Quantitative comparison of ammonia and 3-indoleacetic acid production in halophilic, alkalophilic and haloalkalophilic bacterial isolates in soil

In order to measure the concentration of ammonia production via corrected Nesslerization method and 3-indoleacetic acid as Salkowski method in halophilic, alkalophilic and haloalkalophilic bacterial isolates, soil samples were collected from six different areas of Khorasan Razavi and bacterial isolates isolated and purified using different growth medium accordingly. The alkalophiles isolates showed maximum ammonia production (0.055%) among the three groups of bacteria which this amount was 9.5 times of its average in haloalkalophiles isolates (0.0058%) and 13 times of ammonia production average in halophiles (0.004%). Mean comparison of the concentration3-indoleacetic acid production in three groups also showed that the most isolates of halophiles, alkalophiles and haloalkalophiles were IAA producer with 0.0003, 0.0001 and 0.0021percent respectively that the IAA amount in haloalkalophilic group was about 6 and 14.5 times of it in halophilic and alkalophilic isolates respectively. Equations to predict the concentration of ammonia and 3-indole acetic acid production was only significant in the haloalkalophilic isolates for ammonia production (P=0.046) and halophilic isolates for IAA production (P=0.015) under effect of electrical conductivity and pH in 0.05 probability level. Results represented that the multiple regression analysis for prediction of ammonia and IAA concentrations producing by isolates had not any significant performance in high and low concentrations under effect of electrical conductivity and pH. It seems that the uses of the two sensitive measuring methods (Nesslerization and Salkowski) after some modifications show promises and are recommend able in research due to their ease of implementation and relatively accurate results.Keywords: Alkalophiles; haloalkalophiles; halophiles; 3-indoleacetic acid; nesslerization method; salkowski method

Impact of Silicon Foliar Application on the Growth and Physiological Traits of Carthamus tinctorius L. Exposed to Salt Stress

Althought safflower is a tolerant crop against many environmental stresses, but its yield and performance reduce under stress. The aim of this experiment was to investigate the effect of silicon (Si) application on the possibility of increasing salinity resistance and related mechanisms in safflower. A greenhouse experiment was conducted to investigate the effects of Si spraying (0, 1.5 and 2.5 mM) on safflower plants grown under salt stress condition (non-saline and 10 dS m−1). Salinity reduced seedling emergence percent and rate, growth parameters and disrupted ion uptake but increased emergence time and specifc leaf weight. Spraying of Si increased plant height, fresh and dry weight, leaf area, relative water content (RWC), potassium, calcium and silicon content, while sodium absorption was decreased. As a result, the K+/Na+ and Ca2+/Na+ ratios were increased. Elevated ion contents and ratios indicate an enhanced selectivity of ion uptake following silicon application and may increase ion discrimination against Na+. Treatment with 2.5 mM Si showed the most positive effect on the measured growth traits. Decrement in leaf area ratio under salinity indicates a more severe effect of salinity on leaf area compared to biomass production. On the other hand, silicon reduced the specific leaf weight under stress and non-stress conditions, which revalues the positive effects of silicon on leaf area expansion. Improvement of RWC may a reason for the icrease in leaf area and biomass production. Data shows that spraying with Si especialy with 2.5 mM can reduce salinity stress damage to safflower and increase biomass production

Comparative study of dimensional accuracy in three dental implant impression techniques: Open tray, closed tray with impression coping, and snap cap

Aim: Several impression techniques have been proposed to result passive fitness between the prosthesis and osseointegrated implant. The aim of the study was to compare dimensional accuracy of three impression methods: Open tray, closed tray with impression coping, and closed tray with snap cap. Materials and methods: In this experimental study, a mandibular acrylic model was prepared with a milling machine to place three holes for dental implant analogs (Dio SM) with the dimension of 3.8 � 10 mm into the intended sites (one in midline and two others on the side at a distance of 10 mm) parallel with each other and perpendicular to the plane. Twenty-seven casts were prepared with impression material of polyvinyl siloxane (PVS) and dental stone type IV and divided into three groups. Implant situations were measured by coordinate measuring machine (CMM) and results were analyzed with Kruskal-Wallis and Mann-Whitney test to perform pairwise comparison among the groups. Results: The mean �R values for open tray, closed tray with impression coping, and closed tray with snap cap were respectively, 0.070 ± 0.088, 0.173 ± 0.205, and 0.142 ± 0.044.There were statistically significant differences between open tray and closed tray as well as open tray and snap cap methods (p < 0.05), but there was no statistically significant difference between closed tray and snap cap method (p = 0.1). Conclusion: Regarding the results, open tray impression technique had the highest dimensional accuracy compared with the other two methods. There were no statically significant differences between closed tray with snap cap and closed tray with impression coping technique. Clinical significance: Snap cap technique is less time consuming with similar dimensional accuracy in comparison with open tray impression technique. © 2018 Jaypee Brothers Medical Publishers (P) Ltd

Chemistry of indigenous Zn and Cu in the soil-water system : alkaline sodic and acidic soils / by Amir Fotovat.

Copies of author's previously published articles inserted.Bibliography: leaves 195-230.xx, 320 leaves : ill. (some col.) ; 30 cm.In this study the soil aqueous phase chemistry of Zn and Cu in alkaline sodic soils are investigated. The chemistry of trace metal ions at indigenous concentrations in alkaline sodic soils are reported. Metal ions at low concentrations are measured by the graphite furnace atomic absorption spectrometry (GFAAS) technique.Thesis (Ph.D.)--University of Adelaide, Dept. of Soil Science, 199

Evaluation of Zn[Mn]-Al LDHs as Matrices for Release of B, Zn and Mn in A Simulated Soil Solution

Introduction Boron (B) has a dual effect on living systems, so that the concentration range within which B is changed from a nutrient to a pollutant is rather narrow. Although B plays essential roles in all living organisms, its long-term excessive uptake has adverse effects on either human beings or plants and animals. Furthermore, part of the B that can be used as fertilizer is highly soluble and easily leached into the soil profile leadsing to some problems such as decrease of fertilizer efficiency. Therefore, to improve agricultural productivity through its gradual uptake by plants, the increase of B adsorption in the soil solution is necessary. Many adsorbents have been used for the adsorption of B from aqueous solutions; however, layered double hydroxides (LDHs) have been considered as one of the most effective adsorbents as well as slow releaser fertilizers of inorganic anions such as nitrate, phosphate, etc. The formula of LDHs are typically denoted as [M1-x 2+M x 3+ (OH)2]x+ (An-) x/n .m(H2O), where M2+ and M3+ are divalent and trivalent cations, respectively, the significance of x is the molar ratio of M3+/(M3++ M2+) and An- is the intercalated anion. Although LDH materials are commonly prepared by combining two divalent and trivalent metals, more metals can be introduced in the brucite layer to achieve a large variety of composition and higher adsorption capacity. Stability of LDHs in soil can be affected by numerous factors (e.g. low molecular weight organic acids (LMWOAs)) leading to release of structural cations in addition to interlayer anion. However, there are scarce investigations that have evaluated the potential of ternary LDHs (e.g. Zn–Mn–Al LDH) in desorption of B (as interlayer anion) and release of Zn and Mn (as structural anions) in a simulated soil solution. Therefore, the objectives of this study were, i) to compare the desorption of B capacity of binary LDH (Zn–Al LDH) and ternary LDH (Zn–Mn–Al LDH) in the simulated soil solution, and ii) to investigate the effect of three different electrolytes (potassium nitrate, oxalic acid, and citric acid) on the release of Zn and Mn from synthesized LDHs. Materials and methods  A modified urea hydrolysis method was employed to synthesize Zn–Al and Mn-substituted Zn–Al LDHs with Zn(+Mn)/Al molar ratio of 2. Herein the contents of Mn with respect to Zn corresponded to 2% and 10% molar ratio. Accordingly, the synthesized materials denoted as Zn–Al, Zn–Mn1 and Zn–Mn2 for the samples without Mn, with 2 and 10 mol% Mn with respect to Zn content. For investigation of B desorption at a concentration of 10 mM, 15 mL from equilibrium solutions were substituted with 15 mL of 0.03 M KNO3 and shaken for 240 min. Substitution was repeated four times and A modified urea hydrolysis method was employed to synthesize Zn–Al and Mn-substituted Zn–Al LDHs with Zn (+Mn)/Al molar ratio of 2. Herein the contents of Mn with respect to Zn corresponded to 2% and 10% molar ratio. Accordingly, the synthesized materials denoted as Zn–Al, Zn–Mn1 and Zn–Mn2 for the samples without Mn, with 2 and 10 mol% Mn with respect to Zn content. For investiigatigatingon of B desorption at a concentration of 10 mM, 15 mL from equilibrium solutions were substituted with 15 mL of 0.03 M KNO3 and shaken for 240 min. Substitution was repeated four times and B concentrations in extracts were measured by Azomethine-H method. Furthermore, the supernatant Zn and Mn concentrations were determined by GF-AAS (PG 900). This process was repeated for 1.25 mM oxalic acid and 1.25 mM citric acid to study the effect of these compounds on B desorption as well as release of Zn and Mn. B concentrations in extracts were measured by Azomethine-H method. Furthermore, the supernatant Zn and Mn concentrations were determined by GF-AAS (PG 900). This process was repeated for 1.25 mM oxalic acid and 1.25 mM citric acid to study the effect of these compounds on B desorption as well as release of Zn and Mn. Results and Discussion The adsorption and desorption isotherm were carried out to describe the distribution of B between the liquid and adsorbent. The isotherm data of synthesized LDHs were matched with Freundlich model. The values of 1/n in this model were found between 0 and 1 for all LDHs indicating favorable sorption of B on these compounds. The highest adsorption was observed for ternary LDHs (particularly Zn–Mn2) due to their higher specific surface area and also due to the ion exchange mechanism in combination with surface adsorption. However, the results showed that the percentages of B desorption by potassium nitrate, oxalic acid and citric acid were lower for Zn–Mn1 (19.4, 29.1 and 38.2%, respectively) and Zn–Mn2 (18.6, 28.2 and 35.9 %, respectively) than Zn–Al (30.8, 41.2 and 46.2%, respectively). This observation suggests that the type of LDH, B adsorption mechanism and background electrolyte can affect the amount of B desorption. Furthermore, after 4 successive desorption cycles, the concentration of Zn and Mn increased in the supernatants (particularly in organic acid electrolytes) suggesting dissolution mechanism possibility happened for the studied LDHs. Among the background electrolytes, citric acid was the most effective compound in releasing Zn and Mn, followed by oxalic acid and potassium nitrate. A reason for this such observations could be that with respect to chemical structure, citric acid by three carboxyl groups can form more chelate rings compared to oxalic acid, which contain two carboxyl groups. Therefore, it seems that B containing Zn–Mn–Al LDH may have potential to be used as a slow release fertilizer in soils to supply three essential elements, including B, Zn and Mn simultaneously. However, further studies are required to support such a hypothesis

Evaluating the effect of organic matter on soil quality score functions

Soil quality is important for evaluating the soil fertility and physical condition. Soil physical and chemical indicators should be regarded for determining the soil quality. This research was conducted to study the effect of organic matter on quantitative value of soil quality. Three level (15, 30, and 60 ton/ha) of different organic compounds including municipal waste compost, sewage sludge, cattle manure, and wheat straw to gether with control treatment in three replications were applied into loamy soil. The treated soils were kept for 6 months at 70% of field capacity moisture in greenhouse condition. Then soil quality determined based on non-linear score function by using of 14 physical and chemical indicators. The results showed that the score of control treatment was 52.7, which it belong to class 4, i.e. low quality. Addition of different organic matter into studied soil led to improve soil quality score and soil quality class was increased one to 2 degrees. Among the studied treatments, the highest score of soil quality was obtained in 60 ton/ha sewage sludge and 30 and 60 ton/ha compost. Also, addition the other organic treatments cause to increase the quantitative soil quality score in relation to control, and soil quality class increased one degree. Among the studied indicators, iron (Fe), Manganese (Mn), zinc (Zn) micro-nutrients, aeration porosity (AC), and mean weight diameter of aggregates (MWD) were the important limiting indictors in degrading the soil quality in control treatment, and applying the compost and sewage sludge increased their scores

Effect of Iron Oxides (Ordinary and Nano) and Municipal Solid Waste Compost (MSWC) Coated Sulfur on Wheat (Triticum aestivum L.) Plant Iron Concentration and Growth

Abstract A greenhouse study was conducted to compare the effects of ordinary iron oxide (0.02-0.06 mm) and nano iron oxide (25-250 nm) and five levels of both iron oxides (0, 0.05, 0.1, 0.5, and 1.0 %w/w) and two levels of sulfurous granular compost (MSW) (0 and 2% w/w) on plant height, spike length, grain weight per spike, total plant dry matter weight and thousands grain weight of wheat. The experimental factors were combined in factorial arrangement in a completely randomized design with 3 replications. Results showed that nano iron oxide was superior over ordinary iron oxide in all parameters studied. Fe concentration, spike length, plant height, grain weight per spike, total plant dry weight and thousands grain weight showed increasing trend per increase in both of iron oxides levels. Also, all parameters studied in sulfurous granular compost (MSW) treatment were superior over granular compost without sulfurous (MSW). This increase in all parameters were significantly higher when urban solid waste compost coated with sulfur coupled with nano iron oxide compared to urban sulfurous granular compost (MSW) along with ordinary iron oxide. Keywords: Sulfurous granular compost (MSW), Nano and ordinary iron oxides, Whea

Heavy Metal of Pb and Zn Elements in Mine Wastes by Zeolite and Triple Super Phosphate and their Impacts on Wheat Growth

Abstract\ud Heavy metal pollution in soil and environment can be reduced by their immobilization. The effects of chemical amendments as zeolite with three levels, 0 (Z1), 5% (Z2) and 10% (Z3) and triple super phosphate with three levels, 0 (P1), 0.25% (P2) and 0.5% (P3) on mine wastes collected and uptake of Pb and Zn by plant and wheat growth were determined. The mine waste was from Bama mine around Esfahan with very high total concentration of Pb (2300 mg kg-1) and Zn (16500 mg kg-1). Dry weight and concentrations of Pb and Zn by wheat in amended soils were studied under greenhouse conditions. Result showed that the application of amendments zeolite and phosphorous decreased Pb concentration in above ground plant biomass and Pb concentration was increased in wheat root. The interaction effect of zeolite and phosphorous on Pb concentration in above ground plant biomass and root was not significant. But in case of Zn element, only phosphorous amendment resulted in concentration reduction in above ground plant biomass and increased concentration in wheat root. The interaction effect of zeolite and phosphorous on Zn concentration reduction of above ground plant biomass and increase in Zn concentration of root were not significant. Moreover, wheat growth in the treated mine waste was superior to its growth in untreated mine waste. Zeolite did not show any effect on wheat growth. However, the interaction effects of zeolite and phosphorous on increasing of wheat above ground and root dry weight were significant.\ud \ud Keywords: Soil pollution, Heavy metals, Chemical amendments, Immobilizatio