scholarly journals Changes in soil microbial respiration and physicochemical properties following bonny light crude oil contamination of sandy loam soil

2020 ◽  
Vol 22 (1) ◽  
pp. 153-163
Author(s):  
C.N. Eze ◽  
P.I. Orjiakor ◽  
U.J. Ebeifenadi

This study was undertaken to investigate the effects of Bonny light crude oil contamination of sandy loam soil on aspects of microbial metabolism and physicochemical properties of the soil. Bonny light crude oil (specific gravity = 0.81) was used at eight different levels (0.5%, 1.0%, 2.0%, 2.5%, 5.0%, 10.0%, 15.0% or 20.0% v/w of soil) for the controlled pollution of pristine soil samples, each weighing 1 kg. The experiment lasted for eightweeks. Results of the effects of crude oil on the physicochemical properties of the soil showed that high levels of the oil significantly (p< 0.05) increased soil organic matter but had no significant effect on the pH and moisture content. With the exception of organic carbon, the levels of bioavailable nitrogen, sodium, potassium, calcium, magnesium, sulphur and phosphorus in the test samples with higher levels of crude oil (5.0%, 10.0%, 15.0% and 20.0%) were significantly reduced when compared to their levels in the controls. Similarly, higher levels of the oil significantly (p<0.05) reduced soil microbial phospholipid synthesis and CO emission. 2 Correlation analysis using the Pearson's correlation model showed a positive correlation between soil CO and 2 phospholipid (r = 0.74). Keywords: Contamination, Crude oil, Microbial respiration, Physicochemical properties.

2017 ◽  
Vol 220 ◽  
pp. 504-513 ◽  
Author(s):  
A.D. Samarajeewa ◽  
J.R. Velicogna ◽  
J.I. Princz ◽  
R.M. Subasinghe ◽  
R.P. Scroggins ◽  
...  

Agronomy ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 1281
Author(s):  
Modupe Olufemi Doyeni ◽  
Ausra Baksinskaite ◽  
Skaidre Suproniene ◽  
Vita Tilvikiene

The increasing quantities of organic residues are becoming one of the most important problems for climate change mitigation. Sustainable utilization technologies are required to minimize the effect of recycling on the environment. Nevertheless, treated residues should be part of the circular bioeconomy. One of the most promising processes is the biogas system, with the final products biogas and digestate, which contain valuable nutrients and are therefore suitable as agricultural fertilizers. However, there is lack of research data on the effectiveness of digestate on environmental factors including soil quality as well as crop productivity and quality. In this study, we compare the roles of different digestates (chicken manure digestate, cow manure digestate, and pig manure digestate) on spring wheat productivity, soil microbial activities, and greenhouse gas emissions in loam and sandy loam soil under controlled climate conditions. The liquid digestate applied was equivalent to 170 kg N ha−1 of total N presented. Overall, results showed that the two soil types responded differently to the addition of the digestates, and the benefits depended on soil characteristics as well as on the type of the digestate applied. There was a higher effect on soil microbial activity in sandy loam soil compared to that of loam soil. Chicken manure digestate had the highest value of dehydrogenase activity and soil microbial biomass C of 9.23 µg TPFg−1 h−1 and 175.6 µg g−1 across the two soil types. CO2 and N2O emissions were moderately higher in loam soil when compared to that of sandy loam soil. The highest CO2 peak emission at 0.0107 µg ha−1 h−1 occurred in pig manure digestate in the sandy loam soil, and regular peak patterns observed in loam soil fertilized with pig digestate manure. Chicken manure digestate had the highest peak emissions across both soil types at 0.007950 mg ha−1 h−1 and 0.5667 mg ha−1 h−1 in the loam and sandy loam soil, respectively. The biomass yield varied across the soil types irrespective of the digestate applied. The agricultural benefits of digestates in different receiving soil ecosystems supplying essential nutrients for crop productivity, coupled with its environmental benefits, makes it an encouraging prospect in temperate climate zones.


2015 ◽  
Vol 7 (2) ◽  
pp. 700-708 ◽  
Author(s):  
Sandeep Sharma ◽  
Jatinder Kaur ◽  
H. S. Thind ◽  
Yadvinder Singh ◽  
Neha Sharma ◽  
...  

Assessment of soil quality is an invaluable tool in determining the sustainability and environmental impact of agricultural ecosystems. Soil microbial indices like microbial biomass and microbial activity are important criteria for the determination of soil quality. Laboratory incubation study was undertaken to examine the influence of eight crop residues widely varying in biochemical composition on the periodic changes in important soil microbial indices {(microbial (Cmic: Corg), metabolic (qCO2), carbon mineralization (qC) and microbial biomass change rate (qM) quotients)} at 28 days and 63 days after incubation (DAI) in a sandy loam soil. A. sativa amended soil showed maximum soil respiration rate (14.23 mg CO2-C g-1 soil day-1) whereas T. aestivum amended soil showed maximum microbial biomass C (790 µg/g). The metabolic quotient among different crop residues ranged from 11.1 to 19.8 μg CO2-C μg-biomass-C-1 h-1 at 63 DAI. The results indicate that incorporation of different crop residues has positive effect on microbial flora and their activity. Microbial quotient (Cmic:Corg) was significantly positively correlated with microbial biomass carbon (MBC), qC and qM. The study suggests that the biochemical composition of different crop residues seems to be of better option for long term sustainable crop production with maintenance of soil quality in a sandy loam soil.


2022 ◽  
Vol 9 ◽  
Author(s):  
Ashish Khandelwal ◽  
Ramya Sugavanam ◽  
B. Ramakrishnan ◽  
Anirban Dutta ◽  
Eldho Varghese ◽  
...  

Crude oil contamination of soil and water resources is a widespread issue. The present study evaluated the degradation of aliphatic hydrocarbons (C11–C36) in crude oil by 17 bacteria isolated from a crude oil–contaminated soil. The results suggested that Pseudomonas sp. and Bacillus amyloliquefaciens were the best hydrocarbon-degrading bacteria in the presence of surfactant Tween-80 (0.1% w/v). Based on the present investigation and a previous study, Pseudomonas sp. + B. amyloliquefaciens and fungus Aspergillus sydowii were identified as best oil degraders and were immobilized in alginate–bentonite beads, guargum–nanobenonite water dispersible granules (WDGs), and carboxy methyl cellulose (CMC)–bentonite composite. Sandy loam soil was fortified with 1, 2, and 5% crude oil, and total petroleum hydrocarbon (TPH) degradation efficiency of free cultures and bio-formulations was evaluated in sandy loam soils. Compared to a half-life (t1/2) of 69.7 days in the control soil (1% oil), free cultures of Pseudomonas sp. + B. amyloliquefaciens and A. sydowii degraded TPH with t1/2 of 10.8 and 19.4 days, respectively. Increasing the oil content slowed down degradation, and the t1/2 in the control and soils inoculated with Pseudomonas sp. + B. amyloliquefaciens and A. sydowii was 72.9, 14.7, and 22.2 days (2%) and 87.0, 23.4, and 30.8 days (5%), respectively. Supplementing soil with ammonium sulfate (1%) enhanced TPH degradation by Pseudomonas sp. + B. amyloliquefaciens (t1/2–10 days) and A. sydowii (t1/2–12.7 days). All three bio-formulations were effective in degrading TPH (1%), and the t1/2 was 10.7–11.9 days (Pseudomonas sp. + B. amyloliquefaciens and 14–20.2 days (A. sydowii) and were at par with free cultures. Microbial diversity analysis based on taxonomic markers and functional markers suggested that the bioaugmentation process helped keep soil in the active stage and restored the original microbial population to some extent. The present study concluded that bio-formulations of crude oil–degrading microbes can be exploited for its degradation in the contaminated environment.


Sign in / Sign up

Export Citation Format

Share Document