scholarly journals Monitoring of microbial communities of surface soil

2021 ◽  
Vol 937 (2) ◽  
pp. 022006
Author(s):  
O Zhurlov
Keyword(s):  
Surface Layer ◽  
Microbial Communities ◽  
Surface Soil ◽  
Soil Layer ◽  
Soil Samples ◽  
Molecular Biological Analysis ◽  
Natural Landscapes ◽  
Equidistant Points ◽  
Selection Of ◽  
Comprehensive Study

Abstract Currently, the methods used for sampling soil do not meet modern requirements when conducting comprehensive studies of ecological state of soils. Stratified sampling of soil samples does not allow us to judge the gradients of distribution of agrochemical parameters and microbial communities of surface soil layer in natural landscapes. The use of method of GPS positioning of equidistant points of surface layer of soil in a comprehensive study of agrochemical parameters of soil, the composition of microbial communities of landscape makes it possible to draw up a summary map-scheme (GIS). The article analyzes methodological features of selection of soil samples for agrochemical, bacteriological, and molecular biological analysis. Using example of southern alkaline chernozem with gradient of pH distribution from 7.5 to 8.5 units, the distribution of microbial communities and agrochemical parameters in surface layer of soil of a perennial fallow is shown. The range of changes in agrochemical indicators on site with an area of 1 ha for organic matter was (1.4 ± 0.3% - 5.4 ± 0.5%), ammonium (12.3 ± 1.2 - 26.7 ± 2.7 mg/kg), and nitrate nitrogen (0.9 ± 0.1 - 3.9 ± 0.6 mg/kg). The change in microbial communities corresponded to gradient of soil agrochemical parameters.

scholarly journals Forms and accumulation of copper and zinc in a sandy typic hapludalf soil after long-term application of pig slurry and deep litter

2013 ◽  
Vol 37 (3) ◽  
pp. 812-824 ◽  
Author(s):  
Tadeu Luis Tiecher ◽  
Carlos Alberto Ceretta ◽  
Jucinei José Comin ◽  
Eduardo Girotto ◽  
Alcione Miotto ◽  
...  
Keyword(s):  
Soil Profile ◽  
Surface Soil ◽  
Soil Layer ◽  
Soil Samples ◽  
Pig Slurry ◽  
Soil Layers ◽  
Surface Soil Layer ◽  
N Requirement ◽  
Cu And Zn

Successive applications of pig slurry and pig deep litter may lead to an accumulation of copper (Cu) and zinc (Zn) fractions in the soil profile. The objective of this study was to evaluate the Cu and Zn forms and accumulation in a Sandy Typic Hapludalf soil after long-term application of pig slurry and deep litter. In March 2010, eight years after initiating an experiment in Braço do Norte, Santa Catarina (SC), Brazil, on a Sandy Typic Hapludalf soil, soil samples were collected from the 0-2.5, 2.5-5.0, 5-10 and 10-15 cm layers in treatments consisting of no manure application (control) and with applications of pig slurry and deep litter at two levels: the single and double rate of N requirement for maize and black oat succession. The soil was dried, ground in an agate mortar and analyzed for Cu and Zn contents by 0.01 mol L-1 EDTA and chemically fractionated to determine Cu and Zn. The applications of Pig deep litter and slurry at doses equivalent to 90 kg ha-1 N increased the contents of available Cu and Zn in the surface soil layer, if the double of this dose was applied in pig deep litter or double this dose in pig slurry, Cu and Zn migrated to a depth of 15 cm. Copper is accumulated mainly in the organic and residual fractions, and zinc preferentially in the fraction linked to clay minerals, especially in the surface soil layers.

scholarly journals Spatial Distribution of Toxic Metal(loid)s and Microbial Community Analysis in Soil Vertical Profile at an Abandoned Nonferrous Metal Smelting Site

2020 ◽  
Vol 17 (19) ◽  
pp. 7101
Author(s):  
Jiejie Yang ◽  
Siqi Wang ◽  
Ziwen Guo ◽  
Yan Deng ◽  
Menglong Xu ◽  
...  
Keyword(s):  
Microbial Community ◽  
Microbial Communities ◽  
Soil Layer ◽  
Soil Microbial Communities ◽  
Toxic Metal ◽  
Soil Samples ◽  
Microbial Community Analysis ◽  
Rrna Gene ◽  
High Background ◽  
Top Soil

In this study soils at different depths were collected in a Zn smelting site located in Zhuzhou City, China, in order to understand toxic metal(loid)s distribution and microbial community in vertical soil profile at a smelting site. Except Soil properties and metal(loid)s content, the richness and diversity of microbial communities in soil samples were analyzed via high-throughput Illumina sequencing of 16s rRNA gene amplicons. The results showed that the content of As, Pb, Cu, Cd, Zn, and Mn was relatively high in top soil in comparison to subsoil, while the concentration of Cr in subsoil was comparable with that in top soil due to its relative high background value in this soil layer. The bioavailability of Cd, Mn, Zn, and Pb was relative higher than that of As, Cr, and Cu. The diversity of soil microbial communities decreased with increasing depth, which might be ascribed to the decrease in evenness with increase in depth duo to the influence by environmental conditions, such as pH, TK (total potassium), CEC (cation exchange capacity), ORP (oxidation reduction potential), and Bio-Cu (bioavailable copper). The results also found Acidobacteria, Proteobacteria, Firmicutes, and Chloroflexi were dominant phyla in soil samples. At the genus level, Acinetobacter, Pseudomonas, and Gp7 were dominant soil microorganism. Besides, Environmental factors, such as SOM (soil organic matter), pH, Bio-Cu, Bio-Cd (bioavailable cadmium), and Bio-Pb (bioavailable lead), greatly impacted microbial community in surface soil (1–3 m), while ORP, TK, and AN concentration influenced microbial community in the subsoil (4–10 m).

Spatial Distribution of As-Concentrations in the Contaminated Site by the Highly Toxic As-Chemicals

2014 ◽  
Vol 878 ◽  
pp. 797-805
Author(s):  
Feng Wu Peng ◽  
Ting Zhou ◽  
Shuan Jin Wei ◽  
Li Juan You ◽  
Xue Feng Wang ◽  
...  
Keyword(s):  
Spatial Distribution ◽  
Surface Soil ◽  
Soil Layer ◽  
Exponential Model ◽  
Space Structure ◽  
Soil Samples ◽  
Contaminated Site ◽  
Kriging Interpolation ◽  
Anthropogenic Factors ◽  
Arsenic Content

A total of 2668 surface soil samples (-0.5 m ~ 0 m) and 637 sub-layer soil samples (-1.0 m ~ -0.5 m) were collected from a contaminated site with an area of 26.19 hectares and analyzed the concentration of arsenic, so as to get the spatial distribution of arsenic concentrations in the soil contaminated by highly toxic As-chemicals. The results indicated that spatial correlation of arsenic content in surface soil was moderate. The optimal semivariogram model was the exponential model, and the best interpolation model was simple Kriging interpolation. The arsenic content of sub-layer was similar to that of surface soil in space structure, but weakly correlated. Analysis on the arsenic content in vertical sections showed that contamination was mainly concentrated in surface soil. The arsenic content in most of the collected samples reduced as the soil layer depth increased. Spatial variability of arsenic could be significantly affected by anthropogenic factors such as excavation & destruction of highly toxic As-chemicals and farming.

Outflows of Organic Halide Precursors from Forest Regions

1989 ◽  
Vol 21 (12) ◽  
pp. 1877-1880 ◽  
Author(s):  
S. Saito ◽  
K. Hattori ◽  
T. Okumura
Keyword(s):  
Water Quality ◽  
River Basin ◽  
Surface Soil ◽  
Soil Layer ◽  
Water Quality Monitoring ◽  
Quality Monitoring ◽  
Deep Soil ◽  
Organic Halide ◽  
Forest Regions ◽  
Surface Soil Layer

Outflows of organic halide precursors (OXPs) from forest regions were studied in relation to water quality monitoring in the Yodo River basin. Firstly, the contribution of outflows from forest regions relative to the total was roughly estimated. Then equations for flows of these substances were formulated, divided into four different subflow categories: precipitation; throughfall; surface soil layer; and, deep soil layer. Finally, annual outflow loads were calculated for a test forest area.

scholarly journals Assessment of Seasonal Variability in Soil Nutrients and Its Impact on Soil Quality under Different Land Use Systems of Lower Shiwalik Foothills of Himalaya, India

2021 ◽  
Vol 13 (3) ◽  
pp. 1398
Author(s):  
Tavjot Kaur ◽  
Simerpreet Kaur Sehgal ◽  
Satnam Singh ◽  
Sandeep Sharma ◽  
Salwinder Singh Dhaliwal ◽  
...  
Keyword(s):  
Land Use ◽  
Soil Quality ◽  
Surface Soil ◽  
Sandy Loam ◽  
Monsoon Season ◽  
Soil Layer ◽  
Seasonal Effects ◽  
Land Use Systems ◽  
Post Monsoon ◽  
Significant Difference

The present study was conducted to investigate the seasonal effects of five land use systems (LUSs), i.e., wheat–rice (Triticum aestivum—Oryza sativa) system, sugarcane (Saccharum officinarum), orange (Citrus sinensis) orchard, safeda (Eucalyptus globules) forest, and grassland, on soil quality and nutrient status in the lower Satluj basin of the Shiwalik foothills Himalaya, India. Samples were analyzed for assessment of physico-chemical properties at four soil depths, viz., 0–15, 15–30, 30–45, and 45–60 cm. A total of 120 soil samples were collected in both the seasons. Soil texture was found to be sandy loam and slightly alkaline in nature. The relative trend of soil organic carbon (SOC), macro- and micro-nutrient content for the five LUSs was forest > orchard > grassland > wheat–rice > sugarcane, in the pre- and post-monsoon seasons. SOC was highly correlated with macronutrients and micronutrients, whereas SOC was negatively correlated with soil pH (r = −0.818). The surface soil layer (0–15 cm) had a significantly higher content of SOC, and macro- and micro-nutrients compared to the sub-surface soil layers, due to the presence of more organic content in the soil surface layer. Tukey’s multiple comparison test was applied to assess significant difference (p < 0.05) among the five LUSs at four soil depths in both the seasons. Principle component analysis (PCA) identified that SOC and electrical conductivity (EC) were the most contributing soil indicators among the different land use systems, and that the post-monsoon season had better soil quality compared to the pre-monsoon season. These indicators helped in the assessment of soil health and fertility, and to monitor degraded agroecosystems for future soil conservation.

scholarly journals Biochar induced improvement in root system architecture enhances nutrient assimilation by cotton plant seedlings

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Lei Feng ◽  
Wanli Xu ◽  
Guangmu Tang ◽  
Meiying Gu ◽  
Zengchao Geng
Keyword(s):  
Root System ◽  
System Architecture ◽  
Fine Roots ◽  
Nitrogen Assimilation ◽  
Surface Soil ◽  
Soil Layer ◽  
Root System Architecture ◽  
Seedling Stage ◽  
Agronomic Efficiency ◽  
Surface Soil Layer

Abstract Background Raising nitrogen use efficiency of crops by improving root system architecture is highly essential not only to reduce costs of agricultural production but also to mitigate climate change. The physiological mechanisms of how biochar affects nitrogen assimilation by crop seedlings have not been well elucidated. Results Here, we report changes in root system architecture, activities of the key enzymes involved in nitrogen assimilation, and cytokinin (CTK) at the seedling stage of cotton with reduced urea usage and biochar application at different soil layers (0–10 cm and 10–20 cm). Active root absorption area, fresh weight, and nitrogen agronomic efficiency increased significantly when urea usage was reduced by 25% and biochar was applied in the surface soil layer. Glutamine oxoglutarate amino transferase (GOGAT) activity was closely related to the application depth of urea/biochar, and it increased when urea/biochar was applied in the 0–10 cm layer. Glutamic-pyruvic transaminase activity (GPT) increased significantly as well. Nitrate reductase (NR) activity was stimulated by CTK in the very fine roots but inhibited in the fine roots. In addition, AMT1;1, gdh3, and gdh2 were significantly up-regulated in the very fine roots when urea usage was reduced by 25% and biochar was applied. Conclusion Nitrogen assimilation efficiency was significantly affected when urea usage was reduced by 25% and biochar was applied in the surface soil layer at the seedling stage of cotton. The co-expression of gdh3 and gdh2 in the fine roots increased nitrogen agronomic efficiency. The synergistic expression of the ammonium transporter gene and gdh3 suggests that biochar may be beneficial to amino acid metabolism.

Bacterial influence on the formation of hematite: implications for Martian dormant life

2021 ◽  
pp. 1-15
Author(s):  
Sudeera Wickramarathna ◽  
Rohana Chandrajith ◽  
Atula Senaratne ◽  
Varun Paul ◽  
Padmanava Dash ◽  
...  
Keyword(s):  
Inductively Coupled Plasma ◽  
Soil Layer ◽  
Soil Samples ◽  
Mineral Weathering ◽  
Compositional Variation ◽  
Rrna Gene ◽  
Potential Candidate ◽  
Metabolic Processes ◽  
Extraterrestrial Life ◽  
X Ray

Abstract Previous exploration missions have revealed Mars as a potential candidate for the existence of extraterrestrial life. If life could have existed beneath the Martian subsurface, biosignatures would have been preserved in iron-rich minerals. Prior investigations of terrestrial biosignatures and metabolic processes of geological analogues would be beneficial for identifying past metabolic processes on Mars, particularly morphological and chemical signatures indicative of past life, where biological components could potentially be denatured following continued exposure to extreme conditions. The objective of the research was to find potential implications for Martian subsurface life by characterizing morphological, mineralogical and microbial signatures of hematite deposits, both hematite rock and related soil samples, collected from Highland Complex of Sri Lanka. Rock samples examined through scanning electron microscopy-energy dispersive X-ray (SEM-EDX) spectroscopy. Analysis showed globular and spherical growth layers nucleated by bacteria. EDX results showed a higher iron to oxygen ratio in nuclei colonies compared to growth layers, which indicated a compositional variation due to microbial interaction. X-ray diffraction analysis of the hematite samples revealed variations in chemical composition along the vertical soil profile, with the top surface soil layer being particularly enriched with Fe2O3, suggesting internal dissolution of hematite through weathering. Furthermore, inductively coupled plasma-mass spectrometry analyses carried out on both rock and soil samples showed a possible indication of microbially induced mineral-weathering, particularly release of trapped trace metals in the parent rock. Microbial diversity analysis using 16S rRNA gene sequencing revealed that the rock sample was dominated by Actinobacteria and Proteobacteria, specifically, members of iron-metabolizing bacterial genera, including Mycobacterium, Arthrobacter, Amycolatopsis, Nocardia and Pedomicrobium. These results suggest that morphological and biogeochemical clues derived from studying the role of bacterial activity in hematite weathering and precipitation processes can be implemented as potential comparative tools to interpret similar processes that could have occurred on early Mars.

scholarly journals Winter pasture and cover crops and their effects on soil and summer grain crops

2011 ◽  
Vol 46 (10) ◽  
pp. 1357-1363 ◽  
Author(s):  
Alvadi Antonio Balbinot Junior ◽  
Milton da Veiga ◽  
Anibal de Moraes ◽  
Adelino Pelissari ◽  
Álvaro Luiz Mafra ◽  
...  
Keyword(s):  
Land Use ◽  
Common Bean ◽  
Cover Crops ◽  
Nitrogen Fertilization ◽  
Soil Compaction ◽  
Surface Soil ◽  
Soil Layer ◽  
N Fertilization ◽  
The North ◽  
Oilseed Radish

The objective of this work was to evaluate the effect of winter land use on the amount of residual straw, the physical soil properties and grain yields of maize, common bean and soybean summer crops cultivated in succession. The experiment was carried out in the North Plateau of Santa Catarina state, Brazil, from May 2006 to April 2010. Five strategies of land use in winter were evaluated: intercropping with black oat + ryegrass + vetch, without grazing and nitrogen (N) fertilization (intercropping cover); the same intercropping, with grazing and 100 kg ha-1 of N per year topdressing (pasture with N); the same intercropping, with grazing and without nitrogen fertilization (pasture without N); oilseed radish, without grazing and nitrogen fertilization (oilseed radish); and natural vegetation, without grazing and nitrogen fertilization (fallow). Intercropping cover produces a greater amount of biomass in the system and, consequently, a greater accumulation of total and particulate organic carbon on the surface soil layer. However, land use in winter does not significantly affect soil physical properties related to soil compaction, nor the grain yield of maize, soybean and common bean cultivated in succession.

Pollen Taphonomy in a Canyon Stream

1987 ◽  
Vol 28 (3) ◽  
pp. 393-406 ◽  
Author(s):  
Patricia L. Fall
Keyword(s):  
Surface Soil ◽  
Pollen Grains ◽  
Close Correlation ◽  
Soil Samples ◽  
Alluvial Deposits ◽  
Modern Pollen ◽  
Pollen Types ◽  
Pollen Rain ◽  
Arid Steppe ◽  
Turbulent Water

AbstractSurface soil samples from the forested Chuska Mountains to the arid steppe of the Chinle Valley, Northeastern Arizona, show close correlation between modern pollen rain and vegetation. In contrast, modern alluvium is dominated by Pinus pollen throughout the canyon; it reflects neither the surrounding floodplain nor plateau vegetation. Pollen in surface soils is deposited by wind; pollen grains in alluvium are deposited by a stream as sedimentary particles. Clay-size particles correlate significantly with Pinus, Quercus, and Populus pollen. These pollen types settle, as clay does, in slack water. Chenopodiaceae-Amaranthus, Artemisia, other Tubuliflorae, and indeterminate pollen types correlate with sand-size particles, and are deposited by more turbulent water. Fluctuating pollen frequencies in alluvial deposits are related to sedimentology and do not reflect the local or regional vegetation where the sediments were deposited. Alluvial pollen is unreliable for reconstruction of paleoenvironments.

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