scholarly journals Spatial and temporal variability in microbial activities of coastal acid saline soils of Goa, India

2015 ◽  
Vol 7 (4) ◽  
pp. 3087-3115 ◽  
Author(s):  
G. R. Mahajan ◽  
B. L. Manjunath ◽  
A. M. Latare ◽  
R. D'Souza ◽  
S. Vishwakarma ◽  
...  
Keyword(s):  
Temporal Variability ◽  
Enzyme Activities ◽  
Soil Enzyme ◽  
Saline Soils ◽  
Spatial And Temporal Variability ◽  
Soil Enzyme Activities ◽  
Microbial Activities ◽  
Soil Microbial ◽  
Post Monsoon ◽  
Salinity Levels

Abstract. The aim of the present investigation was to study the spatio-temporal variability of the microbial activities in coastal saline soils (locally called Khazan) of Goa, India (west coast region). The coastal soil salinity is a major constraint for reduced crop yields and abandonment of farming in these areas. Three replicated global positioning based soil samples (0–0.20 m depth) from each of four salinity groups i.e. non-saline (EC=0.08±0.06 dS m−1), weakly saline (EC=2.04±0.06 dS m−1), moderately saline (EC=3.50±0.57 dS m−1) and strongly saline (EC=5.49±0.49 dS m−1) during three seasons–monsoon, post-monsoon and pre-monsoon were collected. Soil microbial activity in terms of soil microbial carbon (MBC), MBC as a fraction of soil organic carbon (SOC) (MBC/SOC), basal soil respiration (BSR), metabolic quotient (qCO2) and soil enzyme activities–dehydrogenase, phosphatase and urease was tested. In all the seasons, the soil cationic composition depended significantly (p<0.01) on salinity levels and the exchangeable sodium (Na) was the second most dominant among the tested cations. The MBC, MBC/SOC and BSR reduced significantly with increasing salinity, whereas qCO2 increased with increased salinity levels. In general, MBC, MBC/SOC and BSR and soil enzyme activities were observed as: salinity levels–strongly saline < moderately saline < weakly saline < non-saline and season–post–monsoon > monsoon > during pre-monsoon season. The mean MBC and MBC/SOC of non-saline soils were 1.61 and 2.28 times higher than that of strongly saline soils, whereas qCO2 of strongly saline soils was 2.4 times higher than that of non-saline soils. This indirectly indicates the salinity stress on the soil microorganisms. Irrespective of season, the soil enzyme activities decreased significantly (p<0.05) with increasing salinity levels. Suitable countermeasures needs to be taken up to alleviate the depressive salinity effect on the microbial and activity for the sustainable crop production in the coastal saline soils of Goa, India.

scholarly journals Effects of Salinity on the Biodegradation of Polycyclic Aromatic Hydrocarbons in Oilfield Soils Emphasizing Degradation Genes and Soil Enzymes

2022 ◽  
Vol 12 ◽  
Author(s):  
Yang Li ◽  
Wenjing Li ◽  
Lei Ji ◽  
Fanyong Song ◽  
Tianyuan Li ◽  
...  
Keyword(s):  
Bacterial Community ◽  
Soil Salinity ◽  
Aromatic Hydrocarbons ◽  
Enzyme Activities ◽  
Soil Enzyme ◽  
Saline Soils ◽  
Soil Enzyme Activities ◽  
Pah Degradation ◽  
Pah Biodegradation ◽  
Polycyclic Aromatic

The biodegradation of organic pollutants is the main pathway for the natural dissipation and anthropogenic remediation of polycyclic aromatic hydrocarbons (PAHs) in the environment. However, in the saline soils, the PAH biodegradation could be influenced by soil salts through altering the structures of microbial communities and physiological metabolism of degradation bacteria. In the worldwide, soils from oilfields are commonly threated by both soil salinity and PAH contamination, while the influence mechanism of soil salinity on PAH biodegradation were still unclear, especially the shifts of degradation genes and soil enzyme activities. In order to explain the responses of soils and bacterial communities, analysis was conducted including soil properties, structures of bacterial community, PAH degradation genes and soil enzyme activities during a biodegradation process of PAHs in oilfield soils. The results showed that, though low soil salinity (1% NaCl, w/w) could slightly increase PAH degradation rate, the biodegradation in high salt condition (3% NaCl, w/w) were restrained significantly. The higher the soil salinity, the lower the bacterial community diversity, copy number of degradation gene and soil enzyme activity, which could be the reason for reductions of degradation rates in saline soils. Analysis of bacterial community structure showed that, the additions of NaCl increase the abundance of salt-tolerant and halophilic genera, especially in high salt treatments where the halophilic genera dominant, such as Acinetobacter and Halomonas. Picrust2 and redundancy analysis (RDA) both revealed suppression of PAH degradation genes by soil salts, which meant the decrease of degradation microbes and should be the primary cause of reduction of PAH removal. The soil enzyme activities could be indicators for microorganisms when they are facing adverse environmental conditions.

scholarly journals Divergence of dominant factors in soil microbial communities and functions in forest ecosystems along a climatic gradient

2018 ◽  
Vol 15 (4) ◽  
pp. 1217-1228 ◽  
Author(s):  
Zhiwei Xu ◽  
Guirui Yu ◽  
Xinyu Zhang ◽  
Nianpeng He ◽  
Qiufeng Wang ◽  
...  
Keyword(s):  
Microbial Communities ◽  
Enzyme Activities ◽  
Soil Microbial Communities ◽  
Soil Enzyme ◽  
Secondary Forests ◽  
Soil Enzyme Activities ◽  
Climatic Zones ◽  
Soil Microbial ◽  
Warm Temperate ◽  
Microbial Plfas

Abstract. Soil microorganisms play an important role in regulating nutrient cycling in terrestrial ecosystems. Most of the studies conducted thus far have been confined to a single forest biome or have focused on one or two controlling factors, and few have dealt with the integrated effects of climate, vegetation, and soil substrate availability on soil microbial communities and functions among different forests. In this study, we used phospholipid-derived fatty acid (PLFA) analysis to investigate soil microbial community structure and extracellular enzymatic activities to evaluate the functional potential of soil microbes of different types of forests in three different climatic zones along the north–south transect in eastern China (NSTEC). Both climate and forest type had significant effects on soil enzyme activities and microbial communities with considerable interactive effects. Except for soil acid phosphatase (AP), the other three enzyme activities were much higher in the warm temperate zone than in the temperate and the subtropical climate zones. The soil total PLFAs and bacteria were much higher in the temperate zone than in the warm temperate and the subtropical zones. The soil β-glucosidase (BG) and N-acetylglucosaminidase (NAG) activities were highest in the coniferous forest. Except for the soil fungi and fungi–bacteria (F/B), the different groups of microbial PLFAs were much higher in the conifer broad-leaved mixed forests than in the coniferous forests and the broad-leaved forests. In general, soil enzyme activities and microbial PLFAs were higher in primary forests than in secondary forests in temperate and warm temperate regions. In the subtropical region, soil enzyme activities were lower in the primary forests than in the secondary forests and microbial PLFAs did not differ significantly between primary and secondary forests. Different compositions of the tree species may cause variations in soil microbial communities and enzyme activities. Our results showed that the main controls on soil microbes and functions vary in different climatic zones and that the effects of soil moisture content, soil temperature, clay content, and the soil N ∕ P ratio were considerable. This information will add value to the modeling of microbial processes and will contribute to carbon cycling in large-scale carbon models.

scholarly journals The influence of halophytic compost, farmyard manure and phosphobacteria on soil microflora and enzyme activities

2008 ◽  
Vol 53 (No. 4) ◽  
pp. 186-192 ◽  
Author(s):  
V. Balakrishnan ◽  
K. Venkatesan ◽  
K.C. Ravindran
Keyword(s):  
Alkaline Phosphatase ◽  
Enzyme Activities ◽  
Microbial Population ◽  
Farmyard Manure ◽  
Soil Enzyme ◽  
Soil Microflora ◽  
Soil Enzyme Activities ◽  
Chemical Fertilizers ◽  
Soil Microbial ◽  
Soil Microbial Population

Biocompost has been identified as an alternative to chemical fertilizers that increased soil microbial population and soil enzyme activities in sustainable farming. The objective of this field study was to evaluate the effect of three halophytic composts in combination with farmyard manure and phosphate solubilising bacteria (<i>Bacillus megaterium</i>) on soil microflora and enzyme activities. The results show that among nine treatments given, the application of <i>Suaeda</i> compost in combination with farmyard manure and phosphate solubilising bacteria (T<sub>9</sub>) significantly increased the soil microflora such as bacteria, fungi and actinomycetes and soil enzyme activities such as dehydrogenases, alkaline phosphatase, cellulase and urease in soil cultivated with <i>Arachis hypogaea</i>.

scholarly journals Change of soil microbial community under long-term fertilization in a reclaimed sandy agricultural ecosystem

PeerJ ◽  
2019 ◽  
Vol 7 ◽  
pp. e6497 ◽  
Author(s):  
Zengru Wang ◽  
Yubing Liu ◽  
Lina Zhao ◽  
Wenli Zhang ◽  
Lichao Liu
Keyword(s):  
Microbial Community ◽  
Crop Yield ◽  
Soil Microbial Community ◽  
Enzyme Activities ◽  
Bacterial Abundance ◽  
Soil Enzyme ◽  
Soil Enzyme Activities ◽  
Soil Microbial Community Structure ◽  
Soil Microbial

The importance of soil microbial flora in agro-ecosystems is well known, but there is limited understanding of the effects of long-term fertilization on soil microbial community succession in different farming management practices. Here, we report the responses of soil microbial community structure, abundance and activity to chemical (CF) and organic fertilization (OF) treatments in a sandy agricultural system of wheat-maize rotation over a 17-year period. Illumina MiSeq sequencing showed that the microbial community diversity and richness showed no significant changes in bacteria but decreased in fungi under both CF and OF treatments. The dominant species showing significant differences between fertilization regimes were Actinobacteria, Acidobacteria and Ascomycota at the phylum level, as well as some unclassified genera of other phyla at the genus level. As expected, soil organic matter content, nutrient element concentrations and bacterial abundance were enhanced by both types of fertilization, especially in OF, but fungal abundance was inhibited by OF. Redundancy analysis revealed that soil enzyme activities were closely related to both bacterial and fungal communities, and the soil nutrient, texture and pH value together determined the community structures. Bacterial abundance might be the primary driver of crop yield, and soil enzyme activities may reflect crop yield. Our results suggest a relatively permanent response of soil microbial communities to the long-term fertilization regimes in a reclaimed sandy agro-ecosystem from a mobile dune, and indicate that the appropriate dosage of chemical fertilizers is beneficial to sandy soil sustainability.

Soil microbial parameters and stability of soil aggregate fractions under different grassland communities on the Loess Plateau, China

Biologia ◽  
2009 ◽  
Vol 64 (3) ◽  
Author(s):  
Shao-shan An ◽  
Axel Mentler ◽  
Veronica Acosta-Martínez ◽  
Winfried Blum
Keyword(s):  
Microbial Biomass ◽  
Enzyme Activities ◽  
Aggregate Stability ◽  
Soil Aggregate ◽  
Soil Enzyme ◽  
Soil Enzyme Activities ◽  
The Loess Plateau ◽  
Soil Microbial ◽  
Aggregate Fractions ◽  
Soil Aggregate Fractions

AbstractOver-grazing and large-scale monocultures on the Loess plateau in China have caused serious soil erosion by water and wind. Grassland revegetation has been reported as one of the most effective counter measures. Therefore, we investigated soil aggregation, aggregate stability and soil microbial activities as key parameters for soil remediation through grassland revegetation.The results showed that soil microbial biomass carbon (Cmic) and microbial biomass nitrogen (Nmic) increased under revegetated grass communities compared to cropland and overgrazed pastures and were higher in surface layers (0–10 cm) than in the subsurface (10–20 cm). Although there are variations between the four investigated grassland communities, their values were 10 to 50 times higher in comparison to the cropland and overgrazed pastures, similar to the increase in soil enzyme activities, such as β-glucosidase and β-glucosaminidase.Soil aggregate stability (SAS) showed clear differences between the different land uses with two main soil aggregate fractions measured by ultra sound: < 63 μm and 100–250 μm, with approximately 70% and 10% of the total soil volume respectively. We also found positive correlations between SAS and soil microbial parameters, such as Cmic, Nmic, and soil enzyme activities. From this, we concluded that revegetation of eroded soils by grasses accelerates soil rehabilitation.

scholarly journals Effects of Allelochemicals, Soil Enzyme Activities, and Environmental Factors on Rhizosphere Soil Microbial Community of Stellera chamaejasme L. along a Growth-Coverage Gradient

2022 ◽  
Vol 10 (1) ◽  
pp. 158
Author(s):  
Jinan Cheng ◽  
Hui Jin ◽  
Jinlin Zhang ◽  
Zhongxiang Xu ◽  
Xiaoyan Yang ◽  
...  
Keyword(s):  
Microbial Community ◽  
Physicochemical Properties ◽  
Soil Microbial Community ◽  
Enzyme Activities ◽  
Rhizosphere Soil ◽  
Soil Enzyme ◽  
Soil Physicochemical Properties ◽  
Soil Enzyme Activities ◽  
Soil Microbial ◽  
Stellera Chamaejasme

Allelochemicals released from the root of Stellera chamaejasme L. into rhizosphere soil are an important factor for its invasion of natural grasslands. The aim of this study is to explore the interactions among allelochemicals, soil physicochemical properties, soil enzyme activities, and the rhizosphere soil microbial communities of S. chamaejasme along a growth-coverage gradient. High-throughput sequencing was used to determine the microbial composition of the rhizosphere soil sample, and high-performance liquid chromatography was used to detect allelopathic substances. The main fungal phyla in the rhizosphere soil with a growth coverage of 0% was Basidiomycetes, and the other sample plots were Ascomycetes. Proteobacteria and Acidobacteria were the dominant bacterial phyla in all sites. RDA analysis showed that neochamaejasmin B, chamaechromone, and dihydrodaphnetin B were positively correlated with Ascomycota and Glomeromycota and negatively correlated with Basidiomycota. Neochamaejasmin B and chamaechromone were positively correlated with Proteobacteria and Actinobacteria and negatively correlated with Acidobacteria and Planctomycetes. Allelochemicals, soil physicochemical properties, and enzyme activity affected the composition and diversity of the rhizosphere soil microbial community to some extent. When the growth coverage of S. chamaejasme reached the primary stage, it had the greatest impact on soil physicochemical properties and enzyme activities.

Response of carbon utilization and enzymatic activities to nitrogen deposition in three forests of subtropical China

2015 ◽  
Vol 45 (4) ◽  
pp. 394-401 ◽  
Author(s):  
Yong-Sheng Wang ◽  
Shu-Lan Cheng ◽  
Gui-Rui Yu ◽  
Hua-Jun Fang ◽  
Jiang-Ming Mo ◽  
...  
Keyword(s):  
Microbial Biomass ◽  
Soil Ph ◽  
Enzyme Activities ◽  
Southern China ◽  
Soil Enzyme ◽  
Total Carbon ◽  
N Addition ◽  
Soil Enzyme Activities ◽  
Microbial Biomass Nitrogen ◽  
Soil Microbial

Nitrogen (N) deposition has been shown to affect soil carbon (C) and N cycling in subtropical forests; however, the underlying microbial mechanisms are poorly understood. We used patterns of community-level physiological profiles and enzyme activities to assess the relative effects of the addition of four N levels (0, 50, 100, and 150 kg·ha−1·year−1) on the soil microbial community in three forest stands (pine, mixed, and broadleaf forests) in southern China, where the forests have been experimentally manipulated for over 8 years. In pine forests, N50 addition significantly increased microbial biomass carbon (MBC) concentration but decreased soil pH levels. N100 addition significantly increased soil peroxidase activity but decreased soil β-1,4-glucosidase activity. In broadleaf forests, N addition increased soil dissolved organic carbon (DOC) concentration and polyphenol oxidase activity but decreased soil MBC concentration and soil pH levels. N addition also significantly increased soil microbial metabolism activity (expressed as average well color development) in pine forest and broadleaf forest soils. However, the mixed forests responded slowly to N additions and exhibited no significant response of C-utilization profiles and soil enzyme activities. Principal component analysis of C-utilization data separated microbial communities with respect to N addition and forest successional stage. In addition, microbial C utilization was driven by soil pH levels. Although enzyme activities were correlated with soil MBC and microbial biomass nitrogen concentrations, stepwise regression results indicated that soil total carbon contents that were integrated with soil pH levels were key integrators of soil enzyme activities. Our results suggest that soil acidification due to N addition increased soil bacterial C utilization and enzyme activities.

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