Inoculation of bacteria for the amelioration of sandy soil under drought

2020 ◽  
Author(s):  
Violeta Carmen Angulo Fernández ◽  
Mariet Hefting ◽  
George Kowalchuk
Keyword(s):  
Soil Compaction ◽  
Biofilm Formation ◽  
Soil Structure ◽  
Soil Microorganisms ◽  
Soil Aggregate ◽  
Soil Aggregation ◽  
Bacterial Strains ◽  
Mean Weight Diameter ◽  
Microbial Strains ◽  
The Mean

<p>Soil degradation represents a pressing worldwide problem that is being accelerated by processes of erosion, depletion of soil organic matter, soil compaction, acidification, salinization, and drought. Soil microorganisms can influence soil aggregation via a range of mechanisms such as the production of exopolysaccharides and other extracellular matrix polymers such those involved in biofilm formation. In this study, we south to use bacteria harboring specific traits to enhance soil aggregation. To this end, 120 bacterial strains were isolated from an experiment field under drought conditions and tested for their ability to grow under drought, salinity tolerance, rapid growth, biofilm, and exopolysacharides production. Based upon this trait assessment, 24 strains were further tested at two moisture levels for their ability to impact soil structure after 8 weeks of incubation at 25ºC. The mean weight diameter (MWD) of water-stable aggregates and carbohydrates were determined for treated soils. Three strains were shown to impact soil aggregate properties at the higher moisture content: one affiliated with <em>Bacillus </em>niacini, one affiliated with <em>Paenarthrobacter </em>nitroguajacolicus and one of unclear classification. The first of these strains also affected soil structure at the lower moisture level. This <em>B. </em>niacini strain also increased the carbohydrate content of the soil, as did two other strains, related to <em>B. </em>wiedmannii and <em>B. </em>aryabhattai, respectively. However, no positive correlation was observed between the MWD and the production of carbohydrates in soil. Our results suggest that soil inoculation with specific microbial strains can improve soil structure.</p>

Impact of maize cob and wood-derived biochar on soybean plant growth and soil aggregate structure in dry land

2020 ◽  
Author(s):  
Hua Ma ◽  
Qirui Li ◽  
Sonoko D. Bellingrath-Kimura
Keyword(s):  
Plant Growth ◽  
Grain Yield ◽  
Soil Structure ◽  
Clay Soil ◽  
Soil Aggregate ◽  
Mean Value ◽  
Soybean Plant ◽  
Aggregate Structure ◽  
Dry Land ◽  
The Mean

<p>Soil structure plays important roles in land degradation, soil fertility, and agricultural productivity and thus has great ecological importance. Soil aggregation is a crucial soil function for maintaining soil porosity and enhancing the stability of soil structure to prevent soil erosion. Biochar was reported to be a binding agent for organic matter in aggregate formation and thus alleviate aggregates degradation. Therefore, this study attempts to a) investigate the impact of the biochar on soybean plant growth, plant nutrients content and soil chemical properties; b) analyze the effect of maize cob biochar (CB) and wood biochar (WB) on soil aggregate structure in vulnerable dry land area.</p><p>Field trial was performed on two sandy soil fields (at MLZ and BDG village) and one loamy clay soil field (at RQ village) which located in Ningxia, China. Two treatments (20 t ha<sup>-1</sup> of CB and WB application) and control were repeated 7 times. In this study, we analyzed biomass, grain yield, and nutrients content of soybean plant while soil nutrients were observed as well. Nine soil aggregate size classes (ASCs) were obtained (>10, 10-7, 7-5, 5-3, 3-2, 2-1, 1-0.5, 0.5-0.25 and <0.25 mm) through dry sieving to analyze soil structure. In addition, soil dry mean weight diameter (dMWD), dry geometric mean diameter (dGMD), and structure coefficient (Ks) were measured to estimate the aggregate stability, erodible fraction, and agronomically valuable fraction. After that, redundancy analysis and ridge regression analysis were applied for further data processing.</p><p>Our results indicated <strong>a</strong><strong>)</strong><strong> </strong><strong>bio</strong><strong>m</strong><strong>ass</strong><strong> </strong><strong>and</strong><strong> gr</strong><strong>ain</strong><strong> </strong><strong>yie</strong><strong>ld</strong><strong>:</strong> both CB and WB significantly increased shoot biomass in loamy clay soil by 48.7% and 45.0%, respectively. In the two sandy soils, biochar indicated no significant enhancement on the plant growth and grain yield. Even though, the mean value of grain yield increased by 29.7% and 35.1% with the CB and WB application in the MLZ field, respectively. CB application also increased the mean value of grain yield by 34.2% in the BDG field. Although the data shows insignificant difference with high standard errors due to field heterogeneity, the mean values can still give insights into agricultural field practices; <strong>b</strong><strong>)</strong><strong> </strong><strong>soil</strong><strong> ag</strong><strong>gre</strong><strong>gat</strong><strong>e</strong><strong> </strong><strong>stru</strong><strong>c</strong><strong>ture</strong><strong>:</strong> soil type exerted stronger influence on soil aggregation and plant growth rather than biochar. The sandy field in MLZ showed high soil loss potential by wind erosion referring to a low value of dGMD, and the loamy clay field showed the highest dMWD, dGMD and Ks values for an ideal aggregate structure for crop growth. Findings indicate that biochar had no significant influence on aggregate structure in both sandy and loamy clay soils; <strong>c</strong><strong>) </strong><strong>soil</strong><strong> nut</strong><strong>rients</strong><strong>:</strong> CB can significantly increase soil total carbon content in RQ and BDG fields. Soil potassium content can be enhanced by CB application in loamy clay soil.</p>

scholarly journals Assessing of soil aggregate stability: the sand-correction and its relevance

2009 ◽  
pp. 29-47
Author(s):  
Andrea Huisz
Keyword(s):  
Wheat Straw ◽  
Soil Structure ◽  
Sandy Loam ◽  
Aggregate Stability ◽  
Index Formula ◽  
Soil Aggregate Stability ◽  
Mean Weight Diameter ◽  
Loam Soil ◽  
The Mean ◽  
Organic Matter Addition

Soil structure and changes in its quality caused by Maize stem (1), Wheat straw (2) and Maize stem & wheat straw (3) addition were assessed by three aggregate-stability indices. We observed that the NSI index formula proposed by Six et al. (2000) was nonsensitive to the changes in soil structure caused by the investigated organic matter addition. Furthermore it overestimates the aggregate-stability of the investigated silty sandy loam soil. Therefore we proposed a new modified NSI formula which is sensitive to the questionable treatments and that resulted in a morerealistic NSI data. The most sensitive index to differences of the investigated treatments were the Mean weight diameter (MWD) proposed by van Bavel (1953, in Kemper és Rosneau, 1986).

Controlling Erosion

1999 ◽  
Author(s):  
Robert F. Keefer
Keyword(s):  
Organic Matter ◽  
Organic Material ◽  
Soil Structure ◽  
Soil Microorganisms ◽  
Soil Aggregation ◽  
Water Infiltration ◽  
Root Penetration ◽  
Animal Remains ◽  
Decomposition Of Organic Matter ◽  
Structure Improvement

Erosion can be controlled by four main means, that is, improving soil structure, covering soil with plants, covering soil with mulch, and using special structures. Soil structure is related to the soil tilth, or physical condition of a soil, with respect to ease of tillage or workability as shown by the fitness of a soil as a seedbed and the ease of root penetration. Other terms relating to soil structure improvement are soil aggregation and the formation of aggregates. Aggregates form when a cementing substance is present in a soil. The most important cementing substances in soil are soil polysaccharides and soil polyuronides produced as by-products from microorganisms during decomposition of organic matter. Other less important cementing substances in soil include clays, Ca, and Fe. Formation of aggregates results in improved water infiltration with reduction in erosion. Decomposition of organic matter in soils can be shown as an equation: . . . Plant and animal remains + O2 + soil microorganisms → CO2 + H2O + elements + humus + synthates + energy . . . The decomposition process has the following features: . . . 1. Oxygen is required; thus soil aeration is important. Anytime a soil is stirred or mixed by cultivation, spading, plowing, some organic matter decomposition occurs. 2. Readily available decomposable organic material is required for the microbes to work on. Green organic material, such as grass clippings, is an excellent substrate. 3. Many different types of soil microorganisms are involved in this process. Decomposition is more rapid in soils at pH 7 (neutral). 4. A product of organic decomposition is humus. Humus has many desirable features that improve a soil for plant growth. 5. Plant or animal remains are not effective in soil aggregation until they begin to decompose. 6. The more rapid the decomposition, the greater effect of soil aggregation. . . . Microbial synthates consist of polymers called “polysaccharides” and “polyuronides.” A polymer is a long-chain compound made up of single monomer units hooked together acting as a unit. The term “poly” means “many” and “saccharide” means “sugar.”

scholarly journals Development and Formulation of the Experimental Dentifrice Based onPassiflora mollissima(Tumbo) with and without Fluoride Anion: Antibacterial Activity on Seven Antimicrobial Strains

2019 ◽  
Vol 2019 ◽  
pp. 1-8 ◽  
Author(s):  
Frank Mayta-Tovalino ◽  
Eloy Gamboa ◽  
Richard Sánchez ◽  
Jorge Rios ◽  
Ramín Medina ◽  
...  
Keyword(s):  
Antimicrobial Activity ◽  
Antibacterial Activity ◽  
Direct Contact ◽  
Antibacterial Effect ◽  
Fluoride Anion ◽  
Bacterial Strains ◽  
Microbial Strains ◽  
The Mean

Objectives. To develop and formulate a new experimental dentifrice with and without fluoride based on the peel and the fruit of thePassiflora mollissima(tumbo) and also to evaluate its antimicrobial activity against seven bacterial strains.Methods. The sample was calculated using the mean comparison formula, obtaining wells (n = 12) for each of the strains evaluated:S. mutans,E. faecalis,Actinomyces,Lactobacillus,C. albicans,S. sanguinis, andS. oralis. The antibacterial activity of the dentifrice was evaluated by the direct contact technique.Results. It was found that the highest antimicrobial activity was only present in pulp-based dentifrices against strains ofS. mutans21.0 ± 1.8,E. faecalis16.3 ± 3.9,Actinomyces22.1 ± 1.3, andLactobacillus21.0 ± 1.3. However, in comparison with other strains such asC. albicans,S. sanguinis, andS. oralis, the peel-based dendrifrice ofPassiflora mollissimaobtained the highest antimicrobial activity.Conclusion. The experimental dentifrice based onPassiflora mollissimahad an antibacterial effect against the seven microbial strains during the first 24 and 48 hours.

Lime application effects on soil aggregate properties: Use of the mean weight diameter and synchrotron-based X-ray μCT techniques

Geoderma ◽  
2019 ◽  
Vol 338 ◽  
pp. 585-596 ◽  
Author(s):  
Talita R. Ferreira ◽  
Luiz F. Pires ◽  
Dorthe Wildenschild ◽  
André M. Brinatti ◽  
Jaqueline A.R. Borges ◽  
...  
Keyword(s):  
Soil Aggregate ◽  
X Ray ◽  
Aggregate Properties ◽  
Mean Weight Diameter ◽  
The Mean ◽  
Lime Application

scholarly journals Soil Aggregate-Associated Carbon Fraction Dynamics during the Process of Tea (Camellia sinensis L.) Planting in Southern Guangxi, China

Forests ◽  
2021 ◽  
Vol 12 (11) ◽  
pp. 1530
Author(s):  
Chao Zhang ◽  
Xinxin He ◽  
Shaoming Ye ◽  
Shengqiang Wang
Keyword(s):  
Soil Aggregates ◽  
Aggregate Size ◽  
Soil Aggregate ◽  
Vital Role ◽  
Soil Layers ◽  
Mean Weight Diameter ◽  
Recalcitrant Carbon ◽  
Tea Plantations ◽  
The Mean ◽  
The Stability

Revealing the variation in soil aggregate-associated organic carbon (Corg) in tea plantations of various planting ages is crucial to shed more light on the accumulation and decomposition of soil Corg in the tea-planting period. This study measured the concentrations of soil Corg, active carbon (Cact), and recalcitrant carbon (Crec) in different-sized aggregates obtained from tea plantations of various planting ages (8, 17, 25, and 43 years old) at the soil depths of 0–20 and 20–40 cm in southern Guangxi, China. According to the wet-sieving approach, soil aggregates were classified as macro- (>0.25 mm) and micro- (<0.25 mm) aggregates, and the former were further divided into coarse (>2 mm), medium (2–1 mm), and fine (1–0.25 mm) fractions. Based on the mean weight diameter (MWD), the stability of soil aggregates was the highest in the 17-year-old tea plantations, and it was closely related to the concentration of soil Cact (0–20 cm: R2 = 0.9744, p < 0.05; 20–40 cm: R2 = 0.8951, p < 0.05), but not Corg (0–20 cm: R2 = 0.1532, p > 0.05; 20–40 cm: R2 = 0.4538, p > 0.05), during the tea-planting process. In the 0–20 and 20–40 cm soil layers, the coarse and medium macro-aggregates had higher concentrations of Corg, Cact, and Crec, regardless of the tea-planting age; meanwhile, the soil Cact/Crec ratio, indicating the Corg availability, increased as aggregate size increased, implying that the soil Corg was younger and more labile in coarse macro-aggregates relative to finer aggregates. Moreover, the tea-planting age significantly affected the Corg, Cact, and Crec reserves in both soil layers. To be specific, continuous tea planting facilitated the accumulation of soil Corg and Crec, but their reserves’ increase rates decreased over time; meanwhile, the soil Cact reserve increased during the early (from 8 to 17 years) tea-planting stage and later decreased. Therefore, during the middle (from 17 to 25 years) and late (from 25 to 43 years) tea-planting stages, maintaining the soil as an Cact pool plays a vital role in facilitating the formation and stabilization of soil aggregates in southern Guangxi, China.

Preliminary in Vitro Investigations on The Inhibitory Activity of The Original Dietary Supplement Oxidal® on Pathogenic Bacterial Strains

2020 ◽  
Vol 11 ◽  
pp. 37-43
Author(s):  
Prof. Teodora P. Popova ◽  
Toshka Petrova ◽  
Ignat Ignatov ◽  
Stoil Karadzhov
Keyword(s):  
Dietary Supplement ◽  
Broad Spectrum ◽  
Pathogenic Bacteria ◽  
Antimicrobial Agents ◽  
Clinical Effectiveness ◽  
Inhibitory Effect ◽  
Diffusion Method ◽  
Bacterial Strains ◽  
Microbial Strains

The antimicrobial action of the dietary supplement Oxidal® was tested using the classic Bauer and Kirby agar-gel diffusion method. Clinical and reference strains of Staphylococcus aureus and Escherichia coli were used in the studies. The tested dietary supplement showed a well-pronounced inhibitory effect against the microbial strains commensurable with that of the broad-spectrum chemotherapeutic agent Enrofloxacin and showed even higher activity than the broad spectrum antibiotic Thiamphenicol. The proven inhibitory effect of the tested dietary supplement against the examined pathogenic bacteria is in accordance with the established clinical effectiveness standards for antimicrobial agents.

scholarly journals Sludge amendment accelerating reclamation process of reconstructed mining substrates

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Dan Li ◽  
Ningning Yin ◽  
Ruiwei Xu ◽  
Liping Wang ◽  
Zhen Zhang ◽  
...  
Keyword(s):  
Soil Structure ◽  
Aggregate Stability ◽  
Soil Aggregate ◽  
Soil Reclamation ◽  
Soil Restoration ◽  
Total Biomass ◽  
Soil Aggregate Stability ◽  
Mining Soil ◽  
Positive Correlations ◽  
Reclamation Process

AbstractWe constructed a mining soil restoration system combining plant, complex substrate and microbe. Sludge was added to reconstructed mine substrates (RMS) to accelerate the reclamation process. The effect of sludge on plant growth, microbial activity, soil aggregate stability, and aggregation-associated soil characteristics was monitored during 10 years of reclamation. Results show that the height and total biomass of ryegrass increases with reclamation time. Sludge amendment increases the aggregate binding agent content and soil aggregate stability. Soil organic carbon (SOC) and light-fraction SOC (LFOC) in the RMS increase by 151% and 247% compared with those of the control, respectively. A similar trend was observed for the glomalin-related soil protein (GRSP). Stable soil aggregate indexes increase until the seventh year. In short, the variables of RMS determined after 3–7 years insignificantly differ from those of the untreated sample in the tenth-year. Furthermore, significant positive correlations between the GRSP and SOC and GRSP and soil structure-related variables were observed in RMS. Biological stimulation of the SOC and GRSP accelerates the recovery of the soil structure and ecosystem function. Consequently, the plant–complex substrate–microbe ecological restoration system can be used as an effective tool in early mining soil reclamation.

scholarly journals Bond Strengthening in Oral Bacterial Adhesion to Salivary Conditioning Films

2008 ◽  
Vol 74 (17) ◽  
pp. 5511-5515 ◽  
Author(s):  
Henny C. van der Mei ◽  
Minie Rustema-Abbing ◽  
Joop de Vries ◽  
Henk J. Busscher
Keyword(s):  
Bacterial Adhesion ◽  
Biofilm Formation ◽  
Specific Interactions ◽  
Adhesion Forces ◽  
Bacterial Strains ◽  
Bacterial Interactions ◽  
Initial Adhesion ◽  
Conditioning Film ◽  
Interacting Surfaces ◽  
Conditioning Films

ABSTRACT Transition from reversible to irreversible bacterial adhesion is a highly relevant but poorly understood step in initial biofilm formation. We hypothesize that in oral biofilm formation, irreversible adhesion is caused by bond strengthening due to specific bacterial interactions with salivary conditioning films. Here, we compared the initial adhesion of six oral bacterial strains to salivary conditioning films with their adhesion to a bovine serum albumin (BSA) coating and related their adhesion to the strengthening of the binding forces measured with bacteria-coated atomic force microscopy cantilevers. All strains adhered in higher numbers to salivary conditioning films than to BSA coatings, and specific bacterial interactions with salivary conditioning films were accompanied by stronger initial adhesion forces. Bond strengthening occurred on a time scale of several tens of seconds and was slower for actinomyces than for streptococci. Nonspecific interactions between bacteria and BSA coatings strengthened twofold faster than their specific interactions with salivary conditioning films, likely because specific interactions require a closer approach of interacting surfaces with the removal of interfacial water and a more extensive rearrangement of surface structures. After bond strengthening, bacterial adhesion forces with a salivary conditioning film remained stronger than those with BSA coatings.

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