improve the biodegradation of biodegradable plastic (BP) mulch films, 1227 fungal strains were isolated from plant surface (phylloplane) and evaluated for BP-degrading ability. Among them, B47-9 a strain isolated from the leaf surface of barley showed the strongest ability to degrade poly-(butylene succinate-co-butylene adipate) (PBSA) and poly-(butylene succinate) (PBS) films. The strain grew on the surface of soil-mounted BP films, produced breaks along the direction of hyphal growth indicated that it secreted a BP-degrading enzyme, and has directly contributing to accelerating the degradation of film. Treatment with the culture filtrate decomposed 91.2 wt%, 23.7 wt%, and 14.6 wt% of PBSA, PBS, and commercially available BP polymer blended mulch film, respectively, on unsterlized soil within 6 days. The PCR-DGGE analysis of the transition of soil microbial community during film degradation revealed that the process was accompanied with drastic changes in the population of soil fungi and Acantamoeba spp., as well as the growth of inoculated strain B47-9. It has a potential for application in the development of an effective method for accelerating degradation of used plastics under actual field conditions.

  17. Soil Organic Carbon Fractions and Stocks Respond to Restoration Measures in Degraded Lands by Water Erosion.

    Science.gov (United States)

    Nie, Xiaodong; Li, Zhongwu; Huang, Jinquan; Huang, Bin; Xiao, Haibing; Zeng, Guangming

    2017-05-01

    Assessing the degree to which degraded soils can be recovered is essential for evaluating the effects of adopted restoration measures. The objective of this study was to determine the restoration of soil organic carbon under the impact of terracing and reforestation. A small watershed with four typical restored plots (terracing and reforestation (four different local plants)) and two reference plots (slope land with natural forest (carbon-depleted) and abandoned depositional land (carbon-enriched)) in subtropical China was studied. The results showed that soil organic carbon, dissolved organic carbon and microbial biomass carbon concentrations in the surface soil (10 cm) of restored lands were close to that in abandoned depositional land and higher than that in natural forest land. There was no significant difference in soil organic carbon content among different topographic positions of the restored lands. Furthermore, the soil organic carbon stocks in the upper 60 cm soils of restored lands, which were varied between 50.08 and 62.21 Mg C ha -1 , were higher than 45.90 Mg C ha -1 in natural forest land. Our results indicated that the terracing and reforestation could greatly increase carbon sequestration and accumulation and decrease carbon loss induced by water erosion. And the combination measures can accelerate the restoration of degraded soils when compared to natural forest only. Forest species almost have no impact on the total amount of soil organic carbon during restoration processes, but can significantly influence the activity and stability of soil organic carbon. Combination measures which can provide suitable topography and continuous soil organic carbon supply could be considered in treating degraded soils caused by water erosion.

  18. Soil Organic Carbon Fractions and Stocks Respond to Restoration Measures in Degraded Lands by Water Erosion

    Science.gov (United States)

    Nie, Xiaodong; Li, Zhongwu; Huang, Jinquan; Huang, Bin; Xiao, Haibing; Zeng, Guangming

    2017-05-01

    Assessing the degree to which degraded soils can be recovered is essential for evaluating the effects of adopted restoration measures. The objective of this study was to determine the restoration of soil organic carbon under the impact of terracing and reforestation. A small watershed with four typical restored plots (terracing and reforestation (four different local plants)) and two reference plots (slope land with natural forest (carbon-depleted) and abandoned depositional land (carbon-enriched)) in subtropical China was studied. The results showed that soil organic carbon, dissolved organic carbon and microbial biomass carbon concentrations in the surface soil (10 cm) of restored lands were close to that in abandoned depositional land and higher than that in natural forest land. There was no significant difference in soil organic carbon content among different topographic positions of the restored lands. Furthermore, the soil organic carbon stocks in the upper 60 cm soils of restored lands, which were varied between 50.08 and 62.21 Mg C ha-1, were higher than 45.90 Mg C ha-1 in natural forest land. Our results indicated that the terracing and reforestation could greatly increase carbon sequestration and accumulation and decrease carbon loss induced by water erosion. And the combination measures can accelerate the restoration of degraded soils when compared to natural forest only. Forest species almost have no impact on the total amount of soil organic carbon during restoration processes, but can significantly influence the activity and stability of soil organic carbon. Combination measures which can provide suitable topography and continuous soil organic carbon supply could be considered in treating degraded soils caused by water erosion.

  19. Monitoring soil for sustainable development and land degradation neutrality

    OpenAIRE

    Tóth, Gergely; Hermann, Tamás; da Silva, Manuela Ravina; Montanarella, Luca

    2018-01-01

    The adoption of the 17 sustainable development goals (SDGs) listed in the 2030 Agenda for Sustainable Development by the United Nations urged the scientific community to generate information for planning and monitoring socioeconomic development and the underlying environmental compartments. SDGs 2, 3, 6, 11, 13, 14, and 15 have targets which commend direct consideration of soil resources. There are five groups of SDGs and assigned SDG indicators where soil plays a central role. Frameworks of ...

  20. Effect of rice straw on the degradation of 14C-parathion in flooded alluvial soil

    International Nuclear Information System (INIS)

    Rajaram, K.P.; Sethunathan, N.

    1975-01-01

    Organic matter, either native or applied, influences the persistence of soil-applied pesticides. The effect of rice straw on the metabolism of parathion in an alluvial soil under flooded condition was investigated. Residues were extracted from the soil at periodic intervals after application of ethoxy 14 C-parathion to rice straw amended and unamended soil employing chloroform-diethyl ether. The radioactivity in the solvent and water fractions were estimated. The activity in the solvent phase decreased more rapidly in the rice straw amended than in unamended soil indicating enhanced degradation of parathion by rice straw amendment. The autoradiograph of thin layer chromatograms of solvent phase revealed the rapid formation of aminoparathion and an unidentified metabolite possessing P-S bond and ethoxy label in amended soil within 3 days. A polar unidentified metabolite was detected in the water phase of the unamended soil at 14 days. (author)

  1. Microbial degradation pathways of the herbicide dichlobenil in soils with different history of dichlobenil-exposure

    International Nuclear Information System (INIS)

    Holtze, Maria S.; Hansen, Hans Christian B.; Juhler, Rene K.; Sorensen, Jan; Aamand, Jens

    2007-01-01

    This is the first detailed study of metabolite production during degradation of the herbicide 2,6-dichlorobenzonitrile (dichlobenil). Degradation of dichlobenil and three potential metabolites: 2,6-dichlorobenzamide (BAM), 2,6-dichlorobenzoic acid (2,6-DCBA) and ortho-chlorobenzamide (OBAM) was studied in soils either previously exposed or not exposed to dichlobenil using a newly developed HPLC method. Dichlobenil was degraded in all four soils; BAM and 2,6-DCBA were only degraded in soils previously exposed to dichlobenil (100% within 35-56 days and 85-100% in 56 days, respectively), and OBAM in all four soils (25-33% removal in 48 days). BAM produced from dichlobenil was either hydrolyzed to 2,6-DCBA or dechlorinated to OBAM, which was further hydrolyzed to ortho-chlorobenzoic acid. BAM was rapidly mineralized in previously exposed soils only. All potential metabolites and the finding that BAM was a dead-end metabolite of dichlobenil in soils not previously exposed to dichlobenil needs to be included in risk assessments of the use of dichlobenil. - BAM produced from dichlobenil was either hydrolyzed to 2,6-DCBA or dechlorinated to OBAM, which was further hydrolyzed to ortho-chlorobenzoic acid

  2. Microbial degradation pathways of the herbicide dichlobenil in soils with different history of dichlobenil-exposure

    Energy Technology Data Exchange (ETDEWEB)

    Holtze, Maria S. [Department of Natural Sciences, Soil and Environmental Chemistry, Royal Veterinary and Agricultural University, Thorvaldsensvej 40, DK-1871 Frederiksberg C (Denmark) and Department of Geochemistry, Geological Survey of Denmark and Greenland, Oster Voldgade 10, DK-1350 Copenhagen K (Denmark) and Section of Genetics and Microbiology, Department of Ecology, Royal Veterinary and Agricultural University, Thorvaldsensvej 40, DK-1871 Frederiksberg C (Denmark)]. E-mail: msh@geus.dk; Hansen, Hans Christian B. [Department of Natural Sciences, Soil and Environmental Chemistry, Royal Veterinary and Agricultural University, Thorvaldsensvej 40, DK-1871 Frederiksberg C (Denmark); Juhler, Rene K. [Department of Geochemistry, Geological Survey of Denmark and Greenland, Oster Voldgade 10, DK-1350 Copenhagen K (Denmark); Sorensen, Jan [Section of Genetics and Microbiology, Department of Ecology, Royal Veterinary and Agricultural University, Thorvaldsensvej 40, DK-1871 Frederiksberg C (Denmark); Aamand, Jens [Department of Geochemistry, Geological Survey of Denmark and Greenland, Oster Voldgade 10, DK-1350 Copenhagen K (Denmark)

    2007-07-15

    This is the first detailed study of metabolite production during degradation of the herbicide 2,6-dichlorobenzonitrile (dichlobenil). Degradation of dichlobenil and three potential metabolites: 2,6-dichlorobenzamide (BAM), 2,6-dichlorobenzoic acid (2,6-DCBA) and ortho-chlorobenzamide (OBAM) was studied in soils either previously exposed or not exposed to dichlobenil using a newly developed HPLC method. Dichlobenil was degraded in all four soils; BAM and 2,6-DCBA were only degraded in soils previously exposed to dichlobenil (100% within 35-56 days and 85-100% in 56 days, respectively), and OBAM in all four soils (25-33% removal in 48 days). BAM produced from dichlobenil was either hydrolyzed to 2,6-DCBA or dechlorinated to OBAM, which was further hydrolyzed to ortho-chlorobenzoic acid. BAM was rapidly mineralized in previously exposed soils only. All potential metabolites and the finding that BAM was a dead-end metabolite of dichlobenil in soils not previously exposed to dichlobenil needs to be included in risk assessments of the use of dichlobenil. - BAM produced from dichlobenil was either hydrolyzed to 2,6-DCBA or dechlorinated to OBAM, which was further hydrolyzed to ortho-chlorobenzoic acid.

  3. Effect of soil compaction on the degradation and ecotoxicological impact of isoproturon

    Science.gov (United States)

    Mamy, L.; Vrignaud, P.; Cheviron, N.; Perreau, F.; Belkacem, M.; Brault, A.; Breuil, S.; Delarue, G.; Touton, I.; Chaplain, V.

    2009-04-01

    Soil is essentially a non-renewable resource which performs many functions and delivers services vital to human activities and ecosystems survival. However the capacity of soil to keep on fully performing its broad variety of crucial functions is damaged by several threats and, among them, chemical contamination by pesticides and compaction due to intensive agriculture practices. How these two threats could interact is largely unknown: compaction may modify the fate of pesticides in soil therefore their effects on the biological functioning of soil. The aim of this work was to study the effect of soil compaction on (1) the degradation of one herbicide, isoproturon (2) the ecotoxicological impact of this herbicide measured through two enzyme activities involved in C (beta-glucosidase) and N (urease) cycles in soil. Undisturbed soil cylinders were sampled in the 2-4 cm layer of La Cage experimental site (INRA, Versailles, France), under intensive agriculture practices. Several soil samples were prepared with different bulk density then treated with isoproturon (IPU). The samples were incubated at 18 ± 1°C in darkness for 63 days. At 0, 2, 7, 14, 28 and 63 days, the concentrations of isoproturon and of two of its main metabolites in soil (monodesmethyl-isoproturon, IPPMU; didesmethyl-isoproturon, IPPU), and the enzyme activities were measured. The results showed that there was no significant difference in IPU degradation under no and moderate soil compaction. IPU was less persistent in the highly compacted soil, but this soil had also higher humidity which is known to increase the degradation. Only one metabolite, IPPMU, was detected independently of the conditions of compaction. The compaction did not modify the effect of IPU on beta-glucosidase and urease activities in the long term, but microbial communities were probably the same in all the soil samples that were initially not compacted. The communities developed in durably compacted zones in the field are

  4. Identification of anthraquinone-degrading bacteria in soil contaminated with polycyclic aromatic hydrocarbons.

    Science.gov (United States)

    Rodgers-Vieira, Elyse A; Zhang, Zhenfa; Adrion, Alden C; Gold, Avram; Aitken, Michael D

    2015-06-01

    Quinones and other oxygenated polycyclic aromatic hydrocarbons (oxy-PAHs) are toxic and/or genotoxic compounds observed to be cocontaminants at PAH-contaminated sites, but their formation and fate in contaminated environmental systems have not been well studied. Anthracene-9,10-dione (anthraquinone) has been found in most PAH-contaminated soils and sediments that have been analyzed for oxy-PAHs. However, little is known about the biodegradation of oxy-PAHs, and no bacterial isolates have been described that are capable of growing on or degrading anthraquinone. PAH-degrading Mycobacterium spp. are the only organisms that have been investigated to date for metabolism of a PAH quinone, 4,5-pyrenequinone. We utilized DNA-based stable-isotope probing (SIP) with [U-(13)C]anthraquinone to identify bacteria associated with anthraquinone degradation in PAH-contaminated soil from a former manufactured-gas plant site both before and after treatment in a laboratory-scale bioreactor. SIP with [U-(13)C]anthracene was also performed to assess whether bacteria capable of growing on anthracene are the same as those identified to grow on anthraquinone. Organisms closely related to Sphingomonas were the most predominant among the organisms associated with anthraquinone degradation in bioreactor-treated soil, while organisms in the genus Phenylobacterium comprised the majority of anthraquinone degraders in the untreated soil. Bacteria associated with anthracene degradation differed from those responsible for anthraquinone degradation. These results suggest that Sphingomonas and Phenylobacterium species are associated with anthraquinone degradation and that anthracene-degrading organisms may not possess mechanisms to grow on anthraquinone. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

  5. THE WORMS COMPOST - EFFECTIVE FERTILIZER FOR IMPROVING DEGRADED SOILS

    Directory of Open Access Journals (Sweden)

    Larisa CREMENEAC

    2013-01-01

    Full Text Available Management of organic waste is a difficult, complex and intractable in Moldova, according to international standards. Acute problem of organic matter from livestock sector waste is generated by storing them in unauthorized areas. Organic waste management strategies require different methods. One of them is organic waste bio conversion technology by worm’s cultivation. As the main natural wealth of the Republic of Moldova, soil requires a special care. Agriculture, in particular, should pay attention to the soil’s humus and nutrient status – and restore losses of humus and the nutrients used by crops. This requires measures to improve soil fertility. Land use provides, first of all return losses of humus and nutrients used by plants. Therefore measures required to improve soil fertility. The essence of the research was to highlight the role of worms compost improve the soil. To this end, in ETS "Maximovca" was organized an experiment that included three groups (two - experimental, to fund worms compost and one - control the natural background. Observations on soil fertility have been conducted over three years. The soil samples were collected by usual methods determined values of organic matter and humus. The results of the investigations, to determine the values of organic matter and humus samples collected from surface and depth 15 cm exceeded that of the sample control group to 29,7%; 11,4% and 34,3%; 37,1% in experimental group I and 9,3%; 11,6% and 45,5%; 45,5% in experimental group II. Therefore, worms compost embedded in a dose of 3-4 tons / ha during three years, has improved the fertility of the soil

  6. Coastal Plain Soil Fertility Degradation And Natural Forest Ecosystem Regeneration

    Science.gov (United States)

    Casagrande, J. C.; Sato, C. A.; Reis-Duarte, R. M.; Soares, M. R.; Galvão Bueno, M. S.

    2009-04-01

    The sand coastal plain vegetation (Restinga Forest) has been described as an ecosystem associated with the Atlantic Forest, constituted of mosaics, which occur in areas of great ecological diversity, particularly the features of the soil which mostly influence the forest, therefore assigned as edaphic community. The Restinga forest is one of the most fragile, showing low resilience to human damage This work was carried out in several points (14) of Restinga Forest (six low - trees from 3 to 10 m high - and eight high forest - trees from 10 to 15 m high) in the litoral coast of the state of São Paulo. Each sample was made of 15 subsamples of each area collected in each depth (one in 0 - 5, 5 - 10, 10 - 15, 15 - 20, and another in 0 - 20, 20 - 40, 40 and 60 cm). Soil characteristics analyzed were pH, P, Na, K, Ca, Mg, S, H + Al, Al, B, Cu, Fe, Mn, Zn contents and base saturation, cation exchange capacity and aluminum saturation. The vegetation physiognomies of Restinga forest (low and high) were associated with soil results and with the history of human occupation. The soils are sandy (2 to 4% of clay), resulting in a low capacity of nutrient retention. Soil fertility analysis to low and high Restinga forest were similar and showed very low contents of phosphorous, calcium and magnesium in all areas investigated. The base saturation was low due to low amounts of Na, K, Ca and Mg. Base saturation presents low level in all cases, less than 10, indicating low nutritional reserve in the soil. The aluminum saturation values varied from 58 to 69%. The level of calcium and magnesium were low in the subsurface soil layer mainly, associate with high aluminum saturation, representing an limiting factor for the root system development in depth. If soil fertility parameters do not show any significant difference between low and high Restinga physiognomy, what make distinction is the recuperation time. In the areas of high Forest can be note a too long time of recuperation

  7. Comparison of degradation between indigenous and spiked bisphenol A and triclosan in a biosolids amended soil

    Energy Technology Data Exchange (ETDEWEB)

    Langdon, Kate A., E-mail: Kate.Langdon@csiro.au [School of Agriculture, Food and Wine and Waite Research Institute, University of Adelaide, South Australia, 5005, Adelaide (Australia); Water for a Healthy Country Research Flagship, Commonwealth Scientific and Industrial Research Organisation (CSIRO), PMB 2, Glen Osmond, South Australia, 5064, Adelaide (Australia); Warne, Michael StJ. [Water for a Healthy Country Research Flagship, Commonwealth Scientific and Industrial Research Organisation (CSIRO), PMB 2, Glen Osmond, South Australia, 5064, Adelaide (Australia); Smernik, Ronald J. [School of Agriculture, Food and Wine and Waite Research Institute, University of Adelaide, South Australia, 5005, Adelaide (Australia); Shareef, Ali; Kookana, Rai S. [Water for a Healthy Country Research Flagship, Commonwealth Scientific and Industrial Research Organisation (CSIRO), PMB 2, Glen Osmond, South Australia, 5064, Adelaide (Australia)

    2013-03-01

    This study compared the degradation of indigenous bisphenol A (BPA) and triclosan (TCS) in a biosolids-amended soil, to the degradation of spiked labelled surrogates of the same compounds (BPA-d{sub 16} and TCS-{sup 13}C{sub 12}). The aim was to determine if spiking experiments accurately predict the degradation of compounds in biosolids-amended soils using two different types of biosolids, a centrifuge dried biosolids (CDB) and a lagoon dried biosolids (LDB). The rate of degradation of the compounds was examined and the results indicated that there were considerable differences between the indigenous and spiked compounds. These differences were more marked for BPA, for which the indigenous compound was detectable throughout the study, whereas the spiked compound decreased to below the detection limit prior to the study completion. The rate of degradation for the indigenous BPA was approximately 5-times slower than that of the spiked BPA-d{sub 16}. The indigenous and spiked TCS were both detectable throughout the study, however, the shape of the degradation curves varied considerably, particularly in the CDB treatment. These findings show that spiking experiments may not be suitable to predict the degradation and persistence of organic compounds following land application of biosolids. - Highlights: ► Degradation of indigenous and spiked compounds from biosolids were compared. ► Differences were observed for both the rate and pattern of degradation. ► Spiked bisphenol A entirely degraded however the indigenous compound remained. ► TCS was detectable during the experiment however the degradation patterns varied. ► Spiking experiments may not be suitable to predict degradation of organic compounds.

  8. Comparison of degradation between indigenous and spiked bisphenol A and triclosan in a biosolids amended soil

    International Nuclear Information System (INIS)

    Langdon, Kate A.; Warne, Michael StJ.; Smernik, Ronald J.; Shareef, Ali; Kookana, Rai S.

    2013-01-01

    This study compared the degradation of indigenous bisphenol A (BPA) and triclosan (TCS) in a biosolids-amended soil, to the degradation of spiked labelled surrogates of the same compounds (BPA-d 16 and TCS- 13 C 12 ). The aim was to determine if spiking experiments accurately predict the degradation of compounds in biosolids-amended soils using two different types of biosolids, a centrifuge dried biosolids (CDB) and a lagoon dried biosolids (LDB). The rate of degradation of the compounds was examined and the results indicated that there were considerable differences between the indigenous and spiked compounds. These differences were more marked for BPA, for which the indigenous compound was detectable throughout the study, whereas the spiked compound decreased to below the detection limit prior to the study completion. The rate of degradation for the indigenous BPA was approximately 5-times slower than that of the spiked BPA-d 16 . The indigenous and spiked TCS were both detectable throughout the study, however, the shape of the degradation curves varied considerably, particularly in the CDB treatment. These findings show that spiking experiments may not be suitable to predict the degradation and persistence of organic compounds following land application of biosolids. - Highlights: ► Degradation of indigenous and spiked compounds from biosolids were compared. ► Differences were observed for both the rate and pattern of degradation. ► Spiked bisphenol A entirely degraded however the indigenous compound remained. ► TCS was detectable during the experiment however the degradation patterns varied. ► Spiking experiments may not be suitable to predict degradation of organic compounds

  9. Degradation and impact of phthalate plasticizers on soil microbial communities

    Energy Technology Data Exchange (ETDEWEB)

    Cartwright, C.D.; Thompson, I.P.; Burns, R.G.

    2000-05-01

    To assess the impact of phthalates on soil microorganisms and to supplement the environmental risk assessment for these xenobiotics, soil was treated with diethyl phthalate (DEP) or di (2-ethyl hexyl) phthalate (DEHP) at 0.1 to 100 mg/g. Bioavailability and membrane disruption were proposed as the characteristics responsible for the observed fate and toxicity of both compounds. Diethyl phthalate was biodegraded rapidly in soil with a half-life of 0.75 d at 20 C, and was not expected to persist in the environment. The DEHP, although biodegradable in aqueous solution, was recalcitrant in soil, because of poor bioavailability and was predicted to account for the majority of phthalate contamination in the environment. Addition of DEP or DEHP to soil at a concentration similar to that detected in nonindustrial environments had no impact on the structural diversity or functional diversity (BIOLOG) of the microbial community. At concentrations representative of a phthalate spill, DEP reduced numbers of both total culturable bacteria and pseudomonads within 1 d. This was due to disruption of membrane fluidity by the lipophilic phthalate, a mechanism not previously attributed to phthalates. However, DEHP had no effect on the microbial community or membrane fluidity, even at 100 mg/g, and was predicted to have no impact on microbial communities in the environment.

  10. The Soil Program of the Restoration Seedbank Initiative: addressing knowledge gaps in degraded soils for use in dryland restoration

    Science.gov (United States)

    Muñoz-Rojas, Miriam; Bateman, Amber; Erickson, Todd E.; Turner, Shane; Merritt, David J.

    2017-04-01

    Global environmental changes and other anthropogenic impacts are rapidly transforming the structure and functioning of ecosystems worldwide. These changes are leading to land degradation with an estimated 25 % of the global land surface being affected. Landscape-scale restoration of these degraded ecosystems has therefore been recognised globally as an international priority. In the resource-rich biodiverse semi-arid Pilbara region of north-west Western Australia hundreds of thousands of hectares are disturbed due to established and emerging iron-ore mine operations. At this scale, the need to develop cost-effective large-scale solutions to restore these landscapes becomes imperative to preserve biodiversity and achieve functionality and sustainability of these ecosystems. The Restoration Seedbank Initiative (RSB) (http://www.plants.uwa.edu.au/ research/restoration-seedbank-initiative) is a five-year multidisciplinary research project that aims to build knowledge and design strategies to restore mine-impacted landscapes in the Pilbara and other arid and semi-arid landscapes worldwide (Kildiseheva et al., 2016). The RSB comprises four research programs that focus on seedbank management and curation, seed storage, seed enhancement, and the use of alternative soil substrates (soil or growing medium program) respectively. These multi-disciplinary programs address the significant challenges of landscape scale restoration in arid systems. In the soil program we follow an integrated approach that includes the characterization of undisturbed ecosystems, assessment of restored soils with the use of soil quality indicators, and design of alternative soil substrates to support the establishment of native plant communities. A series of glasshouse studies and field trials have been conducted in the last three years to advance our knowledge on soil limitations and to provide solutions to effectively overcome these challenges in arid ecosystem restoration. These studies include

  11. Degradability of an Acrylate-Linked, Fluorotelomer Polymer in Soil

    Science.gov (United States)

    Fluorotelomer polymers are used in a broad array of products in modern societies worldwide and, if they degrade at significant rates, potentially are a significant source of perfluorooctanoic acid (PFOA) and related compounds to the environment. To evaluate this possibility, we i...

  12. Biological degradation of triclocarban and triclosan in a soil under aerobic and anaerobic conditions and comparison with environmental fate modelling

    Energy Technology Data Exchange (ETDEWEB)

    Guangguo, Ying [State Key Laboratory of Organic Geochemistry, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640 (China); CSIRO Land and Water, Adelaide Laboratory, PMB2, Glen Osmond SA 5064 (Australia)], E-mail: guang-guo.ying@gig.ac.cn; Xiangyang, Yu [CSIRO Land and Water, Adelaide Laboratory, PMB2, Glen Osmond SA 5064 (Australia); Food Safety Research Institute, Jiangsu Academy of Agricultural Sciences, Nanjing 210014 (China); Kookana, Rai S [CSIRO Land and Water, Adelaide Laboratory, PMB2, Glen Osmond SA 5064 (Australia)

    2007-12-15

    Triclocarban and triclosan are two antimicrobial agents widely used in many personal care products. Their biodegradation behaviour in soil was investigated by laboratory degradation experiments and environmental fate modelling. Quantitative structure-activity relationship (QSAR) analyses showed that triclocarban and triclosan had a tendency to partition into soil or sediment in the environment. Fate modelling suggests that either triclocarban or triclosan 'does not degrade fast' with its primary biodegradation half-life of 'weeks' and ultimate biodegradation half-life of 'months'. Laboratory experiments showed that triclocarban and triclosan were degraded in the aerobic soil with half-life of 108 days and 18 days, respectively. No negative effect of these two antimicrobial agents on soil microbial activity was observed in the aerobic soil samples during the experiments. But these two compounds persisted in the anaerobic soil within 70 days of the experimental period. - Triclocarban and triclosan can be degraded by microbial processes in aerobic soil, but will persist in anaerobic soil.

  13. Biological degradation of triclocarban and triclosan in a soil under aerobic and anaerobic conditions and comparison with environmental fate modelling

    International Nuclear Information System (INIS)

    Ying Guangguo; Yu Xiangyang; Kookana, Rai S.

    2007-01-01

    Triclocarban and triclosan are two antimicrobial agents widely used in many personal care products. Their biodegradation behaviour in soil was investigated by laboratory degradation experiments and environmental fate modelling. Quantitative structure-activity relationship (QSAR) analyses showed that triclocarban and triclosan had a tendency to partition into soil or sediment in the environment. Fate modelling suggests that either triclocarban or triclosan 'does not degrade fast' with its primary biodegradation half-life of 'weeks' and ultimate biodegradation half-life of 'months'. Laboratory experiments showed that triclocarban and triclosan were degraded in the aerobic soil with half-life of 108 days and 18 days, respectively. No negative effect of these two antimicrobial agents on soil microbial activity was observed in the aerobic soil samples during the experiments. But these two compounds persisted in the anaerobic soil within 70 days of the experimental period. - Triclocarban and triclosan can be degraded by microbial processes in aerobic soil, but will persist in anaerobic soil

  14. Effects of spent mushroom compost application on the physicochemical properties of a degraded soil

    Directory of Open Access Journals (Sweden)

    İ. Gümüş

    2017-11-01

    Full Text Available Under field and laboratory conditions, the application of organic amendments has generally shown an improvement in soil physicochemical properties. Here, spent mushroom compost (SMC is proposed as a suitable organic amendment for soil structure restoration. Our study assessed the impact of SMC on the physicochemical properties of a weak-structured and physically degraded soil. The approach involved the establishment of a pot experiment with SMC applications into soil (control, 0.5, 1, 2, 4 and 8 %. Soils were incubated at field capacity (−33 kPa for 21, 42, and 62 days under laboratory conditions. SMC applications into the soil significantly increased the aggregate stability (AS and decreased the modulus of rupture. The application of SMC at rates of 1, 2, 4, and 8 % significantly increased the total nitrogen and soil organic carbon contents of the degraded soil at all incubation periods (p < 0.05. The results obtained in this study indicate that the application of SMC can improve soil physicochemical properties, which may benefit farmers, land managers, and mushroom growers.

  15. Liming effect in the degradation of 14C-glyphosate in soils

    International Nuclear Information System (INIS)

    Arantes, Sayonara A.C.M.; Lavorenti, Arquimedes

    2007-01-01

    Liming is soil fertility management practice essential in tropical soils, in general extremely acidic. This practice, by influencing physical, chemical and biological features of soils may influence the behavior of organic molecules in soils. The glyphosate is one the most widely used pesticides in Brazil in several cultures to pest management control. Studies on its fate in soil are still incipient, mainly under the effect of liming practice The objective of the present study was to verify the effect of liming practice in the degradation of glyphosate in Red Latosol (LE) and Quartzarenic Neosol (RQ) soils and also in the microbial activity of the same soils. The experiment was conducted in a completely randomized design in a 2 x 2 factorial scheme, corresponding to two soils and two management conditions (with liming and without liming), with four replicates. The Radiometric technique was utilized to evaluate the evolution the 14 CO 2 at intervals of 7 days, during 70 days. The study of microbial activity was conducted parallel to the degradation experiment, using the methodology of radiolabelled glucose ( 14 C-glucose), which was measured at intervals of fourteen days, during 70 days. The results showed that in the studied soils, the liming increased the 14 C-glyphosate mineralization and the microbial activity. (author)

  16. Liming effect in the degradation of 14C-glyphosate in soils

    Energy Technology Data Exchange (ETDEWEB)

    Arantes, Sayonara A.C.M.; Lavorenti, Arquimedes [Universidade de Sao Paulo (USP), Piracicaba, SP (Brazil). Escola Superior de Agricultura Luiz de Queiroz]. E-mails: samoreno@esalq.usp.br; alavoren@esalq.usp.br; Tornisielo, Valdemar L. [Centro de Energia Nuclear na Agricultura (CENA), Piracicaba, SP (Brazil)]. E-mail: vltornis@cena.usp.br

    2007-07-01

    Liming is soil fertility management practice essential in tropical soils, in general extremely acidic. This practice, by influencing physical, chemical and biological features of soils may influence the behavior of organic molecules in soils. The glyphosate is one the most widely used pesticides in Brazil in several cultures to pest management control. Studies on its fate in soil are still incipient, mainly under the effect of liming practice The objective of the present study was to verify the effect of liming practice in the degradation of glyphosate in Red Latosol (LE) and Quartzarenic Neosol (RQ) soils and also in the microbial activity of the same soils. The experiment was conducted in a completely randomized design in a 2 x 2 factorial scheme, corresponding to two soils and two management conditions (with liming and without liming), with four replicates. The Radiometric technique was utilized to evaluate the evolution the {sup 14}CO{sub 2} at intervals of 7 days, during 70 days. The study of microbial activity was conducted parallel to the degradation experiment, using the methodology of radiolabelled glucose ({sup 14}C-glucose), which was measured at intervals of fourteen days, during 70 days. The results showed that in the studied soils, the liming increased the {sup 14}C-glyphosate mineralization and the microbial activity. (author)

  17. PHYSICAL AND CHEMICAL DEGRADATION OF AGRICULTURAL SOILS AT SAN PEDRO LAGUNILLAS, NAYARIT

    Directory of Open Access Journals (Sweden)

    Gelacio Alejo Santiago

    2012-08-01

    Full Text Available The objective of this study was to evaluate the degradation to propose strategies for remediation and recovery of agricultural soils of San Pedro Lagunillas, Nayarit, Mexico; considering physical and chemical properties. Soils maintained with natural vegetation but slightly grazed and agricultural soils used for more than 20 years for the production of several crops, were compared. Eight sites were studied (four cultivated and four uncultivated, each agricultural lands (cultivated was located at a distance of 30 to 80 m from its counterpart or soil with natural vegetation (uncultivated. Samples were obtained from the following layers: 0 to 10, 10 to 20 and 20 to 30 cm. The variables evaluated were: particles smaller than 2 mm, pH, organic matter, extractable phosphorus, exchangeable potassium, calcium and magnesium; soil texture and water infiltration rate. An analysis of variance and Tukey means test (α = 0.05 was applied. It was concluded that traditional farming practices led to adverse changes in soil chemical properties, in the upper 20 cm soil layer. Physical properties were also affected because infiltration film and water infiltration rate decreased about 50% in cultivated soils. The overall results in this work evident the need to take appropriate measures to prevent the physical and chemical degradation of cultivated soils in order to preserve this resource and maintain their productivity.

  18. Effects of spent mushroom compost application on the physicochemical properties of a degraded soil

    Science.gov (United States)

    Gümüş, İlknur; Şeker, Cevdet

    2017-11-01

    Under field and laboratory conditions, the application of organic amendments has generally shown an improvement in soil physicochemical properties. Here, spent mushroom compost (SMC) is proposed as a suitable organic amendment for soil structure restoration. Our study assessed the impact of SMC on the physicochemical properties of a weak-structured and physically degraded soil. The approach involved the establishment of a pot experiment with SMC applications into soil (control, 0.5, 1, 2, 4 and 8 %). Soils were incubated at field capacity (-33 kPa) for 21, 42, and 62 days under laboratory conditions. SMC applications into the soil significantly increased the aggregate stability (AS) and decreased the modulus of rupture. The application of SMC at rates of 1, 2, 4, and 8 % significantly increased the total nitrogen and soil organic carbon contents of the degraded soil at all incubation periods (p < 0.05). The results obtained in this study indicate that the application of SMC can improve soil physicochemical properties, which may benefit farmers, land managers, and mushroom growers.

  19. Reclamation status of a degraded pasture based on soil health indicators

    Directory of Open Access Journals (Sweden)

    Cristiane Alcantara dos Santos

    2015-06-01

    Full Text Available Pasture degradation is a concern, especially in susceptible sandy soils for which strategies to recover them must be developed. Microbiological and biochemical soil health indicators are useful in the guindace of soil management practices and sustainable soil use. We assessed the success of threePanicum maximum Jacq. cultivars in the reclamation of a pasture in a sandy Typic Acrudox in the northwest of the state of Paraná, Brazil, based on soil health indicators. On a formerly degraded pasture withUrochloa brizantha (Hochst. ex A. Rich. R.D. Webster, a trial with threeP. maximum (cv. Massai, Tanzânia, or Mombaça was conducted. Lime and phosphate were applied at set-up, and mineral N and K as topdressing. A remnant of degraded pasture adjacent to the trial was used as control. Twenty-three chemical, physical, microbiological and biochemical attributes were assessed for the 0-10 cm topsoil. The procedures for reclamation improved most of the indicators of soil health in relation to the degraded pasture, such as soil P, mineral N, microbial biomass C, ammonification rate, dehydrogenase activity and acid phosphatase. CO2 evolution decreased, whereas microbial biomass C increased in the pasture under reclamation, resulting in a lower metabolic quotient (qCO2 that points to a decrease in metabolic stress of the microbial community. The reclamation of the pasture withP. maximum, especially cv. Mombaça, were evidenced by improvements in the microbiological and biochemical soil health indicators, showing a recovery of processes related to C, N and P cycling in the soil.

  20. Microbial degradation of alpha-cypermethrin in soil by compound-specific stable isotope analysis

    Energy Technology Data Exchange (ETDEWEB)

    Xu, Zemin [MOE Key Laboratory of Environmental Remediation and Ecosystem Health, College of Environmental and Resource Sciences, Zhejiang University, Hangzhou 310058 (China); Shen, Xiaoli [MOE Key Laboratory of Environmental Remediation and Ecosystem Health, College of Environmental and Resource Sciences, Zhejiang University, Hangzhou 310058 (China); Department of Environmental Engineering, Quzhou University, Quzhou 324000 (China); Zhang, Xi-Chang [Laboratory for Teaching in Environmental and Resource Sciences, Zhejiang University, Hangzhou 310058 (China); Liu, Weiping [MOE Key Laboratory of Environmental Remediation and Ecosystem Health, College of Environmental and Resource Sciences, Zhejiang University, Hangzhou 310058 (China); Yang, Fangxing, E-mail: fxyang@zju.edu.cn [MOE Key Laboratory of Environmental Remediation and Ecosystem Health, College of Environmental and Resource Sciences, Zhejiang University, Hangzhou 310058 (China); Department of Effect-Directed Analysis, Helmholtz Center for Environmental Research – UFZ, Leipzig 04318 (Germany)

    2015-09-15

    Highlights: • Alpha-cypermethrin (α-CP) can be degraded by microorganisms in soil. • Biodegradation of α-CP resulted in carbon isotope fractionation. • A relationship was found between carbon isotope ratios and concentrations of α-CP. • An enrichment factor ϵ of α-CP was determined as −1.87‰. • CSIA is applicable to assess biodegradation of α-CP. - Abstract: To assess microbial degradation of alpha-cypermethrin in soil, attenuation of alpha-cypermethrin was investigated by compound-specific stable isotope analysis. The variations of the residual concentrations and stable carbon isotope ratios of alpha-cypermethrin were detected in unsterilized and sterilized soils spiked with alpha-cypermethrin. After an 80 days’ incubation, the concentrations of alpha-cypermethrin decreased to 0.47 and 3.41 mg/kg in the unsterilized soils spiked with 2 and 10 mg/kg, while those decreased to 1.43 and 6.61 mg/kg in the sterilized soils. Meanwhile, the carbon isotope ratios shifted to −29.14 ± 0.22‰ and −29.86 ± 0.33‰ in the unsterilized soils spiked with 2 and 10 mg/kg, respectively. The results revealed that microbial degradation contributed to the attenuation of alpha-cypermethrin and induced the carbon isotope fractionation. In order to quantitatively assess microbial degradation, a relationship between carbon isotope ratios and residual concentrations of alpha-cypermethrin was established according to Rayleigh equation. An enrichment factor, ϵ = −1.87‰ was obtained, which can be employed to assess microbial degradation of alpha-cypermethrin. The significant carbon isotope fractionation during microbial degradation suggests that CSIA is a proper approach to qualitatively detect and quantitatively assess the biodegradation during attenuation process of alpha-cypermethrin in the field.

  1. Simulation of herbicide degradation in different soils by use of Pedo-transfer functions (PTF) and non-linear kinetics.

    Science.gov (United States)

    von Götz, N; Richter, O

    1999-03-01

    The degradation behaviour of bentazone in 14 different soils was examined at constant temperature and moisture conditions. Two soils were examined at different temperatures. On the basis of these data the influence of soil properties and temperature on degradation was assessed and modelled. Pedo-transfer functions (PTF) in combination with a linear and a non-linear model were found suitable to describe the bentazone degradation in the laboratory as related to soil properties. The linear PTF can be combined with a rate related to the temperature to account for both soil property and temperature influence at the same time.

  2. Degradation of soil-sorbed trichloroethylene by stabilized zero valent iron nanoparticles: Effects of sorption, surfactants, and natural organic matter

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Man [Auburn University, Auburn, Alabama; He, Feng [ORNL; Zhao, Dongye [Auburn University, Auburn, Alabama; Hao, Xiaodi [Beijing University of Civil Engineering and Architecture

    2011-01-01

    Zero valent iron (ZVI) nanoparticles have been studied extensively for degradation of chlorinated solvents in the aqueous phase, and have been tested for in-situ remediation of contaminated soil and groundwater. However, little is known about its effectiveness for degrading soil-sorbed contaminants. This work studied reductive dechlorination of trichloroethylene (TCE) sorbed in two model soils (a potting soil and Smith Farm soil) using carboxymethyl cellulose (CMC) stabilized Fe-Pd bimetallic nanoparticles. Effects of sorption, surfactants and dissolved organic matter (DOC) were determined through batch kinetic experiments. While the nanoparticles can effectively degrade soil-sorbed TCE, the TCE degradation rate was strongly limited by desorption kinetics, especially for the potting soil which has a higher organic matter content of 8.2%. Under otherwise identical conditions, {approx}44% of TCE sorbed in the potting soil was degraded in 30 h, compared to {approx}82% for Smith Farm soil (organic matter content = 0.7%). DOC from the potting soil was found to inhibit TCE degradation. The presence of the extracted SOM at 40 ppm and 350 ppm as TOC reduced the degradation rate by 34% and 67%, respectively. Four prototype surfactants were tested for their effects on TCE desorption and degradation rates, including two anionic surfactants known as SDS (sodium dodecyl sulfate) and SDBS (sodium dodecyl benzene sulfonate), a cationic surfactant hexadecyltrimethylammonium (HDTMA) bromide, and a non-ionic surfactant Tween 80. All four surfactants were observed to enhance TCE desorption at concentrations below or above the critical micelle concentration (cmc), with the anionic surfactant SDS being most effective. Based on the pseudo-first-order reaction rate law, the presence of 1 x cmc SDS increased the reaction rate by a factor of 2.5 when the nanoparticles were used for degrading TCE in a water solution. SDS was effective for enhancing degradation of TCE sorbed in Smith Farm

  3. [Degradation characteristics of naphthalene with a Pseudomonas aeruginosa strain isolated from soil contaminated by diesel].

    Science.gov (United States)

    Liu, Wen-Chao; Wu, Bin-Bin; Li, Xiao-Sen; Lu, Dian-Nan; Liu, Yong-Min

    2015-02-01

    Abstract: A naphthalene-degrading bacterium (referred as HD-5) was isolated from the diesel-contaminated soil and was assigned to Pseudomonas aeruginosa according to 16S rDNA sequences analysis. Gene nah, which encodes naphthalene dioxygenase, was identified from strain HD-5 by PCR amplification. Different bioremediation approaches, including nature attenuation, bioaugmentation with strain Pseudomonas aeruginosa, biostimulation, and an integrated degradation by bioaugmentation and biostimulation, were evaluated for their effectiveness in the remediating soil containing 5% naphthalene. The degradation rates of naphthalene in the soil were compared among the different bioremediation approaches, the FDA and dehydrogenase activity in bioremediation process were measured, and the gene copy number of 16S rRNA and nah in soil were dynamically monitored using real-time PCR. It was shown that the naphthalene removal rate reached 71.94%, 62.22% and 83.14% in approaches of bioaugmentation (B), biostimulation(S) and integrated degradation composed of bioaugmentation and biostimulation (BS), respectively. The highest removal rate of naphthalene was achieved by using BS protocol, which also gives the highest FDA and dehydrogenase activity. The gene copy number of 16S rRNA and nah in soil increased by about 2.67 x 10(11) g(-1) and 8.67 x 10(8) g(-1) after 31 days treatment using BS protocol. Above-mentioned results also demonstrated that the screened bacterium, Pseudomonas aeruginosa, could grow well in naphthalene-contaminated soil and effectively degrade naphthalene, which is of fundamental importance for bioremediation of naphthalene-contaminated soil.

  4. Impact of Rangeland Degradation on Soil Physical, Chemical

    African Journals Online (AJOL)

    major threats to enhance a sustainable pastoral-livestock production in Ethiopia. ... overall negative impact on the soil physical and chemical characteristics, demanding ... chemical properties (Gemedo et al., 2006) as well as the rangeland .... parameters such as life forms (annuals and perennials), plant forms (woody plant,.

  5. Fate of glyphosate and degradates in cover crop residues and underlying soil: A laboratory study

    International Nuclear Information System (INIS)

    Cassigneul, A.; Benoit, P.; Bergheaud, V.; Dumeny, V.; Etiévant, V.; Goubard, Y.; Maylin, A.; Justes, E.; Alletto, L.

    2016-01-01

    The increasing use of cover crops (CC) may lead to an increase in glyphosate application for their destruction. Sorption and degradation of "1"4C-glyphosate on and within 4 decaying CC-amended soils were compared to its fate in a bare soil. "1"4C-Glyphosate and its metabolites distribution between mineralized, water-soluble, NH_4OH-soluble and non-extractable fractions was determined at 5 dates during a 20 °C/84-d period. The presence of CC extends "1"4C-glyphosate degradation half-life from 7 to 28 days depending on the CC. "1"4C-Glyphosate dissipation occurred mainly through mineralization in soils and through mineralization and bound residue formation in decaying CC. Differences in sorption and degradation levels were attributed to differences in composition and availability to microorganisms. CC- and soil-specific dissipation patterns were established with the help of explicit relationships between extractability and microbial activity. - Highlights: • Glyphosate sorption on cover crop residues increases with their decomposition degree. • Glyphosate degradation and mineralization are lower in mulch than in soil. • Nonextractable residue formation is one of the main dissipation pathways of glyphosate in cover crop mulch.

  6. Fate of glyphosate and degradates in cover crop residues and underlying soil: A laboratory study

    Energy Technology Data Exchange (ETDEWEB)

    Cassigneul, A. [Université de Toulouse — École d' ingénieurs de Purpan, UMR 1248 AGIR — 75, Voie du TOEC BP 57 611, 31 076, Toulouse cedex 3 (France); INRA, UMR 1402 ECOSYS, 78850 Thiverval-Grignon (France); Benoit, P.; Bergheaud, V.; Dumeny, V.; Etiévant, V. [INRA, UMR 1402 ECOSYS, 78850 Thiverval-Grignon (France); Goubard, Y. [AgroParisTech, UMR 1402 ECOSYS, 78850 Thiverval-Grignon (France); Maylin, A. [Université de Toulouse — École d' ingénieurs de Purpan, UMR 1248 AGIR — 75, Voie du TOEC BP 57 611, 31 076, Toulouse cedex 3 (France); Justes, E. [INRA, UMR 1248 AGIR Auzeville — BP 52 627, 31 326, Castanet-Tolosan cedex (France); Alletto, L. [Université de Toulouse — École d' ingénieurs de Purpan, UMR 1248 AGIR — 75, Voie du TOEC BP 57 611, 31 076, Toulouse cedex 3 (France)

    2016-03-01

    The increasing use of cover crops (CC) may lead to an increase in glyphosate application for their destruction. Sorption and degradation of {sup 14}C-glyphosate on and within 4 decaying CC-amended soils were compared to its fate in a bare soil. {sup 14}C-Glyphosate and its metabolites distribution between mineralized, water-soluble, NH{sub 4}OH-soluble and non-extractable fractions was determined at 5 dates during a 20 °C/84-d period. The presence of CC extends {sup 14}C-glyphosate degradation half-life from 7 to 28 days depending on the CC. {sup 14}C-Glyphosate dissipation occurred mainly through mineralization in soils and through mineralization and bound residue formation in decaying CC. Differences in sorption and degradation levels were attributed to differences in composition and availability to microorganisms. CC- and soil-specific dissipation patterns were established with the help of explicit relationships between extractability and microbial activity. - Highlights: • Glyphosate sorption on cover crop residues increases with their decomposition degree. • Glyphosate degradation and mineralization are lower in mulch than in soil. • Nonextractable residue formation is one of the main dissipation pathways of glyphosate in cover crop mulch.

  7. Occurrence of Hydrocarbon Degrading Genes in the Soils of the Republic of Tatarstan (Russia)

    Science.gov (United States)

    Biktasheva, L. R.; Shalyamova, R. P.; Guseva, U. A.; Galitskaya, P. Yu

    2018-01-01

    Oil pollution is one of the most serious environmental problems nowadays. The ability of soils for self-restoration is important, when choosing the strategy of pollution control. This ability depends on the pull of microbes able to decompose hydrocarbons that were present in the nonpolluted soil prior to pollution. In this study, the occurrence of alkane degrading genes in the soils of the Republic of Tatarstan being one of the oil processing regions in Russia, was investigated. It was found that alkane degrading genes belonging to group I were present in 20 of the 25 soil samples, and their abundances ranged between 0.01 and 0.07%. Alkane degrading genes belonging to group II were not detected in the samples investigated, and those belonging to group III were present in all the samples, and their abundances ranged between 0.06 and 7.25%. No correlation between the alkane degrading gene copy numbers and pH and organic carbon content in soils was revealed.

  8. Degradation of Total Petroleum Hydrocarbon (TPH) in Contaminated Soil Using Bacillus pumilus MVSV3.

    Science.gov (United States)

    Varma, Surendra Sheeba; Lakshmi, Mahalingam Brinda; Rajagopal, Perumalsam; Velan, Manickam

    2017-01-01

     A study on bioremediation of soil contaminated with petroleum sludge was performed using Bacillus pumilus/MVSV3 (Accession number JN089707). In this study, 5 kg of agricultural soil was mixed well with 5% oil sludge and fertilizers containing nitrogen, phosphorus and potassium (N:P:K). The treatment resulted in 97% removal of total petroleum hydrocarbon (TPH) in 122 d in bacteria mixed contaminated soil when compared to 12% removal of TPH in uninoculated contaminated soil. The population of the microorganism remained stable after introduced into the oil environment. The physical and chemical parameters of the soil mixed with sludge showed variation indicating improvement and the pH level decreased during the experiment period. Elemental analysis and Gas Chromatography-Mass Spectroscopy (GC-MS) analysis revealed the bacterial ability to degrade oil sludge components. Growth experiments with Trigonellafoenumgraecum (Fenugreek) showed the applicability of bioremediated soil for the production.

  9. Mapping soil degradation by topsoil grain size using MODIS data

    OpenAIRE

    XIAO, Jieying; SHEN, Yanjun; TATEISHI, Ryutaro

    2005-01-01

    [ABSTRACT] MODIS BRDF reflectance data at the end of April 2004 was selected to make a desertification map base on topsoil grain size by using Gain Size Index at arid and semiarid Asia. After data processing, GSI was applied into desertification mapping, and we find that high GSI area distributed at the desert and its’ marginal area, degraded grassland, desert steppe. The desertification map was output according to the correlation between GSI and grain size distribution, the classification of...

  10. Study of PCB degradation in real contaminated soil

    Czech Academy of Sciences Publication Activity Database

    Ryšlavá, E.; Krejčík, Zdeněk; Macek, Tomáš; Nováková, H.; Demnerová, K.; Macková, M.

    2003-01-01

    Roč. 2003, č. 12 (2003), s. 296-301 ISSN 1018-4619 R&D Projects: GA MŠk LN00A079; GA ČR GA526/01/1292 Grant - others:GA EU(XE) QLK3-CT-2001-00101 Institutional research plan: CEZ:AV0Z4055905; CEZ:AV0Z5052915 Keywords : Phytoremediation * rhizoremediation * PCB degradation Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 0.325, year: 2003

  11. Soil degradation by sulfuric acid disposition on uranium producing sites in south Bulgaria

    International Nuclear Information System (INIS)

    Atanasov, I.; Gribachev, P.

    1997-01-01

    This study assesses the damage of soils caused by spills of sulfuric acid solutions used for in situ leaching of uranium at eight uranium producing (by open-cast method) sites (total area of approximately 220 ha) in the region of Momino-Rakovski (South Bulgaria). The upper soil layer is cinnamonic pseudopodzolic ( or Eutric Planosols by FAO Legend, 1974). The results of the investigation show that the sulfuric acid spills caused strong acidification of upper (0-20 cm) and subsurface (20-60 cm) soil horizons which is expressed as decreasing of pH (H 2 O) to 2.9-3.5 and increasing of exchangeable H + and Al 3+ to 18 and 32% from CEC. Acid degradation of soils is combined with reducing of organic matter content. The average concentration of the total heavy metal content in the upper soil horizon (in ppm) is: Cd=1.5; Cu=30; Pb=25; Zn=40 and U=8. No significant differences were detected between the upper and subsurface soil layers . The heavy metal concentration did not exceed the Bulgarian standards for heavy metals and uranium content of soils. But the coarse texture of the top soil layers, the lack of carbonates, The low CEC and strong acidity determine a low buffering capacity of the investigated soils and this can be considered as hazardous for plants. This indicates that a future soil monitoring should be carried out in the region together with measures for neutralizing of soil acidity

  12. Degradation of pyrene in soil and in vitro by a Bacillus lentus strain ...

    African Journals Online (AJOL)

    A bacterium isolated from an asphalt plant soil and identified as a strain of Bacillus lentus was tested in vitro and in sterilized and native soils for ability to survive and sustain pyrene degradation over a period of 63 days. The exponential growth rate in vitro was 0.049 d-1 and the doubling time 2.65 d. In the control flask ...

  13. Degradation of phenanthrene and pyrene using genetically engineered dioxygenase producing Pseudomonas putida in soil

    Directory of Open Access Journals (Sweden)

    Mardani Gashtasb

    2016-01-01

    Full Text Available Bioremediation use to promote degradation and/or removal of contaminants into nonhazardous or less-hazardous substances from the environment using microbial metabolic ability. Pseudomonas spp. is one of saprotrophic soil bacterium and can be used for biodegradation of polycyclic aromatic hydrocarbons (PAHs but this activity in most species is weak. Phenanthrene and pyrene could associate with a risk of human cancer development in exposed individuals. The aim of the present study was application of genetically engineered P. putida that produce dioxygenase for degradation of phenanthrene and pyrene in spiked soil using high-performance liquid chromatography (HPLC method. The nahH gene that encoded catechol 2,3-dioxygenase (C23O was cloned into pUC18 and pUC18-nahH recombinant vector was generated and transformed into wild P. putida, successfully. The genetically modified and wild types of P. putida were inoculated in soil and pilot plan was prepared. Finally, degradation of phenanthrene and pyrene by this bacterium in spiked soil were evaluated using HPLC measurement technique. The results were showed elimination of these PAH compounds in spiked soil by engineered P. putida comparing to dishes containing natural soil with normal microbial flora and inoculated autoclaved soil by wild type of P. putida were statistically significant (p0.05 but it was few impact on this process (more than 2%. Additional and verification tests including catalase, oxidase and PCR on isolated bacteria from spiked soil were indicated that engineered P. putida was alive and functional as well as it can affect on phenanthrene and pyrene degradation via nahH gene producing. These findings indicated that genetically engineered P. putida generated in this work via producing C23O enzyme can useful and practical for biodegradation of phenanthrene and pyrene as well as petroleum compounds in polluted environments.

  14. Bioremediation Potential of Native Hydrocarbons Degrading Bacteria in Crude Oil Polluted Soil

    Directory of Open Access Journals (Sweden)

    Mariana MARINESCU

    2017-05-01

    Full Text Available Bioremediation of crude oil contaminated soil is an effective process to clean petroleum pollutants from the environment. Crude oil bioremediation of soils is limited by the bacteria activity in degrading the spills hydrocarbons. Native crude oil degrading bacteria were isolated from different crude oil polluted soils. The isolated bacteria belong to the genera Pseudomonas, Mycobacterium, Arthrobacter and Bacillus. A natural biodegradable product and bacterial inoculum were used for total petroleum hydrocarbon (TPH removal from an artificial polluted soil. For soil polluted with 5% crude oil, the bacterial top, including those placed in the soil by inoculation was 30 days after impact, respectively 7 days after inoculum application, while in soil polluted with 10% crude oil,  multiplication top of bacteria was observed in the determination made at 45 days after impact and 21 days after inoculum application, showing once again how necessary is for microorganisms habituation and adaptation to environment being a function of pollutant concentration. The microorganisms inoculated showed a slight adaptability in soil polluted with 5% crude oil, but complete inhibition in the first 30 days of experiment at 10% crude oil.

  15. Role of litter turnover in soil quality in tropical degraded lands of Colombia.

    Science.gov (United States)

    León, Juan D; Osorio, Nelson W

    2014-01-01

    Land degradation is the result of soil mismanagement that reduces soil productivity and environmental services. An alternative to improve degraded soils through reactivation of biogeochemical nutrient cycles (via litter production and decomposition) is the establishment of active restoration models using new forestry plantations, agroforestry, and silvopastoral systems. On the other hand, passive models of restoration consist of promoting natural successional processes with native plants. The objective in this review is to discuss the role of litter production and decomposition as a key strategy to reactivate biogeochemical nutrient cycles and thus improve soil quality in degraded land of the tropics. For this purpose the results of different projects of land restoration in Colombia are presented based on the dynamics of litter production, nutrient content, and decomposition. The results indicate that in only 6-13 years it is possible to detect soil properties improvements due to litter fall and decomposition. Despite that, low soil nutrient availability, particularly of N and P, seems to be major constraint to reclamation of these fragile ecosystems.

  16. Addition of residues and reintroduction of microorganisms in Jatropha curcas cultivated in degraded soil

    Directory of Open Access Journals (Sweden)

    Adriana A. Santos

    2016-04-01

    Full Text Available ABSTRACT The aim of this study was to evaluate, through mycorrhization (root colonization and number of spores of arbuscular mycorrhizal fungi - AMF, leaf acid phosphatase and soil chemical characteristics, the effects of the addition of residues (macrophytes and ash, hydrogel and the reintroduction of microorganisms in a degraded area cultivated with jatropha. Degradation occurred when the surface soil was removed during the construction of a hydroelectric power plant. The experiment was set in a randomized block design, using a 2 x 2 x 4 factorial scheme, i.e., two inoculation treatments (with and without soil-inoculum, two hydrogel treatments (with and without and four with the addition of residues (macrophytes - MAC, ash, MAC + ash and control, without residues applied in the planting hole, with 4 replicates and 5 plants in each replicate. Soil from preserved Cerrado area was used as a source of microorganisms, including AMF. The conclusion is that, after 12 months of planting, the hydrogel increased root colonization, while the chemical characteristics of the degraded soil responded positively to the addition of MAC and MAC + ash, with increase in pH and SB and reduction of Al and H + Al. The addition of the soil-inoculum, along with MAC and MAC + ash, promoted higher mycorrhizal colonization and number of spores and reduced amounts of leaf acid phosphatase, indicating increased absorption of P by the host.

  17. Predictable bacterial composition and hydrocarbon degradation in Arctic soils following diesel and nutrient disturbance.

    Science.gov (United States)

    Bell, Terrence H; Yergeau, Etienne; Maynard, Christine; Juck, David; Whyte, Lyle G; Greer, Charles W

    2013-06-01

    Increased exploration and exploitation of resources in the Arctic is leading to a higher risk of petroleum contamination. A number of Arctic microorganisms can use petroleum for growth-supporting carbon and energy, but traditional approaches for stimulating these microorganisms (for example, nutrient addition) have varied in effectiveness between sites. Consistent environmental controls on microbial community response to disturbance from petroleum contaminants and nutrient amendments across Arctic soils have not been identified, nor is it known whether specific taxa are universally associated with efficient bioremediation. In this study, we contaminated 18 Arctic soils with diesel and treated subsamples of each with monoammonium phosphate (MAP), which has successfully stimulated degradation in some contaminated Arctic soils. Bacterial community composition of uncontaminated, diesel-contaminated and diesel+MAP soils was assessed through multiplexed 16S (ribosomal RNA) rRNA gene sequencing on an Ion Torrent Personal Genome Machine, while hydrocarbon degradation was measured by gas chromatography analysis. Diversity of 16S rRNA gene sequences was reduced by diesel, and more so by the combination of diesel and MAP. Actinobacteria dominated uncontaminated soils with diesel degradation in MAP-treated soils, suggesting this may be an important group to stimulate. The predictability with which bacterial communities respond to these disturbances suggests that costly and time-consuming contaminated site assessments may not be necessary in the future.

  18. From oil spills to barley growth - oil-degrading soil bacteria and their promoting effects.

    Science.gov (United States)

    Mikolasch, Annett; Reinhard, Anne; Alimbetova, Anna; Omirbekova, Anel; Pasler, Lisa; Schumann, Peter; Kabisch, Johannes; Mukasheva, Togzhan; Schauer, Frieder

    2016-11-01

    Heavy contamination of soils by crude oil is omnipresent in areas of oil recovery and exploitation. Bioremediation by indigenous plants in cooperation with hydrocarbon degrading microorganisms is an economically and ecologically feasible means to reclaim contaminated soils. To study the effects of indigenous soil bacteria capable of utilizing oil hydrocarbons on biomass production of plants growing in oil-contaminated soils eight bacterial strains were isolated from contaminated soils in Kazakhstan and characterized for their abilities to degrade oil components. Four of them, identified as species of Gordonia and Rhodococcus turned out to be effective degraders. They produced a variety of organic acids from oil components, of which 59 were identified and 7 of them are hitherto unknown acidic oil metabolites. One of them, Rhodococcus erythropolis SBUG 2054, utilized more than 140 oil components. Inoculating barley seeds together with different combinations of these bacterial strains restored normal growth of the plants on contaminated soils, demonstrating the power of this approach for bioremediation. Furthermore, we suggest that the plant promoting effect of these bacteria is not only due to the elimination of toxic oil hydrocarbons but possibly also to the accumulation of a variety of organic acids which modulate the barley's rhizosphere environment. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  19. Longevity of terrestrial Carbon sinks: effects of soil degradation on greenhouse gas emissions

    Science.gov (United States)

    Kuhn, Nikolaus J.; Berger, Samuel; Kuonen, Samuel

    2013-04-01

    Soil erosion by water is a key process of soil and land degradation. In addition, significant amounts of nutrients and organic Carbon are moved from eroding source areas to landscape sinks. As a consequence, areas affected by erosion suffer a loss of fertility, while sinks experience the development of a stockpile of the deposited sediment, including soil organic matter and nutrients. The deposited nutrients are largely unavailable for the plants growing in these landscape sediment sinks once the thickness of the deposited layer is greater than the rooting depth of the plants. In addition, the deposited organic matter is decomposed slowly through the pack of sediment. At sites of erosion, nutrients have to be replaced and organic matter content of the soil declines due to a destruction of the A horizon. Over time, the risk of a significant reduction in productivity, for example caused by a loss of top soil with a sufficient water storage capacity for maximum plant growth, leads to a decline in CO2 uptake by photosynthesis. Soil organic matter at eroding sites therefore declines and consequently the sediment that is moved to landscape sinks also has a smaller organic matter content than sediment generated from the non-degraded soil. The sediment sinks, on the other hand, emit an increasing amount of greenhouse gases as a consequence of the increasing amount of organic matter deposited while the upslope area is eroded. Over time, the perceived sink effect of soil erosion for greenhouse gases is therefore replaced with a neutral or positive emission balance of erosion in agricultural landscapes. Such a switch from none or a negative emission balance of agricultural landscapes to a positive balance carries the risk of accelerating climate change. In this study, we tried to estimate the risk associated with ongoing soil degradation and closing landscape soil organic matter sinks. Currently observed global erosion rates were linked to known limitations of soil

  20. 2,4-dichlorophenoxyacetic acid degradation in soils

    International Nuclear Information System (INIS)

    Bellinck, Celine; Batistic, L.; Mayaudon, J.

    1979-01-01

    The mineralization of 2,4-D (carboxyl 14 C) applied at 10 ppm was beginning immediately after its application in the soil. At higher concentrations a lag period appeared. The quantity of residual 14 C in the soil after 100 days incubation time reached 8.30 and 90% for initial concentrations of 10, 50 and 500 ppm of 2,4-D. The biostable 14 C which was extractable by water was exclusively constituted of 2,4-D. The mineral amendments P-K and PK inhibited 2,4-D mineralization, while the combination CaMg and also those containing nitrogen activated it. When 500 ppm of 2,4-D were applied one observed the formation of a zymogenous flora which was very active in the decarboxylation of the herbicide but unable to cleave the aromatic ring. These microorganisms probably belong to the genus Arthobacter and Pseudomonas [fr

  1. Chloroacetic acids - Degradation intermediates of organic matter in forest soil

    Czech Academy of Sciences Publication Activity Database

    Matucha, Miroslav; Gryndler, Milan; Schröder, P.; Forczek, Sándor; Uhlířová, H.; Fuksová, Květoslava; Rohlenová, Jana

    2007-01-01

    Roč. 39, č. 1 (2007), s. 382-385 ISSN 0038-0717 R&D Projects: GA ČR GA522/02/0874; GA ČR GA526/05/0636 Institutional research plan: CEZ:AV0Z50380511 Keywords : trichloroacetic acid * dichloroacetic acid * chlorination * soil organic matter Subject RIV: EF - Botanics Impact factor: 2.580, year: 2007

  2. Comparison of degradation between indigenous and spiked bisphenol A and triclosan in a biosolids amended soil.

    Science.gov (United States)

    Langdon, Kate A; Warne, Michael Stj; Smernik, Ronald J; Shareef, Ali; Kookana, Rai S

    2013-03-01

    This study compared the degradation of indigenous bisphenol A (BPA) and triclosan (TCS) in a biosolids-amended soil, to the degradation of spiked labelled surrogates of the same compounds (BPA-d16 and TCS-(13)C12). The aim was to determine if spiking experiments accurately predict the degradation of compounds in biosolids-amended soils using two different types of biosolids, a centrifuge dried biosolids (CDB) and a lagoon dried biosolids (LDB). The rate of degradation of the compounds was examined and the results indicated that there were considerable differences between the indigenous and spiked compounds. These differences were more marked for BPA, for which the indigenous compound was detectable throughout the study, whereas the spiked compound decreased to below the detection limit prior to the study completion. The rate of degradation for the indigenous BPA was approximately 5-times slower than that of the spiked BPA-d16. The indigenous and spiked TCS were both detectable throughout the study, however, the shape of the degradation curves varied considerably, particularly in the CDB treatment. These findings show that spiking experiments may not be suitable to predict the degradation and persistence of organic compounds following land application of biosolids. Copyright © 2013 Elsevier B.V. All rights reserved.

  3. [Characteristics of soil microbes and enzyme activities in different degraded alpine meadows].

    Science.gov (United States)

    Yin, Ya Li; Wang, Yu Qin; Bao, Gen Sheng; Wang, Hong Sheng; Li, Shi Xiong; Song, Mei Ling; Shao, Bao Lian; Wen, Yu Cun

    2017-12-01

    Soil microbial biomass C and N, microbial diversities and enzyme activity in 0-10 cm and 10-20 cm soil layers of different degraded grasslands (non-degradation, ND; light degradation, LD; moderate degradation, MD; sever degradation, SD; and black soil beach, ED) were measured by Biolog and other methods. The results showed that: 1) There were significant diffe-rences between 0-10 cm and 10-20 cm soil layers in soil microbial biomass, diversities and inver-tase activities in all grasslands. 2) The ratio of soil microbial biomass C to N decreased significantly with the grassland degradation. In the 0-10 cm soil layer, microbial biomass C and N in ND and LD were significantly higher than that in MD, SD and ED. Among the latter three kinds of grasslands, there was no difference for microbial biomass C, but microbial biomass N was lower in MD than in the other grasslands. The average color change rate (AWCD) and McIntosh Index (U) also decreased with grassland degradation, but only the reduction from ND to MD was significant. There were no differences among all grasslands for Shannon index (H) and Simpson Index (D). The urease activity was highest in MD and SD, and the activity of phosphatase and invertase was lowest in ED. In the 10-20 cm soil layer, microbial biomass C in ND and LD were significantly higher than that in the other grasslands. Microbial biomass N in LD and ED were significantly higher than that in the other grasslands. Carbon metabolism index in MD was significantly lower than that in LD and SD. AWCD and U index in ND and LD were significantly higher than that in ED. H index and D index showed no difference among different grasslands. The urease activity in ND and MD was significantly higher than that in the other grasslands. The phosphatase activity was highest in MD, and the invertase activity was lowest in MD. 3) The belowground biomass was significantly positively correlated with microbial biomass, carbon metabolic index and phosphatase activity

  4. Assessment of soil degradation and chemical compositions in Rwandan tea-growing areas

    Directory of Open Access Journals (Sweden)

    Jean de la Paix Mupenzi

    2011-10-01

    Full Text Available This study has focused on the processes of soil degradation and chemical element concentration in tea-growing regions of Rwanda, Africa. Soil degradation accelerated by erosion is caused not only by topography but also by human activities. This soil degradation involves both the physical loss and reduction in the amount of topsoil associated with nutrient decline. Soil samples were collected from eleven tropical zones in Rwanda and from variable depth within each collecting site. Of these, Samples from three locations in each zone were analyzed in the laboratory, with the result that the pH of all soil samples is shown to be less than 5 (pH<5 with a general average of 4.4. The elements such as iron (Fe, copper (Cu, manganese (Mn, and zinc (Zn are present in high concentration levels. In contrast calcium (Ca and sodium (Na are present at low-level concentrations and carbon (C was found in minimal concentrations. In addition, elements derived from fertilizers, such as nitrogen (N, phosphorous (P, and potassium (K which is also from minerals such as feldspar, are also present in low-level concentrations. The results indicate that the soil in certain Rwandan tea plantations is acidic and that this level of pH may help explain, in addition to natural factors, the deficiency of some elements such as Ca, Mg, P and N. The use of chemical fertilizers, land use system and the location of fields relative to household plots are also considered to help explain why tea plantation soils are typically degraded.

  5. Predictable bacterial composition and hydrocarbon degradation in Arctic soils following diesel and nutrient disturbance

    Science.gov (United States)

    Bell, Terrence H; Yergeau, Etienne; Maynard, Christine; Juck, David; Whyte, Lyle G; Greer, Charles W

    2013-01-01

    Increased exploration and exploitation of resources in the Arctic is leading to a higher risk of petroleum contamination. A number of Arctic microorganisms can use petroleum for growth-supporting carbon and energy, but traditional approaches for stimulating these microorganisms (for example, nutrient addition) have varied in effectiveness between sites. Consistent environmental controls on microbial community response to disturbance from petroleum contaminants and nutrient amendments across Arctic soils have not been identified, nor is it known whether specific taxa are universally associated with efficient bioremediation. In this study, we contaminated 18 Arctic soils with diesel and treated subsamples of each with monoammonium phosphate (MAP), which has successfully stimulated degradation in some contaminated Arctic soils. Bacterial community composition of uncontaminated, diesel-contaminated and diesel+MAP soils was assessed through multiplexed 16S (ribosomal RNA) rRNA gene sequencing on an Ion Torrent Personal Genome Machine, while hydrocarbon degradation was measured by gas chromatography analysis. Diversity of 16S rRNA gene sequences was reduced by diesel, and more so by the combination of diesel and MAP. Actinobacteria dominated uncontaminated soils with soils, and this pattern was exaggerated following disturbance. Degradation with and without MAP was predictable by initial bacterial diversity and the abundance of specific assemblages of Betaproteobacteria, respectively. High Betaproteobacteria abundance was positively correlated with high diesel degradation in MAP-treated soils, suggesting this may be an important group to stimulate. The predictability with which bacterial communities respond to these disturbances suggests that costly and time-consuming contaminated site assessments may not be necessary in the future. PMID:23389106

  6. Effects of soil organic matter on the development of the microbial polycyclic aromatic hydrocarbons (PAHs) degradation potentials

    International Nuclear Information System (INIS)

    Yang, Y.; Zhang, N.; Xue, M.; Lu, S.T.; Tao, S.

    2011-01-01

    The microbial activity in soils was a critical factor governing the degradation of organic micro-pollutants. The present study was conducted to analyze the effects of soil organic matter on the development of degradation potentials for polycyclic aromatic hydrocarbons (PAHs). Most of the degradation kinetics for PAHs by the indigenous microorganisms developed in soils can be fitted with the Logistic growth models. The microbial activities were relatively lower in the soils with the lowest and highest organic matter content, which were likely due to the nutrition limit and PAH sequestration. The microbial activities developed in humic acid (HA) were much higher than those developed in humin, which was demonstrated to be able to sequester organic pollutants stronger. The results suggested that the nutrition support and sequestration were the two major mechanisms, that soil organic matter influenced the development of microbial PAHs degradation potentials. - Research highlights: → PAH degradation kinetics obey Logistic model. → Degradation potentials depend on soil organic carbon content. → Humin inhibits the development of PAH degradation activity. → Nutrition support and sequestration regulate microbial degradation capacity. - Soil organic matter regulated PAH degradation potentials through nutrition support and sequestration.

  7. A Slurry Biocascade for the Enhanced Degradation of Fuels in Soils

    National Research Council Canada - National Science Library

    Apitz, Sabine

    1994-01-01

    .... In the first step of the cascade, the simplest fuel components (e.g., n-alkanes) are biodegraded. Then, the soil is transferred to the next steps in the cascade, in which different "microbial soups" degrade the next groups of hydrocarbons...

  8. Does microbial cm-scale heterogeneity impact pesticide degradation in and leaching from loamy agricultural soils?

    DEFF Research Database (Denmark)

    Rosenbom, Annette Elisabeth; Binning, Philip John; Aamand, Jens

    2014-01-01

    matrix flow or preferential flow through a soil matrix with a wormhole. MCPA leached, within 250 days, below 1 metre only when degrader biomass was absent and preferential flow occurred. Both biodegradation in the plough layer and the microbially active lining of the wormhole contributed to reducing MCPA...

  9. Exploration of hydrocarbon degrading bacteria on soils contaminated by crude oil from South Sumatera

    Directory of Open Access Journals (Sweden)

    A. Napoleon

    2014-07-01

    Full Text Available The goal of this research was to explore hydrocarbon degrading bacteria on crude oil contaminated soil with potential to degrade hydrocarbon in oil pollutant. The research started by early August 2013 till January 2014. Soil sampling for this research was taken on several places with contaminated soil location such as Benakat, Rimau, and Pengabuan all of it located in South Sumatera. Conclusion from this research Isolates obtained from three (3 sites of contaminated soil and treated using SBS medium were Bacillus cereus, Pseudomonas aeruginosa, Klebsiella pnumoniae, Streptococcus beta hemolisa, Proteus mirabilis, Staphylococcus epidermis and Acinotobacter calcoaceticus. Isolates that survived on 300 ppm of hydrocarbon concentration were Bacillus cereus, Pseudomonas aeruginosa and Acinetobacter cakciaceticus Selected isolates posses the ability to degrade hydrocarbon by breaking hydrocarbon substance as the energy source to support isolates existence up to 1,67 TPH level. Based on results accomplish by this research, we urge for further research involving the capacity of isolates to degrade wide variety of hydrocarbon substance and more to develop the potential of these bacteria for bioremediation.

  10. Characterization of acetanilide herbicides degrading bacteria isolated from tea garden soil.

    Science.gov (United States)

    Wang, Yei-Shung; Liu, Jian-Chang; Chen, Wen-Ching; Yen, Jui-Hung

    2008-04-01

    Three different green manures were added to the tea garden soils separately and incubated for 40 days. After, incubation, acetanilide herbicides alachlor and metolachlor were spiked into the soils, separately, followed by the isolation of bacteria in each soil at designed intervals. Several bacterial strains were isolated from the soils and identified as Bacillus silvestris, B. niacini, B. pseudomycoides, B. cereus, B. thuringiensis, B. simplex, B. megaterium, and two other Bacillus sp. (Met1 and Met2). Three unique strains with different morphologies were chosen for further investigation. They were B. megaterium, B. niacini, and B. silvestris. The isolated herbicide-degrading bacteria showed optimal performance among three incubation temperatures of 30 degrees C and the best activity in the 10 to 50 microg/ml concentration of the herbicide. Each bacterial strain was able to degrade more than one kind of test herbicides. After incubation for 119 days, B. cereus showed the highest activity to degrade alachlor and propachlor, and B. thuringiensis to degrade metolachlor.

  11. Rate of hydrolysis and degradation of the cyanogenic glycoside - dhurrin - in soil

    DEFF Research Database (Denmark)

    Johansen, Henrik; Damgaard, Lars Holm; Olsen, Carl Erik

    2007-01-01

    Cyanogenic glycosides are common plant toxins. Toxic hydrogen cyanide originating from cyanogenic glycosides may affect soil processes and water quality. In this study, hydrolysis, degradation and sorption of dhurrin (4-hydroxymandelonitrile-b-D-glucoside) produced by sorghum has been studied...

  12. Study of aliphatic-aromatic copolyester degradation in sandy soil and its ecotoxicological impact.

    Science.gov (United States)

    Rychter, Piotr; Kawalec, Michał; Sobota, Michał; Kurcok, Piotr; Kowalczuk, Marek

    2010-04-12

    Degradation of poly[(1,4-butylene terephthalate)-co-(1,4-butylene adipate)] (Ecoflex, BTA) monofilaments (rods) in standardized sandy soil was investigated. Changes in the microstructure and chemical composition distribution of the degraded BTA samples were evaluated and changes in the pH and salinity of postdegradation soil, as well as the soil phytotoxicity impact of the degradation products, are reported. A macroscopic and microscopic evaluation of the surface of BTA rod samples after specified periods of incubation in standardized soil indicated erosion of the surface of BTA rods starting from the fourth month of their incubation, with almost total disintegration of the incubated BTA material observed after 22 months. However, the weight loss after this period of time was about 50% and only a minor change in the M(w) of the investigated BTA samples was observed, along with a slight increase in the dispersity (from an initial 2.75 up to 4.00 after 22 months of sample incubation). The multidetector SEC and ESI-MS analysis indicated retention of aromatic chain fragments in the low molar mass fraction of the incubated sample. Phytotoxicity studies revealed no visible damage, such as necrosis and chlorosis, or other inhibitory effects, in the following plants: radish, cres, and monocotyledonous oat, indicating that the degradation products of the investigated BTA copolyester are harmless to the tested plants.

  13. Remediation/restoration of degraded soil in the Central Great plains

    Science.gov (United States)

    Soil degradation became a problem in the arid region in the late 18th and early 19th century, as a consequence of agriculture expansion and conversion of native land to cropland. The objectives of this study are to evaluate the impact of different tillage practices, nitrogen (N) sources, and N rates...

  14. Development and duration of accelerated degradation of nematicides in different soils

    NARCIS (Netherlands)

    Smelt, J.H.; Peppel-Groen, van de A.E.; Pas, van der L.J.T.; Dijksterhuis, A.

    1996-01-01

    The development and duration of accelerated degradation of nematicides were studied in incubation experiments with soils from three experimental fields that had been treated annually for three to ten years with aldicarb, oxamyl, ethoprophos, fenamiphos or 1,3-dichloropropene. Highly accelerated

  15. [Oil degradation by basidiomycetes in soil and peat at low temperatures].

    Science.gov (United States)

    Kulikova, N A; Klein, O I; Pivchenko, D V; Landesman, E O; Pozdnyakova, N N; Turkovskaya, O V; Zaichik, B Ts; Ruzhitskii, A O; Koroleva, O V

    2016-01-01

    A total of 17 basidiomycete strains causing white rot and growing on oil-contaminated substrates have been screened. Three strains with high (Steccherinum murashkinskyi), average (Trametes maxima), and low (Pleurotus ostreatus) capacities for the colonization of oil-contaminated substrates have been selected. The potential for degrading crude oil hydrocarbons has been assessed with the use of fungi grown on nonsterile soil and peat at low temperatures. Candida sp. and Rhodococcus sp. commercial strains have been used as reference organisms with oil-degrading ability. All microorganisms introduced in oil-contaminated soil have proved to be ineffective, whereas the inoculation of peat with basidiomycetes and oil-degrading microorganisms accelerated the destruction of oil hydrocarbons. The greatest degradation potential of oil-aliphatic hydrocarbons has been found in S. murashlinskyi. T. maxima turned out to be the most successful in degrading aromatic hydrocarbons. It has been suggested that aboriginal microflora contributes importantly to the effectiveness of oil-destructing microorganisms. T. maxima and S. murashkinskyi strains are promising for further study as oil-oxidizing agents during bioremediation of oil-contaminated peat soil under conditions of low temperatures.

  16. Biophysical-and socioeconomic aspects of land degradation in the Guadalentin (SE-Spain): towards understanding and effective soil conservation

    International Nuclear Information System (INIS)

    Vente, J. de; Sole-Benet, A.; Boix-Fayos, C.; Nainggolan, D.; Romero-Diaz, A.

    2009-01-01

    Desertification and land degradation have been widely studied in the Guadalentin basin (SE Spain) through various national and international research projects. Most important identified degradation types are due to soil erosion, soil surface crusting, aridity, soil organic matter decline and salinisation. On the one hand, political and socioeconomic drivers have caused important land use and management changes, which have formed an important driver for further land degradation. On the other hand, soil conservation practice were initiated by the government and by individual land users, although there is very limited knowledge on their effectiveness. the objective of this work is to provide and overview of previous studies that addressed land degradation in the Guadalentin and to present an integrated synthesis of the main biophysical and socioeconomic factors identifies in these studies as being responsible for land degradation, with a focus on feasible soil conservation strategies. (Author) 18 refs.

  17. Biophysical-and socioeconomic aspects of land degradation in the Guadalentin (SE-Spain): towards understanding and effective soil conservation

    Energy Technology Data Exchange (ETDEWEB)

    Vente, J. de; Sole-Benet, A.; Boix-Fayos, C.; Nainggolan, D.; Romero-Diaz, A.

    2009-07-01

    Desertification and land degradation have been widely studied in the Guadalentin basin (SE Spain) through various national and international research projects. Most important identified degradation types are due to soil erosion, soil surface crusting, aridity, soil organic matter decline and salinisation. On the one hand, political and socioeconomic drivers have caused important land use and management changes, which have formed an important driver for further land degradation. On the other hand, soil conservation practice were initiated by the government and by individual land users, although there is very limited knowledge on their effectiveness. the objective of this work is to provide and overview of previous studies that addressed land degradation in the Guadalentin and to present an integrated synthesis of the main biophysical and socioeconomic factors identifies in these studies as being responsible for land degradation, with a focus on feasible soil conservation strategies. (Author) 18 refs.

  18. Influence of compost amendments on the diversity of alkane degrading bacteria in hydrocarbon contaminated soils

    Directory of Open Access Journals (Sweden)

    Michael eSchloter

    2014-03-01

    Full Text Available Alkane degrading microorganisms play an important role for bioremediation of petrogenic contaminated environments. In this study, we investigated the effects of compost addition on the diversity of alkane monooxygenase gene (alkB harboring bacteria in oil-contaminated soil originated from an industrial zone in Celje, Slovenia, to improve our understanding about the bacterial community involved in alkane degradation and the effects of amendments. Soil without any amendments (control soil and soil amended with compost of different maturation stages, i 1 year and ii 2 weeks, were incubated under controlled conditions in a microcosm experiment and sampled after 0, 6, 12 and 36 weeks of incubation. By using quantitative real-time PCR higher number of alkB genes could be detected in soil samples with compost compared to the control soil after 6, 12 and 36 weeks mainly if the less maturated compost was added. To get an insight into the composition of the alkB harboring microbial communities, we performed next generation sequencing of alkB gene fragment amplicons. Richness and diversity of alkB gene harboring prokaryotes was higher in soil mixed with compost compared to control soil after 6, 12 and 36 weeks again with stronger effects of the less maturated compost. Comparison of communities detected in different samples and time points based on principle component analysis revealed that the addition of compost in general stimulated the abundance of alkB harboring Actinobacteria during the experiment independent from the maturation stage of the compost compared to the control soils. In addition alkB harboring proteobacteria like Shewanella or Hydrocarboniphaga as well as proteobacteria of the genus Agrobacterium responded positively to the addition of compost to soil The amendment of the less maturated compost resulted in addition in a large increase of alkB harboring bacteria of the Cytophaga group (Microscilla mainly at the early sampling

  19. Indexing Permafrost Soil Organic Matter Degradation Using High-Resolution Mass Spectrometry.

    Science.gov (United States)

    Mann, Benjamin F; Chen, Hongmei; Herndon, Elizabeth M; Chu, Rosalie K; Tolic, Nikola; Portier, Evan F; Roy Chowdhury, Taniya; Robinson, Errol W; Callister, Stephen J; Wullschleger, Stan D; Graham, David E; Liang, Liyuan; Gu, Baohua

    2015-01-01

    Microbial degradation of soil organic matter (SOM) is a key process for terrestrial carbon cycling, although the molecular details of these transformations remain unclear. This study reports the application of ultrahigh resolution mass spectrometry to profile the molecular composition of SOM and its degradation during a simulated warming experiment. A soil sample, collected near Barrow, Alaska, USA, was subjected to a 40-day incubation under anoxic conditions and analyzed before and after the incubation to determine changes of SOM composition. A CHO index based on molecular C, H, and O data was utilized to codify SOM components according to their observed degradation potentials. Compounds with a CHO index score between -1 and 0 in a water-soluble fraction (WSF) demonstrated high degradation potential, with a highest shift of CHO index occurred in the N-containing group of compounds, while similar stoichiometries in a base-soluble fraction (BSF) did not. Additionally, compared with the classical H:C vs O:C van Krevelen diagram, CHO index allowed for direct visualization of the distribution of heteroatoms such as N in the identified SOM compounds. We demonstrate that CHO index is useful not only in characterizing arctic SOM at the molecular level but also enabling quantitative description of SOM degradation, thereby facilitating incorporation of the high resolution MS datasets to future mechanistic models of SOM degradation and prediction of greenhouse gas emissions.

  20. Pyrethroid-Degrading Microorganisms and Their Potential for the Bioremediation of Contaminated Soils: A Review

    Science.gov (United States)

    Cycoń, Mariusz; Piotrowska-Seget, Zofia

    2016-01-01

    Pyrethroid insecticides have been used to control pests in agriculture, forestry, horticulture, public health and for indoor home use for more than 20 years. Because pyrethroids were considered to be a safer alternative to organophosphate pesticides (OPs), their applications significantly increased when the use of OPs was banned or limited. Although, pyrethroids have agricultural benefits, their widespread and continuous use is a major problem as they pollute the terrestrial and aquatic environments and affect non-target organisms. Since pyrethroids are not degraded immediately after application and because their residues are detected in soils, there is an urgent need to remediate pyrethroid-polluted environments. Various remediation technologies have been developed for this purpose; however, bioremediation, which involves bioaugmentation and/or biostimulation and is a cost-effective and eco-friendly approach, has emerged as the most advantageous method for cleaning-up pesticide-contaminated soils. This review presents an overview of the microorganisms that have been isolated from pyrethroid-polluted sites, characterized and applied for the degradation of pyrethroids in liquid and soil media. The paper is focused on the microbial degradation of the pyrethroids that have been most commonly used for many years such as allethrin, bifenthrin, cyfluthrin, cyhalothrin, cypermethrin, deltamethrin, fenpropathrin, fenvalerate, and permethrin. Special attention is given to the bacterial strains from the genera Achromobacter, Acidomonas, Bacillus, Brevibacterium, Catellibacterium, Clostridium, Lysinibacillus, Micrococcus, Ochrobactrum, Pseudomonas, Serratia, Sphingobium, Streptomyces, and the fungal strains from the genera Aspergillus, Candida, Cladosporium, and Trichoderma, which are characterized by their ability to degrade various pyrethroids. Moreover, the current knowledge on the degradation pathways of pyrethroids, the enzymes that are involved in the cleavage of

  1. Evidence for the microbial degradation of imidacloprid in soils of Cameron Highlands

    Directory of Open Access Journals (Sweden)

    Nasrin Sabourmoghaddam

    2015-06-01

    Full Text Available Imidacloprid (1-[(6-chloro-3-pyridinylmethyl]-N-nitro-2-imidazolidinimine, with a novel mode of action is a recent systemic and contact insecticide with high activity against a wide range of pests. Continuous dispersion of this pesticide in the environment and its stability in soil results in environmental pollution which demands remediation. The present research was attempted to isolate and characterize imidacloprid degrading bacteria from vegetable farms of Cameron Highlands in Malaysia. The degradation ability of the isolates was tested in minimal salt medium (MSM for a duration of 25 days and the selected strains were characterized based on their biochemical and molecular characteristics. Levels of imidacloprid in MSM medium were analyzed by high performance liquid chromatography (HPLC. Among 50 soil bacterial isolates Bacillus sp., Brevibacterium sp., Pseudomonas putida F1, Bacillus subtilis and Rhizobium sp. were able to degrade 25.36–45.48% of the initial amount of imidacloprid at the concentration of 25 mg L−1 in C limited media. Brevibacterium sp. was isolated from organic farms that had never been exposed to imidacloprid while the other farms had previously been exposed to different levels of imidacloprid. All bacteria introduced in this study were among the first reports of imidacloprid degrading isolates in C limited media from tropical soil. Therefore, the results of this study demonstrate the effectiveness of using soil bacteria for microbial degradation of imidacloprid. These findings suggest that these strains may be promising candidates for bioremediation of imidacloprid-contaminated soils.

  2. Pyrethroid-Degrading Microorganisms and Their Potential for the Bioremediation of Contaminated Soils: A Review

    Directory of Open Access Journals (Sweden)

    Mariusz Sebastian Cycoń

    2016-09-01

    Full Text Available Pyrethroid insecticides have been used to control pests in agriculture, forestry, horticulture, public health and for indoor home use for more than 20 years. Because pyrethroids were considered to be a safer alternative to organophosphate pesticides (OPs, their applications significantly increased when the use of OPs was banned or limited. Although pyrethroids have agricultural benefits, their widespread and continuous use is a major problem as they pollute the terrestrial and aquatic environments and affect non-target organisms. Since pyrethroids are not degraded immediately after application and because their residues are detected in soils, there is an urgent need to remediate pyrethroid-polluted environments. Various remediation technologies have been developed for this purpose; however, bioremediation, which involves bioaugmentation and/or biostimulation and is a cost-effective and eco-friendly approach, has emerged as the most advantageous method for cleaning-up pesticide-contaminated soils. This review presents an overview of the microorganisms that have been isolated from pyrethroid-polluted sites, characterized and applied for the degradation of pyrethroids in liquid and soil media. The paper is focused on the microbial degradation of the pyrethroids that have been most commonly used for many years such as allethrin, bifenthrin, cyfluthrin, cyhalothrin, cypermethrin, deltamethrin, fenpropathrin, fenvalerate and permethrin. Special attention is given to the bacterial strains from the genera Achromobacter, Acidomonas, Bacillus, Brevibacterium, Catellibacterium, Clostridium, Lysinibacillus, Micrococcus, Ochrobactrum, Pseudomonas, Serratia, Sphingobium, Streptomyces and the fungal strains from the genera Aspergillus, Candida, Cladosporium and Trichoderma, which are characterized by their ability to degrade various pyrethroids. Moreover, the current knowledge on the degradation pathways of pyrethroids, the enzymes that are involved in the

  3. Microbial degradation and impact of Bracken toxin ptaquiloside on microbial communities in soil

    DEFF Research Database (Denmark)

    Engel, Pernille; Brandt, Kristian Koefoed; Rasmussen, Lars Holm

    2007-01-01

    ), but not in the NZ soil (weak acid loamy Entisol). In the DK soil PTA turnover was predominantly due to microbial degradation (biodegradation); chemical hydrolysis was occurring mainly in the uppermost A horizon where pH was very low (3.4). Microbial activity (basal respiration) and growth ([3H]leucine incorporation...... assay) increased after PTA exposure, indicating that the Bracken toxin served as a C substrate for the organotrophic microorganisms. On the other hand, there was no apparent impact of PTA on community size as measured by substrate-induced respiration or composition as indicated by community......-level physiological profiles. Our results demonstrate that PTA stimulates microbial activity and that microorganisms play a predominant role for rapid PTA degradation in Bracken-impacted soils....

  4. Biofuel components change the ecology of bacterial volatile petroleum hydrocarbon degradation in aerobic sandy soil

    International Nuclear Information System (INIS)

    Elazhari-Ali, Abdulmagid; Singh, Arvind K.; Davenport, Russell J.; Head, Ian M.; Werner, David

    2013-01-01

    We tested the hypothesis that the biodegradation of volatile petroleum hydrocarbons (VPHs) in aerobic sandy soil is affected by the blending with 10 percent ethanol (E10) or 20 percent biodiesel (B20). When inorganic nutrients were scarce, competition between biofuel and VPH degraders temporarily slowed monoaromatic hydrocarbon degradation. Ethanol had a bigger impact than biodiesel, reflecting the relative ease of ethanol compared to methyl ester biodegradation. Denaturing gradient gel electrophoresis (DGGE) of bacterial 16S rRNA genes revealed that each fuel mixture selected for a distinct bacterial community, each dominated by Pseudomonas spp. Despite lasting impacts on soil bacterial ecology, the overall effects on VHP biodegradation were minor, and average biomass yields were comparable between fuel types, ranging from 0.40 ± 0.16 to 0.51 ± 0.22 g of biomass carbon per gram of fuel carbon degraded. Inorganic nutrient availability had a greater impact on petroleum hydrocarbon biodegradation than fuel composition. Highlights: ► The effect of 10% ethanol or 20% biodiesel on the biodegradability of volatile petroleum hydrocarbons in soil was investigated. ► Competition for scarce inorganic nutrients between biofuel and VPH degraders slowed monoaromatic hydrocarbon degradation. ► Biofuel effects were transitional. ► Each fuel selected for a distinct predominant bacterial community. ► All bacterial communities were dominated by Pseudomonas spp. - Blending of petroleum with ethanol or biodiesel changes the fuel degrading soil bacterial community structure, but the long-term effects on fuel biodegradability are minor.

  5. Predicting where enhanced atrazine degradation will occur based on soil pH and herbicide use history

    Science.gov (United States)

    Soil bacteria on all continents except Antartica have developed the ability to rapidly degrade the herbicide atrazine, a phenomenon referred to as enhanced degradation. The agronomic significance of enhanced degradation is the potential for reduced residual weed control with atrazine in Corn, Sorgh...

  6. Analytical tools for assessing land degradation and its impact on soil quality

    Science.gov (United States)

    Bindraban, P. S.; Mantel, S.; Bai, Z.; de Jong, R.

    2010-05-01

    Maintaining and enhancing the quality of land is of major importance to sustain future production capacity for food and other agriculture based products like fibers and wood, and for maintaining ecosystems services, including below and above ground biodiversity, provision of soil water and sequestration of carbon. Deterioration of this production base will be detrimental to the provision of the foreseen dramatic increase in human needs for goods and services. For this reason, land degradation, defined as a long-term loss in ecosystem function and productivity, has to be understood properly. Climate, soils, topography and socioeconomic activities are primary factors that can cause, by themselves or in combination, a number of temporary or permanent changes in the landscape, leading to degradation of vegetation and soils. For identifying intervention measures to prevent and revert trends of land deterioration, it is fundamental to know the extent of land degradation and to understand its impact on functional properties of land. To assess the global extent, (Bai et al. 2008) apply a remotely sensed vegetation index that describes the greenness of the vegetation cover as a proxy for biomass. Biomass production has been identified as a strong indicator for soil quality as it is an integral measure for soil, crop and environmental characteristics (Bindraban et al., 2000). Bai and colleagues observed that 24% of the global land has been degrading over the past 26 years - often in very productive areas. The relation with functional properties of land can be made through ecosystem models. Mantel et al. (1999; 2000) applied dynamic crop-soil models to calculate crop productivity at the national level. A baseline scenario that represents the current conditions and a scenario for 20 years of prolonged sheet erosion were modeled to calculate the productivity impact of topsoil erosion for wheat in Uruguay and for maize in Kenya. They concluded that topsoil erosion primarily

  7. Catalytic degradation of the soil fumigant 1,3-dichloropropene in aqueous biochar slurry

    Energy Technology Data Exchange (ETDEWEB)

    Qin, Jiaolong [School of Agriculture and Biology, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai 200240 (China); Cheng, Yuxiao; Sun, Mingxing [Shanghai Entry–Exit Inspection and Quarantine Bureau, Shanghai 200135 (China); Yan, Lili [School of Agriculture and Biology, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai 200240 (China); Shen, Guoqing, E-mail: gqsh@sjtu.edu.cn [School of Agriculture and Biology, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai 200240 (China)

    2016-11-01

    Biochar has been explored as a cost-effective sorbent of contaminants, such as soil fumigant. However, contaminant-loaded biochar probably becomes a source of secondary air pollution. In this study, biochars developed from cow manure and rice husk at 300 °C or 700 °C were used to investigate the catalytic degradation of the soil fumigant 1,3-dichloropropene (1,3-D) in aqueous biochar slurry. Results showed that the adsorption of 1,3-D on the biochars was influenced by Langmuir surface monolayer adsorption. The maximum adsorption capacity of cow manure was greater than that of rice husk at the same pyrolysis temperature. Batch experiments revealed that 1,3-D degradation was improved in aqueous biochar slurry. The most rapid 1,3-D degradation occurred on cow manure-derived biochar produced at 300 °C (C-300), with t{sub 1/2} = 3.47 days. The degradation efficiency of 1,3-D on C-300 was 95.52%. Environmentally persistent free radicals (EPFRs) in biochars were detected via electron paramagnetic resonance (EPR) techniques. Dissolved organic matter (DOM) and hydroxyl radical (·OH) in biochars were detected by using a fluorescence spectrophotometer coupled with a terephthalic acid trapping method. The improvement of 1,3-D degradation efficiency may be attributed to EPFRs and DOM in aqueous biochar slurry. Our results may pose implications in the development of effective reduction strategies for soil fumigant emission with biochar. - Highlights: • Hydrolysis of 1,3-D was accelerated in aqueous biochar slurry. • 1,3-D adsorption kinetics on biochars fitted well with Langmuir model. • Cow manure biochar showed higher catalytic degradation activity for 1,3-D than rice husk biochar did. • EPFRs and DOM have potential roles in 1,3-D degradation on biochar.

  8. Catalytic degradation of the soil fumigant 1,3-dichloropropene in aqueous biochar slurry

    International Nuclear Information System (INIS)

    Qin, Jiaolong; Cheng, Yuxiao; Sun, Mingxing; Yan, Lili; Shen, Guoqing

    2016-01-01

    Biochar has been explored as a cost-effective sorbent of contaminants, such as soil fumigant. However, contaminant-loaded biochar probably becomes a source of secondary air pollution. In this study, biochars developed from cow manure and rice husk at 300 °C or 700 °C were used to investigate the catalytic degradation of the soil fumigant 1,3-dichloropropene (1,3-D) in aqueous biochar slurry. Results showed that the adsorption of 1,3-D on the biochars was influenced by Langmuir surface monolayer adsorption. The maximum adsorption capacity of cow manure was greater than that of rice husk at the same pyrolysis temperature. Batch experiments revealed that 1,3-D degradation was improved in aqueous biochar slurry. The most rapid 1,3-D degradation occurred on cow manure-derived biochar produced at 300 °C (C-300), with t 1/2 = 3.47 days. The degradation efficiency of 1,3-D on C-300 was 95.52%. Environmentally persistent free radicals (EPFRs) in biochars were detected via electron paramagnetic resonance (EPR) techniques. Dissolved organic matter (DOM) and hydroxyl radical (·OH) in biochars were detected by using a fluorescence spectrophotometer coupled with a terephthalic acid trapping method. The improvement of 1,3-D degradation efficiency may be attributed to EPFRs and DOM in aqueous biochar slurry. Our results may pose implications in the development of effective reduction strategies for soil fumigant emission with biochar. - Highlights: • Hydrolysis of 1,3-D was accelerated in aqueous biochar slurry. • 1,3-D adsorption kinetics on biochars fitted well with Langmuir model. • Cow manure biochar showed higher catalytic degradation activity for 1,3-D than rice husk biochar did. • EPFRs and DOM have potential roles in 1,3-D degradation on biochar.

  9. An integrated (nano-bio) technique for degradation of γ-HCH contaminated soil

    Energy Technology Data Exchange (ETDEWEB)

    Singh, Ritu [Ecotoxicology Division, CSIR-Indian Institute of Toxicology Research, Post Box 80, Mahatma Gandhi Marg, Lucknow 226 001, UP (India); Analytical Chemistry Division, CSIR-Indian Institute of Toxicology Research, Post Box 80, Mahatma Gandhi Marg, Lucknow 226 001, UP (India); Manickam, Natesan [Environmental Biotechnology Division, CSIR-Indian Institute of Toxicology Research, Post Box 80, Mahatma Gandhi Marg, Lucknow 226 001, UP (India); Mudiam, Mohana Krishna Reddy [Analytical Chemistry Division, CSIR-Indian Institute of Toxicology Research, Post Box 80, Mahatma Gandhi Marg, Lucknow 226 001, UP (India); Murthy, Ramesh Chandra, E-mail: murthyrc729@gmail.com [Analytical Chemistry Division, CSIR-Indian Institute of Toxicology Research, Post Box 80, Mahatma Gandhi Marg, Lucknow 226 001, UP (India); Misra, Virendra, E-mail: virendra_misra2001@yahoo.co.in [Ecotoxicology Division, CSIR-Indian Institute of Toxicology Research, Post Box 80, Mahatma Gandhi Marg, Lucknow 226 001, UP (India)

    2013-08-15

    Highlights: • An integrated (nano-bio) technique is employed to degrade γ-HCH in soil. • Degradation efficiency of γ-HCH in integrated and individual systems is compared. • Synergistic effect was noticed on γ-HCH degradation in integrated system. • Integrated system was found 1.7–2.1 times more efficient than individual methods. • This technique could be exploited for other chlorinated pesticides as well. -- Abstract: We have evaluated the effect of an integrated (nano-bio) technique involving the use of stabilized Pd/Fe{sup 0} bimetallic nanoparticles (CMC-Pd/nFe{sup 0}) and a Sphingomonas sp. strain NM05, on the degradation of γ-HCH in soil. Factors affecting degradation such as pH, incubation temperature and γ-HCH initial concentration were also studied. The results revealed that γ-HCH degradation efficiency is ∼ 1.7–2.1 times greater in integrated system as compared to system containing either NM05 or CMC-Pd/nFe{sup 0} alone. The integration showed synergistic effect on γ-HCH degradation. Further, cell growth studies indicated that NM05 gets well acclimatized to nanoparticles, showing potential growth in the presence of CMC-Pd/nFe{sup 0} with respect to control system. This study signifies the potential efficacy of integrated technique to become an effective alternative remedial tool for γ-HCH contaminated soil. Further research in this direction could lead to the development of effective remediation strategies for other isomers of HCH and other chlorinated pesticides as well.

  10. Soil bacteria showing a potential of chlorpyrifos degradation and plant growth enhancement

    Directory of Open Access Journals (Sweden)

    Shamsa Akbar

    Full Text Available ABSTRACT Background: Since 1960s, the organophosphate pesticide chlorpyrifos has been widely used for the purpose of pest control. However, given its persistence and toxicity towards life forms, the elimination of chlorpyrifos from contaminated sites has become an urgent issue. For this process bioremediation is the method of choice. Results: Two bacterial strains, JCp4 and FCp1, exhibiting chlorpyrifos-degradation potential were isolated from pesticide contaminated agricultural fields. These isolates were able to degrade 84.4% and 78.6% of the initial concentration of chlorpyrifos (100 mg L-1 within a period of only 10 days. Based on 16S rRNA sequence analysis, these strains were identified as Achromobacter xylosoxidans (JCp4 and Ochrobactrum sp. (FCp1. These strains exhibited the ability to degrade chlorpyrifos in sterilized as well as non-sterilized soils, and were able to degrade 93-100% of the input concentration (200 mg kg-1 within 42 days. The rate of degradation in inoculated soils ranged from 4.40 to 4.76 mg-1 kg-1 d-1 with rate constants varying between 0.047 and 0.069 d-1. These strains also displayed substantial plant growth promoting traits such as phosphate solubilization, indole acetic acid production and ammonia production both in absence as well as in the presence of chlorpyrifos. However, presence of chlorpyrifos (100 and 200 mg L-1 was found to have a negative effect on indole acetic acid production and phosphate solubilization with percentage reduction values ranging between 2.65-10.6% and 4.5-17.6%, respectively. Plant growth experiment demonstrated that chlorpyrifos has a negative effect on plant growth and causes a decrease in parameters such as percentage germination, plant height and biomass. Inoculation of soil with chlorpyrifos-degrading strains was found to enhance plant growth significantly in terms of plant length and weight. Moreover, it was noted that these strains degraded chlorpyrifos at an increased rate (5

  11. Soil bacteria showing a potential of chlorpyrifos degradation and plant growth enhancement.

    Science.gov (United States)

    Akbar, Shamsa; Sultan, Sikander

    2016-01-01

    Since 1960s, the organophosphate pesticide chlorpyrifos has been widely used for the purpose of pest control. However, given its persistence and toxicity towards life forms, the elimination of chlorpyrifos from contaminated sites has become an urgent issue. For this process bioremediation is the method of choice. Two bacterial strains, JCp4 and FCp1, exhibiting chlorpyrifos-degradation potential were isolated from pesticide contaminated agricultural fields. These isolates were able to degrade 84.4% and 78.6% of the initial concentration of chlorpyrifos (100mgL(-1)) within a period of only 10 days. Based on 16S rRNA sequence analysis, these strains were identified as Achromobacter xylosoxidans (JCp4) and Ochrobactrum sp. (FCp1). These strains exhibited the ability to degrade chlorpyrifos in sterilized as well as non-sterilized soils, and were able to degrade 93-100% of the input concentration (200mgkg(-1)) within 42 days. The rate of degradation in inoculated soils ranged from 4.40 to 4.76mg(-1)kg(-1)d(-1) with rate constants varying between 0.047 and 0.069d(-1). These strains also displayed substantial plant growth promoting traits such as phosphate solubilization, indole acetic acid production and ammonia production both in absence as well as in the presence of chlorpyrifos. However, presence of chlorpyrifos (100 and 200mgL(-1)) was found to have a negative effect on indole acetic acid production and phosphate solubilization with percentage reduction values ranging between 2.65-10.6% and 4.5-17.6%, respectively. Plant growth experiment demonstrated that chlorpyrifos has a negative effect on plant growth and causes a decrease in parameters such as percentage germination, plant height and biomass. Inoculation of soil with chlorpyrifos-degrading strains was found to enhance plant growth significantly in terms of plant length and weight. Moreover, it was noted that these strains degraded chlorpyrifos at an increased rate (5.69mg(-1)kg(-1)d(-1)) in planted soil. The

  12. Soil Seed Bank and Plant Community Development in Passive Restoration of Degraded Sandy Grasslands

    Directory of Open Access Journals (Sweden)

    Renhui Miao

    2016-06-01

    Full Text Available To evaluate the efficacy of passive restoration on soil seed bank and vegetation recovery, we measured the species composition and density of the soil seed bank, as well as the species composition, density, coverage, and height of the extant vegetation in sites passively restored for 0, 4, 7, and 12 years (S0, S4, S7, and S12 in a degraded grassland in desert land. Compared with S0, three more species in the soil seed bank at depths of 0–30 cm and one more plant species in the community was detected in S12. Seed density within the topsoil (0–5 cm was five times higher in S12 than that in S0. Plant densities in S7 and S12 were triple and quadruple than that in S0. Plant coverage was increased by 1.5 times (S4, double (S7, and triple (S12 compared with S0. Sørensen’s index of similarity in species composition between the soil seed bank and the plant community were high (0.43–0.63, but it was lower in short-term restoration sites (S4 and S7 than that in no and long-term restoration sites (S0 and S12. The soil seed bank recovered more slowly than the plant community under passive restoration. Passive restoration is a useful method to recover the soil seed bank and vegetation in degraded grasslands.

  13. The importance of Soil Science to understand and remediate Land Degradation and Desertification processes

    Science.gov (United States)

    Bouma, Johan; Keesstra, Saskia; Cerdà, Artemi

    2017-04-01

    Documentation is abundantly available to demonstrate the devastating effect of Land degradation and desertification on sustainable development in many countries. This present a major barrier to achieving the UN Sustainable Development Goals by 2030, as agreed upon at the General Assembly of the UN in September 2015. Research has certainly been successful in reversing these two processes in many case studies but persistant problems remain not only in developing countries but also in developed countries where, for example, soil compaction and loss of soil organic matter due to the industrialization of agriculture, result in a structural decline of agricultural productivity and environmental quality. The problems are quite complex because not only technical matters play a role but also, and often quite prominantly, socio-economic factors. What turn out to be successful remediation procedures at a given location or region, based on the characterization of underlying soil processes, will most likely not work in other regions inhibiting the extrapolation of local research results to areas elsewhere. One important reason for location specificity of research is the variation of soil properties in combination with the location of soils in a given landscape which governs its water, energy and nutrient dynamics, also considering the climate. Different soils are characterized by different natural riks for degradation and , in arid regions, deserticification and their particular remediation potential differs widely as well. Such risks can sometimes be overcome by innovative soil management and knowing the soil type, the climate and landscape processes, extrapolation of such types of innovative management to comparable soils and landscapes elsewhere may be feasible and effective , provided that socio-economic conditions allow the required risk-reducing measures to be realized in practice. More cooperation between soil scientists and physical geographers, familiar with landscape

  14. Bioremediation of soil polluted with crude oil and its derivatives: Microorganisms, degradation pathways, technologies

    Directory of Open Access Journals (Sweden)

    Beškoski Vladimir P.

    2012-01-01

    Full Text Available The contamination of soil and water with petroleum and its products occurs due to accidental spills during exploitation, transport, processing, storing and use. In order to control the environmental risks caused by petroleum products a variety of techniques based on physical, chemical and biological methods have been used. Biological methods are considered to have a comparative advantage as cost effective and environmentally friendly technologies. Bioremediation, defined as the use of biological systems to destroy and reduce the concentrations of hazardous waste from contaminated sites, is an evolving technology for the removal and degradation of petroleum hydrocarbons as well as industrial solvents, phenols and pesticides. Microorganisms are the main bioremediation agents due to their diverse metabolic capacities. In order to enhance the rate of pollutant degradation the technology optimizes the conditions for the growth of microorganisms present in soil by aeration, nutrient addition and, if necessary, by adding separately prepared microorganisms cultures. The other factors that influence the efficiency of process are temperature, humidity, presence of surfactants, soil pH, mineral composition, content of organic substance of soil as well as type and concentration of contaminant. This paper presents a review of our ex situ bioremediation procedures successfully implemented on the industrial level. This technology was used for treatment of soils contaminated by crude oil and its derivatives originated from refinery as well as soils polluted with oil fuel and transformer oil.

  15. Determination of soil degradation from flooding for estimating ecosystem services in Slovakia

    Science.gov (United States)

    Hlavcova, Kamila; Szolgay, Jan; Karabova, Beata; Kohnova, Silvia

    2015-04-01

    Floods as natural hazards are related to soil health, land-use and land management. They not only represent threats on their own, but can also be triggered, controlled and amplified by interactions with other soil threats and soil degradation processes. Among the many direct impacts of flooding on soil health, including soil texture, structure, changes in the soil's chemical properties, deterioration of soil aggregation and water holding capacity, etc., are soil erosion, mudflows, depositions of sediment and debris. Flooding is initiated by a combination of predispositive and triggering factors and apart from climate drivers it is related to the physiographic conditions of the land, state of the soil, land use and land management. Due to the diversity and complexity of their potential interactions, diverse methodologies and approaches are needed for describing a particular type of event in a specific environment, especially in ungauged sites. In engineering studies and also in many rainfall-runoff models, the SCS-CN method has remained widely applied for soil and land use-based estimations of direct runoff and flooding potential. The SCS-CN method is an empirical rainfall-runoff model developed by the USDA Natural Resources Conservation Service (formerly called the Soil Conservation Service or SCS). The runoff curve number (CN) is based on the hydrological soil characteristics, land use, land management and antecedent saturation conditions of soil. Since the method and curve numbers were derived on the basis of an empirical analysis of rainfall-runoff events from small catchments and hillslope plots monitored by the USDA, the use of the method for the conditions of Slovakia raises uncertainty and can cause inaccurate results in determining direct runoff. The objective of the study presented (also within the framework of the EU-FP7 RECARE Project) was to develop the SCS - CN methodology for the flood conditions in Slovakia (and especially for the RECARE pilot site

  16. Degradation of 14C - DDT in soils under moist and flooded conditions with rice straw and green manure amendments

    International Nuclear Information System (INIS)

    Dubey, S.; Dubey, P.S.; Kale, S.P.; Murthy, N.B.K.

    2001-01-01

    Degradation of 14 C - DDT in moist and flooded soils was studied with rice straw and green manure amendments for 100 days. The mineralization of DDT was not significantly influenced by any of the treatments. Rice straw and green manure in flooded soil brought about decrease in extractable 14 C - residues with concomitant increase in soil bound residues. DDT has a very short residence in flooded soils though radiocarbon was more in extractable residues. DDD is the major degradation product in flooded soils. (author)

  17. Effect of sunlight irradiation on photocatalytic pyrene degradation in contaminated soils by micro-nano size TiO2

    International Nuclear Information System (INIS)

    Chang Chien, S.W.; Chang, C.H.; Chen, S.H.; Wang, M.C.; Madhava Rao, M.; Satya Veni, S.

    2011-01-01

    The enhanced catalytic pyrene degradation in quartz sand and alluvial and red soils by micro-nano size TiO 2 in the presence and absence of sunlight was investigated. The results showed that the synergistic effect of sunlight irradiation and TiO 2 was more efficient on pyrene degradation in quartz sand and red and alluvial soils than the corresponding reaction system without sunlight irradiation. In the presence of sunlight irradiation, the photooxidation (without TiO 2 ) of pyrene was very pronounced in alluvial and red soils and especially in quartz sand. However, in the absence of sunlight irradiation, the catalytic pyrene degradation by TiO 2 and the photooxidation (without TiO 2 ) of pyrene were almost nil. This implicates that ultra-violet (UV) wavelength range of sunlight plays an important role in TiO 2 -enhanced photocatalytic pyrene degradation and in photooxidation (without TiO 2 ) of pyrene. The percentages of photocatalytic pyrene degradation by TiO 2 in quartz sand, alluvial and red soils under sunlight irradiation were 78.3, 23.4, and 31.8%, respectively, at 5 h reaction period with a 5% (w/w) dose of the amended catalyst. The sequence of TiO 2 -enhanced catalytic pyrene degradation in quartz sand and alluvial and red soils was quartz sand > red soil > alluvial soil, due to different texture and total organic carbon (TOC) contents of the quartz sand and other two soils. The differential Fourier transform infrared (FT-IR) spectra of degraded pyrene in alluvial soil corroborate that TiO 2 -enhanced photocatalytic degradation rate of degraded pyrene was much greater than photooxidation (without TiO 2 ) rate of degraded pyrene. Based on the data obtained, the importance for the application of TiO 2 -enhanced photocatalytic pyrene degradation and associated organic contaminants in contaminated soils was elucidated. - Highlights: → Synergistic effect of sunlight irradiation and TiO 2 promoted degradation of pyrene. → Micro-nano size TiO 2 enhanced

  18. New strains of oil-degrading microorganisms for treating contaminated soils and wastes

    Science.gov (United States)

    Muratova, A. Yu; Panchenko, L. V.; Semina, D. V.; Golubev, S. N.; Turkovskaya, O. V.

    2018-01-01

    Two new strains Achromobacter marplatensis101n and Acinetobacter sp. S-33, capable of degrading 49 and 46% of oil within 7 days were isolated, identified, and characterized. The application of A. marplatensis 101n in combination with ammonium nitrate (100 mg·kg-1) for 30 days of cultivation resulted in the degradation of 49% of the initial total petroleum hydrocarbon content (274 g·kg-1) in the original highly acid (pH 4.9) oil-contaminated waste. Up to 30% of oil sludge added to a liquid mineral medium at a concentration of 15% was degraded after 10 days of cultivation of A. marplatensis 101n. Application of yellow alfalfa (Medicago falcata L.) plants with Acinetobacter sp. S-33 for bioremediation of oil-sludge-contaminated soil improved the quality of cleanup in comparison with the bacterium- or plant-only treatment. Inoculation of Acinetobacter sp. S-33 increased the growth of both roots and shoots by more than 40%, and positively influenced the soil microflora. We conclude that the new oil-degrading strains, Acinetobacter sp. S-33 and A. marplatensis 101n, can serve as the basis for new bioremediation agents for the treatment of oil contaminated soils and waste.

  19. Degradation of hydrocarbons in soil samples analyzed within accepted analytical holding times

    International Nuclear Information System (INIS)

    Jackson, J.; Thomey, N.; Dietlein, L.F.

    1992-01-01

    Samples which are collected in conjunction with subsurface investigations at leaking petroleum storage tank sites and petroleum refineries are routinely analyzed for benzene, toluene, ethylbenzene, xylenes (BTEX), and total petroleum hydrocarbons (TPH). Water samples are preserved by the addition of hydrochloric acid and maintained at four degrees centigrade prior to analysis. This is done to prevent bacterial degradation of hydrocarbons. Chemical preservation is not presently performed on soil samples. Instead, the samples are cooled and maintained at four degrees centigrade. This study was done to measure the degree of degradation of hydrocarbons in soil samples which are analyzed within accepted holding times. Soil samples were collected and representative subsamples were prepared from the initial sample. Subsamples were analyzed in triplicate for BTEX and TPH throughout the length of the approved holding times to measure the extent of sample constituent degradation prior to analysis. Findings imply that for sandy soils, BTEX and TPH concentrations can be highly dependent upon the length of time which elapses between sample collection and analysis

  20. Least limiting water range of Udox soil under degraded pastures on different sun-exposed faces

    Science.gov (United States)

    Passos, Renato Ribeiro; Marciano da Costa, Liovando; Rodrigues de Assis, Igor; Santos, Danilo Andrade; Ruiz, Hugo Alberto; Guimarães, Lorena Abdalla de Oliveira Prata; Andrade, Felipe Vaz

    2017-07-01

    The efficient use of water is increasingly important and proper soil management, within the specificities of each region of the country, allows achieving greater efficiency. The South and Caparaó regions of Espírito Santo, Brazil are characterized by relief of `hill seas' with differences in the degree of pasture degradation due to sun exposure. The objective of this study was to evaluate the least limiting water range in Udox soil under degraded pastures with two faces of exposure to the sun and three pedoenvironments. In each pedoenvironment, namely Alegre, Celina, and Café, two areas were selected, one with exposure on the North/West face and the other on the South/East face. In each of these areas, undisturbed soil samples were collected at 0-10 cm depth to determine the least limiting water range. The exposed face of the pasture that received the highest solar incidence (North/West) presented the lowest values in least limiting water range. The least limiting water range proved to be a physical quality indicator for Udox soil under degraded pastures.

  1. Kinetic study of adsorption and degradation of aniline, benzoic acid, phenol, and diuron in soil suspensions

    International Nuclear Information System (INIS)

    Dao, T.H.; Lavy, T.L.

    1987-01-01

    Laboratory studies were conducted to investigate the effects of low temperature and accelerated soil-solution contact on soil adsorption of labile organic chemicals. The authors measured the kinetics of adsorption and degradation of 14 C-aniline, 14 C-benzoic acid, 14 C-phenol, and 14 C-diuron in the solution phase at 3 and 22 0 C. In the initial stages of reactions, the adsorption of all four chemicals was instantaneous at both temperatures under accelerated soil and solution mixing. A steady state was observed after the onset of equilibrium for the adsorption reaction for all compounds within 10 to 30 min. Its length varied according to the expected order of susceptibility to microbial degradation, i.e., diuron > aniline > phenol ≥ benzoate. It was apparent that the steady-state period without or in combination with low temperature could be advantageously used to obtain adsorption measurements in microbially active systems. A mechanistic sorption-catalyzed degradation model was evaluated to uncouple mathematically these processes. The model described satisfactorily the disappearance of labile chemicals in soil suspensions. Numerical analysis allowed the concurrent determination of adsorption, desorption, and biodegradation rate coefficients

  2. Degradation of sustainable mulch materials in two types of soil under laboratory conditions

    Science.gov (United States)

    Villena, Jaime; González, Sara; Moreno, Carmen; Aceituno, Patricia; Campos, Juan; Meco, Ramón; María Moreno, Marta

    2017-04-01

    Mulching is a technique used in cultivation worldwide, especially for vegetable crops, for reducing weed growth, minimising or eliminating soil erosion, and often for enhancing total yields. Manufactured plastic films, mainly polyethylene (PE), have been widely used for this purpose due to their excellent mechanical properties, light weight and relatively low prices in recent years. However, the use of PE is associated with serious environmental problems related to its petrochemical origin and its long shelf-life, which causes a waste problem in our crop fields. For this reason, the use of biodegradable mulch materials (biopolymers and papers) as alternative to PE is increasing nowadays, especially in organic farming. However, these materials can suffer an undesirable early degradation (and therefore not fulfilling their function successfully), greatly resulting from the type of soil. For this reason, this study aimed to analyse the degradation pattern of different mulch materials buried in two types of soils, clay and sand, under laboratory conditions (25°C, dark surroundings, constant humidity). The mulch materials used were: 1) black polyethylene (15 µm); black biopolymers (15 µm): 2) maize starch-based, 3) potato starch-based, 4) polylactic acid-based, 5) black paper, 85 g/m2. Periodically (every 15-20 days), the weight and surface loss of the different materials were recorded. The results indicate that mulch degradation was earlier and higher in the clay soil, especially in the paper and in the potato starch-based materials, followed by the maize starch-based mulch, while polylactic acid-based suffered the least and the latest degradation. Keywords: mulch, biodegradable, biopolymer, paper, degradation. Acknowledgements: the research was funded by Project RTA2011-00104-C04-03 from the INIA (Spanish Ministry of Economy and Competitiveness).

  3. Degradation of 14C-lindane in soils of planting ginseng

    International Nuclear Information System (INIS)

    Wang Zhengguo; Zhao Jing; Yao Jianren

    1992-01-01

    14 C-Lindane was used to study degradation of Lindane (γ-BHC) in different types of soil of planting ginseng. Results indicated that Lindane was very slowly mineralized after a 228 day's incubation period in closed system. It took about 9 years to completely mineralize Lindane in the chernozem, and 11 years in the brown calcareous at 20 ppm in the soils. In addition, the rate of Lindane mineralized depended on population and number of microorganism. In this test the fungi played more important role than the bacteria in the Lindane mineralization. 14 C-Lindane residues extracted from the soils were 77.43%-80.54%, and Lindane residues associated with the soils were 13.11%-20.77%

  4. Polyphenols as enzyme inhibitors in different degraded peat soils: Implication for microbial metabolism in rewetted peatlands

    Science.gov (United States)

    Zak, Dominik; Roth, Cyril; Gelbrecht, Jörg; Fenner, Nathalie; Reuter, Hendrik

    2015-04-01

    Recently, more than 30,000 ha of drained minerotrophic peatlands (= fens) in NE Germany were rewetted to restore their ecological functions. Due to an extended drainage history, a re-establishment of their original state is not expected in the short-term. Elevated concentrations of dissolved organic carbon, ammonium and phosphate have been measured in the soil porewater of the upper degraded peat layers of rewetted fens at levels of one to three orders higher than the values in pristine systems; an indicator of increased microbial activity in the upper degraded soil layers. On the other hand there is evidence that the substrate availability within the degraded peat layer is lowered since the organic matter has formerly been subject to intense decomposition over the decades of drainage and intense agricultural use of the areas. Previously however, it was suggested that inhibition of hydrolytic enzymes by polyphenolic substances is suspended during aeration of peat soils mainly due to the decomposition of the inhibiting polyphenols by oxidising enzymes such as phenol oxidase. Accordingly we hypothesised a lack of enzyme inhibiting polyphenols in degraded peat soils of rewetted fens compared to less decomposed peat of more natural fens. We collected both peat samples at the soil surface (0-20 cm) and fresh roots of dominating vascular plants and mosses (as peat parent material) from five formerly drained rewetted sites and five more natural sites of NE Germany and NW Poland. Less decomposed peat and living roots were used to obtain an internal standard for polyphenol analysis and to run enzyme inhibition tests. For all samples we determined the total phenolic contents and in addition we distinguished between the contents of hydrolysable and condensed tannic substances. From a methodical perspective the advantage of internal standards compared to the commercially available standards cyanidin chloride and tannic acid became apparent. Quantification with cyanidin or

  5. Degradation of biodegradable plastic mulch films in soil environment by phylloplane fungi isolated from gramineous plants

    OpenAIRE

    Koitabashi, Motoo; Noguchi, Masako T; Sameshima-Yamashita, Yuka; Hiradate, Syuntaro; Suzuki, Ken; Yoshida, Shigenobu; Watanabe, Takashi; Shinozaki, Yukiko; Tsushima, Seiya; Kitamoto, Hiroko K

    2012-01-01

    To improve the biodegradation of biodegradable plastic (BP) mulch films, 1227 fungal strains were isolated from plant surface (phylloplane) and evaluated for BP-degrading ability. Among them, B47-9 a strain isolated from the leaf surface of barley showed the strongest ability to degrade poly-(butylene succinate-co-butylene adipate) (PBSA) and poly-(butylene succinate) (PBS) films. The strain grew on the surface of soil-mounted BP films, produced breaks along the direction of hyphal growth ind...

  6. Passive warming effect on soil microbial community and humic substance degradation in maritime Antarctic region.

    Science.gov (United States)

    Kim, Dockyu; Park, Ha Ju; Kim, Jung Ho; Youn, Ui Joung; Yang, Yung Hun; Casanova-Katny, Angélica; Vargas, Cristina Muñoz; Venegas, Erick Zagal; Park, Hyun; Hong, Soon Gyu

    2018-06-01

    Although the maritime Antarctic has undergone rapid warming, the effects on indigenous soil-inhabiting microorganisms are not well known. Passive warming experiments using open-top chamber (OTC) have been performed on the Fildes Peninsula in the maritime Antarctic since 2008. When the soil temperature was measured at a depth of 2-5 cm during the 2013-2015 summer seasons, the mean temperature inside OTC (OTC-In) increased by approximately 0.8 °C compared with outside OTC (OTC-Out), while soil chemical and physical characteristics did not change. Soils (2015 summer) from OTC-In and OTC-Out were subjected to analysis for change in microbial community and degradation rate of humic substances (HS, the largest pool of recalcitrant organic carbon in soil). Archaeal and bacterial communities in OTC-In were minimally affected by warming compared with those in OTC-Out, with archaeal methanogenic Thermoplasmata slightly increased in abundance. The abundance of heterotrophic fungi Ascomycota was significantly altered in OTC-In. Total bacterial and fungal biomass in OTC-In increased by 20% compared to OTC-Out, indicating that this may be due to increased microbial degradation activity for soil organic matter (SOM) including HS, which would result in the release of more low-molecular-weight growth substrates from SOM. Despite the effects of warming on the microbial community over the 8-years-experiments warming did not induce any detectable change in content or structure of polymeric HS. These results suggest that increased temperature may have significant and direct effects on soil microbial communities inhabiting maritime Antarctic and that soil microbes would subsequently provide more available carbon sources for other indigenous microbes. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  7. The production and degradation of trichloroacetic acid in soil: Results from in situ soil column experiments

    Czech Academy of Sciences Publication Activity Database

    Heal, M. R.; Dickey, C. A.; Heal, K.V.; Stidson, R.T.; Matucha, Miroslav; Cape, J. N.

    2010-01-01

    Roč. 79, č. 4 (2010), s. 401-407 ISSN 0045-6535 Institutional research plan: CEZ:AV0Z50380511 Keywords : Trichloroacetic acid * TCA * Soil lysimeter Subject RIV: DK - Soil Contamination ; De-contamination incl. Pesticides Impact factor: 3.155, year: 2010

  8. Bioremediation of diuron contaminated soils by a novel degrading microbial consortium.

    Science.gov (United States)

    Villaverde, J; Rubio-Bellido, M; Merchán, F; Morillo, E

    2017-03-01

    Diuron is a biologically active pollutant present in soil, water and sediments. It is persistent in soil, water and groundwater and slightly toxic to mammals and birds as well as moderately toxic to aquatic invertebrates. Its principal product of biodegradation, 3,4-dichloroaniline, exhibits a higher toxicity than diuron and is also persistent in the environment. On this basis, the objective of the study was to determine the potential capacity of a proposed novel diuron-degrading microbial consortium (DMC) for achieving not only diuron degradation, but its mineralisation both in solution as well as in soils with different properties. The consortium was tested in a soil solution where diuron was the only carbon source, and more than 98.8% of the diuron initially added was mineralised after only a few days. The consortium was composed of three diuron-degrading strains, Arthrobacter sulfonivorans, Variovorax soli and Advenella sp. JRO, the latter had been isolated in our laboratory from a highly contaminated industrial site. This work shows for the first time the potential capacity of a member of the genus Advenella to remediate pesticide-contaminated soils. However, neither of the three strains separately achieved mineralisation (ring- 14 C) of diuron in a mineral medium (MSM) with a trace nutrient solution (NS); combined in pairs, they mineralised 40% of diuron in solution, but the most relevant result was obtained in the presence of the three-member consortium, where complete diuron mineralisation was achieved after only a few days. In the presence of the investigated soils in suspension, the capacity of the consortium to mineralise diuron was evaluated, achieving mineralisation of a wide range of herbicides from 22.9 to 69.0%. Copyright © 2016 Elsevier Ltd. All rights reserved.

  9. Effects of interactions between Collembola and soil microbial community on the degradation of glyphosate-based herbicide

    Science.gov (United States)

    Wee, J.; Lee, Y. S.; Son, J.; Kim, Y.; Nam, T. H.; Cho, K.

    2017-12-01

    Glyphosate is the most widely used herbicide because of its broad spectrum activity and effectiveness, however, little is known about adverse effects on non-target species and their interactions. Therefore, in this study, we investigated the effects of glyphosate on interactions between Collembola and soil microbial community and the effect of Collembola on degradation of glyphosate. The experiment carried out in PS container filled with 30g of soil according to OECD 232 guidelines. Investigating the effects of soil microbial community and Collembola on degradation of glyphosate, we prepared defaunated field soil (only maintaining soil microbial community, sampling in May and September, 2016.) and autoclaved soil with 0, 10, 30 adults of Paronychiurus kimi (Collembola) respectively. Survived adults and hatched juveniles of P. kimi were counted after 28-day exposures in both soils spiked with 100 mg/kg of glyphosate. Glyphosate in soil of 7, 14, 21, 28 days after spiking of glyphosate based herbicide was analyzed by spectrophotometer (Jan et al., 2009). Also soil microbial community structure was investigated using phospholipid fatty acids (PLFAs) composition analysis of soils following the procedures given by the Sherlock Microbial Identification System (MIDI Inc., Newark, DE). Glyphosate (100mg/kg soil) has no effects on reproduction and survival of P. kimi in any soils. Also, glyphosate in soils with Collembola was more rapidly degraded. Rapid increase of soil microbial biomass(PLFAs) was shown in soil with Collembola addition. This result showed that glyphosate affected interactions between Collembola and soil microorganisms, and also soil microbial community affected by Collembola changed degradation of glyphosate.

  10. Adsorption-desorption, mobility and degradation of 14C-Glyphosate in two soil series

    International Nuclear Information System (INIS)

    Ismail, B. S.; Zaifah Abdul Kadir; Khairiah Jusoh; Nashriyah Mat

    2002-01-01

    The adsorption desorption and degradation of glyphosate (Roundup) have been studied using 14 C glyphosate in two soils, namely Serdang Series and Sungai Buloh Series. The percentage of adsorption was not significantly different (p 14 C- glyphosate was detected in 0-10 cm zone of the two soils studied. However, in Sungai Buloh Series, a significant amount of 14 C-glyphosate was detected in the 10-20 cm zone. A small amount of 14 C radioactivity was also detected in the leachate of the two soils. The percentage of degradation in the Sungai Buloh and Serdang Series soils was higher at 10 μg/ml and 50 μg/ml, concentration, respectively. At 50 μg/ml concentration the Sungai Buloh Series soil showed higher glyphosate residue (83%) as compared to Serdang Series (48%). In contrast, the glyphosate residue was found to be higher in the Serdang Series (73916) as compared to the Sungai Buloh Series (30%) at 10 μg/ml concentration. (Author)

  11. Pesticides Usage in the Soil Quality Degradation Potential in Wanasari Subdistrict, Brebes, Indonesia

    Directory of Open Access Journals (Sweden)

    Tri Joko

    2017-01-01

    Full Text Available Uncontrolled application of pesticides can contaminate soil and may kill other nontarget organisms. This study aims to determine the usage pattern of pesticides by farmers in Wanasari Subdistrict and study the soil quality degradation potential. This study was a quantitative and qualitative research. Sources of data were collected from observation, questionnaire, and in-depth interview methods. The respondents were shallot farmers who planted shallot during 2013–2016 (n=60. In-depth interview was done with three respondents from the local agricultural extension center (BPP. This study found that there were some different types of insecticides and fungicides that were used in every planting season. The farmers applied pesticides in large amount once every three or four days. They mixed minimally three insecticides and fungicides types about 30–40 ml for each type. Organophosphate residues that were found in soil samples were methidathion residue about 0.014 mg/kg, malathion residue ranging around 0.1370–0.3630 mg/kg, and chlorpyrifos residue in the range of 0.0110–0.0630 mg/kg. The excessive application of pesticides showed the land degradation potential. Soil quality laboratory testing is recommended to ensure the agricultural land condition. Routine assessment of soil quality and pesticide usage control is recommended to keep sustainable ecosystem.

  12. Assessment of soil ecosystem in degraded areas of vineyards after organic treatments

    Science.gov (United States)

    Landi, Silvia; D'Errico, Giada; Gagnarli, Elena; Simoni, Sauro; Goggioli, Donatella; Guidi, Silvia; D'Avino, Lorenzo; Lagomarsino, Alessandra; Valboa, Giuseppe; Castaldini, Maurizio; Elio Agnelli, Alessandro; Fantappiè, Maria; Lorenzetti, Romina; Priori, Simone; Costantini, Edoardo A. C.

    2017-04-01

    In Italian vineyards, it is quite common to have areas characterized by problems in vine health, grape production and quality, often caused by improper land preparation before vine plantation and/or management. Causes for soil malfunctioning can include reduced contribution of the soil fauna to the ecosystem services such as nutrient cycles and organic matter turnover. ReSolVe is a transnational and interdisciplinary project, supported by Core-Organic+ program, aimed at testing the effects of selective agronomic strategies for restoring optimal soil functionality in degraded areas within organic vineyard. For this purpose, the evaluation and biomonitoring of the abundance of soil mesofauna, nematodes and microarthropods, represents an efficient tool to characterize the effects of crop management on soil quality. Assessing enzyme activities involved in the main biogeochemical cycling of C, N, P and S can also provide indication of soil functions and health status. Italian experimental plots are situated in two commercial farms in Tuscany: i) Fontodi, Panzano in Chianti (FI), which has been managed organically for more than 20 years and ii) San Disdagio, Roccastrada (GR), under organic farming since 2014. In each farm, three plots (250 m2 each) in the degraded areas and three relative control plots in the non-degraded areas were selected. The different restoring strategies implemented in each area were: i) compost, produced on farm by manure + pruning residue + grass, ii) faba bean and winter barley green manure, iii) dry mulching after sowing with Trifolium squarrosum L. Each treated and control plot has been studied for soil nematodes, microarthropods, enzymatic activity, and organic matter turnover using tea-bag index, as well as total organic carbon (TOC) and total nitrogen (TN). Soil sampling was carried out to 0-30 cm depth for TOC, TN, enzymes and nematodes and to 10 cm for microarthropods. Tea-bag index was determined following the Keuskamp et al. method

  13. Degradation and utilization of polycyclic aromatic hydrocarbons by indigenous soil bacteria

    International Nuclear Information System (INIS)

    Stetzenbach, L.D.A.

    1986-01-01

    The persistence of industrially derived polycyclic aromatic hydrocarbons in the subsurface may be significantly affected by the metabolism of soil bacteria. This study was conducted to determine the ability of indigenous soil bacteria to decrease the concentration of four polycyclic aromatic hydrocarbons (naphthalene, fluorene, anthracene, and pyrene) and to utilize the compounds as a substrate for growth. Soil cores from petroleum contaminated and noncontaminated sites contained 10 5 -10 7 viable microorganisms per gram dryweight of soil. Gram negative rod-shaped bacteria predominated. Decreases in the concentration of the four polycyclic aromatic hydrocarbons were observed during incubation with bacterial isolates in aqueous suspension by the use of high performance liquid chromatography. Corresponding increases in bacterial numbers indicated utilization of the compounds as a carbon source. Soil samples from the contaminated sites contained greater numbers of bacteria utilizing anthracene and pyrene than soil samples from uncontaminated sites. Degradation rates of the four polycyclic aromatic hydrocarbons were related to the compound, its concentration, and the bacterium. Biodegradation of pyrene was positively correlated with the presence of oxygen. Pyrene was biodegraded by an Acinetobacter sp. under aerobic conditions but not under anaerobic or microaerophilic conditions. Studies with radiolabeled 14 C-anthracene demonstrated utilization of the labeled carbon as a source of carbon by viable bacterial cells in aqueous suspension. Incorporation of 14 C into cellular biomass however was not observed during incubation of 14 C-anthracene in soil

  14. WSA index as an indicator of soil degradation due to erosion

    Science.gov (United States)

    Jaksik, Ondrej; Kodesova, Radka; Schmidtova, Zuzana; Kubis, Adam; Fer, Miroslav; Klement, Ales; Nikodem, Antonin

    2014-05-01

    Knowledge of spatial distribution of soil aggregate stability as an indicator of soil degradation vulnerability is required for many scientific and practical environmental studies. The goal of our study was to assess predisposition of different soil types to change aggregate stability due to erosion. Five agriculture arable lands with different soil types were chosen. The common feature of these sites is relatively large slope and thus soils are impacted by water erosion. The first studied area was in Brumovice. The original soil type was Haplic Chernozem on loess, which was due to erosion changed into Regosol (steep parts) and Colluvial soil (base slope and the tributary valley). A similar process has been described at other four locations Vidim, Sedlcany, Zelezna and Hostoun, where the original soil types were Haplic Luvisol on loess and Haplic Cambisol on gneiss, Haplic Cambisol on shales, and Calcaric Cambisol on marlstone, respectively. The regular and semi-regular soil sampling grids were set at all five sites. The basic soil properties were measured and stability of soil aggregates (WSA index) was evaluated. In all cases, the higher aggregates stability was observed in soils, which were not (or only slightly) affected by water erosion and at base slope and the tributary valley (eroded soil particle accumulation). The lowest aggregate stability was measured at the steepest parts. When comparing individual sites, the highest WSA index, e.g. aggregate stability, was found in Sedlcany (Cambisol). Lower WSA indexes were measured on aggregates from Hostoun (Cambisol), Zelezna (Cambisol), Vidim (Luvisol) and the lowest values were obtained in Brumovice (Chernozem). The largest WSA indexes for Cambisols in comparison to Luvisols and Chernozem could be attributed to higher organic matter content and presence of iron oxides. Slightly higher aggregate stability of Luvisols in comparison to Chernozem, could be explained by the positive influence of clay (especially in

  15. Degradation of MTBE and TBA by a new isolate from MTBE-contaminated soil.

    Science.gov (United States)

    Zhang, Rui-Ling; Huang, Guo-Qiang; Lian, Jing-Yan; Li, Xin-Gang

    2007-01-01

    Methyl tert-butyl ether (MTBE), a gasoline additive, possesses serious problems to the environmental health. In the present study, a bacterial culture named A-3 which could effectively degrade MTBE was isolated from the MTBE contaminated soil. The isolate was identified as Chryseobacterium sp., a new species capable of degrading MTBE. In order to enhance its degradation ability, selected environment factors were investigated. The results showed that the optimal temperature was in the range of 25-30 degrees C, the pH was 7.0, the inoculum size was 2 x 10(8) CFU/ml and the optimal concentration of MTBE was from 50 to 100 mg/L. The maximum MTBE utilization rate (upsilon(max)) was 102 nmol MTBE/(mg cell protein x h). Furthermore, it was found that the isolate could also degrade tert-butyl alcohol (TBA). The degradation rates of TBA were much faster than those of MTBE. The additional TBA would lead to the decrease of the initial MTBE degradation rate and the inhibitory effect of TBA increased with the increase of TBA concentration. Similar protein profiles at least seven peptides were demonstrated after SDS-PAGE analysis of crude extracts obtained from the cells growing in MTBE and TBA culture.

  16. Soil quality changes in land degradation as indicated by soil chemical, biochemical and microbiological properties in a karst area of southwest Guizhou, China

    Science.gov (United States)

    Zhang, Pingjiu; Li, Lianqing; Pan, Genxing; Ren, Jingchen

    2006-12-01

    Not only the nutritional status and biological activity but also the soil ecological functioning or soil health has been impacted profoundly by land degradation in the karst area of southwest China where the karst ecosystems are generally considered as extremely vulnerable to land degradation under intensified land-use changes. The objectives of this study are to elucidate the changes in overall soil quality by a holistic approach of soil nutritional, biological activity, and soil health indicators in the karst area as impacted by intense cultivation and vegetation degradation. Topsoil samples were collected on selected eco-tesserae in a sequence of land degradation in a karst area of southwest Guizhou in 2004. The soil nutrient pools of organic carbon (Corg), extractable extracellular carbon (Cext), total soil nitrogen (Nt), alkali-hydrolyzable nitrogen (Nah), total phosphorus (Pt), available phosphorus (Pa) were analyzed by wet soil chemistry. The soil biological properties were studied by means of measurements of microbial biomass carbon (both by fumigation-extraction, FE-Cmic, and by calculation from substrate-incubation respiration, SIR-Cmic) of respiration [respiration without addition of substrates, basal respiration (BR), and potential respiration (PR) with substrate-incubation] and of soil enzyme activities (invertase, urease, and alkaline phosphatase). Soil health status was assessed by simple indices of Cmic/Corg and BR/Cmic in conjunction with bacterial community structures determined by polymerase chain reaction and denaturing gradient gel electrophoresis. While the nutritional pool parameters, such as Corg and Cext, described basically the changes in soil life-supporting capacity with cultivation interference and vegetation declined, those parameters of biological activity such as FE-Cmic, SIR, and SIR-Cmic as well as bacterial community structures measured by molecular method evidenced well the changes in soil functioning for ecosystem health with

  17. Analysis of Soil Degradation Causes in Phyllostachys edulis Forests with Different Mulching Years

    Directory of Open Access Journals (Sweden)

    Jiancheng Zhao

    2018-03-01

    Full Text Available Moso bamboo (Phyllostachys edulis (Carrière J.Houz. is famous for its fast growth and biomass accumulation, as well as high annual output for timber and bamboo shoots. Organic mulches are widely used to improve shoots’ production in moso bamboo forests. However, continuous mulching management may cause bamboo forest degradation and affect sustainable development. The objective of this study was to identify the degradation mechanism and to provide a theoretical basis for recovery. A complete randomized block design with four treatments was conducted, including mulching for one year (M1, two years (M2, three years (M3 and no-mulching management (NM. Soil nutrient contents, enzyme activities and microbial biomass were determined. With the increase of mulching years, the soil pH value gradually reduced, causing soil acidification, but the content of soil organic matter was inclined to ascend. Soil total nitrogen (TN, total phosphorus (TP and total potassium (TK contents showed an increasing trend, and they were significantly higher in mulching stands than those in NM (p < 0.05. Contents of soil available nutrients (AN, AP and AK increased, then decreased with the increase of mulching years and peaked in M1. With the increase of mulching years, the soil stoichiometry ratio (C/N, C/P and N/P gradually increased. Soil invertase, urease and acid phosphatase activities presented a single-peak curve and reached the maximum within one year after mulching. Total microbial biomass and that of individual groups changed greatly after mulching. Soil microbial biomass increased first and then decreased, and it was the largest in M1. The fungi:bacteria ratio decreased in the first year and then began to rise, while the aerobic:anaerobic ratio showed the opposite trend. According to the overall results, M3 leads to soil acidification, imbalance of the nutrients’ proportion, abnormal enzyme activity and change of soil microbial flora, and rotated mulching

  18. Simplified MPN method for enumeration of soil naphthalene degraders using gaseous substrate.

    Science.gov (United States)

    Wallenius, Kaisa; Lappi, Kaisa; Mikkonen, Anu; Wickström, Annika; Vaalama, Anu; Lehtinen, Taru; Suominen, Leena

    2012-02-01

    We describe a simplified microplate most-probable-number (MPN) procedure to quantify the bacterial naphthalene degrader population in soil samples. In this method, the sole substrate naphthalene is dosed passively via gaseous phase to liquid medium and the detection of growth is based on the automated measurement of turbidity using an absorbance reader. The performance of the new method was evaluated by comparison with a recently introduced method in which the substrate is dissolved in inert silicone oil and added individually to each well, and the results are scored visually using a respiration indicator dye. Oil-contaminated industrial soil showed slightly but significantly higher MPN estimate with our method than with the reference method. This suggests that gaseous naphthalene was dissolved in an adequate concentration to support the growth of naphthalene degraders without being too toxic. The dosing of substrate via gaseous phase notably reduced the work load and risk of contamination. The result scoring by absorbance measurement was objective and more reliable than measurement with indicator dye, and it also enabled further analysis of cultures. Several bacterial genera were identified by cloning and sequencing of 16S rRNA genes from the MPN wells incubated in the presence of gaseous naphthalene. In addition, the applicability of the simplified MPN method was demonstrated by a significant positive correlation between the level of oil contamination and the number of naphthalene degraders detected in soil.

  19. Isolation and characterization of diesel degrading bacteria, Sphingomonas sp. and Acinetobacter junii from petroleum contaminated soil

    Science.gov (United States)

    Zhang, Qiuzhuo; Wang, Duanchao; Li, Mengmeng; Xiang, Wei-Ning; Achal, Varenyam

    2014-03-01

    Two indigenous bacteria of petroleum contaminated soil were characterized to utilize diesel fuel as the sole carbon and energy sources in this work. 16S rRNA gene sequence analysis identified these bacteria as Sphingomonas sp. and Acinetobacter junii. The ability to degrade diesel fuel has been demonstrated for the first time by these isolates. The results of IR analyses showed that Sphingomonas sp. VA1 and A. junii VA2 degraded up to 82.6% and 75.8% of applied diesel over 15 days, respectively. In addition, Sphingomonas sp. VA1 possessed the higher cellular hydrophobicities of 94% for diesel compared to 81% by A. junii VA2. The isolates Sphingomonas sp. VA1 and A. junii VA2 exhibited 24% and 18%, respectively emulsification activity. This study reports two new diesel degrading bacterial species, which can be effectively used for bioremediation of petroleum contaminated sites.

  20. Application of TAM III to study sensitivity of soil organic matter degradation to temperature

    Science.gov (United States)

    Vikegard, Peter; Barros, Nieves; Piñeiro, Verónica

    2014-05-01

    Traditionally, studies of soil biodegradation are based on CO2 dissipation rates. CO2 is a product of aerobic degradation of labile organic substrates like carbohydrates. That limits the biodegradation concept to just one of the soil organic matter fractions. This feature is responsible for some problems to settle the concept of soil organic matter (SOM) recalcitrance and for controversial results defining sensitivity of SOM to temperature. SOM consists of highly complex macromolecules constituted by fractions with different chemical nature and redox state affecting the chemical nature of biodegradation processes. Biodegradation of fractions more reduced than carbohydrates take place through metabolic pathways that dissipate less CO2 than carbohydrate respiration, that may not dissipate CO2, or that even may uptake CO2. These compounds can be considered more recalcitrant and with lower turnover times than labile SOM just because they are degraded at lower CO2 rates that may be just a consequence of the metabolic path. Nevertheless, decomposition of every kind of organic substrate always releases heat. For this reason, the measurement of the heat rate by calorimetry yields a more realistic measurement of the biodegradation of the SOM continuum. TAM III is one of the most recent calorimeters designed for directly measuring in real time the heat rate associated with any degradation process. It is designed as a multichannel system allowing the concomitant measurement of to up 24 samples at isothermal conditions or through a temperature scanning mode from 18 to 100ºC, allowing the continous measure of any sample at controlled non-isothermal conditions. The temperature scanning mode was tested in several soil samples collected at different depths to study their sensitivity to temperature changes from 18 to 35 ºC calculating the Q10 and the activation energy (EA) by the Arrhenius equation. It was attempted to associate the obtained EA values with the soil thermal

  1. Addition of waste and introduction of microorganisms after 45 years of soil degradation

    Directory of Open Access Journals (Sweden)

    Adriana Avelino Santos

    Full Text Available ABSTRACT The construction of hydroelectric power plants (HPP may result in environmental problems, such as extensive areas of exposed subsoil and conditions of extreme degradation. These areas require alternative that minimize impact and allow partial recovery of their ecosystem functions and vegetation. This study aimed to evaluate the effects of residue addition (organic/macrophytes - OR and inorganic/ash - AR, hydrogel, and inoculation of microorganisms in degraded soil, cultivated with Jatropha curcas, through fertility and microbial activity. A conserved Cerrado ("savannah" soil was the source of microorganisms - mainly mycorrhizal fungi. The experiment was conducted for 12 months (during 2010/2011 at the farm of UNESP-School of Engineering/Campus of Ilha Solteira, Selvíria-MS, Brazil, installed in an area where the soil was degraded during the HPP construction, in the 1960s. The experimental design was complete randomized blocks, using a 2×2×4 factorial scheme, i.e., two inoculation treatments (with and without, two hydrogel treatments (with and without, and four residue treatments to introduce the J. curcas (OR, AR, OR + AR, and control without residues, with four replicates and five plants evaluated per replicate. The soil fertility analyses, quantification of microbial biomass carbon (MBC, and released C as CO2 (CO2-C, microbial quotient (qMic, and metabolic quotient (qCO2 were carried out 12 months after planting. The fertility positively responded to the addition of OR and OR + AR, with an increase in pH and SB and reduction in Al and H + Al. The inoculation of soil microorganisms associated with OR and OR + AR residue treatments raised the released CO2-C, MBC, and qMic. The addition of hydrogel combined with OR treatment contributed to the increase in the values of MBC and qMic.

  2. Sphingomonas from petroleum-contaminated soils in Shenfu, China and their PAHs degradation abilities

    Directory of Open Access Journals (Sweden)

    Lisha Zhou

    2016-06-01

    Full Text Available Abstract Members of the Sphingomonas genus are often isolated from petroleum-contaminated soils due to their unique abilities to degrade polycyclic aromatic hydrocarbons (PAHs, which are important for in situ bioremediation. In this study, a combined phenotypic and genotypic approach using streptomycin-containing medium and Sphingomonas -specific PCR was developed to isolate and identify culturable Sphingomonas strains present in petroleum-contaminated soils in the Shenfu wastewater irrigation zone. Of the 15 soil samples examined, 12 soils yielded yellow streptomycin-resistant colonies. The largest number of yellow colony-forming units (CFUs could reach 105 CFUs g-1 soil. The number of yellow CFUs had a significant positive correlation (p < 0.05 with the ratio of PAHs to total petroleum hydrocarbons (TPH, indicating that Sphingomonas may play a key role in degrading the PAH fraction of the petroleum contaminants at this site. Sixty yellow colonies were selected randomly and analyzed by colony PCR using Sphingomonas -specific primers, out of which 48 isolates had PCR-positive signals. The 48 positive amplicons generated 8 distinct restriction fragment length polymorphism (RFLP patterns, and 7 out of 8 phylotypes were identified as Sphingomonas by 16S rRNA gene sequencing of the representative strains. Within these 7 Sphingomonas strains, 6 strains were capable of using fluorene as the sole carbon source, while 2 strains were phenanthrene-degrading Sphingomonas. To the best of our knowledge, this is the first report to evaluate the relationship between PAHs contamination levels and culturable Sphingomonas in environmental samples.

  3. Characterization of dioxygenases and biosurfactants produced by crude oil degrading soil bacteria

    Directory of Open Access Journals (Sweden)

    Santhakumar Muthukamalam

    Full Text Available ABSTRACT Role of microbes in bioremediation of oil spills has become inevitable owing to their eco friendly nature. This study focused on the isolation and characterization of bacterial strains with superior oil degrading potential from crude-oil contaminated soil. Three such bacterial strains were selected and subsequently identified by 16S rRNA gene sequence analysis as Corynebacterium aurimucosum, Acinetobacter baumannii and Microbacterium hydrocarbonoxydans respectively. The specific activity of catechol 1,2 dioxygenase (C12O and catechol 2,3 dioxygenase (C23O was determined in these three strains wherein the activity of C12O was more than that of C23O. Among the three strains, Microbacterium hydrocarbonoxydans exhibited superior crude oil degrading ability as evidenced by its superior growth rate in crude oil enriched medium and enhanced activity of dioxygenases. Also degradation of total petroleum hydrocarbon (TPH in crude oil was higher with Microbacterium hydrocarbonoxydans. The three strains also produced biosurfactants of glycolipid nature as indicated d by biochemical, FTIR and GCMS analysis. These findings emphasize that such bacterial strains with superior oil degrading capacity may find their potential application in bioremediation of oil spills and conservation of marine and soil ecosystem.

  4. Isolation and application of hydrocarbon degradation of indigenous microbial from oil contaminated soil

    International Nuclear Information System (INIS)

    Dadang Sudrajat; Nana Mulyana; Tri Retno DL

    2015-01-01

    The aims of this research are to obtain indigenous potential microbes from bacterial and fungal groups which have capable of degrading hydrocarbon from crude oil contaminated soil. The research carried out were isolation, selection, and identification potential microbial isolates capable of degrading hydrocarbon from oil contaminated soil located at Cepu East Java. The isolates were tested for their growth and ability to degrades crude oil. Each isolate was inoculated unto minimum mineral salt medium (MSM) contained 1% crude oil. Viability and stability test of selected isolates were carried out on irradiated compost carrier materials contained 5% crude oil. The fours series microbial s consortium consists of microbial consortium I, II, III, and IV were tested for the in vitro biodegradability of hydrocarbon. The results shows there sixty two (62) isolates are obtained, among them 42 bacteria and 20 molds. From 42 bacterial isolates, only 8 strains were potent hydrocarbon degraders. Three of these isolates are identified Bacillus cereus (BMC2), Bacillus sp (BMC4), and Pseudomonas sp (BMC6). Whereas from 20 fungal isolates, only 4 strains were potent hydrocarbon degraders. Two of these isolates are identified Aspergillus fumigatus (FMC2) and Aspergillus niger (FMC6). All isolates show good growth in mineral salt medium contained crude oil with decrease in pH. The ability of decrease of TPH content by the bacterial and fungal isolates were 54, 61, 67, 74, and 78% respectively at day 30. The viability and stability of microbial isolates show considerable good viability on irradiated compost carrier materials after 14 days storage. From the fours series microbial consortium, the highest TPH degradation rates is found in microbial consortium III (BMC6, BMC2, and FMC6) with 89,1% in 5 weeks. (author)

  5. Isolation and characterization of mesotrione-degrading Bacillus sp. from soil

    International Nuclear Information System (INIS)

    Batisson, Isabelle; Crouzet, Olivier; Besse-Hoggan, Pascale; Sancelme, Martine; Mangot, Jean-Francois; Mallet, Clarisse; Bohatier, Jacques

    2009-01-01

    Dissipation kinetics of mesotrione, a new triketone herbicide, sprayed on soil from Limagne (Puy-de-Dome, France) showed that the soil microflora were able to biotransform it. Bacteria from this soil were cultured in mineral salt solution supplemented with mesotrione as sole source of carbon for the isolation of mesotrione-degrading bacteria. The bacterial community structure of the enrichment cultures was analyzed by temporal temperature gradient gel electrophoresis (TTGE). The TTGE fingerprints revealed that mesotrione had an impact on bacterial community structure only at its highest concentrations and showed mesotrione-sensitive and mesotrione-adapted strains. Two adapted strains, identified as Bacillus sp. and Arthrobacter sp., were isolated by colony hybridization methods. Biodegradation assays showed that only the Bacillus sp. strain was able to completely and rapidly biotransform mesotrione. Among several metabolites formed, 2-amino-4-methylsulfonylbenzoic acid (AMBA) accumulated in the medium. Although sulcotrione has a chemical structure closely resembling that of mesotrione, the isolates were unable to degrade it. - A Bacillus sp. strain isolated from soil was able to completely and rapidly biotransform the triketone herbicide mesotrione

  6. LEACHING AND DEGRADATION OF 2,4-DICHLOROPHENOXIACETIC ACID, IN COLOMBIA RICE FLOODED SOIL.

    Science.gov (United States)

    Huertas, J; Guerrero, J A; Martinez-Cordon, M J

    2015-01-01

    Rice is mostly cultivated on soil held under flooded conditions. Under these conditions pesticides undergo reductive transformations which are characteristic to rice fields and other anaerobic systems. The present study was undertaken to evaluate the mobility and persistence of 2,4-dichlorophenoxy acetic acid (2,4-D) under laboratory conditions for the rice crop in Espinal, Colombia. A displacement study was performed on a hand packed soil column 30 cm length. After leaching experiment, the soil from column was sliced into six successive sections (5 cm). Methanol acidified (H3PO4 0.25%) extraction was used to determine the herbicide residues in each section. 2,4-D experimental breakthrough curve was analyzed using Stanmod program (inverse problem) to obtain transport parameters. The non-equilibrium physical model fitted well the experimental breakthrough curve. The recovery percent of 2,4-D in leachates was 36.44% after 3.4 pore volumes, and retardation factor was 2.1, indicating low adsorption in that conditions. 2,4-D was rapidly degraded, with DT50 = 11.4 days. The results suggest that 2,4-D under flooded conditions have a high potential for leaching through the soil profile, although the elevated rate of degradation reduced the ground water contamination risk.

  7. Fate of sulfur mustard on soil: Evaporation, degradation, and vapor emission.

    Science.gov (United States)

    Jung, Hyunsook; Kah, Dongha; Chan Lim, Kyoung; Lee, Jin Young

    2017-01-01

    After application of sulfur mustard to the soil surface, its possible fate via evaporation, degradation following absorption, and vapor emission after decontamination was studied. We used a laboratory-sized wind tunnel, thermal desorber, gas chromatograph-mass spectrometry (GC-MS), and 13 C nuclear magnetic resonance ( 13 C NMR) for systematic analysis. When a drop of neat HD was deposited on the soil surface, it evaporated slowly while being absorbed immediately into the matrix. The initial evaporation or drying rates of the HD drop were found to be power-dependent on temperature and initial drop volume. Moreover, drops of neat HD, ranging in size from 1 to 6 μL, applied to soil, evaporated at different rates, with the smaller drops evaporating relatively quicker. HD absorbed into soil remained for a month, degrading eventually to nontoxic thiodiglycol via hydrolysis through the formation of sulfonium ions. Finally, a vapor emission test was performed for HD contaminant after a decontamination process, the results of which suggest potential risk from the release of trace chemical quantities of HD into the environment. Copyright © 2016 Elsevier Ltd. All rights reserved.

  8. Microbial functional diversity and enzymatic activity of soil degraded by sulphur mining reclaimed with various waste

    Science.gov (United States)

    Joniec, Jolanta; Frąc, Magdalena

    2017-10-01

    The aim of the study was to evaluate microbial functional diversity based on community level physiological profiling and β-glucosidase activity changes in soil degraded by sulphur mining and subjected to reclamation with various waste. The experiment was set up in the area of the former `Jeziórko' Sulphur Mine (Poland), on a soilless substrate with a particle size distribution of slightly loamy sand. The experimental variants included the application of post-flotation lime, sewage sludge and mineral wool. The analyses of soil samples included the assessment of the following microbiological indices: β-glucosidase activity and functional diversity average well color development and richness). The results indicate that sewage sludge did not exert a significant impact on the functional diversity of microorganisms present in the reclaimed soil. In turn, the application of other types of waste contributed to a significant increase in the parameters of total metabolic activity and functional diversity of the reclaimed soil. However, the temporal analysis of the metabolic profile of soil microorganisms demonstrated that a single application of waste did not yield a durable, stable metabolic profile in the reclaimed soil. Still, there was an increase in β-glucosidase activity, especially in objects treated with sewage sludge.

  9. Enrichment of degrading microbes and bioremediation of petrochemical contaminants in polluted soil

    International Nuclear Information System (INIS)

    Li, G.; Huang, W.; Zhang, X.; Lerner, D.N.

    2000-01-01

    Soil at a site near Zibo City, China, is polluted with hydrocarbons at concentrations up to 200 g kg -1 dry soil. Samples contained 10 7 microbial cells g -1 dry soil, and the concentration of aerobic degradation bacteria is 10 7 cells g -1 dry soil. The most active species were Xanthomonas, Bacillus and Hyphomicrobium. The nitrogen and phosphorus contents of the polluted soil are typically 0.1 %, and are sufficient to sustain natural or enhanced biodegradation. The BAC (Biological Activated Carbon) system was used to enrich indigenous microbes to enhance bioremediation rates in the laboratory. The BAC used the large surface area and sorption characteristics to fix bacteria and media, and effectively culture and enrich the microbes. Effluent from the BAC system contained up to 4 x 10 11 cells ml -1 , and was introduced to the contaminated soil to enhance biodegradation. The results indicated that the natural biodegradation rate of the petroleum hydrocarbons is lower than the BAC enhanced bioremediation rate, 1.7% as opposed to 42% in 32 days. (Author)

  10. Distribution of hydrocarbon-degrading bacteria in the soil environment and their contribution to bioremediation.

    Science.gov (United States)

    Fukuhara, Yuki; Horii, Sachie; Matsuno, Toshihide; Matsumiya, Yoshiki; Mukai, Masaki; Kubo, Motoki

    2013-05-01

    A real-time PCR quantification method for indigenous hydrocarbon-degrading bacteria (HDB) carrying the alkB gene in the soil environment was developed to investigate their distribution in soil. The detection limit of indigenous HDB by the method was 1 × 10(6) cells/g-soil. The indigenous HDB were widely distributed throughout the soil environment and ranged from 3.7 × 10(7) to 5.0 × 10(8) cells/g-soil, and the ratio to total bacteria was 0.1-4.3 %. The dynamics of total bacteria, indigenous HDB, and Rhodococcus erythropolis NDKK6 (carrying alkB R2) during bioremediation were analyzed. During bioremediation with an inorganic nutrient treatment, the numbers of these bacteria were slightly increased. The numbers of HDB (both indigenous bacteria and strain NDKK6) were gradually decreased from the middle stage of bioremediation. Meanwhile, the numbers of these bacteria were highly increased and were maintained during bioremediation with an organic nutrient. The organic treatment led to activation of not only the soil bacteria but also the HDB, so an efficient bioremediation was carried out.

  11. Plant-associated bacterial degradation of toxic organic compounds in soil.

    LENUS (Irish Health Repository)

    McGuinness, Martina

    2009-08-01

    A number of toxic synthetic organic compounds can contaminate environmental soil through either local (e.g., industrial) or diffuse (e.g., agricultural) contamination. Increased levels of these toxic organic compounds in the environment have been associated with human health risks including cancer. Plant-associated bacteria, such as endophytic bacteria (non-pathogenic bacteria that occur naturally in plants) and rhizospheric bacteria (bacteria that live on and near the roots of plants), have been shown to contribute to biodegradation of toxic organic compounds in contaminated soil and could have potential for improving phytoremediation. Endophytic and rhizospheric bacterial degradation of toxic organic compounds (either naturally occurring or genetically enhanced) in contaminated soil in the environment could have positive implications for human health worldwide and is the subject of this review.

  12. Biodegradation and bioremediation potential of diazinon-degrading Serratia marcescens to remove other organophosphorus pesticides from soils.

    Science.gov (United States)

    Cycoń, Mariusz; Żmijowska, Agnieszka; Wójcik, Marcin; Piotrowska-Seget, Zofia

    2013-03-15

    The ability of diazinon-degrading Serratia marcescens to remove organophosphorus pesticides (OPPs), i.e. chlorpyrifos (CP), fenitrothion (FT), and parathion (PT) was studied in a mineral salt medium (MSM) and in three soils of different characteristics. This strain was capable of using all insecticides at concentration of 50 mg/l as the only carbon source when grown in MSM, and 58.9%, 70.5%, and 82.5% of the initial dosage of CP, FT, and PT, respectively was degraded within 14 days. The biodegradation experiment showed that autochthonous microflora in all soils was characterized by a degradation potential of all tested OPPs; however, the initial lag phases for degradation of CP and FT, especially in sandy soil, were observed. During the 42-day experiment, 45.3%, 61.4% and 72.5% of the initial dose of CP, FT, and PT, respectively, was removed in sandy soil whereas the degradation of CP, FT, and PT in the same period, in sandy loam and silty soils reached 61.4%, 79.7% and 64.2%, and 68.9%, 81.0% and 63.6%, respectively. S. marcescens introduced into sterile soils showed a higher degradation potential (5-13%) for OPPs removal than those observed in non-sterile soil with naturally occurring attenuation. Inoculation of non-sterile soils with S. marcescens enhanced the disappearance rates of all insecticides, and DT50 for CP, FT, and PT was reduced by 20.7, 11.3 and 13.0 days, and 11.9, 7.0 and 8.1 days, and 9.7, 14.5 and 12.6 days in sandy, sandy loam, and silty soils, respectively, in comparison with non-sterile soils with only indigenous microflora. This ability of S. marcescens makes it a suitable strain for bioremediation of soils contaminated with OPPs. Copyright © 2013 Elsevier Ltd. All rights reserved.

  13. ANALYSIS OF THE FLUX OF AN ENDOCRINE DISRUPTING DICARBOXIMIDE AND ITS DEGRADATION PRODUCTS FROM THE SOIL TO THE LOWER TROPOSPHERE

    Science.gov (United States)

    A method for measuring the atmospheric flux of the antiandrogenic dicarboxirnide, vinclozolin, and its degradation products was investigated. A nitric oxide laboratory chamber was modified to measure the flux of semi-volatile compounds. Pesticide application systems and soil in...

  14. Comparison of an ability to degrade MTBE between mixed culture and monoculture isolated from gasoline contaminated soil

    Directory of Open Access Journals (Sweden)

    Wanpen Virojanakud

    2004-02-01

    Full Text Available Methyl tertiary butyl ether (MTBE is an oxygenated compound used to enhance the octane index of gasoline and replace lead in gasoline. MTBE can reduce air pollution but causes water pollution due to its high water solubility and low sorption to soil and thus can easily contaminate the environment. Biodegradation is one of the promising techniques to reduce MTBE contaminated in the environment and MTBE degrader was proposed as an efficient method used to degrade MTBE. In this study, MTBE degraders were isolated from gasoline contaminated soil and then were evaluated with the hypothesis that MTBE degraders could improve biodegradation of MTBE in soil and mixed culture could degrade MTBE more rapidly than monoculture. Gasoline contaminated soil samples were taken from retail gas stations and a motorcycle repair shop in Khon Kaen University. Isolation of MTBE degrader was conducted by using Basal Salt Medium (BSM containing 200 mg/L of MTBE as a carbon source. Mixed culture of MTBE degrader was successfully isolated under aerobic condition. Morphology study was conducted by streaking isolated mixed culture in solid medium, agar slant and identifying the cells shape under a microscope. It was found that this mixed culture was a gram negative bacteria with 7 different isolates. A comparison of the ability to degrade MTBE between mixed culture and monoculture was investigated in BSM containing 100 mg/L of MTBE. The results indicated that a mixed culture degraded MTBE more rapidly than monoculture i.e. 20% within 14 days. Monoculture, J4 and J7, were the most rapid MTBE degraders among the other monocultures in which they degraded 14% of MTBE in 14 days while monoculture J15 could degrade only 1% of MTBE.This preliminary result suggests that mixed cultures degrade MTBE more efficiently than monoculture.

  15. Study on kinetic degradation in soil and horizontal transfer of bt gene by 35S isotopic tracing method

    International Nuclear Information System (INIS)

    Wang Haiyan; Zhang Yanfei; Ye Qingfu

    2012-01-01

    In this study, 35 S isotopic tracing method was applied to investigate kinetic degradation of bt gene from Bt transgenic rice TT51 in two different soil and possibility of its horizontal transfer into soil bacteria as well. Results showed that, during 30 d of aerobic incubation, it was indicated that 35 S-Bt gene was not horizontally transferred into soil microorganisms. The aerobic soil degradation dynamics significantly followed a first-order dissipation pattern for bt gene. After 30 d of incubation, the amount of bt gene reached 9.32% of applied radioactivity for the fluvio-marine yellow loamy soil and 9.92% for the fluvio-aquatic soil, respectively. The half-lives in two soils were 3.53 d for the former soil and 5. 77 d for the latter soil, which means that bt gene was more easily degradable in the weak acidic soil. The use of 35 S labeling proved to be valuable; it served the purpose of validating the rigorousness of experimental protocols, and provided insights into the soil environmental safety assessment for Bt transgenic rice. (authors)

  16. Potential use of soil-born fungi isolated from treated soil in Indonesia to degrade glyphosate herbicide

    Directory of Open Access Journals (Sweden)

    N. Arfarita

    2014-01-01

    Full Text Available The glyphosate herbicide is the most common herbicides used in palm-oil plantations and other agricultural in Indonesial. In 2020, Indonesian government to plan the development of oil palm plantations has reached 20 million hectares of which now have reached 6 million hectares. It means that a huge chemicals particularly glyphosate has been poured into the ground and continues to pollute the soil. However, there is no report regarding biodegradation of glyphosate-contaminated soils using fungal strain especially in Indonesia. This study was to observe the usage of Round Up as selection agent for isolation of soil-born fungi capable to grow on glyphosate as a sole source of phosphorus. Five fungal strains were able to grow consistently in the presence of glyphosate as the sole phosphorus source and identified as Aspergillus sp. strain KRP1, Fusarium sp. strain KRP2, Verticillium sp. strain KRP3, Acremoniumsp. strain GRP1 and Scopulariopsis sp. strain GRP2. This indicates as their capability to utilize and degrade this herbicide. We also used standard medium as control and get seventeen fungal strains. The seventeen fungal strains were identified as species of Botrytis, Fusarium, Aspergillus, Penicillium, Verticillium, Trichoderma and Paecilomyces. These results show the reduction in the number of fungal strains on solid medium containing glyphosate. Of the five isolated fungal species, Verticillium sp. strain KRP3 and Scopulariopsis sp. strain GRP2 were selected for further study based on their highest ratio of growth diameter. This study indicates that treatment of soil with glyphosate degrading fungus would be useful in some areas where this herbicide is extensively used.

  17. Degradation of polycyclic aromatic hydrocarbons by microbial consortia enriched from three soils using two different culture media.

    Science.gov (United States)

    Wu, Manli; Chen, Liming; Tian, Yongqiang; Ding, Yi; Dick, Warren A

    2013-07-01

    A consortium composed of many different bacterial species is required to efficiently degrade polycyclic aromatic hydrocarbons (PAH) in oil-contaminated soil. We obtained six PAH-degrading microbial consortia from three oil-contaminated soils using two different isolation culture media. Denaturing gradient gel electrophoresis (DGGE) and sequence analyses of amplified 16s rRNA genes confirmed the bacterial community was greatly affected by both the culture medium and the soil from which the consortia were enriched. Three bacterial consortia enriched using malt yeast extract (MYE) medium showed higher degradation rates of PAHs than consortia enriched using Luria broth (LB) medium. Consortia obtained from a soil and then added back to that same soil was more effective in degrading PAHs than adding, to the same soil, consortia isolated from other, unrelated soils. This suggests that inoculum used for bioremediation should be from the same, or very similar nearby soils, as the soil that is actually being bioremediated. Copyright © 2013 Elsevier Ltd. All rights reserved.

  18. Degradation of Biofumigant Isothiocyanates and Allyl Glucosinolate in Soil and Their Effects on the Microbial Community Composition.

    Directory of Open Access Journals (Sweden)

    Franziska S Hanschen

    Full Text Available Brassicales species rich in glucosinolates are used for biofumigation, a process based on releasing enzymatically toxic isothiocyanates into the soil. These hydrolysis products are volatile and often reactive compounds. Moreover, glucosinolates can be degraded also without the presence of the hydrolytic enzyme myrosinase which might contribute to bioactive effects. Thus, in the present study the stability of Brassicaceae plant-derived and pure glucosinolates hydrolysis products was studied using three different soils (model biofumigation. In addition, the degradation of pure 2-propenyl glucosinolate was investigated with special regard to the formation of volatile breakdown products. Finally, the influence of pure glucosinolate degradation on the bacterial community composition was evaluated using denaturing gradient gel electrophoresis of 16S rRNA gene amplified from total community DNA. The model biofumigation study revealed that the structure of the hydrolysis products had a significant impact on their stability in the soil but not the soil type. Following the degradation of pure 2-propenyl glucosinolate in the soils, the nitrile as well as the isothiocyanate can be the main degradation products, depending on the soil type. Furthermore, the degradation was shown to be both chemically as well as biologically mediated as autoclaving reduced degradation. The nitrile was the major product of the chemical degradation and its formation increased with iron content of the soil. Additionally, the bacterial community composition was significantly affected by adding pure 2-propenyl glucosinolate, the effect being more pronounced than in treatments with myrosinase added to the glucosinolate. Therefore, glucosinolates can have a greater effect on soil bacterial community composition than their hydrolysis products.

  19. Complex Adaptive Systems, soil degradation and land sensitivity to desertification: A multivariate assessment of Italian agro-forest landscape.

    Science.gov (United States)

    Salvati, Luca; Mavrakis, Anastasios; Colantoni, Andrea; Mancino, Giuseppe; Ferrara, Agostino

    2015-07-15

    Degradation of soils and sensitivity of land to desertification are intensified in last decades in the Mediterranean region producing heterogeneous spatial patterns determined by the interplay of factors such as climate, land-use changes, and human pressure. The present study hypothesizes that rising levels of soil degradation and land sensitivity to desertification are reflected into increasingly complex (and non-linear) relationships between environmental and socioeconomic variables. To verify this hypothesis, the Complex Adaptive Systems (CAS) framework was used to explore the spatiotemporal dynamics of eleven indicators derived from a standard assessment of soil degradation and land sensitivity to desertification in Italy. Indicators were made available on a detailed spatial scale (773 agricultural districts) for various years (1960, 1990, 2000 and 2010) and analyzed through a multi-dimensional exploratory data analysis. Our results indicate that the number of significant pair-wise correlations observed between indicators increased with the level of soil and land degradation, although with marked differences between northern and southern Italy. 'Fast' and 'slow' factors underlying soil and land degradation, and 'rapidly-evolving' or 'locked' agricultural districts were identified according to the rapidity of change estimated for each of the indicators studied. In southern Italy, 'rapidly-evolving' districts show a high level of soil degradation and land sensitivity to desertification during the whole period of investigation. On the contrary, those districts in northern Italy are those experiencing a moderate soil degradation and land sensitivity to desertification with the highest increase in the level of sensitivity over time. The study framework contributes to the assessment of complex local systems' dynamics in affluent but divided countries. Results may inform thematic strategies for the mitigation of land and soil degradation in the framework of action

  20. Earthworms (Eisenia fetida) demonstrate potential for use in soil bioremediation by increasing the degradation rates of heavy crude oil hydrocarbons.

    Science.gov (United States)

    Martinkosky, Luke; Barkley, Jaimie; Sabadell, Gabriel; Gough, Heidi; Davidson, Seana

    2017-02-15

    Crude oil contamination widely impacts soil as a result of release during oil and gas exploration and production activities. The success of bioremediation methods to meet remediation goals often depends on the composition of the crude oil, the soil, and microbial community. Earthworms may enhance bioremediation by mixing and aerating the soil, and exposing soil microorganisms to conditions in the earthworm gut that lead to increased activity. In this study, the common composting earthworm Eisenia fetida was tested for utility to improve remediation of oil-impacted soil. E. fetida survival in soil contaminated with two distinct crude oils was tested in an artificial (lab-mixed) sandy loam soil, and survival compared to that in the clean soil. Crude oil with a high fraction of light-weight hydrocarbons was more toxic to earthworms than the crude oil with a high proportion of heavy polyaromatic and aliphatic hydrocarbons. The heavier crude oil was added to soil to create a 30,000mg/kg crude oil impacted soil, and degradation in the presence of added earthworms and feed, feed alone, or no additions was monitored over time and compared. Earthworm feed was spread on top to test effectiveness of no mixing. TPH degradation rate for the earthworm treatments was ~90mg/day slowing by 200days to ~20mg/day, producing two phases of degradation. With feed alone, the rate was ~40mg/day, with signs of slowing after 500days. Both treatments reached the same end point concentrations, and exhibited faster degradation of aliphatic hydrocarbons C21, decreased. During these experiments, soils were moderately toxic during the first three months, then earthworms survived well, were active and reproduced with petroleum hydrocarbons present. This study demonstrated that earthworms accelerate bioremediation of crude oil in soils, including the degradation of the heaviest polyaromatic fractions. Copyright © 2016 Elsevier B.V. All rights reserved.

  1. Degradation of 2,4-D in soils by Fe₃O₄ nanoparticles combined with stimulating indigenous microbes.

    Science.gov (United States)

    Fang, Guodong; Si, Youbin; Tian, Chao; Zhang, Gangya; Zhou, Dongmei

    2012-03-01

    Degradation of 2,4-dichlorophenoxyacetic acid (2,4-D) in soils by Fe₃O₄ nanoparticles combined with soil indigenous microbes was investigated, and the effects of Fe₃O₄ nanoparticles on soil microbial populations and enzyme activities were also studied. The soils contaminated with 2,4-D were treated with Fe₃O₄ nanoparticles. The microbial populations and enzyme activities were analyzed by dilution plate method and chemical assay, respectively, and the concentration of 2,4-D in soil was determined by high-performance liquid chromatography (HPLC). The results indicated that Fe₃O₄ nanoparticles combined with soil indigenous microbes led to a higher degradation efficiency of 2,4-D than the treatments with Fe₃O₄ nanoparticles or indigenous microbes alone. The degradation of 2,4-D in soils followed the pseudo first-order kinetic. The half-lives of 2,4-D degradation (DT₅₀) of the combined treatments were 0.9, 1.9 and 3.1 days in a Red soil, Vertisol and Alfisol, respectively, which implied that the DT₅₀ of the combination treatments were significantly shorter than that of the treatments Fe₃O₄ nanoparticles or indigenous microbes alone. The effects of Fe₃O₄ nanoparticles on soil microbial populations and enzyme activities were also investigated and compared with the α-Fe₂O₃ nanoparticles. The results suggested that the α-Fe₂O₃ nanoparticles had only comparatively small effects on degradation of 2,4-D in soils, while the Fe₃O₄ nanoparticles not only degraded 2,4-D in soils but also increased the soil microbial populations and enzyme activities; the maximum increase in enzyme activities were 67.8% (amylase), 53.8% (acid phosphatase), 26.5% (catalase) and 38.0% (urease), compared with the untreated soil. Moreover, the introduction of Fe₃O₄ nanoparticles at the different dosage resulted in a variable degradation efficiency of 2,4-D in soil. The method of combining Fe₃O₄ nanoparticles with indigenous soil microbes may

  2. Pesticide nonextractable residue formation in soil: insights from inverse modeling of degradation time series.

    Science.gov (United States)

    Loos, Martin; Krauss, Martin; Fenner, Kathrin

    2012-09-18

    Formation of soil nonextractable residues (NER) is central to the fate and persistence of pesticides. To investigate pools and extent of NER formation, an established inverse modeling approach for pesticide soil degradation time series was evaluated with a Monte Carlo Markov Chain (MCMC) sampling procedure. It was found that only half of 73 pesticide degradation time series from a homogeneous soil source allowed for well-behaved identification of kinetic parameters with a four-pool model containing a parent compound, a metabolite, a volatile, and a NER pool. A subsequent simulation indeed confirmed distinct parameter combinations of low identifiability. Taking the resulting uncertainties into account, several conclusions regarding NER formation and its impact on persistence assessment could nonetheless be drawn. First, rate constants for transformation of parent compounds to metabolites were correlated to those for transformation of parent compounds to NER, leading to degradation half-lives (DegT50) typically not being larger than disappearance half-lives (DT50) by more than a factor of 2. Second, estimated rate constants were used to evaluate NER formation over time. This showed that NER formation, particularly through the metabolite pool, may be grossly underestimated when using standard incubation periods. It further showed that amounts and uncertainties in (i) total NER, (ii) NER formed from the parent pool, and (iii) NER formed from the metabolite pool vary considerably among data sets at t→∞, with no clear dominance between (ii) and (iii). However, compounds containing aromatic amine moieties were found to form significantly more total NER when extrapolating to t→∞ than the other compounds studied. Overall, our study stresses the general need for assessing uncertainties, identifiability issues, and resulting biases when using inverse modeling of degradation time series for evaluating persistence and NER formation.

  3. Are biodiversity indices of spontaneous grass covers in olive orchards good indicators of soil degradation?

    Science.gov (United States)

    Taguas, E. V.; Arroyo, C.; Lora, A.; Guzmán, G.; Vanderlinden, K.; Gómez, J. A.

    2015-03-01

    suitable for describing the soil degradation in the study catchments.

  4. Critical Analysis of Forest Degradation in the Southern Eastern Ghats of India: Comparison of Satellite Imagery and Soil Quality Index

    Science.gov (United States)

    Ramachandran, Andimuthu; Radhapriya, Parthasarathy; Jayakumar, Shanmuganathan; Dhanya, Praveen; Geetha, Rajadurai

    2016-01-01

    India has one of the largest assemblages of tropical biodiversity, with its unique floristic composition of endemic species. However, current forest cover assessment is performed via satellite-based forest surveys, which have many limitations. The present study, which was performed in the Eastern Ghats, analysed the satellite-based inventory provided by forest surveys and inferred from the results that this process no longer provides adequate information for quantifying forest degradation in an empirical manner. The study analysed 21 soil properties and generated a forest soil quality index of the Eastern Ghats, using principal component analysis. Using matrix modules and geospatial technology, we compared the forest degradation status calculated from satellite-based forest surveys with the degradation status calculated from the forest soil quality index. The Forest Survey of India classified about 1.8% of the Eastern Ghats’ total area as degraded forests and the remainder (98.2%) as open, dense, and very dense forests, whereas the soil quality index results found that about 42.4% of the total area is degraded, with the remainder (57.6%) being non-degraded. Our ground truth verification analyses indicate that the forest soil quality index along with the forest cover density data from the Forest Survey of India are ideal tools for evaluating forest degradation. PMID:26812397

  5. Critical Analysis of Forest Degradation in the Southern Eastern Ghats of India: Comparison of Satellite Imagery and Soil Quality Index.

    Science.gov (United States)

    Ramachandran, Andimuthu; Radhapriya, Parthasarathy; Jayakumar, Shanmuganathan; Dhanya, Praveen; Geetha, Rajadurai

    2016-01-01

    India has one of the largest assemblages of tropical biodiversity, with its unique floristic composition of endemic species. However, current forest cover assessment is performed via satellite-based forest surveys, which have many limitations. The present study, which was performed in the Eastern Ghats, analysed the satellite-based inventory provided by forest surveys and inferred from the results that this process no longer provides adequate information for quantifying forest degradation in an empirical manner. The study analysed 21 soil properties and generated a forest soil quality index of the Eastern Ghats, using principal component analysis. Using matrix modules and geospatial technology, we compared the forest degradation status calculated from satellite-based forest surveys with the degradation status calculated from the forest soil quality index. The Forest Survey of India classified about 1.8% of the Eastern Ghats' total area as degraded forests and the remainder (98.2%) as open, dense, and very dense forests, whereas the soil quality index results found that about 42.4% of the total area is degraded, with the remainder (57.6%) being non-degraded. Our ground truth verification analyses indicate that the forest soil quality index along with the forest cover density data from the Forest Survey of India are ideal tools for evaluating forest degradation.

  6. Engineering Pseudomonas putida KT2440 for simultaneous degradation of organophosphates and pyrethroids and its application in bioremediation of soil.

    Science.gov (United States)

    Zuo, Zhenqiang; Gong, Ting; Che, You; Liu, Ruihua; Xu, Ping; Jiang, Hong; Qiao, Chuanling; Song, Cunjiang; Yang, Chao

    2015-06-01

    Agricultural soils are usually co-contaminated with organophosphate (OP) and pyrethroid pesticides. To develop a stable and marker-free Pseudomonas putida for co-expression of two pesticide-degrading enzymes, we constructed a suicide plasmid with expression cassettes containing a constitutive promoter J23119, an OP-degrading gene (mpd), a pyrethroid-hydrolyzing carboxylesterase gene (pytH) that utilizes the upp gene as a counter-selectable marker for upp-deficient P. putida. By introduction of suicide plasmid and two-step homologous recombination, both mpd and pytH genes were integrated into the chromosome of a robust soil bacterium P. putida KT2440 and no selection marker was left on chromosome. Functional expression of mpd and pytH in P. putida KT2440 was demonstrated by Western blot analysis and enzyme activity assays. Degradation experiments with liquid cultures showed that the mixed pesticides including methyl parathion, fenitrothion, chlorpyrifos, permethrin, fenpropathrin, and cypermethrin (0.2 mM each) were degraded completely within 48 h. The inoculation of engineered strain (10(6) cells/g) to soils treated with the above mixed pesticides resulted in a higher degradation rate than in noninoculated soils. All six pesticides could be degraded completely within 15 days in fumigated and nonfumigated soils with inoculation. Theses results highlight the potential of the engineered strain to be used for in situ bioremediation of soils co-contaminated with OP and pyrethroid pesticides.

  7. Modification of degradation-resistant soil organic matter by soil saprobic microfungi

    Czech Academy of Sciences Publication Activity Database

    Řezáčová, Veronika; Hršelová, Hana; Gryndlerová, Hana; Mikšík, Ivan; Gryndler, Milan

    2006-01-01

    Roč. 38, - (2006), s. 2292-2299 ISSN 0038-0717 R&D Projects: GA ČR GA526/03/0188 Institutional research plan: CEZ:AV0Z50200510; CEZ:AV0Z50110509 Keywords : soil microfungi * fulvic acid * humic acid Subject RIV: EE - Microbiology, Virology Impact factor: 2.623, year: 2006

  8. Petroleum degradation by endophytic Streptomyces spp. isolated from plants grown in contaminated soil of southern Algeria.

    Science.gov (United States)

    Baoune, Hafida; Ould El Hadj-Khelil, Aminata; Pucci, Graciela; Sineli, Pedro; Loucif, Lotfi; Polti, Marta Alejandra

    2018-01-01

    Petroleum hydrocarbons are well known by their high toxicity and recalcitrant properties. Their increasing utilization around worldwide led to environmental contamination. Phytoremediation using plant-associated microbe is an interesting approach for petroleum degradation and actinobacteria have a great potential for that. For this purpose, our study aimed to isolate, characterize, and assess the ability of endophytic actinobacteria to degrade crude petroleum, as well as to produce plant growth promoting traits. Seventeen endophytic actinobacteria were isolated from roots of plants grown naturally in sandy contaminated soil. Among them, six isolates were selected on the basis of their tolerance to petroleum on solid minimal medium and characterized by 16S rDNA gene sequencing. All petroleum-tolerant isolates belonged to the Streptomyces genus. Determination by crude oil degradation by gas chromatorgraph-flame ionization detector revealed that five strains could use petroleum as sole carbon and energy source and the petroleum removal achieved up to 98% after 7 days of incubation. These isolates displayed an important role in the degradation of the n-alkanes (C 6 -C 30 ), aromatic and polycyclic aromatic hydrocarbons. All strains showed a wide range of plant growth promoting features such as siderophores, phosphate solubilization, 1-aminocyclopropane-1-carboxylate deaminase, nitrogen fixation and indole-3-acetic acid production as well as biosurfactant production. This is the first study highlighting the petroleum degradation ability and plant growth promoting attributes of endophytic Streptomyces. The finding suggests that the endophytic actinobacteria isolated are promising candidates for improving phytoremediation efficiency of petroleum contaminated soil. Copyright © 2017 Elsevier Inc. All rights reserved.

  9. Sorption and degradation of wastewater-associated pharmaceuticals and personal care products in agricultural soils and sediment.

    Science.gov (United States)

    Zhang, Ting; Wu, Bo; Sun, Na; Ye, Yong; Chen, Huaixia

    2013-01-01

    Pharmaceuticals and personal care products (PPCPs) have drawn popular concerns recently as an emerging class of aquatic contaminants. In this study, adsorption and degradation of four selected PPCPs, metronidazole, tinidazole, caffeine and chloramphenicol, have been investigated in the laboratory using two agricultural soils in China and sediment from Changjiang River. Adsorption tests using a batch equilibrium method demonstrated that adsorption of all tested chemicals in soils could be well described with Freundlich equation, and their adsorption affinity on soil followed the order of chloramphenicol > caffeine > tinidazole > metronidazole. Generally, higher Kf value was associated with soils which had higher organic matter contents (except for caffeine acid in this study). Degradation of selected PPCPs in soils generally followed first-order exponential decay kinetics, and half-lives ranging from 0.97 to 10.21 d. Sterilization generally decreased the degradation rates, indicating that microbial activity played a significant role in the degradation in soils. The degradation rate constant decreased with increasing initial chemical concentrations in soil, implying that the microbial activity was inhibited with high chemical loading levels.

  10. Sulfur isotopic fractionation of carbonyl sulfide during degradation by soil bacteria and enzyme

    Science.gov (United States)

    Kamezaki, Kazuki; Hattori, Shohei; Ogawa, Takahiro; Toyoda, Sakae; Kato, Hiromi; Katayama, Yoko; Yoshida, Naohiro

    2017-04-01

    Carbonyl sulfide (COS) is an atmospheric trace gas that possess great potential for tracer of carbon cycle (Campbell et al., 2008). COS is taken up by vegetation during photosynthesis like absorption of carbon dioxide but COS can not emit by respiration of vegetation, suggesting possible tracer for gross primary production. However, some studies show the COS-derived GPP is larger than the estimates by using carbon dioxide flux because COS flux by photolysis and soil flux are not distinguished (e.g. Asaf et al., 2013). Isotope analysis is a useful tool to trace sources and transformations of trace gases. Recently our group developed a promising new analytical method for measuring the stable sulfur isotopic compositions of COS using nanomole level samples: the direct isotopic analytical technique of on-line gas chromatography-isotope ratio mass spectrometry (GC-IRMS) using fragmentation ions S+ enabling us to easily analyze sulfur isotopes in COS (Hattori et al., 2015). Soil is thought to be important as both a source and a sink of COS in the troposphere. In particular, soil has been reported as a large environmental sink for atmospheric COS. Bacteria isolated from various soils actively degrade COS, with various enzymes such as carbonic anhydrase and COSase (Ogawa et al., 2013) involved in COS degradation. However, the mechanism and the magnitude of bacterial contribution in terms of a sink for atmospheric COS is still uncertain. Therefore, it is important to quantitatively evaluate this contribution using COS sulfur isotope analysis. We present isotopic fractionation constants for COS by laboratory incubation experiments during degradation by soil bacteria and COSase. Incubation experiments were conducted using strains belonging to the genera Mycobacterium, Williamsia, Cupriavidus, and Thiobacillus, isolated from natural soil or activated sludge and enzyme purified from a bacteria. As a result, the isotopic compositions of OCS were increased during degradation of

  11. Detection of Toluene Degradation in Bacteria Isolated from Oil Contaminated Soils

    International Nuclear Information System (INIS)

    Ainon Hamzah; Tavakoli, A.; Amir Rabu

    2011-01-01

    Toluene (C 7 H 8 ) a hydrocarbon in crude oil, is a common contaminant in soil and groundwater. In this study, the ability to degrade toluene was investigated from twelve bacteria isolates which were isolated from soil contaminated with oil. Out of 12 bacterial isolates tested, most of Pseudomonas sp. showed the capability to grow in 1 mM of toluene compared with other isolates on the third day of incubation. Based on enzyme assays towards toluene monooxygenase, Pseudomonas aeruginosa UKMP-14T and Bacillus cereus UKMP-6G were shown to have the highest ability to degrade toluene. The toluene monooxygenase activity was analysed by using two calorimetric methods, Horseradish peroxidase (HRP) and indole-indigo. Both of the methods measured the production of catechol by the enzymatic reaction of toluene monooxygenase. In the HRP assay, the highest enzyme activity was 0.274 U/ mL, exhibited by Pseudomonas aeruginosa UKMP-14T. However, for indole-indigo assay, Bacillus cereus UKMP-6G produced the highest enzyme activity of 0.291 U/ ml. Results from both experiments showed that Pseudomonas aeruginosa UKMP-14T and Bacillus cereus UKMP-6G were able to degrade toluene. (author)

  12. RECARE - Preventing and Remediating Degradation of Soils in Europe through Landcare.

    Science.gov (United States)

    van den Elsen, Erik; Hessel, Rudi; Verzandvoort, Simone; Ritsema, Coen; Geissen, Violette

    2015-04-01

    Although there is a large body of knowledge available on soil threats in Europe, this knowledge is fragmented and incomplete, in particular regarding the complexity and functioning of soil systems and their interaction with human activities. The main aim of the RECARE project is to develop effective prevention, remediation and restoration measures using an innovative trans-disciplinary approach, actively integrating and advancing knowledge of stakeholders and scientists in 17 Case Studies, covering a range of soil threats in different bio-physical and socio-economic environments across Europe. Within these Case Study sites, i) the current state of degradation and conservation will be assessed using a new methodology, based on the WOCAT mapping procedure, ii) impacts of degradation and conservation on soil functions and ecosystem services will be quantified in a harmonized, spatially explicit way, accounting for costs and benefits, and possible trade-offs, iii) prevention, remediation and restoration measures selected and implemented by stakeholders in a participatory process will be evaluated regarding efficacy, and iv) the applicability and impact of these measures at the European level will be assessed using a new integrated bio-physical and socio-economic model, accounting for land use dynamics as a result of for instance economic development and policies. Existing national and EU policies will be reviewed and compared to identify potential incoherence, contradictions and synergies. Policy messages will be formulated based on the Case Study results and their integration at European level. A comprehensive dissemination and communication strategy, including the development of a web-based Dissemination and Communication Hub, will accompany the other activities to ensure that project results are disseminated to a variety of stakeholders at the right time and in the appropriate formats to stimulate renewed care for European soils.

  13. Indicators of structural degradation on intensively cultivated soils of the Piedemonte Llanero

    International Nuclear Information System (INIS)

    Obando, Franco H

    2000-01-01

    In order to evaluate the validity of a diagnosis methodology of structural soil degradation based on the combination of internal morphology of aggregates and measurement of resistance to penetration, a reconnaissance survey of physical degradation processes on intensively cultivated soils in the Piedemonte Llanero was carried out. The internal morphology of soil aggregates was classified into five states; micro-aggregate (μ), compacted (∇ μ), very compacted (∇), cracked compacted (φ) and agglomerate (ψ) defined according to morphological characteristics derived from cultivation practices and wheel traffic. Two crops systems were selected: low-lying rice (mono-cropping) during 30 years) and upland rice, maize, soybean cotton crop rotations during 20 years in two landscapes of the alluvial plain of piedmont (medium terraces of the sub-recent piedmont, TM, and No-flooding Lowland Flats of the Recent Piedmont, PR). A natural forest and 20 years cacao tree plantation was include as benchmark systems. It was found that higher values of resistance to penetration and total density are associated to compact layers (∇ μ, ∇ and φ states) and lower values to the μ a ψ states. The ∇ state was particularly evident on TM under mono-cropping e low-lying rice crop. High values of resistance to penetration of topsoil on PR were rather associated to e textural resistance. Under natural forest and cacao e plantation it was found the micro-aggregate state (μ) o on surface soil. High values of weighed mean diameter of water stable aggregates, DMP, (≥ 5mm) were associated to compacted layers in the crop rotation e systems in PR. it was demonstrated that this methodology developed in France (temperate zone) can be applied to tropical soils

  14. Effects of essential oils from Eucalyptus globulus leaves on soil organisms involved in leaf degradation.

    Directory of Open Access Journals (Sweden)

    Carla Martins

    Full Text Available The replacement of native Portuguese forests by Eucalyptus globulus is often associated with deleterious effects on terrestrial and aquatic communities. Several studies have suggested that such a phenomenon is linked with the leaf essential oils released into the environment during the Eucalyptus leaf degradation process. However, to date, the way these compounds affect leaf degradation in terrestrial systems i.e. by direct toxic effects to soil invertebrates or indirectly by affecting food of soil fauna, is still unknown. In order to explore this question, the effect of essential oils extracted from E. globulus leaves on terrestrial systems was investigated. Fungal growth tests with species known as leaf colonizers (Mucor hiemalis, Alternaria alternata, Penicillium sp., Penicillium glabrum and Fusarium roseum were performed to evaluate the antifungal effect of essential oils. In addition, a reproduction test with the collembolans Folsomia candida was done using a gradient of eucalyptus essential oils in artificial soil. The influence of essential oils on feeding behaviour of F. candida and the isopods Porcellio dilatatus was also investigated through food avoidance and consumption tests. Eucalyptus essential oils were lethal at concentrations between 2.5-20 µL/mL and inhibited growth of all fungal species between 1.25-5 µL/mL. The collembolan reproduction EC50 value was 35.0 (28.6-41.2 mg/kg and both collembola and isopods preferred leaves without oils. Results suggested that the effect of essential oils in leaf processing is related to direct toxic effects on fungi and soil fauna and to indirect effects on the quality and availability of food to soil invertebrates.

  15. Plastic mulching in agriculture. Trading short-term agronomic benefits for long-term soil degradation?

    Energy Technology Data Exchange (ETDEWEB)

    Steinmetz, Zacharias; Wollmann, Claudia; Schaefer, Miriam; Buchmann, Christian; David, Jan [Institute for Environmental Sciences, Group of Environmental and Soil Chemistry, University of Koblenz-Landau, Fortstraße 7, 76829 Landau (Germany); Tröger, Josephine [Department of Psychology, University of Koblenz-Landau, Fortstraße 7, 76829 Landau (Germany); Interdisciplinary Research Group on Environmental Issues, University of Koblenz-Landau, Fortstraße 7, 76829 Landau (Germany); Muñoz, Katherine [Institute for Environmental Sciences, Group of Environmental and Soil Chemistry, University of Koblenz-Landau, Fortstraße 7, 76829 Landau (Germany); Interdisciplinary Research Group on Environmental Issues, University of Koblenz-Landau, Fortstraße 7, 76829 Landau (Germany); Frör, Oliver [Institute for Environmental Sciences, Group of Environmental Economics, University of Koblenz-Landau, Fortstraße 7, 76829 Landau (Germany); Schaumann, Gabriele Ellen, E-mail: schaumann@uni-landau.de [Institute for Environmental Sciences, Group of Environmental and Soil Chemistry, University of Koblenz-Landau, Fortstraße 7, 76829 Landau (Germany)

    2016-04-15

    and public perception from both a psychological and economic perspective in order to develop new support strategies for the transition into a more environment-friendly food production. - Highlights: • Plastic mulching increases yields, fruit quality and water-use efficiency. • Potential pollution by plastic mulches: microplastics, phthalates, agrochemicals. • Plastic mulching may promote soil degradation and soil water repellency. • Biogeochemical processes in plastic-mulched soils are incompletely understood. • The impacts of plastic mulching on ecosystem services need further attention.

  16. Plastic mulching in agriculture. Trading short-term agronomic benefits for long-term soil degradation?

    International Nuclear Information System (INIS)

    Steinmetz, Zacharias; Wollmann, Claudia; Schaefer, Miriam; Buchmann, Christian; David, Jan; Tröger, Josephine; Muñoz, Katherine; Frör, Oliver; Schaumann, Gabriele Ellen

    2016-01-01

    and public perception from both a psychological and economic perspective in order to develop new support strategies for the transition into a more environment-friendly food production. - Highlights: • Plastic mulching increases yields, fruit quality and water-use efficiency. • Potential pollution by plastic mulches: microplastics, phthalates, agrochemicals. • Plastic mulching may promote soil degradation and soil water repellency. • Biogeochemical processes in plastic-mulched soils are incompletely understood. • The impacts of plastic mulching on ecosystem services need further attention.

  17. Actual and potential salt-related soil degradation in an irrigated rice scheme in the Sahelian zone of Mauritania

    NARCIS (Netherlands)

    Asten, van P.J.A.; Barbi'ro, L.; Wopereis, M.C.S.; Maeght, J.L.; Zee, van der S.E.A.T.M.

    2003-01-01

    Salt-related soil degradation due to irrigation activities is considered a major threat to the sustainability of rice cropping under semi-arid conditions in West Africa. Rice productivity problems related to soil salinity, alkalinity and topographic position were observed in an irrigated rice scheme

  18. Land degradation assessment by geo-spatially modeling different soil erodibility equations in a semi-arid catchment.

    Science.gov (United States)

    Saygın, Selen Deviren; Basaran, Mustafa; Ozcan, Ali Ugur; Dolarslan, Melda; Timur, Ozgur Burhan; Yilman, F Ebru; Erpul, Gunay

    2011-09-01

    Land degradation by soil erosion is one of the most serious problems and environmental issues in many ecosystems of arid and semi-arid regions. Especially, the disturbed areas have greater soil detachability and transportability capacity. Evaluation of land degradation in terms of soil erodibility, by using geostatistical modeling, is vital to protect and reclaim susceptible areas. Soil erodibility, described as the ability of soils to resist erosion, can be measured either directly under natural or simulated rainfall conditions, or indirectly estimated by empirical regression models. This study compares three empirical equations used to determine the soil erodibility factor of revised universal soil loss equation prediction technology based on their geospatial performances in the semi-arid catchment of the Saraykoy II Irrigation Dam located in Cankiri, Turkey. A total of 311 geo-referenced soil samples were collected with irregular intervals from the top soil layer (0-10 cm). Geostatistical analysis was performed with the point values of each equation to determine its spatial pattern. Results showed that equations that used soil organic matter in combination with the soil particle size better agreed with the variations in land use and topography of the catchment than the one using only the particle size distribution. It is recommended that the equations which dynamically integrate soil intrinsic properties with land use, topography, and its influences on the local microclimates, could be successfully used to geospatially determine sites highly susceptible to water erosion, and therefore, to select the agricultural and bio-engineering control measures needed.

  19. Assessing toxic levels of hydrocarbons on microbial degrader communities in vadose zone fill soils

    International Nuclear Information System (INIS)

    Schoenberg, T.H.; Long, S.C.

    1995-01-01

    Authentic fill samples were collected from the vadose zone at a highway travel plaza. The contamination at the site is a combination of gasoline, diesel, and waste oil resulting from leaking underground storage tanks. Microbial assessments including plate counts and specific-degrader enumerations were performed to establish the presence of degrader microbial communities, and thus bioremediation potential. Contaminant levels were estimated in samples by quantifying headspace VOCs in collection jars. Physical soil characteristics including soil grain size distribution and moisture content were measured to evaluate the potential ecological variables that would affect implementation of a bioremediation technology. Toxicity screening using the Microtox trademark acute toxicity assay was used to compare the level of toxicity present among samples. These analyses were used to assess the potential for using in situ bioventing remediation to clean-up the leaking underground storage tank spill study site. High contaminant levels appear to have exerted a toxic effect and resulted in smaller total microbial community sizes in highly contaminated areas (thousands of ppmv) of the site. Microtox trademark EC50 results generally corroborated with the trends of the enumeration experiments. Microbial characterization results indicate that in situ bioremediation would be possible at the study site. Soil heterogeneity appears to pose the greatest challenges to the design and implementation of bioremediation at this site

  20. Isolation and characterisation of polychlorinated biphenyl (PCB degrading fungi from a historically contaminated soil

    Directory of Open Access Journals (Sweden)

    Di Toro Sara

    2009-01-01

    Full Text Available Abstract Background Polychlorinated biphenyls (PCBs are widespread toxic pollutants. Bioremediation might be an effective, cost competitive and environment-friendly solution for remediating environmental matrices contaminated by PCBs but it is still unsatisfactory, mostly for the limited biodegradation potential of bacteria involved in the processes. Very little is known about mitosporic fungi potential in PCB bioremediation and their occurrence in actual site historically contaminated soils. In the present study, we characterised the native mycoflora of an aged dump site soil contaminated by about 0.9 g kg-1 of Aroclor 1260 PCBs and its changing after aerobic biotreatment with a commercial complex source of bacteria and fungi. Fungi isolated from the soil resulting from 120 days of treatment were screened for their ability to adsorb or metabolise 3 target PCBs. Results The original contaminated soil contained low loads of few fungal species mostly belonging to the Scedosporium, Penicillium and Aspergillus genera. The fungal load and biodiversity generally decreased throughout the aerobic treatment. None of the 21 strains isolated from the treated soil were able to grow on biphenyl (200 mg L-1 or a mixture of 2-chlorobiphenyl, 4,4'-dichlorobiphenyl and 2,2',5,5'-tetrachlorobiphenyl (20 mg L-1 each as sole carbon sources. However, 16 of them grew in a mineral medium containing the same PCBs mixture and glucose (10 g L-1. Five of the 6 isolates, which displayed the faster and more extensive growth under the latter conditions, were found to degrade the 3 PCBs apparently without the involvement of ligninolytic enzymes; they were identified as Penicillium chrysogenum, Scedosporium apiospermum, Penicillium digitatum and Fusarium solani. They are the first PCB degrading strains of such species reported so far in the literature. Conclusion The native mycoflora of the actual site aged heavily contaminated soil was mainly constituted by genera often

  1. Enhanced degradation of spiro-insecticides and their leacher enol derivatives in soil by solarization and biosolarization techniques.

    Science.gov (United States)

    Fenoll, José; Garrido, Isabel; Vela, Nuria; Ros, Caridad; Navarro, Simón

    2017-04-01

    The leaching potential of three insecticides (spirodiclofen, spiromesifen, and spirotetramat) was assessed using disturbed soil columns. Small quantities of spirodiclofen and spiromesifen were detected in leachate fraction, while spirotetramat residues were not found in the leachates. In addition, the transformation products (enol derivatives) are relatively more mobile than the parent compounds and may leach into groundwater. Moreover, the use of disinfection soil techniques (solarization and biosolarization) to enhance their degradation rates in soil was investigated. The results show that both practices achieved a reduction in the number of juvenile nematodes, enhancing in a parallel way degradation rates of the insecticides and their enol derivatives as compared with the non-disinfected soil. This behavior can be mainly attributed to the increase in soil temperature and changes in microbial activity. All insecticides showed similar behavior under solarization and biosolarization conditions. As a consequence, both agronomic techniques could be considered as suitable strategies for detoxification of soils polluted with the studied pesticides.

  2. Degradation of chlorpyrifos contaminated soil by bioslurry reactor operated in sequencing batch mode: bioprocess monitoring

    International Nuclear Information System (INIS)

    Mohan, S. Venkata; Sirisha, K.; Rao, N. Chandrasekhara; Sarma, P.N.; Reddy, S. Jayarama

    2004-01-01

    Bioslurry reactor (SS-SBR) was studied for the degradation of chlorpyrifos contaminated soil using native mixed microflora, by adopting sequencing batch mode (anoxic-aerobic-anoxic) operation. Reactor operation was monitored for a total cycle period of 72 h consisting of 3 h of FILL, 64 h REACT, 2 h of SETTLE, and 3 h of DECANT with chlorpyrifos concentrations of 3000 μg/g, 6000 μg/g and 12000 μg/g. At 3000 μg/g of chlorpyrifos concentration, 91% was degraded after 72 h of the cycle period, whereas in the case of 6000 μg/g of chlorpyrifos, 82.5% was degraded. However, for 12000 μg/g of chlorpyrifos, only 14.5% degradation was observed. The degradation rate was rapid at lower substrate concentration and 12000 μg/g of substrate concentration was found to be inhibitory. Chlorpyrifos removal rate was slow during the initial phase of the sequence operation. Half-life of chlorpyrifos degradation (t 0.5 ) was estimated to be 6.3 h for 3000 μg/g of substrate, 17.5 h for 6000 μg/g and 732.2 h for 12000 μg/g. Process performance was assessed by monitoring chlorpyrifos concentration and biochemical process parameters viz., pH, oxidation and reduction potential (ORP), dissolved oxygen (DO), oxygen consumption rate (OCR) and microbial count (CFU) during sequence operation. From the experimental data obtained it can be concluded that the rate-limiting step with the bioslurry phase reactor in the process of chlorpyrifos degradation may be attributed to the concentration of substrate present in either soil or liquid phase. Periodic operations (SBR) by varying individual components of substrate with time in each process step place micro-organisms under nutritional changes from feast to famine and maintains a wide distribution in the population of micro-organisms resulting in high uptake of the substrate in the bioslurry reactor

  3. Degradation of chlorpyrifos contaminated soil by bioslurry reactor operated in sequencing batch mode: bioprocess monitoring

    Energy Technology Data Exchange (ETDEWEB)

    Mohan, S. Venkata [Biochemical and Environmental Engineering Centre, Indian Institute of Chemical Technology, Hyderabad 500007 (India); Sirisha, K. [Electrochemical Research Laboratories, Department of Chemistry, Sri Venkateswara University, Tirupati 517502 (India); Rao, N. Chandrasekhara [Biochemical and Environmental Engineering Centre, Indian Institute of Chemical Technology, Hyderabad 500007 (India); Sarma, P.N. [Biochemical and Environmental Engineering Centre, Indian Institute of Chemical Technology, Hyderabad 500007 (India); Reddy, S. Jayarama [Electrochemical Research Laboratories, Department of Chemistry, Sri Venkateswara University, Tirupati 517502 (India)]. E-mail: profjreddy_s@yahoo.co.in

    2004-12-10

    Bioslurry reactor (SS-SBR) was studied for the degradation of chlorpyrifos contaminated soil using native mixed microflora, by adopting sequencing batch mode (anoxic-aerobic-anoxic) operation. Reactor operation was monitored for a total cycle period of 72 h consisting of 3 h of FILL, 64 h REACT, 2 h of SETTLE, and 3 h of DECANT with chlorpyrifos concentrations of 3000 {mu}g/g, 6000 {mu}g/g and 12000 {mu}g/g. At 3000 {mu}g/g of chlorpyrifos concentration, 91% was degraded after 72 h of the cycle period, whereas in the case of 6000 {mu}g/g of chlorpyrifos, 82.5% was degraded. However, for 12000 {mu}g/g of chlorpyrifos, only 14.5% degradation was observed. The degradation rate was rapid at lower substrate concentration and 12000 {mu}g/g of substrate concentration was found to be inhibitory. Chlorpyrifos removal rate was slow during the initial phase of the sequence operation. Half-life of chlorpyrifos degradation (t{sub 0.5}) was estimated to be 6.3 h for 3000 {mu}g/g of substrate, 17.5 h for 6000 {mu}g/g and 732.2 h for 12000 {mu}g/g. Process performance was assessed by monitoring chlorpyrifos concentration and biochemical process parameters viz., pH, oxidation and reduction potential (ORP), dissolved oxygen (DO), oxygen consumption rate (OCR) and microbial count (CFU) during sequence operation. From the experimental data obtained it can be concluded that the rate-limiting step with the bioslurry phase reactor in the process of chlorpyrifos degradation may be attributed to the concentration of substrate present in either soil or liquid phase. Periodic operations (SBR) by varying individual components of substrate with time in each process step place micro-organisms under nutritional changes from feast to famine and maintains a wide distribution in the population of micro-organisms resulting in high uptake of the substrate in the bioslurry reactor.

  4. Isolation and Characterization of Phenanthrene Degrading Bacteria from Diesel Fuel-Contaminated Antarctic Soils

    Directory of Open Access Journals (Sweden)

    Alejandro Gran-Scheuch

    2017-08-01

    Full Text Available Antarctica is an attractive target for human exploration and scientific investigation, however the negative effects of human activity on this continent are long lasting and can have serious consequences on the native ecosystem. Various areas of Antarctica have been contaminated with diesel fuel, which contains harmful compounds such as heavy metals and polycyclic aromatic hydrocarbons (PAH. Bioremediation of PAHs by the activity of microorganisms is an ecological, economical, and safe decontamination approach. Since the introduction of foreign organisms into the Antarctica is prohibited, it is key to discover native bacteria that can be used for diesel bioremediation. By following the degradation of the PAH phenanthrene, we isolated 53 PAH metabolizing bacteria from diesel contaminated Antarctic soil samples, with three of these isolates exhibiting a high phenanthrene degrading capacity. In particular, the Sphingobium xenophagum D43FB isolate showed the highest phenanthrene degradation ability, generating up to 95% degradation of initial phenanthrene. D43FB can also degrade phenanthrene in the presence of its usual co-pollutant, the heavy metal cadmium, and showed the ability to grow using diesel-fuel as a sole carbon source. Microtiter plate assays and SEM analysis revealed that S. xenophagum D43FB exhibits the ability to form biofilms and can directly adhere to phenanthrene crystals. Genome sequencing analysis also revealed the presence of several genes involved in PAH degradation and heavy metal resistance in the D43FB genome. Altogether, these results demonstrate that S. xenophagum D43FB shows promising potential for its application in the bioremediation of diesel fuel contaminated-Antarctic ecosystems.

  5. Effect of catchment land use and soil type on the concentration, quality, and bacterial degradation of riverine dissolved organic matter

    DEFF Research Database (Denmark)

    Autio, Iida; Soinne, Helena; Helin, Janne

    2016-01-01

    We studied the effects of catchment characteristics (soil type and land use) on the concentration and quality of dissolved organic matter (DOM) in river water and on the bacterial degradation of terrestrial DOM. The share of organic soil was the strongest predictor of high concentrations...... of dissolved organic carbon, nitrogen, and phosphorus (DOC, DON, and DOP, respectively), and was linked to DOM quality. Soil type was more important than land use in determining the concentration and quality of riverine DOM. On average, 5–9 % of the DOC and 45 % of the DON were degraded by the bacterial...

  6. Degradation of polyisoprene rubber by newly isolated Bacillus sp. AF-666 from soil.

    Science.gov (United States)

    Shah, A A; Hasan, F; Shah, Z; Mutiullah; Hameed, A

    2012-01-01

    Various microorganisms were screened for their ability to degrade polyisoprene rubber (natural rubber latex gloves). Strain AF-666, newly isolated from a soil sample, was selected as the best strain having the ability to grow on polyisoprene containing plates. The strain identified as Bacillus sp. AF-666, was found to degrade polyisoprene rubber, both on basal agar plates (latex overlay) as well as in liquid medium. Qualitative analysis of degradation was done through scanning electron microscopy (SEM) and Fourier transform infrared (FTIR) spectroscopy SEM showed changes in surface morphology, like appearance of pits and cracks, and marked difference in transmittance spectra of test and control due to changes in the functional groups, was detected through FTIR. CO2 evolution as a result of rubber degradation, was calculated gravimetrically by Sturm Test. About 4.43 g/1 of CO2 was produced in case of test, whereas, 1.57 g/1 in case of control. The viable number of cells (CFU/ml) was also higher in test than in control. Present study may provide an opportunity for further studies on the applications of biotechnological processes as a tool for rubber waste management.

  7. Evaluation of Aliphatic and Aromatic Compounds Degradation by Indigenous Bacteria Isolated from Soil Contaminated with Petroleum

    Directory of Open Access Journals (Sweden)

    Farhad Gilavand

    2015-12-01

    Full Text Available Background:  The major of this study was to isolate oil-degrading bacteria from soil contaminated with petroleum and examining the removal of hydrocarbons by these bacteria. Methods: Oil-degrading colonies were purified from the samples obtained of around Ahvaz oil wells. Organic matter degradation was investigated with 1 g of crude oil in basal salt medium (BSM as sole carbon source. The growth rate was determined through total protein assay and hydrocarbon consuming was measured through organic carbon oxidation and titration by dichromate as oxidizing agent. Results: Two potential isolates named S1 and S2 strains were screened and identified as Planococcus and Pseudomonas aeruginosa. As results for S1 and S2 could degrade 80.86 and 65.6% of olive oil, 59.6 and 35.33 of crude oil, while 32 and 26.15 % of coal tar were consumed during 14 days incubation. Conclusion: The results of this investigation showed these indigenous strains high capability to biodegradation at short time and are desirable alternatives for treatment of oil pollutants.

  8. Influence of pore structure on solute transport in degraded and undegraded fen peat soils

    Directory of Open Access Journals (Sweden)

    C. Kleimeier

    2017-10-01

    Full Text Available In peat soils, decomposition and degradation reduce the proportion of large pores by breaking down plant debris into smaller fragments and infilling inter-particle pore spaces. This affects water flow and solute migration which, in turn, influence reactive transport processes and biogeochemical functions. In this study we conducted flow-through reactor experiments to investigate the interplay between pore structure and solute transport in samples of undegraded and degraded peat collected in Canada and Germany, respectively. The pore size distributions and transport parameters were characterised using the breakthrough curve and two-region non-equilibrium transport model analyses for a non-reactive solute. The results of transport characterisation showed a higher fraction of immobile pores in the degraded peat with higher diffusive exchanges of solutes between the mobile and immobile pores associated with the dual-porosity structure. The rates of steady-state potential nitrate reduction were compared with pore fractions and exchange coefficients to investigate the influence of pore structure on the rates of nitrate reduction. The results indicated that the degraded peat has potential to provide the necessary boundary conditions to support nitrate removal and serves as a favourable substrate for denitrification, due to the nature of its pore structure and its lower organic carbon content compared to undegraded peat.

  9. Potential of bacteria isolated from landfill soil in degrading low density polyethylene plastic

    Science.gov (United States)

    Munir, E.; Sipayung, F. C.; Priyani, N.; Suryanto, D.

    2018-03-01

    Plastic is an important material and used for many purposes. It is returned to the environment as a waste which is recently considered as the second largest solid waste. The persistency of plastic in the environment has been attracted researchers from a different point of view. The study of the degradation of plastic using bacteria isolated from local landfill soil was conducted. Low density polyethylene (LDPE) plastic was used as tested material. Potential isolates were obtained by culturing the candidates in mineral salt medium broth containing LDPE powder. Two of ten exhibited better growth response in the selection media and were used in degradation study. Results showed that isolate SP2 and SP4 reduced the weight of LDPE film significantly to a weight loss of 10.16% and 12.06%, respectively after four weeks of incubation. Scanning electron micrograph analyses showed the surface of LDPE changed compared to the untreated film. It looked rough and cracked, and bacteria cells attached to the surface was also noticed. Fourier transform infrared spectroscopy analyses confirmed the degradation of LDPE film. These results indicated that bacteria isolated from landfill might play an important role in degrading plastic material in the landfill.

  10. Study The Properties and Weight Loss Degradation of The Blend LDPE/Cellulose in Soil Environment

    Directory of Open Access Journals (Sweden)

    Zuhair Jabbar Abdul Ameer

    2017-05-01

    Full Text Available Wider applications of polyethylene (PE in packaging and agriculture have raised serious issue of waste disposal and pollution. Therefore, it is necessary to raise its biodegradability by additives.In this study, we will add cellulose to low density polyethylene to prepare polymer blend have ability to degradation in soil environment.The samples were prepared by using twin screw extruder.LDPE and CELL have been mixing with different weight proportions, and studied their properties in order to determine its compliance with the required specifications to be able to be used biodegradable polymers. To improve the viability of decomposition PEG has been added to the resulting blend. Several tests were applied to identify those properties such as tensile,hardness, density and creep test. FTIR, digital microscope and SEM test acheved in order to determine the miscibility and blend morphology befor and after degradation.The results show that,the blend weight loss increase with increasing CELL percent.

  11. Reorganization of vegetation, hydrology and soil carbon after permafrost degradation across heterogeneous boreal landscapes

    International Nuclear Information System (INIS)

    Torre Jorgenson, M; Harden, Jennifer; Manies, Kristen; Kanevskiy, Mikhail; Shur, Yuri; O’Donnell, Jonathan; Wickland, Kim; Striegl, Robert; Ewing, Stephanie; Zhuang Qianlai; Koch, Josh

    2013-01-01

    The diversity of ecosystems across boreal landscapes, successional changes after disturbance and complicated permafrost histories, present enormous challenges for assessing how vegetation, water and soil carbon may respond to climate change in boreal regions. To address this complexity, we used a chronosequence approach to assess changes in vegetation composition, water storage and soil organic carbon (SOC) stocks along successional gradients within four landscapes: (1) rocky uplands on ice-poor hillside colluvium, (2) silty uplands on extremely ice-rich loess, (3) gravelly–sandy lowlands on ice-poor eolian sand and (4) peaty–silty lowlands on thick ice-rich peat deposits over reworked lowland loess. In rocky uplands, after fire permafrost thawed rapidly due to low ice contents, soils became well drained and SOC stocks decreased slightly. In silty uplands, after fire permafrost persisted, soils remained saturated and SOC decreased slightly. In gravelly–sandy lowlands where permafrost persisted in drier forest soils, loss of deeper permafrost around lakes has allowed recent widespread drainage of lakes that has exposed limnic material with high SOC to aerobic decomposition. In peaty–silty lowlands, 2–4 m of thaw settlement led to fragmented drainage patterns in isolated thermokarst bogs and flooding of soils, and surface soils accumulated new bog peat. We were not able to detect SOC changes in deeper soils, however, due to high variability. Complicated soil stratigraphy revealed that permafrost has repeatedly aggraded and degraded in all landscapes during the Holocene, although in silty uplands only the upper permafrost was affected. Overall, permafrost thaw has led to the reorganization of vegetation, water storage and flow paths, and patterns of SOC accumulation. However, changes have occurred over different timescales among landscapes: over decades in rocky uplands and gravelly–sandy lowlands in response to fire and lake drainage, over decades to

  12. Construction of PAH-degrading mixed microbial consortia by induced selection in soil.

    Science.gov (United States)

    Zafra, German; Absalón, Ángel E; Anducho-Reyes, Miguel Ángel; Fernandez, Francisco J; Cortés-Espinosa, Diana V

    2017-04-01

    Bioremediation of polycyclic aromatic hydrocarbons (PAHs)-contaminated soils through the biostimulation and bioaugmentation processes can be a strategy for the clean-up of oil spills and environmental accidents. In this work, an induced microbial selection method using PAH-polluted soils was successfully used to construct two microbial consortia exhibiting high degradation levels of low and high molecular weight PAHs. Six fungal and seven bacterial native strains were used to construct mixed consortia with the ability to tolerate high amounts of phenanthrene (Phe), pyrene (Pyr) and benzo(a)pyrene (BaP) and utilize these compounds as a sole carbon source. In addition, we used two engineered PAH-degrading fungal strains producing heterologous ligninolytic enzymes. After a previous selection using microbial antagonism tests, the selection was performed in microcosm systems and monitored using PCR-DGGE, CO 2 evolution and PAH quantitation. The resulting consortia (i.e., C1 and C2) were able to degrade up to 92% of Phe, 64% of Pyr and 65% of BaP out of 1000 mg kg -1 of a mixture of Phe, Pyr and BaP (1:1:1) after a two-week incubation. The results indicate that constructed microbial consortia have high potential for soil bioremediation by bioaugmentation and biostimulation and may be effective for the treatment of sites polluted with PAHs due to their elevated tolerance to aromatic compounds, their capacity to utilize them as energy source. Copyright © 2016 Elsevier Ltd. All rights reserved.

  13. Characterization of Trapped Lignin-Degrading Microbes in Tropical Forest Soil

    Energy Technology Data Exchange (ETDEWEB)

    DeAngelis, Kristen; Allgaier, Martin; Chavarria, Yaucin; Fortney, Julian; Hugenholtz, Phillip; Simmons, Blake; Sublette, Kerry; Silver, Whendee; Hazen, Terry

    2011-07-14

    Lignin is often the most difficult portion of plant biomass to degrade, with fungi generally thought to dominate during late stage decomposition. Lignin in feedstock plant material represents a barrier to more efficient plant biomass conversion and can also hinder enzymatic access to cellulose, which is critical for biofuels production. Tropical rain forest soils in Puerto Rico are characterized by frequent anoxic conditions and fluctuating redox, suggesting the presence of lignin-degrading organisms and mechanisms that are different from known fungal decomposers and oxygen-dependent enzyme activities. We explored microbial lignin-degraders by burying bio-traps containing lignin-amended and unamended biosep beads in the soil for 1, 4, 13 and 30 weeks. At each time point, phenol oxidase and peroxidase enzyme activity was found to be elevated in the lignin-amended versus the unamended beads, while cellulolytic enzyme activities were significantly depressed in lignin-amended beads. Quantitative PCR of bacterial communities showed more bacterial colonization in the lignin-amended compared to the unamended beads after one and four weeks, suggesting that the lignin supported increased bacterial abundance. The microbial community was analyzed by small subunit 16S ribosomal RNA genes using microarray (PhyloChip) and by high-throughput amplicon pyrosequencing based on universal primers targeting bacterial, archaeal, and eukaryotic communities. Community trends were significantly affected by time and the presence of lignin on the beads. Lignin-amended beads have higher relative abundances of representatives from the phyla Actinobacteria, Firmicutes, Acidobacteria and Proteobacteria compared to unamended beads. This study suggests that in low and fluctuating redox soils, bacteria could play a role in anaerobic lignin decomposition.

  14. Characterization of trapped lignin-degrading microbes in tropical forest soil

    Energy Technology Data Exchange (ETDEWEB)

    DeAngelis, K.M.; Allgaier, M.; Chavarria, Y.; Fortney, J.L.; Hugenholz, P.; Simmons, B.; Sublette, K.; Silver, W.L.; Hazen, T.C.

    2011-03-01

    Lignin is often the most difficult portion of plant biomass to degrade, with fungi generally thought to dominate during late stage decomposition. Lignin in feedstock plant material represents a barrier to more efficient plant biomass conversion and can also hinder enzymatic access to cellulose, which is critical for biofuels production. Tropical rain forest soils in Puerto Rico are characterized by frequent anoxic conditions and fluctuating redox, suggesting the presence of lignin-degrading organisms and mechanisms that are different from known fungal decomposers and oxygen-dependent enzyme activities. We explored microbial lignin-degraders by burying bio-traps containing lignin-amended and unamended biosep beads in the soil for 1, 4, 13 and 30 weeks. At each time point, phenol oxidase and peroxidase enzyme activity was found to be elevated in the lignin-amended versus the unamended beads, while cellulolytic enzyme activities were significantly depressed in lignin-amended beads. Quantitative PCR of bacterial communities showed more bacterial colonization in the lignin-amended compared to the unamended beads after one and four weeks, suggesting that the lignin supported increased bacterial abundance. The microbial community was analyzed by small subunit 16S ribosomal RNA genes using microarray (PhyloChip) and by high-throughput amplicon pyrosequencing based on universal primers targeting bacterial, archaeal, and eukaryotic communities. Community trends were significantly affected by time and the presence of lignin on the beads. Lignin-amended beads have higher relative abundances of representatives from the phyla Actinobacteria, Firmicutes, Acidobacteria and Proteobacteria compared to unamended beads. This study suggests that in low and fluctuating redox soils, bacteria could play a role in anaerobic lignin decomposition.

  15. Degradation of deicing chemicals affects the natural redox system in airfield soils.

    Science.gov (United States)

    Lissner, Heidi; Wehrer, Markus; Jartun, Morten; Totsche, Kai Uwe

    2014-01-01

    During winter operations at airports, large amounts of organic deicing chemicals (DIC) accumulate beside the runways and infiltrate into the soil during spring. To study the transport and degradation of DIC in the unsaturated zone, eight undisturbed soil cores were retrieved at Oslo airport, Norway, and installed as lysimeters at a nearby field site. Before snowmelt in 2010 and 2011, snow amended with a mix of the DICs propylene glycol (PG) and formate as well as bromide as conservative tracer was applied. Water samples were collected and analyzed until summer 2012. Water flow and solute transport varied considerably among the lysimeters but also temporally between 2010 and 2011. High infiltration rates during snowmelt resulted in the discharge of up to 51 and 82% PG in 2010 and 2011, respectively. The discharge of formate remained comparatively low, indicating its favored degradation even at freezing temperatures compared with PG. Manganese (Mn) and iron (Fe) were observed in the drainage in autumn owing to the anaerobic degradation of residual PG during summer. Our findings suggest that upper boundary conditions, i.e., snow cover and infiltration rate, and the extent of preferential flowpaths, control water flow and solute transport of bromide and PG during snowmelt. PG may therefore locally reach deeper soil regions where it may pose a risk for groundwater. In the long term, the use of DIC furthermore causes the depletion of potential electron acceptors and the transport of considerable amounts of Fe and Mn. To avoid an overload of the unsaturated zone with DIC and to maintain the natural redox system, the development of suitable remediation techniques is required.

  16. Conservation Farming and Changing Climate: More Beneficial than Conventional Methods for Degraded Ugandan Soils

    Directory of Open Access Journals (Sweden)

    Drake N. Mubiru

    2017-06-01

    Full Text Available The extent of land affected by degradation in Uganda ranges from 20% in relatively flat and vegetation-covered areas to 90% in the eastern and southwestern highlands. Land degradation has adversely affected smallholder agro-ecosystems including direct damage and loss of critical ecosystem services such as agricultural land/soil and biodiversity. This study evaluated the extent of bare grounds in Nakasongola, one of the districts in the Cattle Corridor of Uganda and the yield responses of maize (Zea mays and common bean (Phaseolus vulgaris L. to different tillage methods in the district. Bare ground was determined by a supervised multi-band satellite image classification using the Maximum Likelihood Classifier (MLC. Field trials on maize and bean grain yield responses to tillage practices used a randomized complete block design with three replications, evaluating conventional farmer practice (CFP; permanent planting basins (PPB; and rip lines, with or without fertilizer in maize and bean rotations. Bare ground coverage in the Nakasongola District was 187 km2 (11% of the 1741 km2 of arable land due to extreme cases of soil compaction. All practices, whether conventional or the newly introduced conservation farming practices in combination with fertilizer increased bean and maize grain yields, albeit with minimal statistical significance in some cases. The newly introduced conservation farming tillage practices increased the bean grain yield relative to conventional practices by 41% in PPBs and 43% in rip lines. In maize, the newly introduced conservation farming tillage practices increased the grain yield by 78% on average, relative to conventional practices. Apparently, conservation farming tillage methods proved beneficial relative to conventional methods on degraded soils, with the short-term benefit of increasing land productivity leading to better harvests and food security.

  17. Degradation and plant uptake of nonylphenol (NP) and nonylphenol-12-ethoxylate (NP12EO) in four contrasting agricultural soils

    International Nuclear Information System (INIS)

    Sjoestroem, A.E.; Collins, C.D.; Smith, S.R.; Shaw, G.

    2008-01-01

    Nonylphenol polyethoxylates (NPEOs) are surfactants found ubiquitously in the environment due to widespread industrial and domestic use. Biodegradation of NPEOs produces nonylphenol (NP), an endocrine disruptor. Sewage sludge application introduces NPEOs and NP into soils, potentially leading to accumulation in soils and crops. We examined degradation of NP and nonylphenol-12-ethoxylate (NP12EO) in four soils. NP12EO degraded rapidly (initial half time 0.3-5 days). Concentrations became undetectable within 70-90 days, with a small increase in NP concentrations after 30 days. NP initially degraded quickly (mean half time 11.5 days), but in three soils a recalcitrant fraction of 26-35% remained: the non-degrading fraction may consist of branched isomers, resistant to biodegradation. Uptake of NP by bean plants was also examined. Mean bioconcentration factors for shoots and seeds were 0.71 and 0.58, respectively. Removal of NP from the soil by plant uptake was negligible (0.01-0.02% of initial NP). Root concentrations were substantially higher than shoot and seed concentrations. - Degradation curves of nonylphenol (NP) and nonylphenol-12-ethoxylate (NP12EO) in four soils indicate that 26-35% of NP is recalcitrant, with minor NP ingrowth from NP12EO breakdown

  18. Use of olive oil for soil extraction and ultraviolet degradation of polychlorinated dibenzo-p-dioxins and dibenzofurans.

    Science.gov (United States)

    Isosaari, P; Tuhkanen, T; Vartiainen, T

    2001-03-15

    This paper represents a successful laboratory-scale photolysis of soil-bound tetra- to octachlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) in olive oil. The irradiation source consisted of two blacklight lamps emitting light at a near-ultraviolet range. Samples used in the experiments included pure 1,2,3,4,6,7,8-heptachlorodibenzofuran, PCDD/F extract made of a wood preservative (chlorophenol product Ky 5), and soil that was highly contaminated with PCDD/Fs. Degradation of 1,2,3,4,6,7,8-heptachlorodibenzofuran dissolved in olive oil proceeded rapidlywith a first-order reaction half-life of 13 min. Irradiation of a soil sample resulted in an 84% reduction in PCDD/F toxicity equivalent (I-TEQ) in 17.5 h. A more complete degradation of soil-bound PCDD/Fs was achieved after extraction of the soil with olive oil. The oil was effective in solubilizing PCDD/Fs. After one extraction at room temperature, only 9% of I-TEQ remained in soil. Irradiation of the resulting extract reduced toxicity of the extract by 99%, and even the highly chlorinated congeners octachlorodibenzo-p-dioxin and octachlorodibenzofuran degraded easily (97 and 99% degradation, respectively). Photodegradation byproducts found included diphenyl ether and small amounts of dechlorination products, which were mainly nontoxic PCDD/Fs. Degradation was probably mediated by light absorption of unsaturated fatty acids and phenolic compounds in olive oil, leading to sensitized photolysis of PCDD/Fs.

  19. Soil degradation of parthenin-does it contradict the role of allelopathy in the invasive weed Parthenium hysterophorus L.?

    Science.gov (United States)

    Belz, Regina G; van der Laan, Michael; Reinhardt, Carl F; Hurle, Karl

    2009-09-01

    The invasive success of Parthenium hysterophorus L. is thought to be partially attributable to allelopathy mediated by the plant metabolite parthenin. To assess the ecological significance of parthenin release from plant material, its persistence and phytotoxicity in soil was studied. Results show parthenin is rapidly degraded with an average DT (50) of 59 h under standard experimental conditions. Degradation was delayed in sterilized soils, at lower soil moisture, and higher parthenin concentrations. Higher temperatures, higher CEC(pot)/clay content of soils, soil preconditioning with parthenin, and P. hysterophorus infestation accelerated degradation. Physico-chemical and biological processes are, therefore, expected to govern the fate of parthenin in soil. Parthenin exhibited low soil phytotoxicity and did not accumulate over time. Along with the indicated reduction in bioavailability and development of hormetic effects, results suggest that for parthenin to have detrimental allelopathic effects, it requires high P. hysterophorus densities that result in high soil levels of parthenin and soil conditions that favor the persistence of parthenin. In light of this, the ecological significance of parthenin is discussed.

  20. Novel Chryseobacterium sp. PYR2 degrades various organochlorine pesticides (OCPs) and achieves enhancing removal and complete degradation of DDT in highly contaminated soil.

    Science.gov (United States)

    Qu, Jie; Xu, Yang; Ai, Guo-Min; Liu, Ying; Liu, Zhi-Pei

    2015-09-15

    Long term residues of organochlorine pesticides (OCPs) in soils are of great concerning because they seriously threaten food security and human health. This article focuses on isolation of OCP-degrading strains and their performance in bioremediation of contaminated soil under ex situ conditions. A bacterium, Chryseobacterium sp. PYR2, capable of degrading various OCPs and utilizing them as a sole carbon and energy source for growth, was isolated from OCP-contaminated soil. In culture experiments, PYR2 degraded 80-98% of hexachlorocyclohexane (HCH) or 1,1,1-trichloro-2,2-bis (4-chlorophenyl) ethane (DDT) isomers (50 mg L(-1)) in 30 days. A pilot-scale ex situ bioremediation study of highly OCP-contaminated soil augmented with PYR2 was performed. During the 45-day experimental period, DDT concentration was reduced by 80.3% in PYR2-augmented soils (35.37 mg kg(-1) to 6.97 mg kg(-1)) but by only 57.6% in control soils. Seven DDT degradation intermediates (metabolites) were detected and identified in PYR2-augmented soils: five by GC/MS: 1,1-dichloro-2,2-bis (4-chlorophenyl) ethane (DDD), 1,1-dichloro-2,2-bis (4-chlorophenyl) ethylene (DDE), 1-chloro-2,2-bis (4-chlorophenyl) ethylene (DDMU), 1-chloro-2,2-bis (4-chlorophenyl) ethane (DDMS), and dichlorobenzophenone (DBP); and two by LC/MS: 4-chlorobenzoic acid (PCBA) and 4-chlorophenylacetic acid (PCPA). Levels of metabolites were fairly stable in control soils but varied greatly with time in PYR2-augmented soils. Levels of DDD, DDMU, and DDE in PYR2-augmented soils increased from day 0 to day 30 and then decreased by day 45. A DDT biodegradation pathway is proposed based on our identification of DDT metabolites in PYR2-augmented systems. PYR2 will be useful in future studies of OCP biodegradation and in bioremediation of OCP-contaminated soils. Copyright © 2015 Elsevier Ltd. All rights reserved.

  1. Occurrence of hydrocarbon degrading bacteria in soil in Kukawa, Borno State

    Directory of Open Access Journals (Sweden)

    IA Allamin

    2014-05-01

    Full Text Available Soil samples were collected from five sites covering petroleum exploration station in Kukawa, Kukawa Local Government Area of Borno State, Nigeria between October, 2012 and February, 2013 at two different depths (0-10cm and 10-20cm to enumerate and identify hydrocarbon degrading bacteria in the soil. Total aerobic heterotrophic bacteria (TAHB were enumerated on Nutrient agar (NA, and Hydrocarbon utilizing bacteria (HUB enumerated on Oil agar (OA. The bacterial isolates were identified using morphological and biochemical tests. It was observed that the microorganisms (TAHB, and HUB were more densely populated at 10cm depth. (TAHB: 5.3×108 - 11.4×108cfu/g, and HUB: 2.4×105 - 5.3×105 cfu/g, than at 20 cm depth (TAHB: 3.0×108 - 5.7×108 cfu/g, and HUB: 2.1×105 - 4.8×105 cfu/g. The HUB was identified as species of Bacillus, Pseudomonas, Klebsiella, Lactobacillus, Micrococcus, Corynebacterium, and Actinomyces. Bacillus, and Pseudomonas species were more constantly isolated than other isolates and they constitute 100% of total bacterial isolates. The potential of hydrocarbon utilizing bacteria isolated to degrade hydrocarbon was studied. Nineteen (19 bacterial species was screened, Bacillus subtilis, Pseudomonas aeruginosa, Bacillus cereus, Klebsiella pneumoniae, Micrococcus leteus,and Lactobacillus casei, utilized and degrade crude oil at considerably high rates after 21 days of incubation. The degradation efficiency was confirmed by GC-MS analysis, which indicated that the bacterial isolates utilized most of the crude oil components particularly straight chain alkanes and cycloalkanes DOI: http://dx.doi.org/10.3126/ije.v3i2.10503 International Journal of the Environment Vol.3(2 2014: 36-47

  2. Aggregation of surface mine soil by interaction between VAM fungi and lignin degradation products of lespedeza

    Energy Technology Data Exchange (ETDEWEB)

    Rothwell, F.M. (USDA Forest Service, Berea, KY (USA). Northeastern Forest Experiment Station, Forestry Sciences Laboratory)

    1984-01-01

    The external mycelium of a vesicular-arbuscular mycorrhizal (VAM) fungus was effective in aggregating a sandy loam minesoil. The polysaccharide nature of the soil binding agent on hyphal surfaces and on the surfaces of sand particles in contact with the hyphae within the aggregate was demonstrated with the periodic acid-Schiff reagent staining reaction. A possible stabilizing mechanism for macroaggregates was proposed that involves a coupling reaction between glucosamines in the hyphal walls of the fungus with phenolic compounds released during lignin degradation of sericea lespedeza root tissue. 28 refs.

  3. Characterization of Carbofuran Degrading Bacteria Obtained from Potato Cultivated Soils with Different Pesticide Application Records

    OpenAIRE

    Castellanos Rozo, José; Sánchez Nieves, Jimena; Uribe Vélez, Daniel; Moreno Chacón, Leonardo; Melgarejo Muñoz, Luz Marina

    2013-01-01

    Eighty-two bacterial isolates with potential Carbofuran degradation activity (Furadan®3SC) were obtained from soils cultivated with the potato variety Unica (Solanum tuberosum) in Silos, Norte de Santander (Colombia), with different records of pesticide application. The bacteria were selected for their ability to grow at 25 °C for 72 h in media containing 200 mg L-1 of analytical Carbofuran as the sole source of carbon and/ or nitrogen. The results showed that ten isolates, 12% of those obtai...

  4. Interrelationships of Land Use/Cover Change and Topography with Soil Acidity and Salinity as Indicators of Land Degradation

    Directory of Open Access Journals (Sweden)

    Ramita Manandhar

    2014-03-01

    Full Text Available As soil is the basis of all terrestrial ecosystems, degraded soil means lower fertility, reduced biodiversity and reduced human welfare. Therefore the focus of this paper is on elucidating the influence of land use and land cover (LULC change on two important soil quality indicators that are fundamental to effective measures for ameliorating soil degradation; namely soil acidity and soil salinity in the Lower Hunter Valley of New South Wales, Australia. First, Analysis of Variance was used to elucidate the effects of LULC categories on soil acidity and salinity. The results indicate that soils under Vineyard have significantly higher pH. In contrast there is no significant effect of LULC or its change on soil salinity. To further elucidate the complex interactions of these soil quality indicators with landscape attributes over 20 years and other terrain attributes, multivariate ordination techniques (correspondence analysis and canonical correspondence analysis were used. The results show that elevation exerted a more dominant influence on pH than the LULC types and their dynamics. In comparison, salinity of the soil appears to be higher in subsoil layers under woodland than under other LULC categories. The environmental implications of these interactions, as evidenced by this study, provide some insights for future land use planning in the region.

  5. Identification of degradation routes of metamitron in soil microcosms using 13C-isotope labeling.

    Science.gov (United States)

    Wang, Shizong; Miltner, Anja; Nowak, Karolina M

    2017-01-01

    Metamitron is one of the most commonly used herbicide in sugar beet and flower bulb cultures. Numerous laboratory and field studies on sorption and degradation of metamitron were performed. Detailed biodegradation studies in soil using 13 C-isotope labeling are still missing. Therefore, we aimed at providing a detailed turnover mass balance of 13 C 6 -metamitron in soil microcosms over 80 days. In the biotic system, metamitron mineralized rapidly, and 13 CO 2 finally constituted 60% of the initial 13 C 6 -metamitron equivalents. In abiotic control experiments CO 2 rose to only 7.4% of the initial 13 C 6 -metamitron equivalents. The 13 C label from 13 C 6 -metamitron was incorporated into microbial amino acids that were ultimately stabilized in the soil organic matter forming presumably harmless biogenic residues. Finally, 13 C label from 13 C 6 -metamitron was distributed between the 13 CO 2 and the 13 C-biogenic residues indicating nearly complete biodegradation. The parallel increase of 13 C-alanine, 13 C-glutamate and 13 CO 2 indicates that metamitron was initially biodegraded via the desamino-metamitron route suggesting its relevance in the growth metabolism. In later phases of biodegradation, the "Rhodococcus route" was indicated by the low 13 CO 2 evolution and the high relevance of the pyruvate pathway, which aims at biomolecule synthesis and seems to be related to starvation. This is a first report on the detailed degradation route of metamitron in soil. Copyright © 2016 Elsevier Ltd. All rights reserved.

  6. Impact of long term pesticide usage on soil microbial activities and 14C-monocrotophos degradation

    International Nuclear Information System (INIS)

    Tayaputch, N.; Pimpan, P.; Phaikaew, Y.; Chukiatwatana, L.

    2001-01-01

    The effects of long term pesticide usage on soil microbial activities and degradation of 14 C-monocrotophos was observed under cotton field conditions. The experimental field was divided into treated and untreated plots. Pesticides were applied to treated plots at weekly intervals as in common practice in Thailand. The total numbers of applications were 11, 16 and 16 for first, second and third crop seasons, during the three years from 1996 to 1998. Soil samples at depths of 0-15 cm and 15-30 cm were sampled before and after pesticide application for the first two crops, while in the third crop season only the surface layer of soil was taken. The samples were assessed for CO 2 from respiration, soil microbial population, iron reduction capacity, and rates of nitrification. Soil biomass and microbial activities as measured from respiration and iron reduction decreased in the treated plots at both depths after each pesticide application over the three crop seasons, whereas samples from untreated plots at both depths did not show decreases. Repeated application of pesticides did not show any effect on nitrification rates of the first crop but there was inhibition in the second and third crops. Soil columns, treated with 14 C-monocrotophos one week after last pesticide application, were harvested after 0, 3, 6, 9, 18, 24 and 30 months. Extractable residues of 14 C were found only in the 0-15 cm layer. In treated and untreated plots, residues declined from 80.17 and 85.68 to 0.44% of the applied 14 C within 6 months. The long term usage of pesticides did not affect the half-life of 14 C-monocrotophos. Bound residues of 14 C were found at the highest concentrations, 18.94 and 12.58% of that applied, at 6 months in treated and untreated plots, thereafter the binding decreased to 4.68 and 2.74% within 30 months. (author)

  7. Dissipation, degradation and uptake of 14C-carbofuran in a Panamanian Alfisol soil

    International Nuclear Information System (INIS)

    Gonzalez, J.E.; Saiz, E.B. de; Gonzalez, L.; Perez, O.; Caballos, J.

    1999-01-01

    The dissipation, degradation and leaching of carbon-14 labelled carbofuran was studied in a micro-lysimeter system with disturbed and undisturbed soil cores of an Alfisol from El Ejido, Panama. The micro-lysimeters were conditioned under the environment prior to the application of the insecticide. Each lysimeter was treated with 14C-labelled carbofuran at a concentration of 1.7 μg carbofuran/g soil and maize seed were sown in the treated soil. Samples of soil were taken at 0, 8, 15, 30, 60, 90 and 180 days after treatment. The plant material was separated and the soil was analyzed by radiometric techniques for total, extractable and non-extractable residues. The total 14C-radioactivity decreased with time to 30% of the originally applied activity. Extractable residues decreased with time to 2.5% whereas, the un-extractable residues increased to 35.5% of the original. Residues in the plant foliage were in the range of 0.5 to 0.9 μg/g and showed highest concentration during the first 30 days after germination. Extractable residues included carbofuran, 3-hydroxy-carbofuran and 3-keto-carbofuran. The amount of radioactivity leached was in the range of 19.2 to 22.8% of original. It is concluded that carbofuran residues move easily in soil-maize system. Maize plants rapidly absorb the insecticide and C14-activity predominates 15 to 30 days post-treatment. Dissipation of carbofuran occurs soon, with a halflife of 30 days. (author)

  8. Atrazine degradation and enzyme activities in an agricultural soil under two tillage systems.

    Science.gov (United States)

    Mahía, Jorge; Martín, Angela; Carballas, Tarsy; Díaz-Raviña, Montserrat

    2007-05-25

    The content of atrazine and its metabolites (hydroxyatrazine, deethylatrazine and deisopropylatrazine) as well as the activities of two soil enzymes (urease and beta-glucosidase) were evaluated in an acid agricultural soil, located in a temperate humid zone (Galicia, NW Spain), with an annual ryegrass-maize rotation under conventional tillage (CT) and no tillage (NT). Samples were collected during two consecutive years from the arable layer at two depths (0-5 cm and 5-20 cm) and different times after atrazine application. Hydroxyatrazine and deisopropylatrazine were the main metabolites resulting from atrazine degradation in the acid soil studied, the highest levels being detected in the surface layer of the NT treatment. A residual effect of atrazine was observed since hydroxyatrazine was detected in the arable layer (0-5 cm, 5-20 cm) even one year after the herbicide application. Soil enzyme activities in the upper 5 cm layer under NT were consistently higher than those in the same layer under CT. Urease and beta-glucosidase activities decreased with depth in the profile under NT but they did not show any differences between the two depths for the plots under CT. For both tillage systems enzyme activities also reflected temporal changes during the maize cultivation; however, no consistent effect of the herbicide application was observed.

  9. Arresting Environmental Degradation Through Accelerated On-site Soil Sedimentation and Revegetation Using Microcatchments and Reseeding

    International Nuclear Information System (INIS)

    Mnene, W.N.; Wandera, F.P.; Lebbie, S.H.

    1999-01-01

    Degradation of arid and semi arid lands (ASALs) through denudation has been found to result in lowered capacity to support livestock, particularly under extensive production systems. After a Participatory Rural Appraisal (PRA) in Kajiado District, an opportunity was identified in the pastoral reserves grazing areas involving the combined use of monochromators (specifically pitting) and re seeding with adapted forage species. Treatments were imposed before the 1996 short rainy seasons. Data were collected on soil sedimentation as well as herbaceous cover and standing crop. Much of the soil deposit comprised of fine silt-clay in the pits and sand on the up-slope. No soil deposit was observed on the down-slope of the pits. This increased in subsequent rainy seasons. Although seeding was done by broadcasting to cover whole plots, establishment was only evident where it is pitted. Volunteer herbaceous vegetation expressed themselves and plant cover tended to also increase in freshly deposited soil from one wet season to another. Herbage was particularly dense on the crescents of the pits

  10. Sorption, degradation and mobility of ptaquiloside, a carcinogenic Bracken (Pteridium sp.) constituent, in the soil environment

    DEFF Research Database (Denmark)

    Rasmussen, Lars Holm; Lauren, Denis; Hansen, Hans Christian Bruun

    2005-01-01

    Ptaquiloside (PTA) is a carcinogenic norsesquiterpene glucoside produced by Bracken in amounts up to at least 13 500 mg m2. The toxin is transferred from Bracken to the underlying soil from where it may leach to surface and groundwaters impairing the quality of drinking water. The objectives of t...... where PTA and a non-sorbing tracer showed almost coincident break-through. Leaching of PTA to the aqueous environment will be most extensive on sandy soils, having pH >4 and poor in organic matter which are exposed to high precipitation rates during cold seasons.......Ptaquiloside (PTA) is a carcinogenic norsesquiterpene glucoside produced by Bracken in amounts up to at least 13 500 mg m2. The toxin is transferred from Bracken to the underlying soil from where it may leach to surface and groundwaters impairing the quality of drinking water. The objectives...... of the present study were to characterize the solubility, degradation and retention of PTA in soils in order to evaluate the risk for groundwater contamination. PTA was isolated from Bracken. The logarithmic octanol–water and ethyl acetate–water partitioning coefficients for PTA were 0.63 and 0.88, respectively...

  11. Deterministic three-half-order kinetic model for microbial degradation of added carbon substrates in soil

    International Nuclear Information System (INIS)

    Brunner, W.; Focht, D.D.

    1984-01-01

    The kinetics of mineralization of carbonaceous substrates has been explained by a deterministic model which is applicable to either growth or nongrowth conditions in soils. The mixed-order nature of the model does not require a priori decisions about reaction order, discontinuity period of lag or stationary phase, or correction for endogenous mineralization rates. The integrated equation is simpler than the integrated form of the Monod equation because of the following: (i) only two, rather than four, interdependent constants have to be determined by nonlinear regression analysis, (ii) substrate or product formation can be expressed explicitly as a function of time, (iii) biomass concentration does not have to be known, and (iv) the required initial estimate for the nonlinear regression analysis can be easily obtained from a linearized form rather than from an interval estimate of a differential equation. 14 CO 2 evolution data from soil have been fitted to the model equation. All data except those from irradiated soil gave us better fits by residual sum of squares (RSS) by assuming growth in soil was linear (RSS =0.71) as opposed to exponential (RSS = 2.87). The underlying reasons for growth (exponential versus linear), no growth, and relative degradation rates of substrates are consistent with the basic mechanisms from which the model is derived. 21 references

  12. Crop residue stabilization and application to agricultural and degraded soils: A review.

    Science.gov (United States)

    Medina, Jorge; Monreal, Carlos; Barea, José Miguel; Arriagada, César; Borie, Fernando; Cornejo, Pablo

    2015-08-01

    Agricultural activities produce vast amounts of organic residues including straw, unmarketable or culled fruit and vegetables, post-harvest or post-processing wastes, clippings and residuals from forestry or pruning operations, and animal manure. Improper disposal of these materials may produce undesirable environmental (e.g. odors or insect refuges) and health impacts. On the other hand, agricultural residues are of interest to various industries and sectors of the economy due to their energy content (i.e., for combustion), their potential use as feedstock to produce biofuels and/or fine chemicals, or as a soil amendments for polluted or degraded soils when composted. Our objective is review new biotechnologies that could be used to manage these residues for land application and remediation of contaminated and eroded soils. Bibliographic information is complemented through a comprehensive review of the physico-chemical fundamental mechanisms involved in the transformation and stabilization of organic matter by biotic and abiotic soil components. Copyright © 2015 Elsevier Ltd. All rights reserved.

  13. Visible and infrared spectroscopy to evaluate soil quality in degraded sites: an applicative study in southern Italy

    Science.gov (United States)

    Ancona, Valeria; Matarrese, Raffaella; Salvatori, Rosamaria; Salzano, Roberto; Regano, Simona; Calabrese, Angelantonio; Campanale, Claudia; Felice Uricchio, Vito

    2014-05-01

    Land degradation processes like organic matter impoverishment and contamination are growing increasingly all over the world due to a non-rational and often sustainable spread of human activities on the territory. Consequently the need to characterize and monitor degraded sites is becoming very important, with the aim to hinder such main threats, which could compromise drastically, soil quality. Visible and infrared spectroscopy is a well-known technique/tool to study soil properties. Vis-NIR spectral reflectance, in fact, can be used to characterize spatial and temporal variation in soil constituents (Brown et al., 2006; Viscarra Rossel et al., 2006), and potentially its surface structure (Chappell et al., 2006, 2007). It is a rapid, non-destructive, reproducible and cost-effective analytical method to analyse soil properties and therefore, it can be a useful method to study land degradation phenomena. In this work, we present the results of proximal sensing investigations of three degraded sites (one affected by organic and inorganic contamination and two affected by soil organic matter decline) situated southern Italy close to Taranto city (in Apulia Region). A portable spectroradiometer (ASD-FieldSpec) was used to measure the reflectance properties in the spectral range between 350-2500 nm of the soil, in the selected sites, before and after a recovery treatment by using compost (organic fertilizer). For each measurement point the soil was sampled in order to perform chemical analyses to evaluate soil quality status. Three in-situ campaigns have been carried out (September 2012, June 2013, and September 2013), collecting about 20 soil samples for each site and for each campaign. Chemical and spectral analyses have been focused on investigating soil organic carbon, carbonate content, texture and, in the case of polluted site, heavy metals and organic toxic compounds. Statistical analyses have been carried out to test a prediction model of different soil quality

  14. Enhanced degradation activity by endophytic bacteria of plants growing in hydrocarbon contaminated soil

    Energy Technology Data Exchange (ETDEWEB)

    Phillips, L.; Germida, J.J. [Saskatchewan Univ., Saskatoon, SK (Canada); Greer, C.W. [National Research Council of Canada, Montreal, PQ (Canada). Biotechnology Research Inst.

    2006-07-01

    The feasibility of using phytoremediation for cleaning soils contaminated with petroleum hydrocarbons was discussed. Petroleum hydrocarbons are problematic because of their toxicity, mobility and persistence in the environment. Appropriate clean-up methods are needed, given that 60 per cent of Canada's contaminated sites contain these compounds. Phytoremediation is an in situ biotechnology in which plants are used to facilitate contaminant removal. The approach relies on a synergistic relationship between plants and their root-associated microbial communities. Previous studies on phytoremediation have focussed on rhizosphere communities. However, it is believed that endophytic microbes may also play a vital role in organic contaminant degradation. This study investigated the structural and functional dynamics of both rhizosphere and endophytic microbial communities of plants from a phytoremediation field site in south-eastern Saskatchewan. The former flare pit contains up to 10,000 ppm of F3 to F4 hydrocarbon fractions. Root samples were collected from tall wheatgrass, wild rye, saltmeadow grass, perennial ryegrass, and alfalfa. Culture-based and culture-independent methods were used to evaluate the microbial communities associated with these roots. Most probable number assays showed that the rhizosphere communities contained more n-hexadecane, diesel fuel, and PAH degraders. However, mineralization assays with 14C labelled n-hexadecane, naphthalene, and phenanthrene showed that endophytic communities had more degradation activities per standardized initial degrader populations. Total community DNA samples taken from bulk, rhizosphere, and endophytic samples, were analyzed by denaturing gradient gel electrophoresis. It was shown that specific bacteria increased in endophytic communities compared to rhizosphere communities. It was suggested plants may possibly recruit specific bacteria in response to hydrocarbon contamination, thereby increasing degradation

  15. Application of poultry processing industry waste: a strategy for vegetation growth in degraded soil.

    Science.gov (United States)

    do Nascimento, Carla Danielle Vasconcelos; Pontes Filho, Roberto Albuquerque; Artur, Adriana Guirado; Costa, Mirian Cristina Gomes

    2015-02-01

    The disposal of poultry processing industry waste into the environment without proper care, can cause contamination. Agricultural monitored application is an alternative for disposal, considering its high amount of organic matter and its potential as a soil fertilizer. This study aimed to evaluate the potential of poultry processing industry waste to improve the conditions of a degraded soil from a desertification hotspot, contributing to leguminous tree seedlings growth. The study was carried out under greenhouse conditions in a randomized blocks design and a 4 × 2 factorial scheme with five replicates. The treatments featured four amounts of poultry processing industry waste (D1 = control 0 kg ha(-1); D2 = 1020.41 kg ha(-1); D3 = 2040.82 kg ha(-1); D4 = 4081.63 kg ha(-1)) and two leguminous tree species (Mimosa caesalpiniaefolia Benth and Leucaena leucocephala (Lam.) de Wit). The poultry processing industry waste was composed of poultry blood, grease, excrements and substances from the digestive system. Plant height, biomass production, plant nutrient accumulation and soil organic carbon were measured forty days after waste application. Leguminous tree seedlings growth was increased by waste amounts, especially M. caesalpiniaefolia Benth, with height increment of 29.5 cm for the waste amount of 1625 kg ha(-1), and L. leucocephala (Lam.) de Wit, with maximum height increment of 20 cm for the waste amount of 3814.3 kg ha(-1). M. caesalpiniaefolia Benth had greater initial growth, as well as greater biomass and nutrient accumulation compared with L. leucocephala (Lam.) de Wit. However, belowground biomass was similar between the evaluated species, resulting in higher root/shoot ratio for L. leucocephala (Lam.) de Wit. Soil organic carbon did not show significant response to waste amounts, but it did to leguminous tree seedlings growth, especially L. leucocephala (Lam.) de Wit. Poultry processing industry waste contributes to leguminous tree seedlings growth

  16. Territorial Systems, Regional Disparities and Sustainability: Economic Structure and Soil Degradation in Italy

    Directory of Open Access Journals (Sweden)

    Luca Salvati

    2014-05-01

    Full Text Available The present study was devoted to identify the evolutionary path of a number of local systems in a Mediterranean country vulnerable to soil degradation (SD in the last decades. A multivariate analysis was used to evaluate the socio-ecological conditions and to estimate rapidity-of-change of local systems by considering 6 bio-physical factors predisposing soil to degradation and 23 socioeconomic indicators over fifty years (1960–2010. Results indicate that systems’ development paths diverged during the investigated time period reflecting changes in the spatial organization and in the economic base of entire regions. Interestingly, economic performance and environmental quality do not seem to follow opposite trajectories. Local systems characterized by low per-capita income, agricultural specialization and population ageing, seem not to be associated with better and more stable ecological conditions. Local systems in affluent areas, featuring a mix of socioeconomic conditions with the prevalence of services in the economy and tourism specialization, showed relatively good ecological conditions and moderate-to-low SD vulnerability. Thus, affluent local systems do not necessarily reflect a higher pressure on the environment. These findings suggest that areas with a changing socio-demographic profile and a dynamic economic structure are compatible with low and stable levels of SD vulnerability.

  17. Screening and identification of p,p¢-DDT degrading soil isolates

    Directory of Open Access Journals (Sweden)

    Vorasan Sobhon

    2008-04-01

    Full Text Available DDT is an organochlorine pesticide that can persist in the environment resulting in environmental problem with chronic effects on human and animal health. The determination of p,p¢-DDT in soil samples from 23 agricultural areas in Songkhla Province found DDT residue in the ranges of 0.17-9.84 ng/g soil. After repeated culturing in mineral salts-yeast extract medium (MSYM with an addition of 25 ppm p,p¢-DDT (DDT25, 167 morphologically different bacterial strains were isolated. Out of 167 isolates, only 5 strains showed p,p¢-DDT degrading ability as indicated by clear zone around the colony when grown on nutrient agar supplemented up to 100 ppm p,p¢-DDT. These 5 isolates include SB1A01, SB2A02, SB1A10, SB1A12 and SB1B05. Growth of these isolates in MSYM+DDT25 after 10 days indicated reductions of p,p¢-DDT by 30.5, 20.3, 37.4, 30.4 and 32.2%, respectively. Based on the morphological characteristics and 16S rDNA analysis, isolate SB1A10 which showed the highest degradation ability was found to be 99% identical (1360/1362 to Staphylococcus haemolyticus.

  18. Characterization of Crude Oil Degrading Bacteria Isolated from Contaminated Soils Surrounding Gas Stations.

    Science.gov (United States)

    Abou-Shanab, Reda A I; Eraky, Mohamed; Haddad, Ahmed M; Abdel-Gaffar, Abdel-Rahman B; Salem, Ahmed M

    2016-11-01

    A total of twenty bacterial cultures were isolated from hydrocarbon contaminated soil. Of the 20 isolates, RAM03, RAM06, RAM13, and RAM17 were specifically chosen based on their relatively higher growth on salt medium amended with 4 % crude oil, emulsion index, surface tension, and degradation percentage. These bacterial cultures had 16S rRNA gene sequences that were most similar to Ochrobactrum cytisi (RAM03), Ochrobactrum anthropi (RAM06 and RAM17), and Sinorhizobium meliloti (RAM13) with 96 %, 100 % and 99 %, and 99 % similarity. The tested strains revealed a promising potential for bioremediation of petroleum oil contamination as they could degrade >93 % and 54 % of total petroleum hydrocarbons (TPHs) in a liquid medium and soil amended with 4 % crude oil, respectively, after 30 day incubation. These bacteria could effectively remove both aliphatic and aromatic petroleum hydrocarbons. In conclusion, these strains could be considered as good prospects for their application in bioremediation of hydrocarbon contaminated environment.

  19. Pre-oxidation of low-density polyethylene (LDPE) by ultraviolet light (UV) promotes enhanced degradation of LDPE in soil.

    Science.gov (United States)

    Tribedi, Prosun; Dey, Samrat

    2017-11-09

    Polyethylene represents nearly 64% of all the synthetic plastics produced and are mainly used for domestic and industrial applications. Their extensive use poses a serious environmental threat because of their non-biodegradable nature. Among all the polyethylene remediation strategies, in situ bioremediation happens to be the safest and efficient one. In the current study, efforts had been given to compare the extent of LDPE degradation under UV-treated and UV-untreated conditions by soil microcosm. Landfill soil was collected and UV-treated and UV-untreated LDPE were added separately to the soil following incubation under similar conditions. Electron microscopic images as well as the weight loss and the tensile strength results clearly revealed that UV-treated LDPE showed better degradation than the non-treated ones in soil. To elucidate the mechanism of this enhanced biodegradation, the bond spectra of differentially treated LDPE were analyzed by FTIR. The results obtained from bond spectra studies revealed that UV treatment increases both carbonyl and terminal double-bond index of the LDPE, thereby making it highly susceptible for microbial degradation. Moreover, incubation of UV-treated LDPE with soil favors better adherence of metabolically active and significantly higher number of microorganisms on it. Taken together, all these results demonstrate the higher microbial association and their better metabolic potential to the UV-treated LDPE that lead to enhanced degradation of the LDPE by the soil microorganisms.

  20. Clay minerals and metal oxides strongly influence the structure of alkane-degrading microbial communities during soil maturation.

    Science.gov (United States)

    Steinbach, Annelie; Schulz, Stefanie; Giebler, Julia; Schulz, Stephan; Pronk, Geertje J; Kögel-Knabner, Ingrid; Harms, Hauke; Wick, Lukas Y; Schloter, Michael

    2015-07-01

    Clay minerals, charcoal and metal oxides are essential parts of the soil matrix and strongly influence the formation of biogeochemical interfaces in soil. We investigated the role of these parental materials for the development of functional microbial guilds using the example of alkane-degrading bacteria harbouring the alkane monooxygenase gene (alkB) in artificial mixtures composed of different minerals and charcoal, sterile manure and a microbial inoculum extracted from an agricultural soil. We followed changes in abundance and community structure of alkane-degrading microbial communities after 3 and 12 months of soil maturation and in response to a subsequent 2-week plant litter addition. During maturation we observed an overall increasing divergence in community composition. The impact of metal oxides on alkane-degrading community structure increased during soil maturation, whereas the charcoal impact decreased from 3 to 12 months. Among the clay minerals illite influenced the community structure of alkB-harbouring bacteria significantly, but not montmorillonite. The litter application induced strong community shifts in soils, maturated for 12 months, towards functional guilds typical for younger maturation stages pointing to a resilience of the alkane-degradation function potentially fostered by an extant 'seed bank'.

  1. Fine scale spatial variability of microbial pesticide degradation in soil: scales, controlling factors, and implications

    Directory of Open Access Journals (Sweden)

    Arnaud eDechesne

    2014-12-01

    Full Text Available Pesticide biodegradation is a soil microbial function of critical importance for modern agriculture and its environmental impact. While it was once assumed that this activity was homogeneously distributed at the field scale, mounting evidence indicates that this is rarely the case. Here, we critically examine the literature on spatial variability of pesticide biodegradation in agricultural soil. We discuss the motivations, methods, and main findings of the primary literature. We found significant diversity in the approaches used to describe and quantify spatial heterogeneity, which complicates inter-studies comparisons. However, it is clear that the presence and activity of pesticide degraders is often highly spatially variable with coefficients of variation often exceeding 50% and frequently displays nonrandom spatial patterns. A few controlling factors have tentatively been identified across pesticide classes: they include some soil characteristics (pH and some agricultural management practices (pesticide application, tillage, while other potential controlling factors have more conflicting effects depending on the site or the pesticide. Evidence demonstrating the importance of spatial heterogeneity on the fate of pesticides in soil has been difficult to obtain but modelling and experimental systems that do not include soil’s full complexity reveal that this heterogeneity must be considered to improve prediction of pesticide biodegradation rates or of leaching risks. Overall, studying the spatial heterogeneity of pesticide biodegradation is a relatively new field at the interface of agronomy, microbial ecology, and geosciences and a wealth of novel data is being collected from these different disciplinary perspectives. We make suggestions on possible avenues to take full advantage of these investigations for a better understanding and prediction of the fate of pesticides in soil.

  2. Adsorption and degradation of sulfadiazine and sulfamethoxazole in an agricultural soil system under an anaerobic condition: Kinetics and environmental risks.

    Science.gov (United States)

    Shen, Genxiang; Zhang, Yu; Hu, Shuangqing; Zhang, Hongchang; Yuan, Zhejun; Zhang, Wei

    2018-03-01

    Sulfonamides, one of the commonest antibiotics, were widely used on humans and livestock to control pathema and bacterial infections resulting in further environmental risks. The present study evaluated the adsorption and degradation of sulfadiazine (SDZ) and sulfamethoxazole (SMX) in an agricultural soil system under an anaerobic condition. Low sorption coefficients (K d , 1.22 L kg -1 for SDZ and 1.23 L kg -1 for SMX) obtained from Freundlich isotherms experiment indicated that poor sorption of both antibiotics may pose a high risk to environment due to their high mobility and possibility of entering surface and ground water. Degradation occurred at a lower rate under the anaerobic environment, where both two antibiotics had higher persistence in sterile and non-sterile soils with degradation ratio  20 d. Additionally, the addition of manure slightly increased degradation rates of SDZ and SMX, but there were no significant differences between single and repeated manure application at a later stage (p > 0.05), which suggested that the degradation was affected by both biotic and abiotic factors. Degradation rates would be slower at a higher concentration, indicating that degradation kinetics of SDZ and SMX were dependent on initial concentrations. During the degradation period, the antibiotics removal may change temperature, pH, sulfate and nitrate in soil, which suggested that the variation of antibiotics concentrations was related to the changes of soil physicochemical properties. An equation was proposed to elucidate the link between adsorption and degradation under different conditions, and to predict potential environmental risks of antibiotics. Copyright © 2017 Elsevier Ltd. All rights reserved.

  3. Alkane and crude oil degrading bacteria from the petroliferous soil of India

    International Nuclear Information System (INIS)

    Roy, I.; Mishra, A.K.; Ray, A.K.

    1991-01-01

    It has been estimated that approximately 0.5 percent of transported crude oil finds its way into seawater, largely through accidental spills and discharge of ballast and wash water from oil tankers. Some microorganisms are well known for their ability to degrade a variety of hydrocarbons present in crude oil. Oil spills at sea or on land have demonstrated the hydrocarbon-degrading potential of these organisms. Under laboratory conditions, nitrogen may be supplied in soluble form (inorganic salts of ammonia or nitrate of urea). Since most natural aquatic environments are deficient in utilizable forms of nitrogen, it is necessary to add the same exogeneously, but because of rapid dilution the added source of nitrogen does not remain effective. The need for nitrogen supplements may be overcome by appropriate choice of microbes with the genetic capacity to fix molecular nitrogen. In this paper the authors are reporting the isolation of a strain of Pseudomonas stutzeri from the petroliferous soil of India. This strain has the capacity to degrade alkane and crude oil and to fix nitrogen

  4. Occurrence, diversity and community structure of culturable atrazine degraders in industrial and agricultural soils exposed to the herbicide in Shandong Province, P.R. China

    OpenAIRE

    Bazhanov, Dmitry P.; Li, Chengyun; Li, Hongmei; Li, Jishun; Zhang, Xinjian; Chen, Xiangfeng; Yang, Hetong

    2016-01-01

    Background Soil populations of bacteria rapidly degrading atrazine are critical to the environmental fate of the herbicide. An enrichment bias from the routine isolation procedure prevents studying the diversity of atrazine degraders. In the present work, we analyzed the occurrence, diversity and community structure of soil atrazine-degrading bacteria based on their direct isolation. Methods Atrazine-degrading bacteria were isolated by direct plating on a specially developed SM agar. The atra...

  5. The viability of prescribed fire for mitigating the soil degradational impacts of wildfire

    Science.gov (United States)

    Shakesby, R. A.; Bento, C. P. M.; Ferreira, C. S. S.; Ferreira, A. J. D.; Stoof, C. R.; Urbanek, E.; Walsh, R. P. D.

    2012-04-01

    Prescribed (controlled) fire has become an important strategy primarily to limit the likelihood of more devastating wildfire. The considerable increase in wildfire activity in recent decades throughout the Mediterranean, and in Portugal in particular, has meant that this strategy has become increasingly popular despite inherent fears of people about fire of any sort. Despite many studies of the impact of wildfire on soil erosion and degradation, relatively little research has assessed impacts of prescribed fire on soil in Portugal or elsewhere in the Mediterranean. As part of the DESIRE research programme, this paper addresses this research gap by investigating hillslope-scale losses of soil, soil organic matter and selected nutrients before and after an experimental fire (representing a 'worst case-scenario' prescribed fire) in a shrub-vegetated catchment in central Portugal. Comparison is provided by post-fire monitoring of a nearby hillslope affected by a wildfire of moderate severity. Hillslope-scale measurements were carried out over c. 3 years using sediment fences with contributing areas of up to c. 0.5 ha. Eroded sediment was periodically removed from the fences both before and after the fire at intervals ranging from a few weeks to several months depending on rainfall characteristics and logistics. Erosion expressed as g/m2 and g/m2/mm of rainfall was determined. Figures for long-term (c. 10 years) erosion under unburnt conditions for this vegetation type were obtained from a small bounded plot and from sediment accumulating in a weir pool draining a sub-catchment within the prescribed-fire catchment. In addition, soil organic matter and selected nutrients, including K2O, P2O5 and Total N, were measured in the eroded sediment and in the pre-burn and post-burn in situ soil. The results indicate that both the wildfire and prescribed fire caused erosion that was orders of magnitude higher than for long-term plot-scale and hillslope-scale erosion recorded

  6. Effect of Soil Fumigation on Degradation of Pendimethalin and Oxyfluorfen in Laboratory and Ginger Field Studies.

    Science.gov (United States)

    Huang, Bin; Li, Jun; Fang, Wensheng; Liu, Pengfei; Guo, Meixia; Yan, Dongdong; Wang, Qiuxia; Cao, Aocheng

    2016-11-23

    Herbicides are usually applied to agricultural fields following soil fumigation to provide effective weed control in high-value cash crops. However, phytotoxicity has been observed in ginger seedlings following the application of herbicides in fumigated fields. This study tested a mixture of herbicides (pendimethalin and oxyfluorfen) and several fumigant treatments in laboratory and field studies to determine their effect on the growth of ginger. The results showed that soil fumigation significantly (P oxyfluorfen was extended by an average of about 1.19 times in the field and 1.32 times in the laboratory. Moreover, the extended period of herbicide degradation in the fumigant and nonfumigant treatments significantly reduced ginger plant height, leaf number, stem diameter, and the chlorophyll content. The study concluded that applying a dose below the recommended rate of these herbicides in chloropicrin (CP) or CP + 1,3-dichloropropene fumigated ginger fields is appropriate, as application of the recommended herbicide dose in fumigated soil may be phytotoxic to ginger.

  7. A study of dissipation, degradation and binding of 14C-labeled endosulfan to soil in model lysimeter

    International Nuclear Information System (INIS)

    Gonzalez, J.E.; Ceballos, J.; Amor, A.; Saiz, E.B. de

    1999-01-01

    The degradation, dissipation and binding of α-endosulfan in two agricultural soils and sand was studied in lysimeter system under outdoor conditions, using 14 C labeled insecticide. Dissipation was rapid during the first few weeks after application. The half life of disappearance was 38 to 61 days for the soils from Cerro Punta and El Ejido, whereas, in sand it was 91 days. The insecticide degraded by oxidation at the sulfite group to the sulfate. The resultant product underwent further degradation to form 14 CO 2 and bound residues. Although a significant amount of 14 C leached through the sand, which contained less that 0.1% organic matter, there was no leaching of endosulfan through the other two types of soil, when leaching was started immediately after treatment. (author)

  8. Iron-mediated stabilization of soil carbon amplifies the benefits of ecological restoration in degraded lands.

    Science.gov (United States)

    Silva, Lucas C R; Doane, Timothy A; Corrêa, Rodrigo S; Valverde, Vinicius; Pereira, Engil I P; Horwath, William R

    2015-07-01

    Recent observations across a 14-year restoration chronosequence have shown an unexpected accumulation of soil organic carbon in strip-mined areas of central Brazil. This was attributed to the rapid plant colonization that followed the incorporation of biosolids into exposed regoliths, but the specific mechanisms involved in the stabilization of carbon inputs from the vegetation remained unclear. Using isotopic and elemental analyses, we tested the hypothesis that plant-derived carbon accumulation was triggered by the formation of iron-coordinated complexes, stabilized into physically protected (occluded) soil fractions. Confirming this hypothesis, we identified a fast formation of microaggregates shortly after the application of iron-rich biosolids, which was characterized by a strong association between pyrophosphate-extractable iron and plant-derived organic matter. The formation of microaggregates preceded the development of macroaggregates, which drastically increased soil carbon content (-140 Mg C/ha) a few years after restoration. Consistent with previous theoretical work, iron-coordinated organic complexes served as nuclei for aggregate formation, reflecting the synergistic effect of biological, chemical, and physical mechanisms of carbon stabilization in developing soils. Nevertheless, iron was not the only factor affecting soil carbon content. The highest carbon accumulation was observed during the period of highest plant diversity (> 30 species; years 3-6), declining significantly with the exclusion of native species by invasive grasses (years 9-14). Furthermore, the increasing dominance of invasive grasses was associated with a steady decline in the concentration of soil nitrogen and phosphorus per unit of accumulated carbon. These results demonstrate the importance of interdependent ecological and biogeochemical processes, and the role of soil-plant interactions in determining the success of restoration efforts. In contrast with previous but

  9. DETERMINATION OF KINETICS OF DEGRADATION AND MOBILITY OF DITHIOCARBAMATES FUNGICIDES IN AQUEOUS MEDIA AND IN MOROCCAN SOIL

    Directory of Open Access Journals (Sweden)

    Said El Antri

    2010-07-01

    Full Text Available Contribution analysis of dithiocarbamates pesticides used on tomatoes treatment has been reported. The study is focused on analysis and determination of some dithiocarbamates like, Maneb, Mancozeb, Zineb and Propineb, in order to achieve accurate impact of theses pesticides on water and soil. Analysis method is based on decomposition of dithiocarbamate by heating under acidic attack to give carbon disulfide complexed with copper acetate solution in presence of diethanolamine. Complex formed is dosed spectrophotometrically at 435 nm. Degradation kinetic of dithiocarbamate in aqueous media have been realized and proved that dithiocarbamate are degraded by simple air exposition. In the other hand, pH affects also dithiocarbamate degradation by increasing hydroxyl ions to participate for dithiocarbamate instability. Dithiocarbamate mobility on Moroccan soils samples have been realised and don’t have the same degradation mode.

  10. Human-induced Arctic moistening.

    Science.gov (United States)

    Min, Seung-Ki; Zhang, Xuebin; Zwiers, Francis

    2008-04-25

    The Arctic and northern subpolar regions are critical for climate change. Ice-albedo feedback amplifies warming in the Arctic, and fluctuations of regional fresh water inflow to the Arctic Ocean modulate the deep ocean circulation and thus exert a strong global influence. By comparing observations to simulations from 22 coupled climate models, we find influence from anthropogenic greenhouse gases and sulfate aerosols in the space-time pattern of precipitation change over high-latitude land areas north of 55 degrees N during the second half of the 20th century. The human-induced Arctic moistening is consistent with observed increases in Arctic river discharge and freshening of Arctic water masses. This result provides new evidence that human activity has contributed to Arctic hydrological change.

  11. Coupled Metagenomic and Chemical Analyses of Degrading Fungal Necromass and Implications for Fungal contributions to Stable Soil Organic Carbon

    Science.gov (United States)

    Egerton-Warburton, L. M.; Schreiner, K. M.; Morgan, B. S. T.; Schultz, J.; Blair, N. E.

    2016-12-01

    Fungi comprise a significant portion of total soil biomass, the turnover of which must represent a dominant flux within the soil carbon cycle. Fungal organic carbon (OC) can turn over on time scales of days to months, but this process is poorly understood. Here, we examined temporal changes in the chemical and microbial community composition of fungal necromass during a 2-month decomposition experiment in which Fusarium avenaceum (a common saprophyte) was exposed to a natural soil microbial community. Over the course of the experiment, residual fungal necromass was harvested and analyzed using FTIR and thermochemolysis-GCMS to examine chemical changes in the tissue. In addition, genomic DNA was extracted from tissues, amplified with barcoded ITS primers, and sequenced using the high-throughput Illumina platform to examine changes in microbial community composition. Up to 80% of the fungal necromass turned over in the first week. This rapid degradation phase corresponded to colonization of the necromass by known chitinolytic soil fungi including Mortierella species. Members of the Zygomycota and Ascomycota were among the dominant fungal groups involved in degradation with very small contributions from Basidiomycota. At the end of the 2-month degradation, only 15% of the original necromass remained. The residual material was rich in amide and C-O moieties which is consistent with previous work predicting that peptidoglycans are the main residual product from microbial tissue degradation. Straight-chain fatty acids exhibited varying degradation profiles, with some fatty acids (e.g. C16, C18:1) degrading more rapidly than bulk tissue while others maintained steady concentrations relative to bulk OC (C18) or increased in concentration throughout the degradation sequence (C24). These results indicate that the turnover of fungal necromass has the potential to rapidly and significantly influence a variety of soil OC properties including C/N ratios, lipid biomarker

  12. Coupled Metagenomic and Chemical Analyses of Degrading Fungal Necromass and Implications for Microbial Contributions to Stable Soil OC

    Science.gov (United States)

    Schreiner, K. M.; Morgan, B. S. T.; Schultz, J.; Blair, N. E.; Egerton-Warburton, L. M.

    2014-12-01

    Fungi comprise a significant portion of total soil biomass, the turnover of which must represent a dominant flux within the soil carbon cycle. Fungal OC can turn over on time scales of days to months, but this process is poorly understood. Here, we examined temporal changes in the chemical and microbial community composition of fungal necromass during a 2 month decomposition experiment in which Fusarium avenaceum (a common saprophyte) was exposed to a natural soil microbial community. Over the course of the experiment, residual fungal necromass was harvested and analyzed using FTIR and thermochemolysis-GCMS to examine chemical changes in the tissue. Additionally, genomic DNA was extracted from tissues, amplified with barcoded ITS primers, and sequenced using the high-throughput Illumina platform to examine changes in microbial community composition. Up to 80% of the fungal necromass turned over in the first week. This rapid degradation phase corresponded to colonization of the necromass by known chitinolytic soil fungi including Mortierella species. Zygomycetes and Ascomycetes were among the dominant fungal species involved in degradation with very small contributions from Basidiomycetes. At the end of the 2 month degradation, only 15% of the original necromass remained. The residual material was rich in amide and C-O moieties which is consistent with previous work predicting that peptidoglycans are the main residual product from microbial tissue degradation. Straight-chain fatty acids exhibit varying degradation profiles, with some fatty acids (e.g. C16 and C18:1) degrading more rapidly than bulk tissue, others maintaining steady concentrations relative to bulk OC (e.g. C18), and some increasing in concentration throughout the degradation (e.g. C24). These results indicate that the turnover of fungal necromass has the potential to significantly influence a variety of soil OC properties, including C/N ratios, lipid biomarker distributions, and OC turnover times.

  13. Crude oil degradation potential of bacteria isolated from oil-polluted soil and animal wastes in soil amended with animal wastes

    Directory of Open Access Journals (Sweden)

    Voke O. Urhibo

    2017-03-01

    Full Text Available The influence of animal wastes on crude oil degradation potential of strains of Proteus vulgaris and Bacillus subtilis isolated from animal wastes (poultry and pig droppings and petroleum-polluted soil was compared in laboratory studies. Both bacterial strains were selected for high crude oil degradation ability after screening many isolates by the 2,6-dichlorophenol indophenol method. Analyses by gas chromatography (GC showed that degradation of crude oil was markedly enhanced (88.3–97.3% vs 72.1–78.8% in soil amended with animal wastes as indicated by the reduction of total petroleum hydrocarbon (TPH. TPH reduction by animal waste bacterial strains in animal waste-amended soil was more than the reduction by strains from soil contaminated with petroleum (P < 0.001. The greatest reduction of TPH (96.6–97.3% vs 80.4–95.9% was by poultry waste strains and it occurred in soil amended with poultry waste. GC analyses of n-alkanes showed that although shorter chains were preferentially degraded [32.0–78.5% (C8–23 vs 6.3–18.5% (C24–36] in normal soil, biodegradation of longer chains increased to 38.4–46.3% in animal waste-amended soil inoculated with the same animal wastes’ strains. The results indicate that these animal waste strains may be of potential application for bioremediation of oil-polluted soil in the presence of the wastes from where they were isolated.

  14. The role of soil physics in fighting soil degradation. A case study in the Valencia Region, Spain

    Directory of Open Access Journals (Sweden)

    Ingelmo-Sánchez, Florencio

    1990-12-01

    Full Text Available Taking into consideration the peculiar characteristics of climate, topography, geology, soils and managing systems in the Valencia region, some proven general facts in soil Physics are presented, emphasizing some points needing further investigation which, as a whole, fall within the framework of actions in controlling soil degradation processes. The text is divided into two sections: the first, and longer, deals with the study of hydrological and erosion processes. Involving Soil Physics In the explanation of some behaviours and mechanisms; in the second, the various mechanisms of physical degradation leading to soil compaction are shown, and the main causes and Impacts are also determined.

    [es] Teniendo en cuenta las características peculiares del clima, topografía, geología, suelos y sistemas de manejo en la Región Valenciana, se exponen algunos hechos probados como suficientemente generales en la Física de suelos y algunos de los avances más significativos de dicha disciplina, enmarcando al mismo tiempo aspectos que necesitan ser Investigados, como base para la aplicación de un modelo conceptual de actuación para el control de los procesos de degradación del suelo. La exposición queda dividida, por consideraciones didácticas, en dos apartados. El primero, más extenso, se dedica al estudio de los procesos hidrológicos y erosivos, implicando a la Física del Suelo en la explicación de algunos comportamientos y mecanismos. En el segundo, se exponen los diferentes mecanismos de degradación física que conducen a la compactación del suelo, identificándose las principales causas y las repercusiones.
    [fr] Compte tenu des particulières caractéristiques du climat, topographie, géologie, sols et systèmes d'aménagement des sols dans la Région de Valence, on expose Ici quelques sujets bien connus, sur la Physique du Sol, et on signale certains rapports qui doivent être recherchés pour l'application d'un mod

  15. Degradation of Triazine-2-(14C Metsulfuron-Methyl in Soil from an Oil Palm Plantation.

    Directory of Open Access Journals (Sweden)

    B S Ismail

    Full Text Available Triazine-2-(14C metsulfuron-methyl is a selective, systemic sulfonylurea herbicide. Degradation studies in soils are essential for the evaluation of the persistence of pesticides and their breakdown products. The purpose of the present study was to investigate the degradation of triazine-2-(14C metsulfuron-methyl in soil under laboratory conditions. A High Performance Liquid Chromatograph (HPLC equipped with an UV detector and an on-line radio-chemical detector, plus a Supelco Discovery column (250 x 4.6 mm, 5 μm, and PRP-1 column (305 x 7.0 mm, 10 μm was used for the HPLC analysis. The radioactivity was determined by a Liquid Scintillation Counter (LSC in scintillation fluid. The soil used was both sterilized and non-sterilized in order to observe the involvement of soil microbes. The estimated DT50 and DT90 values of metsulfuron-methyl in a non-sterile system were observed to be 13 and 44 days, whereas in sterilized soil, the DT50 and DT90 were 31 and 70 days, respectively. The principal degradation product after 60 days was CO2. The higher cumulative amount of (14CO2 in (14C-triazine in the non-sterilized soil compared to that in the sterile system suggests that biological degradation by soil micro-organisms significantly contributes to the dissipation of the compound. The major routes of degradation were O-demethylation, sulfonylurea bridge cleavage and the triazine "ring-opened."

  16. Soil physical degradation by human activities in the zone II of the basin of Burgos, Tamaulipas, Mexico

    International Nuclear Information System (INIS)

    Arias Mino, F.; Espinosa Rmirez, M.; Andrade Limas, E.; Castro Meza, B.; Romero Diaz, A.

    2009-01-01

    The objective of this work was to characterize the physical degradation of the soil for antropic activities during the years 2007 and 2008 in the II zone of the Burgos Basin in Tamaulipas, Mexico. In this region, human action manifests itself due to activities such as agriculture, livestock and industry. The conventional farming, based mainly on the cultivation of sorghum, is characterized by great mechanization and tilling the soil which has contributed in large measure to aggravate erosion processes. There is also some logging, mainly for charcoal production and, recently, has joined the exploration and exploitation of natural gas. We used the methodology for Assessment of Soil Degradation (ASSOD) to identify, located and define the types of soil degradation within physiographic units. Results showed that nearly 74% of the study area presents some kind of degradation. The main process was water erosion, followed, by compaction and wind erosion. The main factors are essentially overgrazing and inadequate farming practices. Approximately 60% of the units evaluated presented a moderate level of degradation, but the speed of this process indicates that maintenance works are needed to reverse. (Author) 7 refs.

  17. Inoculation of soil with an Isoproturon degrading microbial community reduced the pool of "real non-extractable" Isoproturon residues.

    Science.gov (United States)

    Zhu, Xiaomin; Schroll, Reiner; Dörfler, Ulrike; Chen, Baoliang

    2018-03-01

    During pesticides degradation, biogenic non-extractable residues ("apparent NER") may not share the same environmental fate and risks with the "real NER" that are bound to soil matrix. It is not clear how microbial community (MC) inoculation for pesticides degradation would influence the NER composition. To investigate degradation efficiency of pesticides Isoproturon (IPU) and NER composition following MC inoculation, clay particles harboring MC that contains the IPU degrading strain, Sphingomonas sp., were inoculated into soil receiving 14 C-labeled IPU addition. Mineralization of IPU was greatly enhanced with MC inoculation that averagely 55.9% of the applied 14 C-IPU was consumed up into 14 CO 2 during 46 days soil incubation. Isoproturon degradation was more thorough with MC than that in the control: much less amount of metabolic products (4.6% of applied IPU) and NER (35.4%) formed in MC treatment, while the percentages were respectively 30.3% for metabolites and 49.8% for NER in the control. Composition of NER shifted with MC inoculation, that relatively larger amount of IPU was incorporated into the biogenic "apparent NER" in comparison with "real NER". Besides its well-recognized role on enhancing mineralization, MC inoculation with clay particles benefits soil pesticides remediation in term of reducing "real NER" formation, which has been previously underestimated. Copyright © 2017 Elsevier Inc. All rights reserved.

  18. Quantitative Analysis of Relevant Soil, Land-use and Climate Characteristics on Landscape Degradation in Hungary

    Science.gov (United States)

    Kertesz, Adam; Mika, Janos; Jakab, Gergely; Palinkas, Melinda

    2017-04-01

    The objective of our research is to survey degradation processes acting in each micro-region of Hungary in connection with geographical and climatic characteristics. A survey of land degradation processes has been carried out at medium scale (1:50 000) to identify the affected areas of the region. Over 18,000 rectangles of Hungary have been digitally characterised for several types of land degradation. Water-flow type gully erosion and soil-loss (RUSLE, 2015: Esdac-data) are studied for dependent variables in this study. USDA textural classes, available water capacity, bulk density, clay content, coarse fragments, silt content, sand content, soil parent material, soil texture, land-use type (Corine, 2012) are used for non-climatic variables. Some of these characteristics are quantified in a non-scalable way, so the first step was to arrange these qualitative codes or pseudo-numbers into monotonous order for including them into the following multi-regression analyses. Data available from the CarpatClim Project (www.carpatclim-eu.org/pages/home) for 1961-2010 are also used in their 50 years averages is seasonal and annual resolution. The selected variables from this gridded data set are global radiation, daily mean temperature, maximum and minimum temperature, number of extreme cold days (20 mm), days with utilizable precipitation (>1mm/d), potential evapotranspiration, Palmer Index (PDSI), Palfai Index (PAI), relative humidity and wind speed at 10 m height. The gully erosion processes strongly depend on the investigated non-climatic variables, mostly on parent material and slope. The group of further climatic factors is formed by winter relative humidity, wind speed and all-year round Palmer index. Besides leading role of the above non-climatic factors, additional effects of the significant climate variables are difficult to interpret. Nevertheless, the partial effects of these climate variables are combined with future climate scenarios available from GCM and RCM

  19. Apparent Contradiction: Psychrotolerant Bacteria from Hydrocarbon-Contaminated Arctic Tundra Soils That Degrade Diterpenoids Synthesized by Trees

    Science.gov (United States)

    Yu, Zhongtang; Stewart, Gordon R.; Mohn, William W.

    2000-01-01

    Resin acids are tricyclic terpenoids occurring naturally in trees. We investigated the occurrence of resin acid-degrading bacteria on the Arctic tundra near the northern coast of Ellesmere Island (82°N, 62°W). According to most-probable-number assays, resin acid degraders were abundant (103 to 104 propagules/g of soil) in hydrocarbon-contaminated soils, but they were undetectable (soil) in pristine soils from the nearby tundra. Plate counts indicated that the contaminated and the pristine soils had similar populations of heterotrophs (106 to 107 propagules/g of soil). Eleven resin acid-degrading bacteria belonging to four phylogenetically distinct groups were enriched and isolated from the contaminated soils, and representative isolates of each group were further characterized. Strains DhA-91, IpA-92, and IpA-93 are members of the genus Pseudomonas. Strain DhA-95 is a member of the genus Sphingomonas. All four strains are psychrotolerant, with growth temperature ranges of 4°C to 30°C (DhA-91 and DhA-95) or 4°C to 22°C (IpA-92 and IpA-93) and with optimum temperatures of 15 to 22°C. Strains DhA-91 and DhA-95 grew on the abietanes, dehydroabietic and abietic acids, but not on the pimaranes, isopimaric and pimaric acids. Strains IpA-92 and IpA-93 grew on the pimaranes but not the abietanes. All four strains grew on either aliphatic or aromatic hydrocarbons, which is unusual for described resin acid degraders. Eleven mesophilic resin acid degraders did not use hydrocarbons, with the exception of two Mycobacterium sp. strains that used aliphatic hydrocarbons. We conclude that hydrocarbon contamination in Arctic tundra soil indirectly selected for resin acid degraders, selecting for hydrocarbon degraders that coincidentally use resin acids. Psychrotolerant resin acid degraders are likely important in the global carbon cycle and may have applications in biotreatment of pulp and paper mill effluents. PMID:11097882

  20. The current structure of key actors involved in research on land and soil degradation

    Science.gov (United States)

    Escadafal, Richard; Barbero, Celia; Exbrayat, Williams; Marques, Maria Jose; Ruiz, Manuel; El Haddadi, Anass; Akhtar-Schuster, Mariam

    2013-04-01

    Land and soil conservation topics, the final mandate of the United Convention to Combat desertification in drylands, have been diagnosed as still suffering from a lack of guidance. On the contrary, climate change and biodiversity issues -the other two big subjects of the Rio Conventions- seem to progress and may benefit from the advice of international panels. Arguably the weakness of policy measures and hence the application of scientific knowledge by land users and stakeholders could be the expression of an inadequate research organization and a lack of ability to channel their findings. In order to better understand the size, breadth and depth of the scientific communities involved in providing advice to this convention and to other bodies, this study explores the corpus of international publications dealing with land and/or with soils. A database of several thousands records including a significant part of the literature published so far was performed using the Web of Science and other socio-economic databases such as FRANCIS and CAIRN. We extracted hidden information using bibliometric methods and data mining applied to these scientific publications to map the key actors (laboratories, teams, institutions) involved in research on land and on soils. Several filters were applied to the databases in combination with the word "desertification". The further use of Tetralogie software merges databases, analyses similarities and differences between keywords, disciplines, authors and regions and identifies obvious clusters. Assessing their commonalities and differences, the visualisation of links and gaps between scientists, organisations, policymakers and other stakeholders is possible. The interpretation of the 'clouds' of disciplines, keywords, and techniques will enhance the understanding of interconnections between them; ultimately this will allow diagnosing some of their strengths and weaknesses. This may help explain why land and soil degradation remains a

  1. Diphenylarsinic acid contaminated soil remediation by titanium dioxide (P25) photocatalysis: Degradation pathway, optimization of operating parameters and effects of soil properties

    Energy Technology Data Exchange (ETDEWEB)

    Wang, A-nan [Key Laboratory of Soil Environment and Pollution Remediation, Institute of Soil Science, Chinese Academy of Sciences, Nanjing 210008 (China); Graduate School of Chinese Academy of Sciences, Beijing 100039 (China); Teng, Ying [Key Laboratory of Soil Environment and Pollution Remediation, Institute of Soil Science, Chinese Academy of Sciences, Nanjing 210008 (China); Hu, Xue-feng [Yantai Institute of Coastal Zone Research, Chinese Academy of Sciences, Yantai 264003 (China); Wu, Long-hua; Huang, Yu-juan [Key Laboratory of Soil Environment and Pollution Remediation, Institute of Soil Science, Chinese Academy of Sciences, Nanjing 210008 (China); Luo, Yong-ming, E-mail: ymluo@yic.ac.cn [Key Laboratory of Soil Environment and Pollution Remediation, Institute of Soil Science, Chinese Academy of Sciences, Nanjing 210008 (China); Yantai Institute of Coastal Zone Research, Chinese Academy of Sciences, Yantai 264003 (China); Christie, Peter [Key Laboratory of Soil Environment and Pollution Remediation, Institute of Soil Science, Chinese Academy of Sciences, Nanjing 210008 (China)

    2016-01-15

    Diphenylarsinic acid (DPAA) is formed during the leakage of arsenic chemical weapons in sites and poses a high risk to biota. However, remediation methods for DPAA contaminated soils are rare. Here, the photocatalytic oxidation (PCO) process by nano-sized titanium dioxide (TiO{sub 2}) was applied to degrade DPAA in soil. The degradation pathway was firstly studied, and arsenate was identified as the final product. Then, an orthogonal array experimental design of L{sub 9}(3){sup 4}, only 9 experiments were needed, instead of 81 experiments in a conventional one-factor-at-a-time, was used to optimize the operational parameters soil:water ratio, TiO{sub 2} dosage, irradiation time and light intensity to increase DPAA removal efficiency. Soil:water ratio was found to have a more significant effect on DPAA removal efficiency than other properties. The optimum conditions to treat 4 g soil with a DPAA concentration of 20 mg kg{sup −1} were found to be a 1:10 soil: water ratio, 40 mW cm{sup −2} light intensity, 5% TiO{sub 2} in soil, and a 3-hour irradiation time, with a removal efficiency of up to 82.7%. Furthermore, this method (except for a change in irradiation time from 3 to 1.5 h) was validated in nine different soils and the removal efficiencies ranged from 57.0 to 78.6%. Removal efficiencies were found to be negatively correlated with soil electrical conductivity, organic matter content, pH and total phosphorus content. Finally, coupled with electron spin resonance (ESR) measurement, these soil properties affected the generation of OH• by TiO{sub 2} in soil slurry. This study suggests that TiO{sub 2} photocatalytic oxidation is a promising treatment for removing DPAA from soil. - Highlights: • DPAA was degraded into arsenate through TiO{sub 2} (P25) photocatalytic oxidation. • Soil/water ratio was more influential on the removal of DPAA in soil by TiO{sub 2} (P25). • Soil properties affected the adsorption of DPAA and the generation of OH• by Ti

  2. Diphenylarsinic acid contaminated soil remediation by titanium dioxide (P25) photocatalysis: Degradation pathway, optimization of operating parameters and effects of soil properties

    International Nuclear Information System (INIS)

    Wang, A-nan; Teng, Ying; Hu, Xue-feng; Wu, Long-hua; Huang, Yu-juan; Luo, Yong-ming; Christie, Peter

    2016-01-01

    Diphenylarsinic acid (DPAA) is formed during the leakage of arsenic chemical weapons in sites and poses a high risk to biota. However, remediation methods for DPAA contaminated soils are rare. Here, the photocatalytic oxidation (PCO) process by nano-sized titanium dioxide (TiO_2) was applied to degrade DPAA in soil. The degradation pathway was firstly studied, and arsenate was identified as the final product. Then, an orthogonal array experimental design of L_9(3)"4, only 9 experiments were needed, instead of 81 experiments in a conventional one-factor-at-a-time, was used to optimize the operational parameters soil:water ratio, TiO_2 dosage, irradiation time and light intensity to increase DPAA removal efficiency. Soil:water ratio was found to have a more significant effect on DPAA removal efficiency than other properties. The optimum conditions to treat 4 g soil with a DPAA concentration of 20 mg kg"−"1 were found to be a 1:10 soil: water ratio, 40 mW cm"−"2 light intensity, 5% TiO_2 in soil, and a 3-hour irradiation time, with a removal efficiency of up to 82.7%. Furthermore, this method (except for a change in irradiation time from 3 to 1.5 h) was validated in nine different soils and the removal efficiencies ranged from 57.0 to 78.6%. Removal efficiencies were found to be negatively correlated with soil electrical conductivity, organic matter content, pH and total phosphorus content. Finally, coupled with electron spin resonance (ESR) measurement, these soil properties affected the generation of OH• by TiO_2 in soil slurry. This study suggests that TiO_2 photocatalytic oxidation is a promising treatment for removing DPAA from soil. - Highlights: • DPAA was degraded into arsenate through TiO_2 (P25) photocatalytic oxidation. • Soil/water ratio was more influential on the removal of DPAA in soil by TiO_2 (P25). • Soil properties affected the adsorption of DPAA and the generation of OH• by TiO_2.

  3. Aerobic degradation of N-methyl-4-nitroaniline (MNA by Pseudomonas sp. strain FK357 isolated from soil.

    Directory of Open Access Journals (Sweden)

    Fazlurrahman Khan

    Full Text Available N-Methyl-4-nitroaniline (MNA is used as an additive to lower the melting temperature of energetic materials in the synthesis of insensitive explosives. Although the biotransformation of MNA under anaerobic condition has been reported, its aerobic microbial degradation has not been documented yet. A soil microcosms study showed the efficient aerobic degradation of MNA by the inhabitant soil microorganisms. An aerobic bacterium, Pseudomonas sp. strain FK357, able to utilize MNA as the sole carbon, nitrogen, and energy source, was isolated from soil microcosms. HPLC and GC-MS analysis of the samples obtained from growth and resting cell studies showed the formation of 4-nitroaniline (4-NA, 4-aminophenol (4-AP, and 1, 2, 4-benzenetriol (BT as major metabolic intermediates in the MNA degradation pathway. Enzymatic assay carried out on cell-free lysates of MNA grown cells confirmed N-demethylation reaction is the first step of MNA degradation with the formation of 4-NA and formaldehyde products. Flavin-dependent transformation of 4-NA to 4-AP in cell extracts demonstrated that the second step of MNA degradation is a monooxygenation. Furthermore, conversion of 4-AP to BT by MNA grown cells indicates the involvement of oxidative deamination (release of NH2 substituent reaction in third step of MNA degradation. Subsequent degradation of BT occurs by the action of benzenetriol 1, 2-dioxygenase as reported for the degradation of 4-nitrophenol. This is the first report on aerobic degradation of MNA by a single bacterium along with elucidation of metabolic pathway.

  4. EDTA addition enhances bacterial respiration activities and hydrocarbon degradation in bioaugmented and non-bioaugmented oil-contaminated desert soils.

    Science.gov (United States)

    Al Kharusi, Samiha; Abed, Raeid M M; Dobretsov, Sergey

    2016-03-01

    The low number and activity of hydrocarbon-degrading bacteria and the low solubility and availability of hydrocarbons hamper bioremediation of oil-contaminated soils in arid deserts, thus bioremediation treatments that circumvent these limitations are required. We tested the effect of Ethylenediaminetetraacetic acid (EDTA) addition, at different concentrations (i.e. 0.1, 1 and 10 mM), on bacterial respiration and biodegradation of Arabian light oil in bioaugmented (i.e. with the addition of exogenous alkane-degrading consortium) and non-bioaugmented oil-contaminated desert soils. Post-treatment shifts in the soils' bacterial community structure were monitored using MiSeq sequencing. Bacterial respiration, indicated by the amount of evolved CO2, was highest at 10 mM EDTA in bioaugmented and non-bioaugmented soils, reaching an amount of 2.2 ± 0.08 and 1.6 ± 0.02 mg-CO2 g(-1) after 14 days of incubation, respectively. GC-MS revealed that 91.5% of the C14-C30 alkanes were degraded after 42 days when 10 mM EDTA and the bacterial consortium were added together. MiSeq sequencing showed that 78-91% of retrieved sequences in the original soil belonged to Deinococci, Alphaproteobacteria, Gammaproteobacteia and Bacilli. The same bacterial classes were detected in the 10 mM EDTA-treated soils, however with slight differences in their relative abundances. In the bioaugmented soils, only Alcanivorax sp. MH3 and Parvibaculum sp. MH21 from the exogenous bacterial consortium could survive until the end of the experiment. We conclude that the addition of EDTA at appropriate concentrations could facilitate biodegradation processes by increasing hydrocarbon availability to microbes. The addition of exogenous oil-degrading bacteria along with EDTA could serve as an ideal solution for the decontamination of oil-contaminated desert soils. Copyright © 2016 Elsevier Ltd. All rights reserved.

  5. Remediation of saline soils contaminated with crude oil using the halophyte Salicornia persica in conjunction with hydrocarbon-degrading bacteria.

    Science.gov (United States)

    Ebadi, Ali; Khoshkholgh Sima, Nayer Azam; Olamaee, Mohsen; Hashemi, Maryam; Ghorbani Nasrabadi, Reza

    2018-05-08

    The negative impact of salinity on plant growth and the survival of rhizosphere biota complicates the application of bioremediation to crude oil-contaminated saline soils. Here, a comparison was made between the remedial effect of treating the soil with Pseudomonas aeruginosa, a salinity tolerant hydrocarbon-degrading consortium in conjunction with either the halophyte Salicornia persica or the non-halophyte Festuca arundinacea. The effect of the various treatments on salinized soils was measured by assessing the extent of total petroleum hydrocarbon (TPH) degradation, the soil's dehydrogenase activity, the abundance of the bacteria and the level of phytotoxicity as measured by a bioassay. When a non-salinized soil was assessed after a treatment period of 120 days, the ranking for effectiveness with respect to TPH removal was F. arundinacea > P. aeruginosa > S. persica > no treatment control, while in the presence of salinity, the ranking changed to S. persica > P. aeruginosa > F. arundinacea > no treatment control. Combining the planting of S. persica or F. arundinacea with P. aeruginosa inoculation ("bioaugmentation") boosted the degradation of TPH up to 5-17%. Analyses of the residual oil contamination revealed that long chain alkanes (above C20) were particularly strongly degraded following the bioaugmentation treatments. The induced increase in dehydrogenase activity and the abundance of the bacteria (3.5 and 10 fold respectively) achieved in the bioaugmentation/S. persica treatment resulted in 46-76% reduction in soil phytotoxicity in a saline soil. The indication was that bioaugmentation of halophyte can help to mitigate the adverse effects on the effectiveness of bioremediation in a crude oil-contaminated saline soil. Copyright © 2018 Elsevier Ltd. All rights reserved.

  6. Degradation and persistence of cotton pesticides in sandy loam soils from Punjab, Pakistan.

    Science.gov (United States)

    Tariq, Muhammad Ilyas; Afzal, Shahzad; Hussain, Ishtiaq

    2006-02-01

    The present study evaluated the influence of temperature, moisture, and microbial activity on the degradation and persistence of commonly used cotton pesticides, i.e., carbosulfan, carbofuran, lambda-cyhalothrin, endosulfan, and monocrotophos, with the help of laboratory incubation and lysimeter studies on sandy loam soil (Typic Ustocurepts) in Pakistan. Drainage from the lysimeters was sampled on days 49, 52, 59, 73, 100, 113, and 119 against the pesticide application on days 37, 63, 82, 108, and 137 after the sowing of cotton. Carbofuran, monocrotophos, and nitrate were detected in the drainage samples, with an average value, respectively, of 2.34, 2.6 microg/L, and 15.6 mg/L for no-tillage and 2.16, 2.3 microg/L, and 13.4 mg/L for tillage. In the laboratory, pesticide disappearance kinetics were measured with sterile and nonsterile soils from 0 to 10 cm in depth at 15, 25, and 35 degrees C and 50% and 90% field water capacities. Monocrotophos and carbosulfan dissipation followed first-order kinetics while others followed second-order kinetics. The results of incubation studies showed that temperature and moisture contents significantly reduced the t(1/2) (half-life) values of pesticides in sterile and nonsterile soil, but the effect of microbial activity was nearly significant that might be due to less organic carbon (0.3%). The presence of carbofuran and monocrotophos in the soil profile (0-10, 10-30, 30-60, 60-90, 90-150 cm) and the higher concentrations of endosulfan and lambda-cyhalothrin in the top layer (0-10 cm) showed the persistence of the pesticides. The detection of endosulfan and lambda-cyhalothrin in the 10-30 cm soil layer might be due to preferential flow. The data generated from this study could be helpful for risk assessment studies of pesticides and for validating pesticide transport models for sandy loam soils in cotton-growing areas of Pakistan.

  7. Biochar in Co-Contaminated Soil Manipulates Arsenic Solubility and Microbiological Community Structure, and Promotes Organochlorine Degradation

    Science.gov (United States)

    Gregory, Samuel J.; Anderson, Christopher W. N.; Camps-Arbestain, Marta; Biggs, Patrick J.; Ganley, Austen R. D.; O’Sullivan, Justin M.; McManus, Michael T.

    2015-01-01

    We examined the effect of biochar on the water-soluble arsenic (As) concentration and the extent of organochlorine degradation in a co-contaminated historic sheep-dip soil during a 180-d glasshouse incubation experiment. Soil microbial activity, bacterial community and structure diversity were also investigated. Biochar made from willow feedstock (Salix sp) was pyrolysed at 350 or 550°C and added to soil at rates of 10 g kg-1 and 20 g kg-1 (representing 30 t ha-1 and 60 t ha-1). The isomers of hexachlorocyclohexane (HCH) alpha-HCH and gamma-HCH (lindane), underwent 10-fold and 4-fold reductions in concentration as a function of biochar treatment. Biochar also resulted in a significant reduction in soil DDT levels (P biochar treatments after 60 days of treatment compared to the control. 16S amplicon sequencing revealed that biochar-amended soil contained more members of the Chryseobacterium, Flavobacterium, Dyadobacter and Pseudomonadaceae which are known bioremediators of hydrocarbons. We hypothesise that a recorded short-term reduction in the soluble As concentration due to biochar amendment allowed native soil microbial communities to overcome As-related stress. We propose that increased microbiological activity (dehydrogenase activity) due to biochar amendment was responsible for enhanced degradation of organochlorines in the soil. Biochar therefore partially overcame the co-contaminant effect of As, allowing for enhanced natural attenuation of organochlorines in soil. PMID:25923541

  8. Effect of soil and water conservation on rehabilitation of degraded lands and crop productivity in Maego watershed, North Ethiopia

    Directory of Open Access Journals (Sweden)

    Gebremariam Yaebiyo Dimtsu

    2018-04-01

    Full Text Available Many soil and water conservation (SWC measures were undertaken to decrease land degradation in Ethiopia. However, evaluation of their performance is essential to understand their success or failure and readjusting accordingly in the future planning.  Therefore, the objective of this study was to evaluate effectiveness of SWC measures in rehabilitation of degraded watershed and increase crop productivity in Maego watershed, Ethiopia. Seventy six sample plots were randomly taken from treated and untreated sub-watersheds for woody species and soil sampling. Crops yield was measured on top side, middle zone and below side of SWC structures. There were significantly higher woody species density and diversity, total nitrogen (TN, soil organic matter (SOM and soil moisture in the treated uncultivated land than the untreated one. The highest tree and sapling species density and diversity, TN and SOM were recorded on the exclosure part of the treated sub-watershed. Landscape position affected soil fertility, but has no effect on woody species density and diversity. The highest barley and wheat yield was measured on top side of SWC structures. Therefore, physical SWC structures should be integrated with exclosure to enhance rehabilitation of degraded watersheds/landscapes. Integration of biological SWC measures that improve soil fertility are essential on the cultivated land of the watershed. Most of the existing SWC structures, especially the old ones are filled with accumulated sediment, so maintenance is needed.

  9. Effects of PV Module Soiling on Glass Surface Resistance and Potential-Induced Degradation: Preprint

    Energy Technology Data Exchange (ETDEWEB)

    Hacke, Peter; Burton, Patrick; Hendrickson, Alex; Spartaru, Sergiu; Glick, Stephen; Terwilliger, Kent

    2015-12-03

    The sheet resistance of three soil types (Arizona road dust, soot, and sea salt) on glass were measured by the transmission line method as a function of relative humidity (RH) between 39% and 95% at 60 degrees C. Sea salt yielded a 3.5 order of magnitude decrease in resistance on the glass surface when the RH was increased over this RH range. Arizona road dust showed reduced sheet resistance at lower RH, but with less humidity sensitivity over the range tested. The soot sample did not show significant resistivity change compared to the unsoiled control. Photovoltaic modules with sea salt on their faces were step-stressed between 25% and 95% RH at 60 degrees C applying -1000 V bias to the active cell circuit. Leakage current from the cell circuit to ground ranged between two and ten times higher than that of the unsoiled controls. Degradation rate of modules with salt on the surface increased with increasing RH and time.

  10. Community diversity, structure and carbon footprint of nematode food web following reforestation on degraded Karst soil.

    Science.gov (United States)

    Hu, Ning; Li, Hui; Tang, Zheng; Li, Zhongfang; Tian, Jing; Lou, Yilai; Li, Jianwei; Li, Guichun; Hu, Xiaomin

    2016-06-17

    We examined community diversity, structure and carbon footprint of nematode food web along a chronosequence of T. Sinensis reforestation on degraded Karst. In general, after the reforestation: a serious of diversity parameters and community indices (Shannon-Weinier index (H'), structure index (SI), etc.) were elevated; biomass ratio of fungivores to bacterivores (FFC/BFC), and fungi to bacteria (F/B) were increased, and nematode channel ratio (NCR) were decreased; carbon footprints of all nematode trophic groups, and biomass of bacteria and fungi were increased. Our results indicate that the Karst aboveground vegetation restoration was accompanied with belowground nematode food web development: increasing community complexity, function and fungal dominance in decomposition pathway, and the driving forces included the bottom-up effect (resource control), connectedness of functional groups, as well as soil environments.

  11. Soil burial method for plastic degradation performed by Pseudomonas PL-01, Bacillus PL-01, and indigenous bacteria

    Science.gov (United States)

    Shovitri, Maya; Nafi'ah, Risyatun; Antika, Titi Rindi; Alami, Nur Hidayatul; Kuswytasari, N. D.; Zulaikha, Enny

    2017-06-01

    Lately, plastic bag is becoming the most important pollutant for environment since it is difficult to be naturally degraded due to it consists of long hydrocarbon polymer chains. Our previous study indicated that our pure isolate Pseudomonas PL-01 and Bacillus PL-01 could degrade about 10% plastic bag. This present study was aimed to find out whether Pseudomonas PL01 and Bacillus PL01 put a positive effect to indigenous bacteria from marginal area in doing plastic degradation with a soil burial method. Beach sand was used as a representative marginal area, and mangrove sediment was used as a comparison. Plastics were submerged into unsterile beach sand with 10% of Pseudomonas PL-01 or Bacillus PL-01 containing liquid minimal salt medium (MSM) separately, while other plastics were submerged into unsterile mangrove sediments. After 4, 8, 12 and 16 weeks, their biofilm formation on their plastic surfaces and plastic degradation were measured. Results indicated that those 2 isolates put positive influent on biofilm formation and plastic degradation for indigenous beach sand bacteria. Bacillus PL-01 put higher influent than Pseudomonas PL-01. Plastic transparent was preferable degraded than black and white plastic bag `kresek'. But anyhow, indigenous mangrove soil bacteria showed the best performance in biofilm formation and plastic degradation, even without Pseudomonas PL-01 or Bacillus PL-01 addition. Fourier Transform Infrared (FTIR) analysis complemented the results; there were attenuated peaks with decreasing peaks transmittances. This FTIR peaks indicated chemical functional group changes happened among the plastic compounds after 16 weeks incubation time.

  12. Determination of degradation rates of organic substances in the unsaturated soil zone depending on the grain size fractions of various soil types

    Science.gov (United States)

    Fichtner, Thomas; Stefan, Catalin; Goersmeyer, Nora

    2015-04-01

    Rate and extent of the biological degradation of organic substances during transport through the unsaturated soil zone is decisively influenced by the chemical and physical properties of the pollutants such as water solubility, toxicity and molecular structure. Furthermore microbial degradation processes are also influenced by soil-specific properties. An important parameter is the soil grain size distribution on which the pore volume and the pore size depends. Changes lead to changes in air and water circulation as well as preferred flow paths. Transport capacity of water inclusive nutrients is lower in existing bad-drainable fine pores in soils with small grain size fractions than in well-drainable coarse pores in a soil with bigger grain size fractions. Because fine pores are saturated with water for a longer time than the coarse pores and oxygen diffusion in water is ten thousand times slower than in air, oxygen is replenished much slower in soils with small grain size fractions. As a result life and growth conditions of the microorganisms are negatively affected. This leads to less biological activity, restricted degradation/mineralization of pollutants or altered microbial processes. The aim of conducted laboratory column experiments was to study the correlation between the grain size fractions respectively pore sizes, the oxygen content and the biodegradation rate of infiltrated organic substances. Therefore two columns (active + sterile control) were filled with different grain size fractions (0,063-0,125 mm, 0,2-0,63 mm and 1-2 mm) of soils. The sterile soil was inoculated with a defined amount of a special bacteria culture (sphingobium yanoikuae). A solution with organic substances glucose, oxalic acid, sinaphylic alcohol and nutrients was infiltrated from the top in intervals. The degradation of organic substances was controlled by the measurement of dissolved organic carbon in the in- and outflow of the column. The control of different pore volumes

  13. Estimation of p,p'-DDT degradation in soil by modeling and constraining hydrological and biogeochemical controls.

    Science.gov (United States)

    Sanka, Ondrej; Kalina, Jiri; Lin, Yan; Deutscher, Jan; Futter, Martyn; Butterfield, Dan; Melymuk, Lisa; Brabec, Karel; Nizzetto, Luca

    2018-08-01

    Despite not being used for decades in most countries, DDT remains ubiquitous in soils due to its persistence and intense past usage. Because of this it is still a pollutant of high global concern. Assessing long term dissipation of DDT from this reservoir is fundamental to understand future environmental and human exposure. Despite a large research effort, key properties controlling fate in soil (in particular, the degradation half-life (τ soil )) are far from being fully quantified. This paper describes a case study in a large central European catchment where hundreds of measurements of p,p'-DDT concentrations in air, soil, river water and sediment are available for the last two decades. The goal was to deliver an integrated estimation of τ soil by constraining a state-of-the-art hydrobiogeochemical-multimedia fate model of the catchment against the full body of empirical data available for this area. The INCA-Contaminants model was used for this scope. Good predictive performance against an (external) dataset of water and sediment concentrations was achieved with partitioning properties taken from the literature and τ soil estimates obtained from forcing the model against empirical historical data of p,p'-DDT in the catchment multicompartments. This approach allowed estimation of p,p'-DDT degradation in soil after taking adequate consideration of losses due to runoff and volatilization. Estimated τ soil ranged over 3000-3800 days. Degradation was the most important loss process, accounting on a yearly basis for more than 90% of the total dissipation. The total dissipation flux from the catchment soils was one order of magnitude higher than the total current atmospheric input estimated from atmospheric concentrations, suggesting that the bulk of p,p'-DDT currently being remobilized or lost is essentially that accumulated over two decades ago. Copyright © 2018 Elsevier Ltd. All rights reserved.

  14. Degradation of 14C-parathion 'in vitro' by microorganisms isolated from a gley humic soil

    International Nuclear Information System (INIS)

    Andrea, M.M. de; Ruegg, E.F.

    1982-01-01

    It was determined 'in vitro' the degradation of Parathion by a bacterium and a fungus isolated from a sample of Gley Humic soil previously treated with repeated applications of the insecticide. In a qualitative colorimetric assay hydrolisis of parathion to p-nitrophenol just the bacterium gave a positive answer. In quantitative assays of 14 C-parathion degradation in culture media containing both microorganisms, organic solvents extractions resulted in organic and aqueous phases, which were analysed by liquid scintillation counting and thin-layer chromatography. In a mineral salts medium plus buffer, the bacterium and the fungus behaved differently from the control, because part of the 14 C-insecticide was metabolized to, at least, one metabolite and besides, the microorganisms presented smaller percentages of total recovery. The largest percentage of the radio carbon recovery from the extracts of the medium containing the fungus plus extract of yeast, was obtained from the aqueous phase and the existence of other metabolite was demonstrated by chromatograms of the organic phase. (Author) [pt

  15. Isolation and characterization of mesophilic, oxalate-degrading Streptomyces from plant rhizosphere and forest soils

    Science.gov (United States)

    Sahin, Nurettin

    2004-10-01

    The present work was aimed at the isolation of additional new pure cultures of oxalate-degrading Streptomyces and its preliminary characterization for further work in the field of oxalate metabolism and taxonomic studies. Mesophilic, oxalate-degrading Streptomyces were enriched and isolated from plant rhizosphere and forest soil samples. Strains were examined for cultural, morphological (spore chain morphology, spore mass colour, diffusible and melanin pigment production), physiological (antibiosis, growth in the presence of inhibitory compounds, assimilation of organic acids and enzyme substrates) and chemotaxonomic characters (cellular lipid components and diagnostic cell-wall diamino acid). The taxonomic data obtained were analysed by using the simple matching (SSM) and Jaccard (SJ) coefficients, clustering was achieved using the UPGMA algorithm. All strains were able to utilize sodium-, potassium-, calcium- and ammonium-oxalate salts. Based on the results of numerical taxonomy, isolates were grouped into five cluster groups with a ≥70% SSM similarity level. Streptomyces rochei was the most common of the cluster groups, with a Willcox probability of P>0.8. Streptomyces antibioticus, S. anulatus, S. fulvissimus, S. halstedii and S. violaceusniger are newly reported as oxalate-utilizing Streptomyces.

  16. Plastic degrading fungi Trichoderma viride and Aspergillus nomius isolated from local landfill soil in Medan

    Science.gov (United States)

    Munir, E.; Harefa, R. S. M.; Priyani, N.; Suryanto, D.

    2018-03-01

    Plastic is a naturally recalcitrant polymer, once it enters the environment, it will remain there for many years. Accumulation of plastic as wastes in the environment poses a serious problem and causes an ecological threat. Alternative strategies to reduce accumulation of plastic wastes have been initiated and implemented from a different aspect including from microbiological view point. The study to obtain potential fungi in degrading plastic molecule has been initiated in our laboratory. Low density polyethylene (LDPE) plastic was used as a tested material. Candidate fungi were isolated from local landfill soil. The fungi were cultured in mineral salt medium broth containing LDPE powder. Two of nine isolates showed best growth response in broth media containing LDPE. These isolates (RH03 and RH06) were used in degradation test. Results showed that isolate RH03 and RH06 reduced the weight of LDPE film by 5.13% and 6.63%, respectively after 45 days of cultivation. The tensile strength of treated film even reduced significantly by 58% and 40% of each isolate. Analyses of electron micrograph exhibited grove ands rough were formed on the surface of LDPE film. These were not found in the untreated film. Furthermore, molecular analysis through polymerase chain reaction and DNA sequencing indicated that RH03 is Trichoderma viride and RH06 is Aspergillus nomius with 97% and 96% similarities, respectively.

  17. Degradability studies of PLA nanocomposites under controlled water sorption and soil burial conditions

    Science.gov (United States)

    Norazlina, H.; Hadi, A. A.; Qurni, A. U.; Amri, M.; Mashelmie, S.; Kamal, Y.

    2018-04-01

    Polymer blended nanocomposites based on polylactic acid (PLA) were prepared via a simple melting process and investigated for its biodegradation behaviour. The treated CNTs were surface modified by using acid treatment and characterisations of composites were done by using Fourier Transform Infra-Red (FTIR) and UV-Vis. FTIR spectra and UV-Vis peak confirmed the surface modification of CNTs. The water uptake and weight loss behaviour based on CNTs and m-CNTs loading at different temperatures (25° and 45°C) were studied. It was found that the water absorption and weight loss of nanocomposites increased by the incorporation of CNTs and m-CNTs. Moisture induced degradation of composite samples was significant at elevated temperature. The addition of treated CNTs successfully reduced the water uptake and weight loss of nanocomposites due to less hydrolytic effect of water on nanocomposites. In soil burial test, the weight loss increases with addition of nanofiller. The loading of m-CNT reduced the ability of nanocomposites degradation.

  18. Production of rhamnolipids and diesel oil degradation by bacteria isolated from soil contaminated by petroleum.

    Science.gov (United States)

    Leite, Giuseppe G F; Figueirôa, Juciane V; Almeida, Thiago C M; Valões, Jaqueline L; Marques, Walber F; Duarte, Maria D D C; Gorlach-Lira, Krystyna

    2016-03-01

    Biosurfactants are microbial secondary metabolites. The most studied are rhamnolipids, which decrease the surface tension and have emulsifying capacity. In this study, the production of biosurfactants, with emphasis on rhamnolipids, and diesel oil degradation by 18 strains of bacteria isolated from waste landfill soil contaminated by petroleum was analyzed. Among the studied bacteria, gram-positive endospore forming rods (39%), gram positive rods without endospores (17%), and gram-negative rods (44%) were found. The following methods were used to test for biosurfactant production: oil spreading, emulsification, and hemolytic activity. All strains showed the ability to disperse the diesel oil, while 77% and 44% of the strains showed hemolysis and emulsification of diesel oil, respectively. Rhamnolipids production was observed in four strains that were classified on the basis of the 16S rRNA sequences as Pseudomonas aeruginosa. Only those strains showed the rhlAB gene involved in rhamnolipids synthesis, and antibacterial activity against Escherichia coli, P. aeruginosa, Staphylococcus aureus, Bacillus cereus, Erwinia carotovora, and Ralstonia solanacearum. The highest production of rhamnolipids was 565.7 mg/L observed in mineral medium containing olive oil (pH 8). With regard to the capacity to degrade diesel oil, it was observed that 7 strains were positive in reduction of the dye 2,6-dichlorophenolindophenol (2,6-DCPIP) while 16 had the gene alkane mono-oxygenase (alkB), and the producers of rhamnolipids were positive in both tests. Several bacterial strains have shown high potential to be explored further for bioremediation purposes due to their simultaneous ability to emulsify, disperse, and degrade diesel oil. © 2015 American Institute of Chemical Engineers Biotechnol. Prog., 32:262-270, 2016. © 2015 American Institute of Chemical Engineers.

  19. Soil Degradation Evaluated by a 27 years Landsat image (Vis-Nir-Swir-Tir), climate and digital elevation derivatives

    Science.gov (United States)

    Dematte, J. A., Sr.; Santos, N. V.; de Almeida Malzoni, M. M.; Poppiel, R. R.; Fongaro, C. T.; Rizzo, R.; Safanelli, J. L.; Sayão, V. M.; Mendes, W. S.

    2017-12-01

    According to Food and Agriculture Organization of the United Nations, 30% of the global soils are degraded. Therefore, novel researches on soil degradation process are imperative to prevent damages on social and environmental dynamics. Since we have a wide world dimension, and few manpower, we have to focus on high dimensional evaluation techniques such as remote sensing. The main goal of this work was to develop a method, based on a 27 years time-series of satellite images (Landsat), from which determine the most important factors on soil degradation. The area is located in south Brazil with a 1400 km2 area. The steps of the method are as follows: a) we collected images from the area and based on a novel technique determined the areas with exposed soils; b) we quantified soil properties such as clay and capacity of ionic exchange based on pixel spectra signature; c) the technique also indicated how many times a single pixel was with bare soil during the period; d) we also determined the surface temperature based on band 6; e) using elevation model we created the layers LS factor, drainage density, topographic wetness index, solar radiation; f) we also determined climate information (water balance); g) organic matter (OM) was also estimated. All factors from item a to f were balanced and overlapped (GIS) to generate an index of soil degradation, SD (fig 1a) - values from 1 (low risk) to 5 (high risk). We concluded that 30% of the area is degraded. SD presented coherent values with OM and validate the method. We observed that areas with higher SD (5) contain 43.6% less OM than the ones with low risk (1). In addition, the soil spectral reflectance curve was analyzed concluding that degraded soils shows higher intensity. The current land use (fig 1b) was correlated demonstrating that a higher risk of SD happens mainly in sugar cane (41.6%) in contrast to pasture (16.9%) and forestry (11.7%). Therefore, this approach allows land uses decision-making and public policies.

  20. Effects of sawdust and organo mineral fertilizer and their residual effect on the yield of maize on degrades soil

    International Nuclear Information System (INIS)

    Dania, S.O.; Fagbola, O.; Isitekhale, H.H.E.

    2012-01-01

    Conventional mineral fertilizer alone cannot sustain arable crop production in soil which top layer has been eroded hence it is necessary to employ the application of organic base fertilizer. A greenhouse experiment was conducted to investigate the effects of sawdust, organo mineral fertilizer and their residual effects on the growth and yield of maize. Organo mineral fertilizer is the combination of organic manure and mineral fertilizer. Simulated degraded soil was used and the experimental design was a 2 x 2 x 3 factorial in a completely randomized design with three replicates. The factors investigated were: two levels of organo mineral fertilizer (with and without), two levels of soil amendment (with and without sawdust) and three levels of application methods. The methods of organo mineral fertilizer used were ring, subsurface and mixed methods. The amendment of soil to sawdust was ratio 1:1 by volume. The growth and yield of maize was significantly (p = 0.05) higher in non-amended soil with OMF under different application methods compared to soil amended with sawdust with or without OMF application. Ring method of application of OMF in non-amended soil significantly increased the growth and yield of maize compared to other methods of OMF application. The residual effect of OMF and sawdust on the growth and yield of maize was significantly higher in non-amended soil with OMF under different application methods compared to soil amended with sawdust. Addition of sawdust to soil does not improve the growth and yield of maize with or without OMF and under different application methods. Organo mineral fertilizer using ring and subsurface application methods has a beneficial effect in improving the growth and yield of maize in degraded soil where the top layer has been eroded. (author)

  1. Effects of sawdust and organo mineral fertilizer and their residual effect on the yield of maize on degraded soil

    International Nuclear Information System (INIS)

    Dania, S.O.; Fagbola, O.

    2012-01-01

    Conventional mineral fertilizer alone cannot sustain arable crop production in soil which top layer has been eroded hence it is necessary to employ the application of organic base fertilizer. A greenhouse experiment was conducted to investigate the effects of sawdust, organo mineral fertilizer and their residual effects on the growth and yield of maize. Organo mineral fertilizer is the combination of organic manure and mineral fertilizer. Simulated degraded soil was used and the experimental design was a 2 x 2 x 3 factorial in a completely randomized design with three replicates. The factors investigated were: two levels of organo mineral fertilizer (with and without), two levels of soil amendment (with and without sawdust) and three levels of application methods. The methods of organo mineral fertilizer used were ring, subsurface and mixed methods. The amendment of soil to sawdust was ratio 1: 1 by volume. The growth and yield of maize was significantly (p = 0.05) higher in non-amended soil with OMF under different application methods compared to soil amended with sawdust with or without OMF application. Ring method of application of OMF in non-amended soil significantly increased the growth and yield of maize compared to other methods of OMF application. The residual effect of OMF and sawdust on the growth and yield of maize was significantly higher in non-amended soil with OMF under different application methods compared to soil amended with sawdust. Addition of sawdust to soil does not improve the growth and yield of maize with or without OMF and under different application methods. Organo mineral fertilizer using ring and subsurface application methods has a beneficial effect in improving the growth and yield of maize in degraded soil where the top layer has been eroded. (author)

  2. Degradation of 14C-ETU in a soil profile investigated by means of incubation in two different incubation systems

    International Nuclear Information System (INIS)

    Bech, A.; Johannesen, H.

    1994-07-01

    The purpose of the paper is to elucidate the mechanism of biodegradation of ethylenethiourea (ETU) in arable soils, both on the surface and in the deeper layers. The effect of incubation system upon the ETU biodegradation was studied by incubation of undisturbed and mixed soil cores in tubes or flasks respectively. The total mineralization of ETU to CO2 in the ploughed layer and in the deeper layers is investigated by means of biodegradation tests with 14 C-ETU in soil samples collected from 15, 60 and 100 cm depth. ETU microbial biodegradation was studied in a series of tests covering conversion and isolation of ETU degrading microorganisms. (EG) 86 refs

  3. Three-year study of fast-growing trees in degraded soils amended with composts: Effects on soil fertility and productivity.

    Science.gov (United States)

    Madejón, Paula; Alaejos, Joaquin; García-Álbala, José; Fernández, Manuel; Madejón, Engracia

    2016-03-15

    Currently, worries about the effects of intensive plantations on long-term nutrient supply and a loss of productivity have risen. In this study two composts were added to degraded soils where this type of intensive crops were growing, to avoid the soil fertility decrease and try to increase biomass production. For the experiment, two degraded soils in terms of low organic carbon content and low pH were selected in South-West Spain: La Rábida (RA) and Villablanca (VI) sites. Both study sites were divided into 24 plots. In RA, half of the plots were planted with Populus x canadensis "I-214"; the other half was planted with Eucalyptus globulus. At the VI site, half of the plots were planted with Paulownia fortunei, and the other plots were planted with Eucalyptus globulus. For each tree and site, three treatments were established (two organic composts and a control without compost), with four replications per treatment. The organic amendments were "alperujo" compost, AC, a solid by-product from the extraction of olive oil, and BC, biosolid compost. During the three years of experimentation, samples of soils and plants were analyzed for studying chemical and biochemical properties of soil, plant growth and plant nutritional status and biomass production. The composts increased total organic carbon, water-soluble carbon, nutrients and pH of soil only in the most acidic soil. Soil biochemical quality was calculated with the geometric mean of the enzymatic activities (Dehydrogenase, β-glucosidase, Phosphatase and Urease activities) determined in soils. The results showed a beneficial improvement in comparison with soils without compost. However, the best results were found in the growth and biomass production of the studied trees, especially in Eucalyptus. Nutritional levels of leaves of the trees were, in general, in the normal established range for each species, although no clear effect of the composts was observed. The results of this study justify the addition of

  4. Soil, water, and nutrient losses from management alternatives for degraded pasture in Brazilian Atlantic Rainforest biome.

    Science.gov (United States)

    Rocha Junior, Paulo Roberto da; Andrade, Felipe Vaz; Mendonça, Eduardo de Sá; Donagemma, Guilherme Kangussú; Fernandes, Raphael Bragança Alves; Bhattharai, Rabin; Kalita, Prasanta Kumar

    2017-04-01

    The objective of this study was to evaluate sediment, water and nutrient losses from different pasture managements in the Atlantic Rainforest biome. A field study was carried out in Alegre Espiríto Santo, Brazil, on a Xanthic Ferralsol cultivated with braquiaria (Brachiaria brizantha). The six pasture managements studied were: control (CON), chisel (CHI), fertilizer (FER), burned (BUR), plowing and harrowing (PH), and integrated crop-livestock (iCL). Runoff and sediment samples were collected and analyzed for calcium (Ca), magnesium (Mg), potassium (K), phosphorus (P) and organic carbon contents. Soil physical attributes and above and below biomass were also evaluated. The results indicated that higher water loss was observed for iCL (129.90mm) and CON (123.25mm) managements, and the sediment losses were higher for CON (10.24tha -1 ) and BUR (5.20tha -1 ) managements when compared to the other managements. Majority of the nutrients losses occurred in dissolved fraction (99% of Ca, 99% of Mg, 96% of K, and 65% of P), whereas a significant fraction of organic carbon (80%) loss occurred in a particulate form. Except for P, other nutrients (Ca, Mg and K) and organic carbon losses were higher in coarse sediment compared to fine sediment. The greater losses of sediment, organic carbon, and nutrients were observed for CON followed by BUR management (plosses from various practices, to reduce pasture degradation, farmers should adopt edaphic practices by applying lime and fertilize to improve pasture growth and soil cover, and reducing soil erosion in the hilly Brazilian Atlantic Rainforest biome. Copyright © 2016. Published by Elsevier B.V.

  5. Soil-derived microbial consortia enriched with different plant biomass reveal distinct players acting in lignocellulose degradation

    NARCIS (Netherlands)

    de Lima Brossi, Maria Julia; Jiménez Avella, Diego; Cortes Tolalpa, Larisa; van Elsas, Jan

    Here, we investigated how different plant biomass, and-for one substrate-pH, drive the composition of degrader microbial consortia. We bred such consortia from forest soil, incubated along nine aerobic sequential - batch enrichments with wheat straw (WS1, pH 7.2; WS2, pH 9.0), switchgrass (SG, pH

  6. Spatial variation in biodiversity, soil degradation and productivity in agricultural landscapes in the highlands of Tigray, northern Ethiopia

    NARCIS (Netherlands)

    Hadgu, K.M.; Rossing, W.A.H.; Kooistra, L.; Bruggen, van A.H.C.

    2009-01-01

    There is a growing concern about food security and sustainability of agricultural production in developing countries. However, there are limited attempts to quantify agro-biodiversity losses and relate these losses to soil degradation and crop productivity, particularly in Tigray, Ethiopia. In this

  7. The key microorganisms for anaerobic degradation of pentachlorophenol in paddy soil as revealed by stable isotope probing

    International Nuclear Information System (INIS)

    Tong, Hui; Liu, Chengshuai; Li, Fangbai; Luo, Chunling; Chen, Manjia; Hu, Min

    2015-01-01

    Highlights: • SIP suggested that Dechloromonas can mineralize PCP in soil. • Methanosaeta and Methanocella acquired PCP-derived carbon. • Lactate enhanced microbial degradation of PCP in soil. - Abstract: Pentachlorophenol (PCP) is a common residual persistent pesticide in paddy soil and has resulted in harmful effect on soil ecosystem. The anaerobic microbial transformation of PCP, therefore, has been received much attentions, especially the functional microbial communities for the reductive transformation. However, the key functional microorganisms for PCP mineralization in the paddy soil still remain unknown. In this work, DNA-based stable isotope probing (SIP) was applied to explore the key microorganisms responsible for PCP mineralization in paddy soil. The SIP results indicated that the dominant bacteria responsible for PCP biodegradation belonged to the genus Dechloromonas of the class β-Proteobacteria. In addition, the increased production of 13 CH 4 and 13 CO 2 indicated that the addition of lactate enhanced the rate of biodegradation and mineralization of PCP. Two archaea classified as the genera of Methanosaeta and Methanocella of class Methanobacteria were enriched in the heavy fraction when with lactate, whereas no archaea was detected in the absence of lactate. These findings provide direct evidence for the species of bacteria and archaea responsible for anaerobic PCP or its breakdown products mineralization and reveal a new insight into the microorganisms linked with PCP degradation in paddy soil

  8. The key microorganisms for anaerobic degradation of pentachlorophenol in paddy soil as revealed by stable isotope probing

    Energy Technology Data Exchange (ETDEWEB)

    Tong, Hui [Guangdong Key Laboratory of Agricultural Environment Pollution Integrated Control, Guangdong Institute of Eco-Environmental and Soil Sciences, Guangzhou 510650 (China); Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640 (China); University of Chinese Academy of Sciences, Beijing 100049 (China); Liu, Chengshuai [State Key Laboratory of Environmental Geochemistry, Institute of Geochemistry, Chinese Academy of Sciences, Guiyang 550009 (China); Li, Fangbai, E-mail: cefbli@soil.gd.cn [Guangdong Key Laboratory of Agricultural Environment Pollution Integrated Control, Guangdong Institute of Eco-Environmental and Soil Sciences, Guangzhou 510650 (China); Luo, Chunling [Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640 (China); Chen, Manjia; Hu, Min [Guangdong Key Laboratory of Agricultural Environment Pollution Integrated Control, Guangdong Institute of Eco-Environmental and Soil Sciences, Guangzhou 510650 (China)

    2015-11-15

    Highlights: • SIP suggested that Dechloromonas can mineralize PCP in soil. • Methanosaeta and Methanocella acquired PCP-derived carbon. • Lactate enhanced microbial degradation of PCP in soil. - Abstract: Pentachlorophenol (PCP) is a common residual persistent pesticide in paddy soil and has resulted in harmful effect on soil ecosystem. The anaerobic microbial transformation of PCP, therefore, has been received much attentions, especially the functional microbial communities for the reductive transformation. However, the key functional microorganisms for PCP mineralization in the paddy soil still remain unknown. In this work, DNA-based stable isotope probing (SIP) was applied to explore the key microorganisms responsible for PCP mineralization in paddy soil. The SIP results indicated that the dominant bacteria responsible for PCP biodegradation belonged to the genus Dechloromonas of the class β-Proteobacteria. In addition, the increased production of {sup 13}CH{sub 4} and {sup 13}CO{sub 2} indicated that the addition of lactate enhanced the rate of biodegradation and mineralization of PCP. Two archaea classified as the genera of Methanosaeta and Methanocella of class Methanobacteria were enriched in the heavy fraction when with lactate, whereas no archaea was detected in the absence of lactate. These findings provide direct evidence for the species of bacteria and archaea responsible for anaerobic PCP or its breakdown products mineralization and reveal a new insight into the microorganisms linked with PCP degradation in paddy soil.

  9. Investigation on the photocatalytic degradation of pyrene on soil surfaces using nanometer anatase TiO2 under UV irradiation

    International Nuclear Information System (INIS)

    Dong Dianbo; Li Peijun; Li Xiaojun; Zhao Qing; Zhang Yinqiu; Jia Chunyun; Li Peng

    2010-01-01

    Photocatalytic degradation of pyrene on soil surfaces was investigated in the presence of nanometer anatase TiO 2 under a variety of conditions. After being spiked with pyrene, soil samples loaded with different amounts of TiO 2 (0%, 1%, 2%, 3%, and 4%, w/w) were exposed to UV irradiation for 25 h. The results indicated that the photocatalytic degradation of pyrene followed pseudo-first-order kinetics. TiO 2 accelerated the degradation of pyrene generally as indicated by the half-life reduction from 45.90 to 31.36 h, corresponding to the TiO 2 amounts from 0% to 4%, respectively. The effects of H 2 O 2 , light intensity and humic acids on the degradation of pyrene were also investigated. The degradation of pyrene increased along with increasing the concentration of H 2 O 2 , light intensity and the concentration of humic acids. All results indicated that the photocatalytic method in the presence of nanometer anatase TiO 2 was an advisable choice for the treatments of PAHs polluted soil in the future.

  10. Mineralization of organic matter in gray forest soil and typical chernozem with degraded structure due to physical impacts

    Science.gov (United States)

    Semenov, V. M.; Zhuravlev, N. S.; Tulina, A. S.

    2015-10-01

    The dynamics of the organic matter mineralization in the gray forest soil and typical chernozem with structure disturbed by physical impacts (grinding and extraction of water-soluble substances) were studied in two long-term experiments at the constant temperature and moisture. The grinding of soil to particles of 0.1, day-1) and difficultly mineralizable (0.01 > k 3 > 0.001, day-1) fractions in the active pool of soil organic matter. The results of the studies show that the destruction of the structural-aggregate status is one of the reasons for the active soil organic matter depletion and, as a consequence, for the degradation of the properties inherent to the undisturbed soils.

  11. Soils

    International Nuclear Information System (INIS)

    Freudenschuss, A.; Huber, S.; Riss, A.; Schwarz, S.; Tulipan, M.

    2001-01-01

    For Austria there exists a comprehensive soil data collection, integrated in a GIS (geographical information system). The content values of pollutants (cadmium, mercury, lead, copper, mercury, radio-cesium) are given in geographical charts and in tables by regions and by type of soil (forests, agriculture, greenland, others) for the whole area of Austria. Erosion effects are studied for the Austrian region. Legal regulations and measures for an effective soil protection, reduction of soil degradation and sustainable development in Austria and the European Union are discussed. (a.n.)

  12. Degradation of oil products in a soil from a Russian Barents hot-spot during electrodialytic remediation

    DEFF Research Database (Denmark)

    Pedersen, Kristine B.; Lejon, Tore; Jensen, Pernille Erland

    2016-01-01

    A highly oil-polluted soil from Krasnoe in North-West Russia was used to investigate the degradation of organic pollutants during electrodialytic remediation. Removal efficiencies were up to 70 % for total hydrocarbons (THC) and up to 65 % for polyaromatic hydrocarbons (PAH). Relatively more...... of the lighter PAH compounds and THC fractions were degraded. A principal component analysis (PCA) revealed a difference in the distribution of PAH compounds after the remediation. The observed clustering of experiments in the PCA scores plot was assessed to be related to the stirring rate. Multivariate analysis...... of the experimental settings and final concentrations in the 12 experiments revealed that the stirring rate of the soil suspension was by far the most important parameter for the remediation for both THC and PAH. Light was the second most important variable for PAH and seems to influence degradation. The experimental...

  13. The influence of soil and landfill leachate microorganisms in the degradation of PVC/PCL films cast from DMF

    Directory of Open Access Journals (Sweden)

    Adriana de Campos

    2012-01-01

    Full Text Available While the use of plastics continues to increase in our daily lives in a growing range products, these materials are very persistent in the environment. The blending of aliphatic polyesters with other thermoplastic polymers is a profitable way of producing materials with changed physical properties and biodegradability, which can facilitate microbial adhesion to the polymer matrix and help to reduce (post-consumer degradation time of these materials in landfills. This study was an investigation of the biodegradation of films of blends of poly(vinyl chloride (PVC and poly(ε-caprolactone (PCL by soil microorganisms and leachate, by means of respirometry, infrared absorption spectroscopy (FTIR, differential calorimetry scanning (DSC, scanning electron microscopy (SEM, contact angle and weight loss. The results showed that in the soil, the films suffered oxidative biodegradation. The PCL promoted degradation of the PVC in the film of PVC/PCL and the PVC inhibited the rapid degradation of the PCL.

  14. Dynamics of indigenous bacterial communities associated with crude oil degradation in soil microcosms during nutrient-enhanced bioremediation.

    Science.gov (United States)

    Chikere, Chioma B; Surridge, Karen; Okpokwasili, Gideon C; Cloete, Thomas E

    2012-03-01

    present study therefore demonstrated that the soil investigated harbours hydrocarbon-degrading bacterial populations which can be biostimulated to achieve effective bioremediation of oil-contaminated soil.

  15. Chemical Characterization of the Degradation of Necromass from Four Ascomycota Fungi: Implications for Soil Organic Carbon Turnover and Storage

    Science.gov (United States)

    Bruner, V. J.; Schreiner, K. M.; Blair, N. E.; Egerton, L.

    2016-12-01

    Terrestrial soils store vast amounts of organic carbon, approximately twice as much carbon as is currently in the atmospheric CO2 pool. Despite its importance in the global carbon cycle, much is still unknown about the source, turnover, and stability of this soil organic carbon (SOC) pool. For example, fungi are known to play an important role in shaping the chemistry of SOC by degrading common biopolymers, and fungal biomass has been found to be a significant portion of living microbial SOC, dominating over bacteria in some soils by as much as 90%. And yet, despite growing evidence that microbial necromass may be larger contributors to SOC than previously thought, very little is known about the specific degradation patterns of fungal necromass and subsequently its potential chemical contributions to long-lived SOC pools. This study addresses these knowledge gaps through a time-series analysis of the degradation patterns of fungal tissue from four different saprotrophic Ascomyota species in temperate restored prairie soils. Fungal tissue was buried in soils both within a temperature- and light-controlled laboratory environment, and in a field environment, and harvested at intervals from 1 day to two months. After harvest, chemical analysis of the dried tissue by thermochemolysis pyrolysis-GCMS was used for relative quantitation of a variety of common biomolecules and biopolymers within the fungal tissue that may be long lived in soils, including chitin, glucan, mannan, ergosterol, and melanin. The degradation of these specific molecules, bulk fungal tissue, and bulk C and N within the tissue, is modeled to (1) show that a small portion of fungal necromass persists in the environment even after the period of the experiment and could serve as a contributor to long-lived SOC, and (2) provide quantitative information on the contribution of fungal tissue to global SOC pools.

  16. Construction and applications of DNA probes for detection of polychlorinated biphenyl-degrading genotypes in toxic organic-contaminated soil environments

    International Nuclear Information System (INIS)

    Walia, S.; Khan, A.; Rosenthal, N.

    1990-01-01

    Several DNA probes for polychlorinated biphenyl (PCB)-degrading genotypes were constructed from PCB-degrading bacteria. These laboratory-engineered DNA probes were used for the detection, enumeration, and isolation of specific bacteria degrading PCBs. Dot blot analysis of purified DNA from toxic organic chemical-contaminated soil bacterial communities showed positive DNA-DNA hybridization with a 32P-labeled DNA probe (pAW6194, cbpABCD). Less than 1% of bacterial colonies isolated from garden topsoil and greater than 80% of bacteria isolated from PCB-contaminated soils showed DNA homologies with 32P-labeled DNA probes. Some of the PCB-degrading bacterial isolates detected by the DNA probe method did not show biphenyl clearance. The DNA probe method was found to detect additional organisms with greater genetic potential to degrade PCBs than the biphenyl clearance method did. Results from this study demonstrate the usefulness of DNA probes in detecting specific PCB-degrading bacteria, abundance of PCB-degrading genotypes, and genotypic diversity among PCB-degrading bacteria in toxic chemical-polluted soil environments. We suggest that the DNA probe should be used with caution for accurate assessment of PCB-degradative capacity within soils and further recommend that a combination of DNA probe and biodegradation assay be used to determine the abundance of PCB-degrading bacteria in the soil bacterial community

  17. Bacteria capable of degrading anthracene, phenanthrene, and fluoranthene as revealed by DNA based stable-isotope probing in a forest soil

    Energy Technology Data Exchange (ETDEWEB)

    Song, Mengke [Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640 (China); Jiang, Longfei [College of Life Sciences, Nanjing Agricultural University, Nanjing 210095 (China); Zhang, Dayi [Lancaster Environment Centre, Lancaster University, Lancaster LA1 4YQ (United Kingdom); Luo, Chunling, E-mail: clluo@gig.ac.cn [Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640 (China); Wang, Yan [Key Laboratory of Industrial Ecology and Environmental Engineering (MOE), School of Environmental Science and Technology, Dalian University of Technology, Dalian 116024 (China); Yu, Zhiqiang [Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640 (China); Yin, Hua [College of Environment and Energy, South China University of Technology, Guangzhou 510006 (China); Zhang, Gan [Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640 (China)

    2016-05-05

    Highlights: • Investigate PAHs degraders in forest carbon-rich soils via DNA-SIP. • Rhodanobacter is identified to metabolite anthracene for the first time. • The first fluoranthene degrader belongs to Acidobacteria. • Different functions of PAHs degraders in forest soils from contaminated soils. - Abstract: Information on microorganisms possessing the ability to metabolize different polycyclic aromatic hydrocarbons (PAHs) in complex environments helps in understanding PAHs behavior in natural environment and developing bioremediation strategies. In the present study, stable-isotope probing (SIP) was applied to investigate degraders of PAHs in a forest soil with the addition of individually {sup 13}C-labeled phenanthrene, anthracene, and fluoranthene. Three distinct phylotypes were identified as the active phenanthrene-, anthracene- and fluoranthene-degrading bacteria. The putative phenanthrene degraders were classified as belonging to the genus Sphingomona. For anthracene, bacteria of the genus Rhodanobacter were the putative degraders, and in the microcosm amended with fluoranthene, the putative degraders were identified as belonging to the phylum Acidobacteria. Our results from DNA-SIP are the first to directly link Rhodanobacter- and Acidobacteria-related bacteria with anthracene and fluoranthene degradation, respectively. The results also illustrate the specificity and diversity of three- and four-ring PAHs degraders in forest soil, contributes to our understanding on natural PAHs biodegradation processes, and also proves the feasibility and practicality of DNA-based SIP for linking functions with identity especially uncultured microorganisms in complex microbial biota.

  18. Biochar in co-contaminated soil manipulates arsenic solubility and microbiological community structure, and promotes organochlorine degradation.

    Directory of Open Access Journals (Sweden)

    Samuel J Gregory

    Full Text Available We examined the effect of biochar on the water-soluble arsenic (As concentration and the extent of organochlorine degradation in a co-contaminated historic sheep-dip soil during a 180-d glasshouse incubation experiment. Soil microbial activity, bacterial community and structure diversity were also investigated. Biochar made from willow feedstock (Salix sp was pyrolysed at 350 or 550°C and added to soil at rates of 10 g kg-1 and 20 g kg-1 (representing 30 t ha-1 and 60 t ha-1. The isomers of hexachlorocyclohexane (HCH alpha-HCH and gamma-HCH (lindane, underwent 10-fold and 4-fold reductions in concentration as a function of biochar treatment. Biochar also resulted in a significant reduction in soil DDT levels (P < 0.01, and increased the DDE:DDT ratio. Soil microbial activity was significantly increased (P < 0.01 under all biochar treatments after 60 days of treatment compared to the control. 16S amplicon sequencing revealed that biochar-amended soil contained more members of the Chryseobacterium, Flavobacterium, Dyadobacter and Pseudomonadaceae which are known bioremediators of hydrocarbons. We hypothesise that a recorded short-term reduction in the soluble As concentration due to biochar amendment allowed native soil microbial communities to overcome As-related stress. We propose that increased microbiological activity (dehydrogenase activity due to biochar amendment was responsible for enhanced degradation of organochlorines in the soil. Biochar therefore partially overcame the co-contaminant effect of As, allowing for enhanced natural attenuation of organochlorines in soil.

  19. Biodegradation Ability and Catabolic Genes of Petroleum-Degrading Sphingomonas koreensis Strain ASU-06 Isolated from Egyptian Oily Soil

    Directory of Open Access Journals (Sweden)

    Abd El-Latif Hesham

    2014-01-01

    Full Text Available Polycyclic aromatic hydrocarbons (PAHs are serious pollutants and health hazards. In this study, 15 PAHs-degrading bacteria were isolated from Egyptian oily soil. Among them, one Gram-negative strain (ASU-06 was selected and biodegradation ability and initial catabolic genes of petroleum compounds were investigated. Comparison of 16S rRNA gene sequence of strain ASU-06 to published sequences in GenBank database as well as phylogenetic analysis identified ASU-06 as Sphingomonas koreensis. Strain ASU-06 degraded 100, 99, 98, and 92.7% of 100 mg/L naphthalene, phenanthrene, anthracene, and pyrene within 15 days, respectively. When these PAHs present in a mixed form, the enhancement phenomenon appeared, particularly in the degradation of pyrene, whereas the degradation rate was 98.6% within the period. This is the first report showing the degradation of different PAHs by this species. PCR experiments with specific primers for catabolic genes alkB, alkB1, nahAc, C12O, and C23O suggested that ASU-06 might possess genes for aliphatic and PAHs degradation, while PAH-RHDαGP gene was not detected. Production of biosurfactants and increasing cell-surface hydrophobicity were investigated. GC/MS analysis of intermediate metabolites of studied PAHs concluded that this strain utilized these compounds via two main pathways, and phthalate was the major constant product that appeared in each day of the degradation period.

  20. Combined use of alkane-degrading and plant growth-promoting bacteria enhanced phytoremediation of diesel contaminated soil.

    Science.gov (United States)

    Tara, Nain; Afzal, Muhammad; Ansari, Tariq M; Tahseen, Razia; Iqbal, Samina; Khan, Qaiser M

    2014-01-01

    Inoculation of plants with pollutant-degrading and plant growth-promoting microorganisms is a simple strategy to enhance phytoremediation activity. The objective of this study was to determine the effect of inoculation of different bacterial strains, possessing alkane-degradation and 1-amino-cyclopropane-1 -carboxylic acid (ACC) deaminase activity, on plant growth and phytoremediation activity. Carpet grass (Axonopus affinis) was planted in soil spiked with diesel (1% w/w) for 90 days and inoculated with different bacterial strains, Pseudomonas sp. ITRH25, Pantoea sp. BTRH79 and Burkholderia sp. PsJN, individually and in combination. Generally, bacterial application increased total numbers of culturable hydrocarbon-degrading bacteria in the rhizosphere ofcarpet grass, plant biomass production, hydrocarbon degradation and reduced genotoxicity. Bacterial strains possessing different beneficial traits affect plant growth and phytoremediation activity in different ways. Maximum bacterial population, plant biomass production and hydrocarbon degradation were achieved when carpet grass was inoculated with a consortium of three strains. Enhanced plant biomass production and hydrocarbon degradation were associated with increased numbers of culturable hydrocarbon-degrading bacteria in the rhizosphere of carpet grass. The present study revealed that the combined use of different bacterial strains, exhibiting different beneficial traits, is a highly effective strategy to improve plant growth and phytoremediation activity.

  1. Isolation and Identification of Carcinogen Acenaphthene-Degrading Endemic Bacteria from Crude Oil Contaminated Soils around Abadan Refinery

    Directory of Open Access Journals (Sweden)

    Farshid Kafilzadeh

    2012-12-01

    Full Text Available Background and Objective: PAHs are non-polar organic compounds consisting of two or more fused benzene multi-rings. Among these compounds, acenaphthene is a multi-ring hydrocarbon that occurs abundantly in nature. Use of microorganisms to clean the contaminations of soil can be cheap and effective. The most important acenaphthene-degrading bacteria are pseudomonas, micrococcus, and Bacillus. The goal of this study was to isolate and identify the bacteria which degrade acenaphthene in soils around Abadan Refinery and to investigate the relation between the levels of environmental pollution with acenaphthene. Materials and Methods: Soil samples were collected from three areas around Abadan Refinery. The number of the bacteria was counted on the nutrient agar culture with and without acenaphthene. Isolation of the bacteria was done by culturing the samples on acenaphthene broth with a mineral-salt medium, and on an acenaphthene agar medium. Then, the bacteria were identified via biochemical diagnostic tests. Results: The logarithm average of the bacteria was 4.786 ± 0.073 at a medium with acenaphthene, which was 6.671 ± 0.073 less than that of the control medium. The maximum number of degrading bacteria was 7.089 ± 0.089 at Station C, and the minimum number of the degrading bacteria was 4.485 ± 0.089 at Station B. In this study, Bacillus sp, Micrococcus Luteus, Corynebacterium sp, Staphylococcus epidermidis, and Pseudomonas sp bacteria were isolated and identified in terms of frequency, respectively. Conclusion: The results of this study showed that the soil around Abadan Refinery contained a great number of acenaphthene degrading bacteria, especially Bacillus and Micrococcus.

  2. Stereoselective Degradation and Molecular Ecological Mechanism of Chiral Pesticides Beta-Cypermethrin in Soils with Different pH Values.

    Science.gov (United States)

    Yang, Zhong-Hua; Ji, Guo-Dong

    2015-12-15

    For decades, pesticides have been widely used for agricultural activities around the world, and the environmental problems caused by these compounds have raised widespread concern. However, the different enantioselective behaviors of chiral pesticide enantiomers are often ignored. Here, the selective degradation patterns and mechanisms of chiral pesticide enantiomers were successfully investigated for the first time in the soils of three cultivation areas with different pH values. Beta-cypermethrin was chosen as the target analyte. We found that the degradation rates of the four isomers of beta-cypermethrin were different. We used stepwise regression equations between degradation rates and functional genes to quantitatively study their relationships. Quantitative response analysis revealed that different isomers have different equations even under identical conditions. The results of path analysis showed that a single functional gene can make different direct and indirect contributions to the degradation of different isomers. Finally, the high-throughput technology was used to analysis the genome of the three tested soils and then compared the main microbial communities in them. We have successfully devised a method to investigate the molecular biological mechanisms of the selective degradation behavior of chiral compounds, thus enabling us to better understand these mechanisms.

  3. A study on residues and degradation of 14C-phoxim in spring wheat plants and soil

    International Nuclear Information System (INIS)

    Zhu Shuxiu; Yin Lishang

    1988-01-01

    A potting experiment on residues and degradation of 14 C-phoxim in spring wheat plants and soil was conducted in 1984∼1986. Seed dressing or soil mixing and spraying with 14 C-phoxim had been done at sowing and seedling stage respectively. The radioactivities of samples were detected on the low background (3cpm) GM or Backman LS 7800 liquid scintillation counter. The transmission, dissociation and residues of 14 C-phoxim in spring wheat plants and soil were investigated. The amount of 14 C-phoxim residues in the grains was determined. The dissipation of the residues of 14 C-phoxim after the harvesting of spring wheat plants were discussed; the residues could be decomposed into 14 CO 2 , dissolved in evaporated liquid and throwed into air, or stored in soil

  4. Soil Degradation-Induced Decline in Productivity of Sub-Saharan African Soils: The Prospects of Looking Downwards the Lowlands with the Sawah Ecotechnology

    Directory of Open Access Journals (Sweden)

    Sunday E. Obalum

    2012-01-01

    Full Text Available The paper provides an insight into the problem of land degradation in Sub-Saharan Africa, with emphasis on soil erosion and its effect on soil quality and productivity, and proposes a lowland-based rice-production technology for coping with the situation. Crop yields are, in addition to the degree of past and current erosion, determined by a number of interacting variables. This, coupled with the generally weak database on erosion-induced losses in crop yield in spite of the region’s high vulnerability to erosion, makes it difficult to attain a reliable inference on the cause-effect relationship between soil loss and productivity. Available data suggest, however, that the region is at risk of not meeting up with the challenges of agriculture in this 21st century. Based on the few studies reviewed, methodology appears to have an overwhelming influence on the erosion-productivity response, whereas issues bordering on physical environment and soil affect the shape of the response curve. We argue that the sawah ecotechnology has the potential of countering the negative agronomic and environmental impacts of land degradation in Sub-Saharan Africa. This is a farmer-oriented, low-cost system of managing soil, water, and nutrient resources for enhancing lowland rice productivity and realizing Green Revolution in the region.

  5. Soil Degradation-Induced Decline in Productivity of Sub-Saharan African Soils: The Prospects of Looking Downwards the Lowlands with the Sawah Ecotechnology

    OpenAIRE

    Obalum, Sunday E.; Buri, Mohammed M.; Nwite, John C.; Hermansah; Watanabe, Yoshinori; Igwe, Charles A.; Wakatsuki, Toshiyuki

    2012-01-01

    The paper provides an insight into the problem of land degradation in Sub-Saharan Africa, with emphasis on soil erosion and its effect on soil quality and productivity, and proposes a lowland-based rice-production technology for coping with the situation. Crop yields are, in addition to the degree of past and current erosion, determined by a number of interacting variables. This, coupled with the generally weak database on erosion-induced losses in crop yield in spite of the region’s high vul...

  6. Assessment of Soil Degradation by Erosion Based on Analysis of Soil Properties Using Aerial Hyperspectral Images and Ancillary Data, Czech Republic

    Directory of Open Access Journals (Sweden)

    Daniel Žížala

    2017-01-01

    Full Text Available The assessment of the soil redistribution and real long-term soil degradation due to erosion on agriculture land is still insufficient in spite of being essential for soil conservation policy. Imaging spectroscopy has been recognized as a suitable tool for soil erosion assessment in recent years. In our study, we bring an approach for assessment of soil degradation by erosion by means of determining soil erosion classes representing soils differently influenced by erosion impact. The adopted methods include extensive field sampling, laboratory analysis, predictive modelling of selected soil surface properties using aerial hyperspectral data and the digital elevation model and fuzzy classification. Different multivariate regression techniques (Partial Least Square, Support Vector Machine, Random forest and Artificial neural network were applied in the predictive modelling of soil properties. The properties with satisfying performance (R2 > 0.5 were used as input data in erosion classes determination by fuzzy C-means classification method. The study was performed at four study sites about 1 km2 large representing the most extensive soil units of the agricultural land in the Czech Republic (Chernozems and Luvisols on loess and Cambisols and Stagnosols on crystalline rocks. The influence of site-specific conditions on prediction of soil properties and classification of erosion classes was assessed. The prediction accuracy (R2 of the best performing models predicting the soil properties varies in range 0.8–0.91 for soil organic carbon content, 0.21–0.67 for sand content, 0.4–0.92 for silt content, 0.38–0.89 for clay content, 0.73–089 for Feox, 0.59–0.78 for Fed and 0.82 for CaCO3. The performance and suitability of different properties for erosion classes’ classification are highly variable at the study sites. Soil organic carbon was the most frequently used as the erosion classes’ predictor, while the textural classes showed lower

  7. Degradation of Red Ferralitic (Rhodic Ferralsol soils grown with tobacco (Nicotiana tabacum L. in the Artemisa province, Cuba

    Directory of Open Access Journals (Sweden)

    Óscar Ricote Jorge

    2017-01-01

    Full Text Available “Partido” is a tobacco growing area which extends for some 3000 hectares among the municipalities of San Antonio de los Baños, Güira de Melena and Alquízar in the Cuban province of Artemisa. Predominant soils are Red Ferralitic (Rhodic Ferralsol according to the World Reference Base, with a strong tendency to alkalinization which has a negative impact on the quality of their agricultural use. The aim of this research was to quantify the geographical extension of the degradation process, to determine how deep it happens along the soil profile and to establish its possible relationship with the quality and quantity of water applied to tobacco fields. The chemical, physical and mineralogical analyses of two test pits carried out in the area were compared: one profile without agricultural use with one characteristic soil profile under continuous production. After being subjected to the same irrigation regime in laboratory conditions, it was concluded that degradation affects to 89.56% of the area of tobacco soils evaluated. This phenomenon occurs very deeply along the soil profile and happens downwards, causing the accumulation of calcium and the loss of sodium and potassium in the superficial horizon, what is shown in pH rises. Such processes, associated to irrigation water and to insufficient rainfall regime which are traditional in the territory, have led to changes in the mineralogical composition of these tobacco soils appearance of minerals such as gibbsite which was absent in uncultivated Red Ferralitic soils, which involve the modification of soil classification at gender level.

  8. Interaction between aeschynomene spp and rhizobiaceae strains from soils degraded by alluvium mining process

    International Nuclear Information System (INIS)

    Orozco, F H; Medina M; Restrepo, L R; Cuartas, A M

    2001-01-01

    The interaction between isolated bacterial from indigenous legumes of degraded soils by alluvium mining process and different species of aeschynomene was evaluated under nursery conditions. An essay was made in material from mining zone and the experimental design was random blocks with 21 treatment and four repetitions. The results were measured by dry weight of biomass and nodules, foliar nitrogen contains and percentage of occupation in the nodules by strains evaluated. In general terms, evaluated plants showed high specificity by the treatments. Specie of A. Americana was the best, because of its precocity and high production of biomass and nitrogen. Both types of A. falcata responded well to an isolated of rhizobium, while A. americana and A. villosa were better with strains of bradyrhizobium. Nitrogen concentration in all species of aeschynomene was very different. A. villosa presented higher concentration (28-34 9 kg - 1). We found a significant correlation for dry weight between nodules and biomass (r 0.82-0.93 P<0.001). We also found important difference among size of nodules of the species evaluated; it was independent of inoculated strain

  9. Natural and bioremediated selective degradation of polycyclic aromatic alkyl isomers in oil-contaminated soils

    International Nuclear Information System (INIS)

    Sauer, T.C.; McCarthy, K.; Uhler, A.; Porta, A.

    1995-01-01

    In studies where 2- to 6-ring polycyclic aromatic hydrocarbons (PAHs) are determined as part of characterizing released oil constituents in environmental samples, the changes in composition of PAHs from weathering (e.g., evaporation, dissolution) and biodegradation are most often represented by PAH alkyl homologue distributions. Concentrations of PAH alkyl groups are the sum of individual PAH isomers of similar carbon number; such as for C2-naphthalenes, the C2 alkyl group consists of dimethyl and ethyl substitutions on the parent naphthalene. In weathering and degradation studies, the changes in relative concentration of the individual isomers within an alkyl group are rarely reported. In a field study of oiled soils, the authors looked at the selective losses, for a period of a year, of individual PAH alkyl isomers that occur both naturally by weathering processes and through the use of bioremediation technology. Results showed that decreases in alkyl group concentrations were not always represented by similar losses of each isomer in the alkyl group, but were often due to the preferential or selective loss of certain isomers in the group

  10. Oil characterisation: assessment of composition, risks, degradation and remediation potential of total petroleum hydrocarbons in soil

    International Nuclear Information System (INIS)

    Lookman, R.; Vanermen, G.; Van De Weghe, H.; Gemoets, J.; Van der Sterren, G.; Alphenaar, A.

    2005-01-01

    Several methods are available for the characterization of petroleum hydrocarbons. The TPHCWG (Total Petroleum Hydrocarbon Criteria Working Group) developed a method based on a silica column separation of aromatics and aliphatics and a GC-FID subdivision into equivalent-carbon fractions (EC) ('TPH-method'). This method was mainly developed for assessing human risks of oil compounds. Within NOBIS (Dutch Research program Biological In-situ Remediation), another method was developed based upon an equilibrium-experiment of the oil-polluted soil with water (column recirculation), which was further developed by TTE ('TTE-method'). This method uses measured water solubilities of individual oil components and GC-retention times yielding a subdivision of the hydrocarbons into compound classes that are relevant for assessing the remediation potential of the specific oil pollution. In this paper we present results of a research project in which we developed a new method, the 'OK-method' that combines these two procedures and allows a complete characterisation of the oil in terms of composition, (human) risks, volatility, solubility, plume behaviour (migration velocities of the soluble components) and aerobic degradation potential. (authors)

  11. Oil characterisation: assessment of composition, risks, degradation and remediation potential of total petroleum hydrocarbons in soil

    Energy Technology Data Exchange (ETDEWEB)

    Lookman, R.; Vanermen, G.; Van De Weghe, H.; Gemoets, J. [Vito, Mol (Belgium); Van der Sterren, G.; Alphenaar, A. [TTE, Deventer (Netherlands)

    2005-07-01

    Several methods are available for the characterization of petroleum hydrocarbons. The TPHCWG (Total Petroleum Hydrocarbon Criteria Working Group) developed a method based on a silica column separation of aromatics and aliphatics and a GC-FID subdivision into equivalent-carbon fractions (EC) ('TPH-method'). This method was mainly developed for assessing human risks of oil compounds. Within NOBIS (Dutch Research program Biological In-situ Remediation), another method was developed based upon an equilibrium-experiment of the oil-polluted soil with water (column recirculation), which was further developed by TTE ('TTE-method'). This method uses measured water solubilities of individual oil components and GC-retention times yielding a subdivision of the hydrocarbons into compound classes that are relevant for assessing the remediation potential of the specific oil pollution. In this paper we present results of a research project in which we developed a new method, the 'OK-method' that combines these two procedures and allows a complete characterisation of the oil in terms of composition, (human) risks, volatility, solubility, plume behaviour (migration velocities of the soluble components) and aerobic degradation potential. (authors)

  12. Application of hyper spectral imagings techniques to study soil degradation in arid environments. (Los Monegros, Spain); Aplicacion de tecnicas hiperespectrales de imagen al estudio de la degradacion de suelos en ambientes aridos (Los Monegros, Espana)

    Energy Technology Data Exchange (ETDEWEB)

    Gumuzzio Such, A.; Palacios Orueta, A.; Schmid, T.; Dominguez, J. A.; Gumuzzio, J.

    2009-07-01

    The aim of this work is to identify characteristics associated to soils affected by degradation within and arid area of Spain using optical hyper spectral airborne data. The methodological approach was developed to determine the spatial distribution of selected soils affected by degradation processes. A satisfactory spatial distribution is obtained where the corresponding soil characteristics are closely related to degradation processes. (Author) 2 refs.

  13. Evaluation of the the temperature and humidity effect in the Atrazine degradation in the Saldana soil (Tolima) for liquid chromatography of high resolution

    International Nuclear Information System (INIS)

    Acevedo Buitrago Baudilio; Guerrero Jairo A; Lozano Amanda; Fuentes Cilia

    2000-01-01

    In this study was designed an experiment under laboratory conditions with temperature and soil moisture controlled. The effect of these two factors was evaluated in atrazine d