The Experts below are selected from a list of 39942 Experts worldwide ranked by ideXlab platform
C Garcia - One of the best experts on this subject based on the ideXlab platform.
-
effects of atrazine on Microbial Activity in semiarid Soil
Applied Soil Ecology, 2007Co-Authors: Jose L Moreno, Asuncion Aliaga, Simon Navarro, T Hernandez, C GarciaAbstract:Abstract The effect of an atrazine formulation on Microbial biomass, Microbial respiration, ATP content and dehydrogenase and urease Activity in a semiarid Soil and the influence of time on the response of Soil Microbial Activity to the herbicide treatment were assessed. The atrazine formulation was added to Soil as aqueous solutions of different concentrations of active ingredient to obtain a range of concentrations in the Soil from 0.2 to 1000 mg kg−1. Microcosms of Soil with the different herbicide concentrations and untreated control Soil were incubated for 6 h, 16 and 45 days. In general, an increase in the measured microbiological and biochemical parameters with atrazine concentration in Soil was observed. The increase in Microbial Activity with atrazine pollution was noticeable after lengthy incubation.
-
bioremediation of oil refinery sludge by landfarming in semiarid conditions influence on Soil Microbial Activity
Environmental Research, 2005Co-Authors: J A Marin, Teresa Hernández, C GarciaAbstract:Bioremediation of a refinery sludge containing hydrocarbons in a semi-arid climate using landfarming techniques is described. The objective of this study was to assess the ability of this technique to reduce the total hydrocarbon content added to the Soil with the refinery sludge in semiarid climate (low rain and high temperature). In addition, we have evaluated the effect of this technique on the Microbial Activity of the Soil involved. For this, biological parameters (carbon fractions, Microbial biomass carbon, basal respiration and ATP) and biochemical parameters(different enzymatic activities) were determined. The results showed that 80% of the hydrocarbons were eliminated in eleven months, half of this reduction taking place during the first three months. The labile carbon fractions, MBC, basal respiration and ATP of the Soils submitted to landfarming showed higher values than the control Soil during the first months of the process, although these values fell down by the end of the experimental period as the hydrocarbons were degraded by mineralisation. All the enzymatic activities studied: oxidoreductases such as dehydrogenase Activity, and hydrolases of C(beta-glucosidase Activity) and N Cycle (urease and protease) showed higher values in the Soils amended with the refinery sludge than in the control. As in the case of the previous parameters, these value fell down as the bioremediation of the hydrocarbons progressed, many of them reaching levels similar to those of the control Soil after eleven months.
-
Soil Microbial Activity after restoration of a semiarid Soil by organic amendments
Soil Biology & Biochemistry, 2003Co-Authors: M T Hernandez, C GarciaAbstract:Unsuitable agricultural practices together with adverse environmental conditions have led to degradation of Soil in many Mediterranean areas. One method for recovering degraded Soils in semiarid regions, is to add organic matter in order to improve Soil characteristics, thereby enhancing biogeochemical nutrient cycles. In this study, the effect of adding the organic fraction of urban wastes (both fresh and composted) on different carbon fractions and on microbiological and biochemical parameters (Microbial biomass C, basal respiration and different enzymatic activities) of a degraded Soil of SE Spain has been assessed in a 2 year experiment. Three months after the addition of the organic material, spontaneous plant growth occurred and the plant cover lasted until the end of the experiment. Organic Soil amendment initially increased the levels of Soil organic matter, Microbial biomass, basal respiration and some enzyme activities related to the C and N cycles These values decreased but always remained higher than those of the unamended Soil. The results indicate that the addition of urban organic waste is beneficial for recovering degraded Soils, the Microbial Activity of which clearly increases with amendment. The incorporation of compost seemed to have a greater positive effect on the Soil characteristics studied than the incorporation of fresh organic matter.
-
toxicity of cadmium to Soil Microbial Activity effect of sewage sludge addition to Soil on the ecological dose
Applied Soil Ecology, 2002Co-Authors: Jose L Moreno, Teresa Hernández, Aurelia Perez, C GarciaAbstract:Cadmium has a toxic effect on Soil Microbial Activity which plays an important role in nutrient cycling and, therefore, in maintaining Soil fertility. In addition, the mobility of this heavy metal in Soil is affected by the addition of urban wastes such as sewage sludge. This study was conducted to determine the effect of sewage sludge amendment of a semiarid Soil, previously polluted with Cd, on the toxic effect of this heavy metal on Soil Microbial biomass and its Activity. Dehydrogenase Activity, ATP content, Microbial Soil respiration and Microbial biomass carbon were used as bioindicators of the toxic effect of Cd. The inhibition of Microbial Activity and biomass by different Cd concentrations ranging from 0 to 8000 mg Cd kg −1 Soil was described by three mathematical models in order to calculate three ecological doses of Cd: ED50 ,E D 10, and ED5 .I n general, higher ED values were calculated for the sewage sludge amended Soil than for unamended Soil. Thus the Cd toxicity to Microbial Activity of the sewage sludge amended Soil can be considered lower than that of the unamended Soil. Moreover, increased ED values with time after Soil Cd contamination were observed. © 2002 Elsevier Science B.V. All rights reserved.
Teresa Hernández - One of the best experts on this subject based on the ideXlab platform.
-
impact of compost application during 5 years on crop production Soil Microbial Activity carbon fraction and humification process
Communications in Soil Science and Plant Analysis, 2016Co-Authors: Keiji Jindo, Teresa Hernández, Carmen Chocano, Melgares J De Aguilar, D Gonzalez, Carlos J GarciaAbstract:ABSTRACTCompost amendment is considered as a practical tool to increase the Soil organic matter (SOM), which contributes to agricultural sustainability. The objective of the present work was to evaluate the impacts of organic Soil management over 5 years on orchard prune production (Prunus salicina), Microbial Activity, Soil carbon (C) fraction, and stabilization degrees of Soil humification. Plot experiment was designed with two different Soil managements: i) for minimizing anthropogenic disturbances, only mulching of orchard residues derived from prune tree plot area was applied to Soil surface (S + V); and ii) the amendment of composted manure was annually practiced in addition to the utilization of orchard residues inside the plot area (S + V + C). After 5 years, the Soil with the continuous compost application (S + V + C) showed higher productivity of Prunus salicina (21.4%), greater fruit diameter (7.8%), and heavier fruit weight (22.4%) than the Soil without compost application (S + V). Nutrient co...
-
Response of Soil Microbial Activity and Biodiversity in Soils Polluted with Different Concentrations of Cypermethrin Insecticide
Archives of Environmental Contamination and Toxicology, 2015Co-Authors: Manuel Tejada, Teresa Hernández, Carlos Garcia, Isidoro GómezAbstract:We performed a laboratory study into the effect of cypermethrin insecticide applied to different concentrations on biological properties in two Soils [Typic Xerofluvent (Soil A) and Xerollic Calciorthid (Soil B)]. Two kg of each Soil were polluted with cypermethrin at a rate of 60, 300, 600, and 1,200 g ha^−1 (C1, C2, C3, and C4 treatments). A nonpolluted Soil was used as a control (C0 treatment). For all treatments and each experimental Soil, Soil dehydrogenase, urease, β-glucosidase, phosphatase, and arylsulphatase activities and Soil Microbial community were analysed by phospholipid fatty acids, which were measured at six incubation times (3, 7, 15, 30, 60, and 90 days). The behavior of the enzymatic activities and Microbial population were dependent on the dose of insecticide applied to the Soil. Compared with the C0 treatment, in Soil A, the maximum inhibition of the enzymatic activities was at 15, 30, 45, and 90 days for the C1, C2, C3, and C4 treatments, respectively. However, in Soil B, the maximum inhibition occurred at 7, 15, 30, and 45 days for the C1, C2, C3, and C4 treatments, respectively. These results suggest that the cypermethrin insecticide caused a negative effect on Soil enzymatic activities and Microbial diversity. This negative impact was greater when a greater dose of insecticide was used; this impact was also greater in Soil with lower organic matter content. For both Soils, and from these respective days onward, the enzymatic activities and Microbial populations progressively increased by the end of the experimental period. This is possibly due to the fact that the insecticide or its breakdown products and killed Microbial cells, subsequently killed by the insecticide, are being used as a source of energy or as a carbon source for the surviving microorganisms for cell proliferation.
-
Soil organic carbon buffers heavy metal contamination on semiarid Soils effects of different metal threshold levels on Soil Microbial Activity
European Journal of Soil Biology, 2009Co-Authors: J L Moreno, Felipe Bastida, Teresa Hernández, Margarita Ros, Carlos GarciaAbstract:Abstract Traditionally, three threshold levels have been accepted for heavy metal concentrations in agricultural Soils, depending on Soil pH. The aim of this work was to ascertain how the three threshold values proposed for Cd (3, 6.5, and 12.5 mg kg−1) and Zn (300, 650, and 1300 mg kg−1) really affect Soil Microbial Activity. Two Soils, a scrubland Soil and a forest Soil, differing widely in their organic C content, were used in this study. Despite the different Soil characteristics, the fractions of Cd and Zn extracted with a solution of diethylenetriaminepentaacetic acid (DTPA) showed little difference between Soils. Parameters, such as Microbial biomass C (Cmic), Soil basal respiration (BR), adenosine triphosphate (ATP) content, dehydrogenase Activity (DHA), urease Activity (UA), alkaline phosphatase Activity (APA), and β-glucosidase (β-GA), were less affected by heavy metals in the forest Soil than in the scrubland Soil. In general, the simultaneous addition of both metals had a synergistic effect on Microbial Activity, and this treatment produced a significant decrease of Microbial Activity of both Soils with respect to control. The highest level (L3) of Cd, Zn and Cd + Zn treatments produced significant decrease of Microbial and biochemical parameters in both Soils.
-
bioremediation of oil refinery sludge by landfarming in semiarid conditions influence on Soil Microbial Activity
Environmental Research, 2005Co-Authors: J A Marin, Teresa Hernández, Carlos GarciaAbstract:Bioremediation of a refinery sludge containing hydrocarbons in a semi-arid climate using landfarming techniques is described. The objective of this study was to assess the ability of this technique to reduce the total hydrocarbon content added to the Soil with the refinery sludge in semiarid climate (low rain and high temperature). In addition, we have evaluted the effect of this techique on the Microbial Activity of the Soil involved. For this, biological parameters (carbon fractions, Microbial bilmass carbon, basal respiration and ATP) and biochemical parameters(different enzymatic activities) were determined. The results showed that 80% of the hydrocarbons were eiminated in eleven months, half of this reduction taking place during the first three months. The labile carbon fractions, MBC, basal respiration and ATP of the Soils submitted to landfarming showed higher values than the control Soil during the first months of the process, although these values fell down by the end of the experimental period as the hydrocarbons were degraded by mineralisation. All the enzymatic activities studied: oxydoreductases such as dehydrogenase Activity, and hydrolases of C(β-glucosidase Activity) and N Cycle (urease and protease) showed higher values in the Soils amended with the refinery sludge than in the control. As in the case of the previous parameters, these value fell down as the bioremediation of the hydrocarbons progressed, many of them reaching levels similar to those of the control Soil after eleven months.
-
bioremediation of oil refinery sludge by landfarming in semiarid conditions influence on Soil Microbial Activity
Environmental Research, 2005Co-Authors: J A Marin, Teresa Hernández, C GarciaAbstract:Bioremediation of a refinery sludge containing hydrocarbons in a semi-arid climate using landfarming techniques is described. The objective of this study was to assess the ability of this technique to reduce the total hydrocarbon content added to the Soil with the refinery sludge in semiarid climate (low rain and high temperature). In addition, we have evaluated the effect of this technique on the Microbial Activity of the Soil involved. For this, biological parameters (carbon fractions, Microbial biomass carbon, basal respiration and ATP) and biochemical parameters(different enzymatic activities) were determined. The results showed that 80% of the hydrocarbons were eliminated in eleven months, half of this reduction taking place during the first three months. The labile carbon fractions, MBC, basal respiration and ATP of the Soils submitted to landfarming showed higher values than the control Soil during the first months of the process, although these values fell down by the end of the experimental period as the hydrocarbons were degraded by mineralisation. All the enzymatic activities studied: oxidoreductases such as dehydrogenase Activity, and hydrolases of C(beta-glucosidase Activity) and N Cycle (urease and protease) showed higher values in the Soils amended with the refinery sludge than in the control. As in the case of the previous parameters, these value fell down as the bioremediation of the hydrocarbons progressed, many of them reaching levels similar to those of the control Soil after eleven months.
Irisconstanze Beck - One of the best experts on this subject based on the ideXlab platform.
-
effects of sulfonamide and tetracycline antibiotics on Soil Microbial Activity and Microbial biomass
Chemosphere, 2005Co-Authors: Soren Thielebruhn, Irisconstanze BeckAbstract:Increasingly often Soil residual concentrations of pharmaceutical antibiotics are detected, while their ecotoxic relevance is scarcely known. Thus, dose related effects of two antibiotics, sulfapyridine and oxytetracycline, on microorganisms of two different topSoils were investigated. The fumigation-extracted Microbial C (EC) and ergosterol were determined to indicate Soil Microbial and fungal biomass, respectively. Microbial Activity was tested as basal respiration (BR), dehydrogenase Activity (DHA), substrate-induced respiration (SIR), and Fe(III) reduction. The BR and DHA were uninfluenced even at antibiotic concentrations of 1000 l gg � 1 . This revealed that an activation of Microbial growth through nutrient substrate addition is required to test possible effects of the bacteriostatic antibiotics. In addition, the effects of both antibiotics were time dependent, showing that short-term tests were not suitable. Clear dose–response relations were determined with SIR when the short-term incubation of 4 h was extended into the growth phase of the microorganisms (24 and 48 h). The Fe(III) reduction test, with a 7-d incubation, was also found to be suitable for toxicity testing of antibiotics in Soils. Effective doses inhibiting the Microbial Activity by 10% (ED10) ranged from total antibiotic concentrations of 0.003–7.35 l gg � 1 , depending on the antibiotic compound and its Soil adsorption. Effective solution concentrations (EC10), calculated from distribution coefficients, ranged from 0.2 to 160 ng g � 1 . The antibiotics significantly (p < 0.05) reduced numbers of Soil bacteria, resulting in dose related shifts in the fungal:bacterial ratio, which increased during 14 d, as determined from analysis of ergosterol and EC. It was concluded that pharmaceutical antibiotics can exert a temporary selective pressure on Soil microorganisms even at environmentally relevant concentrations. � 2005 Elsevier Ltd. All rights reserved.
-
effects of sulfonamide and tetracycline antibiotics on Soil Microbial Activity and Microbial biomass
Chemosphere, 2005Co-Authors: Soren Thielebruhn, Irisconstanze BeckAbstract:Abstract Increasingly often Soil residual concentrations of pharmaceutical antibiotics are detected, while their ecotoxic relevance is scarcely known. Thus, dose related effects of two antibiotics, sulfapyridine and oxytetracycline, on microorganisms of two different topSoils were investigated. The fumigation-extracted Microbial C (EC) and ergosterol were determined to indicate Soil Microbial and fungal biomass, respectively. Microbial Activity was tested as basal respiration (BR), dehydrogenase Activity (DHA), substrate-induced respiration (SIR), and Fe(III) reduction. The BR and DHA were uninfluenced even at antibiotic concentrations of 1000 μg g−1. This revealed that an activation of Microbial growth through nutrient substrate addition is required to test possible effects of the bacteriostatic antibiotics. In addition, the effects of both antibiotics were time dependent, showing that short-term tests were not suitable. Clear dose–response relations were determined with SIR when the short-term incubation of 4 h was extended into the growth phase of the microorganisms (24 and 48 h). The Fe(III) reduction test, with a 7-d incubation, was also found to be suitable for toxicity testing of antibiotics in Soils. Effective doses inhibiting the Microbial Activity by 10% (ED10) ranged from total antibiotic concentrations of 0.003–7.35 μg g−1, depending on the antibiotic compound and its Soil adsorption. Effective solution concentrations (EC10), calculated from distribution coefficients, ranged from 0.2 to 160 ng g−1. The antibiotics significantly (p
-
effects of sulfonamide and tetracycline antibiotics on Soil Microbial Activity and Microbial biomass
Chemosphere, 2005Co-Authors: Soren Thielebruhn, Irisconstanze BeckAbstract:Increasingly often Soil residual concentrations of pharmaceutical antibiotics are detected, while their ecotoxic relevance is scarcely known. Thus, dose related effects of two antibiotics, sulfapyridine and oxytetracycline, on microorganisms of two different topSoils were investigated. The fumigation-extracted Microbial C (E(C)) and ergosterol were determined to indicate Soil Microbial and fungal biomass, respectively. Microbial Activity was tested as basal respiration (BR), dehydrogenase Activity (DHA), substrate-induced respiration (SIR), and Fe(III) reduction. The BR and DHA were uninfluenced even at antibiotic concentrations of 1000 microg g(-1). This revealed that an activation of Microbial growth through nutrient substrate addition is required to test possible effects of the bacteriostatic antibiotics. In addition, the effects of both antibiotics were time dependent, showing that short-term tests were not suitable. Clear dose-response relations were determined with SIR when the short-term incubation of 4h was extended into the growth phase of the microorganisms (24 and 48 h). The Fe(III) reduction test, with a 7-d incubation, was also found to be suitable for toxicity testing of antibiotics in Soils. Effective doses inhibiting the Microbial Activity by 10% (ED(10)) ranged from total antibiotic concentrations of 0.003-7.35 microg g(-1), depending on the antibiotic compound and its Soil adsorption. Effective solution concentrations (EC(10)), calculated from distribution coefficients, ranged from 0.2 to 160 ng g(-1). The antibiotics significantly (p<0.05) reduced numbers of Soil bacteria, resulting in dose related shifts in the fungal:bacterial ratio, which increased during 14 d, as determined from analysis of ergosterol and E(C). It was concluded that pharmaceutical antibiotics can exert a temporary selective pressure on Soil microorganisms even at environmentally relevant concentrations.
Manyun Zhang - One of the best experts on this subject based on the ideXlab platform.
-
cumulative effects of repeated chlorothalonil application on Soil Microbial Activity and community in contrasting Soils
Journal of Soils and Sediments, 2016Co-Authors: Manyun Zhang, Ying Teng, Jun Wang, Peter Christie, Yongming LuoAbstract:Purpose Chlorothalonil (CTN) has received much attention due to its broad-spectrum antifungal function and repeated applications in agriculture production practice. An incubation experiment was conducted to study the accumulating effects of CTN repeated application on Soil Microbial activities, biomass, and community and to contrast the discrepancy of effects in contrasting Soils.
-
cumulative effects of repeated chlorothalonil application on Soil Microbial Activity and community in contrasting Soils
Journal of Soils and Sediments, 2016Co-Authors: Manyun Zhang, Ying Teng, Jun Wang, Peter Christie, Yongming LuoAbstract:Chlorothalonil (CTN) has received much attention due to its broad-spectrum antifungal function and repeated applications in agriculture production practice. An incubation experiment was conducted to study the accumulating effects of CTN repeated application on Soil Microbial activities, biomass, and community and to contrast the discrepancy of effects in contrasting Soils. Different dosage CTN (5 mg kg−1, T1, and 25 mg kg−1, T5) was applied into two contrasting Soils at 7-day intervals. Soil samples were taken 7 days after each application to assess Soil enzyme activities and gene abundances. At the end of incubation, the Soil samples were also taken to analyze Microbial communities in the two test Soils. Soil fluorescein diacetate hydrolysis (FDAH) and urease activities were inhibited by CTN repeated applications. After 28 days of incubation, bacterial 16S rRNA gene abundances in T1 and T5 treatments were significantly lower than those in the CK treatments (46.4 and 36.6 % of the CK treatment in acidic red Soil, 53.6 and 37.9 % of the CK treatment in paddy Soil). Archaeal 16S rRNA gene abundances of T1 and T5 treatments were observed the similar trends (56.1 and 40.8 % of the CK treatment in acidic red Soil, 45.6 and 43.7 % of the CK treatment in paddy Soil). Repeated applications at 25 mg kg−1 exerted significantly negative effects on the Shannon-Weaver, Simpson and McIntosh indices. Microbial Activity, biomass, and functional diversity were significantly inhibited by repeated CTN application at the higher dosage (25 mg kg−1), but the inhibitory effects by the application at the recommended dosage (5 mg kg−1) were erratic. More emphasis needs to be placed on the Soil type and cumulative toxicity from repeated CTN application when assessing environmental risk.
Carlos Garcia - One of the best experts on this subject based on the ideXlab platform.
-
Response of Soil Microbial Activity and Biodiversity in Soils Polluted with Different Concentrations of Cypermethrin Insecticide
Archives of Environmental Contamination and Toxicology, 2015Co-Authors: Manuel Tejada, Teresa Hernández, Carlos Garcia, Isidoro GómezAbstract:We performed a laboratory study into the effect of cypermethrin insecticide applied to different concentrations on biological properties in two Soils [Typic Xerofluvent (Soil A) and Xerollic Calciorthid (Soil B)]. Two kg of each Soil were polluted with cypermethrin at a rate of 60, 300, 600, and 1,200 g ha^−1 (C1, C2, C3, and C4 treatments). A nonpolluted Soil was used as a control (C0 treatment). For all treatments and each experimental Soil, Soil dehydrogenase, urease, β-glucosidase, phosphatase, and arylsulphatase activities and Soil Microbial community were analysed by phospholipid fatty acids, which were measured at six incubation times (3, 7, 15, 30, 60, and 90 days). The behavior of the enzymatic activities and Microbial population were dependent on the dose of insecticide applied to the Soil. Compared with the C0 treatment, in Soil A, the maximum inhibition of the enzymatic activities was at 15, 30, 45, and 90 days for the C1, C2, C3, and C4 treatments, respectively. However, in Soil B, the maximum inhibition occurred at 7, 15, 30, and 45 days for the C1, C2, C3, and C4 treatments, respectively. These results suggest that the cypermethrin insecticide caused a negative effect on Soil enzymatic activities and Microbial diversity. This negative impact was greater when a greater dose of insecticide was used; this impact was also greater in Soil with lower organic matter content. For both Soils, and from these respective days onward, the enzymatic activities and Microbial populations progressively increased by the end of the experimental period. This is possibly due to the fact that the insecticide or its breakdown products and killed Microbial cells, subsequently killed by the insecticide, are being used as a source of energy or as a carbon source for the surviving microorganisms for cell proliferation.
-
Soil organic carbon buffers heavy metal contamination on semiarid Soils effects of different metal threshold levels on Soil Microbial Activity
European Journal of Soil Biology, 2009Co-Authors: J L Moreno, Felipe Bastida, Teresa Hernández, Margarita Ros, Carlos GarciaAbstract:Abstract Traditionally, three threshold levels have been accepted for heavy metal concentrations in agricultural Soils, depending on Soil pH. The aim of this work was to ascertain how the three threshold values proposed for Cd (3, 6.5, and 12.5 mg kg−1) and Zn (300, 650, and 1300 mg kg−1) really affect Soil Microbial Activity. Two Soils, a scrubland Soil and a forest Soil, differing widely in their organic C content, were used in this study. Despite the different Soil characteristics, the fractions of Cd and Zn extracted with a solution of diethylenetriaminepentaacetic acid (DTPA) showed little difference between Soils. Parameters, such as Microbial biomass C (Cmic), Soil basal respiration (BR), adenosine triphosphate (ATP) content, dehydrogenase Activity (DHA), urease Activity (UA), alkaline phosphatase Activity (APA), and β-glucosidase (β-GA), were less affected by heavy metals in the forest Soil than in the scrubland Soil. In general, the simultaneous addition of both metals had a synergistic effect on Microbial Activity, and this treatment produced a significant decrease of Microbial Activity of both Soils with respect to control. The highest level (L3) of Cd, Zn and Cd + Zn treatments produced significant decrease of Microbial and biochemical parameters in both Soils.
-
bioremediation of oil refinery sludge by landfarming in semiarid conditions influence on Soil Microbial Activity
Environmental Research, 2005Co-Authors: J A Marin, Teresa Hernández, Carlos GarciaAbstract:Bioremediation of a refinery sludge containing hydrocarbons in a semi-arid climate using landfarming techniques is described. The objective of this study was to assess the ability of this technique to reduce the total hydrocarbon content added to the Soil with the refinery sludge in semiarid climate (low rain and high temperature). In addition, we have evaluted the effect of this techique on the Microbial Activity of the Soil involved. For this, biological parameters (carbon fractions, Microbial bilmass carbon, basal respiration and ATP) and biochemical parameters(different enzymatic activities) were determined. The results showed that 80% of the hydrocarbons were eiminated in eleven months, half of this reduction taking place during the first three months. The labile carbon fractions, MBC, basal respiration and ATP of the Soils submitted to landfarming showed higher values than the control Soil during the first months of the process, although these values fell down by the end of the experimental period as the hydrocarbons were degraded by mineralisation. All the enzymatic activities studied: oxydoreductases such as dehydrogenase Activity, and hydrolases of C(β-glucosidase Activity) and N Cycle (urease and protease) showed higher values in the Soils amended with the refinery sludge than in the control. As in the case of the previous parameters, these value fell down as the bioremediation of the hydrocarbons progressed, many of them reaching levels similar to those of the control Soil after eleven months.
-
Soil Microbial Activity as a biomarker of degradation and remediation processes
Soil Biology & Biochemistry, 2000Co-Authors: Jose A Pascual, Teresa Hernández, Carlos Garcia, Jose L Moreno, Margarita RosAbstract:Abstract Several organic matter fractions together with biological and biochemical parameters were measured in a range of intensively farmed Soils in SE Spanish Mediterranean region, which had been abandoned (i.e. not used in agriculture) for different periods of time. These Soils were compared with adjacent natural Soils that had never been used for agriculture. There was a general decline of total organic carbon (TOC), extractable humic substances, water-soluble carbon (WSC) and carbohydrates, Microbial biomass and respiration with the time elapsed since abandonment. There was also a decline in plant cover in the abandoned Soils. When a degraded Soil was amended with municipal solid waste at rates of 6.5 and 26 kg m−2 as a potential means of remediation, TOC, humic substances, WSC, Microbial biomass and respiration rates significantly increased but only at the higher rate of amendment. Plant cover was significantly enhanced by both rates of the amendments and was still present 10 years after the amendment. These data confirm that agricultural Soil abandonment leads to Soil degradation and that the addition of urban waste could be a suitable technique with which to restore their quality.
