scholarly journals Biochar alleviates metal toxicity and improves microbial community functions in a soil co-contaminated with cadmium and lead

Biochar ◽  
2021 ◽  
Author(s):  
Nahid Azadi ◽  
Fayez Raiesi
Keyword(s):  
Heavy Metals ◽  
Low Temperature ◽  
Organic Carbon ◽  
Enzymatic Activity ◽  
Microbial Activity ◽  
Contaminated Soils ◽  
Metal Availability ◽  
Soil Microbial ◽  
Labile C ◽  
Cadmium And Lead

AbstractSoil amendment with biochar alleviates the toxic effects of heavy metals on microbial functions in single-metal contaminated soils. Yet, it is unclear how biochar application would improve microbial activity and enzymatic activity in soils co-polluted with toxic metals. The present research aimed at determining the response of microbial and biochemical attributes to addition of sugarcane bagasse biochar (SCB) in cadmium (Cd)-lead (Pb) co-contaminated soils. SCBs (400 and 600 °C) decreased the available concentrations of Cd and Pb, increased organic carbon (OC) and dissolved organic carbon (DOC) contents in soil. The decrease of metal availability was greater with 600 °C SCB than with 400 °C SCB, and metal immobilization was greater for Cd (16%) than for Pb (12%) in co-spiked soils amended with low-temperature SCB. Biochar application improved microbial activity and biomass, and enzymatic activity in the soils co-spiked with metals, but these positive impacts of SCB were less pronounced in the co-spiked soils than in the single-spiked soils. SCB decreased the adverse impacts of heavy metals on soil properties largely through the enhanced labile C for microbial assimilation and partly through the immobilization of metals. Redundancy analysis further confirmed that soil OC was overwhelmingly the dominant driver of changes in the properties and quality of contaminated soils amended with SCB. The promotion of soil microbial quality by the low-temperature SCB was greater than by high-temperature SCB, due to its higher labile C fraction. Our findings showed that SCB at lower temperatures could be applied to metal co-polluted soils to mitigate the combined effects of metal stresses on microbial and biochemical functions.

scholarly journals SOIL DEVELOPMENT AND PROPERTIES OF MICROBIAL BIOMASS SUCCESSION IN RECLAIMED SITES IN BULGARIA

2019 ◽  
Vol 7 ◽  
pp. 1008-1014
Author(s):  
Veneta V. Stefanova ◽  
Petar G. Petrov
Keyword(s):  
Heavy Metals ◽  
Microbial Activity ◽  
Vegetation Type ◽  
Soil Microbial Activity ◽  
Soil Development ◽  
Substrate Quality ◽  
Mining Sites ◽  
Soil Microbial ◽  
Physico Chemical ◽  
Chemical Conditions

One of the most important preconditions of ecosystem rehabilitation in post mining landscapes is the process of soil development. In this context, the microbial activity in soil plays an important role. Microbial activity was studied in several reclaimed post mining sites resulted from the mining activity in Bulgaria. The studied soils are characterized by different biogenicity. The development of the total microflora in soils is higher in the surface layers but in depth, their number decreases due to the inhibiting effect of pollutants (heavy metals) and a change in the physico-chemical conditions. The dominant microorganisms are non-spore bacteria and all studied soils showed the development of pigment types of bacteria resulting from the high content of heavy metals. The composition of the microorganisms is poor, which can be taken as an indicator that the microbicenosis is still in the process of formation. In depth, their number is reduced by applying the effect of contamination. The mineralization coefficient values are the highest in the field with the greatest age of re-cultivation, where humidification is the most advanced. The study shows that vegetation type and litter quality seem to be more important for soil microbial activity than the substrate quality on the reclaimed sites.

scholarly journals The availability of Cd, Pb and Zn and their relationships with soil pH and microbial biomass in soils amended by natural clinoptilolite

2011 ◽  
Vol 51 (No. 1) ◽  
pp. 26-33 ◽  
Author(s):  
G. Mühlbachová ◽  
T. Šimon ◽  
M. Pechová
Keyword(s):  
Heavy Metal ◽  
Microbial Biomass ◽  
Contaminated Soils ◽  
Metal Availability ◽  
Maximum Increase ◽  
Glucose Addition ◽  
Soil Microbial ◽  
Significant Relationships ◽  
Metal Contents ◽  
Natural Clinoptilolite

The relationships among soil microbial biomass, pH and available of heavy metal fractions were evaluated in longterm contaminated soils during an incubation experiment with the amendment of zeolite (natural clinoptilolite) and the subsequent addition of glucose. The values of pH after the addition of glucose decreased during the first day of incubation approximately at about one unit and corresponded with the maximum increase of microbial biomass. The available heavy metal contents extracted by H<sub>2</sub>O, 1 mol/l NH<sub>4</sub>NO<sub>3</sub> and 0.005 mol/l DTPA increased during the first two days of incubation. Only a few significant relationships were found between the available metal contents and pH or microbial biomass. This fact could be ascribed to the different dynamics of the microbial biomass, pH and metal availability after glucose addition, when the highest metal contents during the incubation were usually reached one day later in respect to the greatest changes of pH and microbial activity. In comparison to soils without zeolite addition, the variants with natural clinoptilolite showed lower heavy metal contents in all used extractants with the exception of Cd which in H<sub>2</sub>O extracts tended to increase.

scholarly journals Is microbial activity in tropical forests limited by phosphorus availability? Evidence from a tropical forest in China

2019 ◽  
Author(s):  
Taiki Mori ◽  
Xiankai Lu ◽  
Cong Wang ◽  
Qinggong Mao ◽  
Senhao Wang ◽  
...  
Keyword(s):  
Organic Matter ◽  
Organic Carbon ◽  
Tropical Forest ◽  
Microbial Activity ◽  
Tropical Forests ◽  
Microbial Respiration ◽  
P Fertilization ◽  
Soil Microbial ◽  
Prevailing Paradigm ◽  
P Addition

AbstractThe prevailing paradigm for soil microbial activity in tropical forests is that microbial activity is limited by phosphorus (P) availability. Thus, exogenous P addition should increase rates of organic matter decomposition. Studies have also confirmed that soil respiration is accelerated when P is added experimentally. However, we hypothesize that the increased rates of soil microbial respiration could be due to the release of organic material from the surface of soil minerals when P is added, because P is more successful at binding to soil particles than organic compounds. In this study, we demonstrate that P addition to soil is associated with significantly higher dissolved organic carbon (DOC) content in a tropical evergreen forest in southern China. Our results indicate that P fertilization stimulated soil respiration but suppressed litter decomposition. Results from a second sorption experiment revealed that the recovery ratio of added DOC in the soil of a plot fertilized with P for 9 years was larger than the ratio in the soil of a non-fertilized plot, although the difference was small. We also conducted a literature review on the effects of P fertilization on the decomposition rates of litter and soil organic matter at our study site. Previous studies have consistently reported that P addition led to higher response ratios of soil microbial respiration than litter decomposition. Therefore, experiments based on P addition cannot be used to test whether microbial activity is P-limited in tropical forest soils, because organic carbon desorption occurs when P is added. Our findings suggest that the prevailing paradigm on the relationship between P and microbial activity in tropical forest soils should be re-evaluated.

Effects of probiotics on soil microbial activity, biomass and enzymatic activity under cover crops in field and greenhouse studies

2016 ◽  
Vol 90 (5) ◽  
pp. 811-827 ◽  
Author(s):  
Ahsan M. Rajper ◽  
Ranjith P. Udawatta ◽  
Robert J. Kremer ◽  
Chung-ho Lin ◽  
Shibu Jose
Keyword(s):  
Enzymatic Activity ◽  
Microbial Activity ◽  
Cover Crops ◽  
Soil Microbial Activity ◽  
Soil Microbial

Microbial activity and diversity in long-term mixed contaminated soils with respect to polyaromatic hydrocarbons and heavy metals

2012 ◽  
Vol 99 ◽  
pp. 10-17 ◽  
Author(s):  
Palanisami Thavamani ◽  
Seidu Malik ◽  
Michael Beer ◽  
Mallavarapu Megharaj ◽  
Ravi Naidu
Keyword(s):  
Heavy Metals ◽  
Microbial Activity ◽  
Contaminated Soils ◽  
Polyaromatic Hydrocarbons

scholarly journals Bioremediation of Spent Engine Oil on Selected Contaminated Soils within Ilorin Metropolis

2020 ◽  
Vol 8 (1) ◽  
pp. 91-104
Author(s):  
Elizabeth Adeyinka AJIBOYE ◽  
Hikmat Omolara SULAYMAN ◽  
Abdullahi Taiwo AJAO
Keyword(s):  
Heavy Metals ◽  
Organic Matter ◽  
Organic Carbon ◽  
Contaminated Soils ◽  
Physicochemical Parameters ◽  
Soil Samples ◽  
Engine Oil ◽  
Biochemical Tests ◽  
Spent Engine Oil ◽  
Before And After

The research aimed to investigate the bioremediation of spent engine oil on selected contaminated soils within Ilorin metropolis. To achieve this, soil samples were collected from three (3) mechanic workshops along Taiwo axis within the metropolis. The soil samples were then subjected to bioremediation using the land-farming approach. The physicochemical parameters of the soil samples before and after bioremediation were analyzed using standard methods. Bacteria were isolated using standard procedures and identified using biochemical tests and molecular methods. Results for the physicochemical parameters of the soil samples before bioremediation include particle size (all sandy in nature); pH (6.00 ± 0.14 - 6.20 ± 0.14); Organic carbon (14.65 ± 3.20 - 17.54 ± 1.87), Organic matter (33.50 ± 0.85 - 43.45 ± 9.12) and heavy metals (ND - 11.74 ± 0.07). Values after bioremediation for pH, organic carbon, organic matter and heavy metals were 8.25 ± 0.07 - 8.90 ± 0.14, 13.07 ± 0.05 - 13.25 ± 0.84, 37.25 ± 1.06 - 44.80 ± 1.13, ND - 9.40 ± 0.04 respectively. Values for bacterial count before and after bioremediation of the soil samples were 8.00  1.41 - 67.50 ± 2.12 x 105 CFU/mL and 6.50 ± 2.12 - 164.00 ± 11.31 x 105 CFU/mL respectively. Bacterial isolates were identified as Pseudomonas sp., Enterobacter sp., Acinetobacter sp., and Bacillus sp. while the hydrocarbon-utilizing bacteria were identified as Thalassospira mesophila strain JCM 18969; Pseudomonas fluorescens F113; Siccibacter turicensis LMG 23730; Pseudomonas Zeshuii strain KACC 15471; Pseudomonas stutzeri strain CGMCC 1.1803 and Marinobacter hydrocarbonoclasticus strain ATCC 49840. In conclusion, the bacteria isolates effectively bioremediated the spent engine oil contaminated soils with a reduction of hydrocarbon pollutants.

scholarly journals Labile carbon limits late winter microbial activity near Arctic treeline

2020 ◽  
Author(s):  
Patrick F. Sullivan ◽  
Madeline C. Stokes ◽  
Cameron K. McMillan ◽  
Michael N. Weintraub
Keyword(s):  
Nutrient Cycling ◽  
Microbial Activity ◽  
Microbial Respiration ◽  
Soil Microbial Communities ◽  
The Arctic ◽  
Late Winter ◽  
Soil Microbial ◽  
Arctic Soils ◽  
Labile C ◽  
Soil Temperatures

It is well established that soil microbial communities remain active during much of the Arctic winter, despite soil temperatures that are often well below −10°C1. Overwinter microbial activity has important effects on global carbon (C) budgets2, nutrient cycling and vegetation community composition3. Microbial respiration is highly temperature sensitive in frozen soils, as liquid water and solute availability decrease rapidly with declining temperature4. Thus, temperature is considered the ultimate control on overwinter soil microbial activity in the Arctic. Warmer winter soils are thought to yield greater microbial respiration of available C, greater overwinter CO2 efflux and a flush of nutrients that could be available for plant uptake at thaw3. Rising air temperature, combined with changes in timing and/or depth of snowpack development, is leading to warmer Arctic winter soils5. Using observational and experimental approaches in the field and in the laboratory, we demonstrate that persistently warm winter soils can lead to labile C starvation of the microbial community and reduced respiration rates, despite the high C content of most arctic soils. If Arctic winter soil temperatures continue to rise, microbial C limitation will reduce cold season CO2 emissions and alter soil nutrient cycling, if not countered by greater labile C inputs.

Grazing and mowing impact on soil organic carbon and microbial activity in grassland soil

2020 ◽  
Author(s):  
Aliia Gilmullina ◽  
Cornelia Rumpel ◽  
Evgenia Blagodatskaya ◽  
Michaela Dippold ◽  
Frederique Louault ◽  
...  
Keyword(s):  
Organic Carbon ◽  
Soil Organic Carbon ◽  
Microbial Activity ◽  
Enzyme Activities ◽  
Management Practices ◽  
Grazing Intensity ◽  
Grassland Management ◽  
Bare Soil ◽  
Microbial Biomass C ◽  
Soil Microbial

&lt;p&gt;Grassland management practices, such as grazing with varying animal density and mowing may impact the processes leading to soil organic carbon (SOC) accumulation. Although, they serve similar agricultural purposes, they differ in their effect on plant physiology and their influence on SOC remains uncertain. We hypothesised that both practices affect SOC storage differently due to an altered plant C input and changed growth and physiological response leading consequently to contrasting soil microbial activity.&lt;/p&gt;&lt;p&gt;Based on this, our experiment included the investigation of three grassland treatments: grazing at two intensities and mowing which are located at the experimental station of SOERE ACBB (Clermont-Ferrand, France). Additionally, we included bare soil and unmanaged abandoned site considering as negative and positive controls, accordingly. The aim of the study was to estimate how grazing and mowing affect SOC chemical characteristics and its link with microbial activity.&lt;/p&gt;&lt;p&gt;Our results show highest SOC contents under low grazing intensity, whereas SOC content under high grazing intensity was lower and did not differ from abandoned grassland. SOC content under mowing was lowest among all treatments but still higher compared to bare soil. Microbial biomass C (MBC) followed a similar pattern under high grazing intensity and positive control whereas it was similar under mowing and low grazing intensity and lowest under bare soil. Absolute enzyme activities showed a similar tendency as SOC content. However, enzyme activities per MBC resulted in highest values under low grazing intensity and similarly lower values under all other treatments.&lt;/p&gt;&lt;p&gt;These results demonstrate that microbial parameters responded to management in various ways most probably related to the differences in dung and litter inputs. We suggest that dung input under high grazing intensity increased MBC and consequently compensated for plant removal thus keeping SOC contents increasing. Consequently, grazing at both intensities allows to maintain SOC at similar levels as in absence of management. While on unmanaged land high SOC may be related to absence of harvest, on grazed land it may be related to stimulation of microbial activity due to animal activity. Mowing treatment on the other hand did not allow to increase SOC.&lt;/p&gt;&lt;p&gt;We conclude that the presence of animals in the system is essential to improve soil heath, biogeochemical cycling, and SOC storage.&lt;/p&gt;

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