scholarly journals Effects of Metribuzin on the abundance and activity of some groups of soil microorganisms

Pesticidi ◽  
2003 ◽  
Vol 18 (2) ◽  
pp. 99-107 ◽  
Author(s):  
Ljiljana Radivojevic ◽  
Ljiljana Santric ◽  
Radmila Stankovic-Kalezic ◽  
Dragica Brkic ◽  
Vaskrsija Janjic

Effects of the metribuzin herbicide on soil microorganisms were investigated Trials were set up on a chernozem soil in laboratory environment. Metribuzin application rates were 0.3, 0.6, 1.2 and 2.4 mg a.i./500g air-dry soil at 10?C, 20?C and 30?C. Soil respiration (amount of released CO2) and abundance of total microflora, fungi, actinomycetes, cellulolytics, ammonifiers nitrifiers, aerobic nitrogen fixiers (Azotobacter) and anaerobic nitrogen fixiers (Clostridium) were studied. Metribuzin was found to inhibit soil respiration, causing statistically highly significant changes of that area of microbiological activity in almost all trial variants. The effect of metribuzin on microorganism abundance varied. It caused a decrease in total microflora, fungi, cellulolytics, nitrifiers, and aerobic and anaerobic nitrogen fixiers (Azotobacter and Clostridium) at all temperatures, and reduced the abundance of actinomycetes at 10?C and 30?C. No effect on ammonifiers was recorded.

Pesticidi ◽  
2003 ◽  
Vol 18 (2) ◽  
pp. 109-114
Author(s):  
Ljiljana Santric ◽  
Vaskrsija Janjic ◽  
Ljiljana Radivojevic

Effect of the herbicide Fomesafen on the abundance of soil microorganisms was investigated. The abundance of total microflora, fungi, actinomycetes aerobic nitrogen fixing bacteria (Azotobacter) and cellulolytic bacteria was studied. Trials were set up on smonitza and alluvium soil types in laboratory environment. Fomesafen was applied at 0.2 and 0.4 kg/ha rate. Microbiological analysis was done 1, 3, 7, 14, 30 and 60 days after treatment. The acquired results showed that fomesafen had caused a decrease in the abundance of total microorganisms, aerobic nitrogen fixing bacteria and cellulolytic bacteria, the highest effect being recorded in the interval between the 7th and 14th post-treatment days. The most susceptible genus was Azotobacter. Fomesafen was found to cause an increase in the abundance of actinomycetes, while no shangein fungi abundance was recorded. No difference in the intensity of effect on the investigated parameters was found between the applied rate and soil type, except a 36% reduction of total microorganisms on smonitza and 51% on alluvium, and 48% reduction of cellulolytic bacteria on smonitza and 41% on alluvium.


2013 ◽  
Vol 27 (2) ◽  
pp. 151-158 ◽  
Author(s):  
S. Jezierska-Tys ◽  
A. Rutkowska

Abstract The effect of chemicals (Reglone 200 SL and Elastiq 550 EC) on soil microorganisms and their enzymatic activity was estimated. The study was conducted in a field experiment which was set up in the split-block design and comprised three treatments. Soil samples were taken six times, twice in each year of study. The results showed that the application of chemicals generally had no negative effect on the number of soil microorganisms. The application of Reglone 200 SL caused an increase of proteolytic and ureolytic activity and affected the activity of dehydrogenases, acid and alkaline phosphatases in the soil. The soil subjected of Elastiq 550 EC was characterized by lower activity of dehydrogenases, protease, urease and alkaline phosphatase.


2021 ◽  
pp. 155335062110080
Author(s):  
Lara Blanco Terés ◽  
Carlos Cerdán Santacruz ◽  
Javier García Septiem ◽  
Rocío Maqueda González ◽  
José María Lopesino González ◽  
...  

Introduction: The pandemic produced by SARS-CoV-2 has obliged us to set up the tele-assistance to offer a continuity of care. This implies an innovation, being the degree of satisfaction of patients unknown. Methods: A telephonic survey was conducted with the validated in the Spanish tool Telehealth Usability Questionnaire (Telehealth Usability Questionnaire; rating from 1-7) of all candidate patients assisted consecutively in the Coloproctology Unit. We included demographic variables, education level, job status, diagnosis and consultation type. A descriptive study was done. The relationship between the willingness of consultation model in the future (telemedicine vs traditional) and the categorical variables was analysed through the chi-squared test. Results: A total of 115 patients were included. The average age was 59.9 years, being 60% women. The average score in each of the survey items was higher than 6 in all the questions but 1. 26.1% of the surveyed patients confessed being advocated to tele-assistance in the future. The only factors related to greater willingness to tele-assistance were male gender (37% vs 18.8%; P = .03) and a higher academic preparation level in favour of higher technical studies (35.9%) and university studies (32.4%) opposite to the rest ( P = .043). The rest of variables studied, job status, labour regimen, diagnostic group and consultation type did not show any relationship. Conclusions: A vast majority of patients answered favourably to almost all the items of the survey. However, only 26.1% of them would choose a model of tele-assistance without restrictions.


2020 ◽  
Vol 21 (12) ◽  
pp. 4364
Author(s):  
Giuseppa De Luca ◽  
Barbara Cardinali ◽  
Lucia Del Mastro ◽  
Sonia Lastraioli ◽  
Franca Carli ◽  
...  

Molecular characterization of Circulating Tumor Cells (CTCs) is still challenging, despite attempts to minimize the drawbacks of Whole Genome Amplification (WGA). In this paper, we propose a Next-Generation Sequencing (NGS) optimized protocol based on molecular tagging technology, in order to detect CTCs mutations while skipping the WGA step. MDA-MB-231 and MCF-7 cell lines, as well as leukocytes, were sorted into pools (2–5 cells) using a DEPArray™ system and were employed to set up the overall NGS procedure. A substantial reduction of reagent volume for the preparation of libraries was performed, in order to fit the limited DNA templates directly derived from cell lysates. Known variants in TP53, KRAS, and PIK3CA genes were detected in almost all the cell line pools (35/37 pools, 94.6%). No additional alterations, other than those which were expected, were found in all tested pools and no mutations were detected in leukocytes. The translational value of the optimized NGS workflow is confirmed by sequencing CTCs pools isolated from eight breast cancer patients and through the successful detection of variants. In conclusion, this study shows that the proposed NGS molecular tagging approach is technically feasible and, compared to traditional NGS approaches, has the advantage of filtering out the artifacts generated during library amplification, allowing for the reliable detection of mutations and, thus, making it highly promising for clinical use.


Author(s):  
Janja Kuzevski ◽  
Nada Milosevic ◽  
Sasa Krstanovic ◽  
Zora Jelicic

In sugar beet production, one of the most important factors that affect the yield, apart from genetic properties, is the use of mineral fertilizers. Considerate amounts of mineral fertilizers are used in sugar beet production. However, if agroecological conditions are not optimum, mineral fertilizers cannot be completely absorbed, which may lead to soil contamination. Therefore, research has been focusing on ways of using atmospheric nitrogen by means of nitrogen-fixing bacteria. Numerous researches have proved that one part of mineral fertilizers can be replaced by biological nitrogen. The aim of this research was to determine the effect of genotype, azotobacter and the amount of mineral fertilizers on the root yield of sugar beet and on the microbiological activity of the sugar beet rhizospheric soil. Three hybrids of sugar beet were used during the two years of the research. The seed of the hybrids was inoculated with three strains of azotobacter. Various amounts of NPK were used (0;30;60;90 kg/ha). At the end of the vegetation period, the following were determined: root yield, total number of bacteria, number of azotobacter, oligotrophic bacteria, ammonifiers, fungi, and actinomycetes in soil. Dehydrogenase activity was measured. The results were processed statistically (analysis of variance for factorial trials) and the effect of the factors was determined upon the expected mean square values. The yield was mainly affected by the amount of mineral fertilizers. However, the effect of mineral fertilizers was different with different inoculation treatments. The effect of the examined factors was dependant upon genotype, amount of mineral fertilizers, inoculation and the year of trials. The interaction between genotype, mineral fertilizers, inoculation and the year of trials was the factor that had the greatest effect on the number of almost all the examined soil microorganisms.


Author(s):  
Zaven A. Arabadzhyan

After a century since the Soviet-Iranian Treaty was signed in 1921 authors of the article consider its significance from a new viewpoint – as the backing of the sovereignty of Iran and Russia that supported development of their relations. Authors examine the way it complied with the interests of Russia and Iran, and its impact on the bilateral relations in the 20th century. The signing of the Treaty secured the sovereignty of Iran, served as the base for the development of equal relations between the two neighboring states and opened up Iran for relations with foreign states. For the Russia, this document was a step towards breaking its diplomatic isolation. The authors emphasize that Russia had granted almost all its property to Iran which contributed to the improvement of the financial situation in Iran and served as a base for the development of mutually beneficial economic relations between the two countries. The authors mention that the property transfer clause was connected with the security of the Soviet Russia. This fact was reflected in the Article 6 of the Treaty. The Treaty set up the basement for the legal status of the Caspian Sea as a closed sea in the states' joint usage. The Convention on the Legal Status of the Caspian Sea, signed in 2018, to some extent retained the special regime of the sea and reflected the spirit of the Treaty of 1921. Although in IRI there are different views about the Treaty some experts consider that it generally complied with Iran's national interests.


2015 ◽  
Vol 39 (1) ◽  
pp. 31-39 ◽  
Author(s):  
Ivanildo Amorim de Oliveira ◽  
Milton César Costa Campos ◽  
José Marques Junior ◽  
Renato Eleotério de Aquino ◽  
Daniel de Bortoli Teixeira ◽  
...  

The lack of information concerning the variability of soil properties has been a major concern of researchers in the Amazon region. Thus, the aim of this study was to evaluate the spatial variability of soil chemical properties and determine minimal sampling density to characterize the variability of these properties in five environments located in the south of the State of Amazonas, Brazil. The five environments were archaeological dark earth (ADE), forest, pasture land, agroforestry operation, and sugarcane crop. Regular 70 × 70 m mesh grids were set up in these areas, with 64 sample points spaced at 10 m distance. Soil samples were collected at the 0.0-0.1 m depth. The chemical properties of pH in water, OM, P, K, Ca, Mg, H+Al, SB, CEC, and V were determined at these points. Data were analyzed by descriptive and geostatistical analyses. A large part of the data analyzed showed spatial dependence. Chemical properties were best fitted to the spherical model in almost all the environments evaluated, except for the sugarcane field with a better fit to the exponential model. ADE and sugarcane areas had greater heterogeneity of soil chemical properties, showing a greater range and higher sampling density; however, forest and agroforestry areas had less variability of chemical properties.


2013 ◽  
pp. 51-54
Author(s):  
Lajos Karancsi

The field research was set up on chernozem soil at the Látókép AGTC KIT research area of the University of Debrecen. The study focused on yield, water utilization, nutrient reaction and the amount of yield per kg fertilizer of corn hybrid NX 47279 in 2011 and 2012. Based on the yield results it can be concluded that the largest yield in 2011 was 15 963 kg ha-1 at level N120+PK, while in 2012, the maximum yield amounted to 14 972 kg ha-1 at level N90+PK. Surplus yield per kg fertilizer proved that in 2011 level N30+PK resulted in the highest surplus yield (42.3 kg kg-1) compared to the control treatment. In 2012, yield growth was 18.0 kg kg-1 compared to the control treatment. We measured at level N60+PK 17,5 kg kg-1 compared to at level N30+PK, at the N90+PK 17,7 kg kg-1 compared to at level N60+PK. level N30+PK kg kg-1, 17.5 kg kg-1 at level N60+PK and 17.7 kg kg-1 at level N90+PK compared to the control treatment. Results of the regression analysis showed that the amount of nitrogen fertilizer was 117 kg ha-1 in 2011 and 111 kg ha-1 in 2012 in order to reach maximum yield. Doses of fertilizers above the amounts previously mentioned resulted in yield decrease. Our results indicated that in the drought year of 2012 the hybrid used available water more efficiently than in 2011. The hybrid produced 59 kg ha-1 yield in 2012 and 51.9 kg ha-1 in 2011 at an optimum nutrition level.


2014 ◽  
pp. 55-59
Author(s):  
Lajos Karancsi

The research was set up on chernozem soil at the Látókép MÉK research area of the University of Debrecen in Hungary. We examined the following factors of the hybrid P9494, P9578, PR37N01 and PR37M81 in 2013.Yield, yield production per 1 kg fertilizer, water utilization and nutrient reaction. We found that the best yield results were achieved at level N120+PK in case of hybrid P9494 (17 132 kg ha-1) P9578 (16 838 kg ha-1) and PR37N01 (17 476 kg ha-1) and at level N150+PK for hybrid PR37M81 (16 754 kg ha-1). Results of yield per 1 kg NPK studies indicate that the most intense yield growth occurred at level N30+PK compared to the control treatment. This means that yield production per 1 kg NPK was 39.2 kg kg-1 in the case of hybrid P9494, 54.2 kg kg-1 in the case of P9578, 17.6 kg kg-1 for PR37N01 and 44.2 kg kg-1 in the case of PR37M81. After comparing corn hybrids’ water utilization, our conclusion was that the control treatment achieved the worst results in the case of each hybrid (P9494: 20.8 kg mm-1, P9578: 21.0 kg mm-1, PR37N01: 26.2 kg mm-1, PR37M81: 19.5 kg mm-1). For hybrid P9494, P9578 and P37N01, the best water utilization results were measured at level N120+PK (31.5 kg mm-1, 31,0 kg mm-1 and 32.1 kg mm-1), while PR37M81 reached the highest values at level N150+PK (30.8 kg mm-1). We determined the hybrids’ nutrient reaction and its optimum fertilizer values. The best nutrient reaction results were achieved by hybrid PR37N01, while that of hybrid PR37M81 proved to be the weakest.


2018 ◽  
Vol 1 ◽  
pp. 27
Author(s):  
Leah Nyangasi ◽  
Dickson Andala ◽  
Charles Onindo ◽  
Alphonse Wanyonyi ◽  
Josphine Chepngetich

Background: Electrospinning is a technique for producing nanofibers, useful in many fields of nanotechnology. The size and morphology of the nanofibers obtained depends on the polymer solution properties, the parameters of the equipment and the conditions of the surrounding. In almost all reported electrospinning set ups, a pump ,which regulates the flow of the polymer solution, has been included as one of the requirements. In this study, the effects of solution concentration, viscosity, voltage and the distance from the tip of the syringe to the aluminum collector on the morphology and diameters of poly(methyl methacrylate)(PMMA) fibers were investigated, using a pump-free electrospinning set up. Methods: Varied PMMA concentration (50 -120 mg/mL), voltage (10-18 kV) and distance (5 – 18 cm) of electrospinning were studied and the optimum electrospinning conditions identified.  PMMA/ titanium isopropoxide solution of ratio 1:2 was prepared, electrospun at optimized conditions (15 kV, 18 cm, Dichloromethane/Dimethylformamide 60:40) and the fibers obtained analyzed using a scanning electron microscope. Results: Solutions of PMMA whose concentrations were less than 50 mg/mL, produced beads on fibers, whereas those at ~ 100 mg/mL formed the best bead-free fibers of diameter 350±50 nm. The results showed a direct dependence of fiber diameter on the solution viscosity. Fibers of larger diameters were obtained when the distance from the tip of the syringe to the aluminum collector and voltage were increased but at higher distances (>18 kV) fewer fibers were collected. When the voltage was steadily increased, the fibers broadened and the diameters were non-uniform due to splaying and splitting. Increasing the distance between the pipette-tip and the collector from 10 to 18 cm resulted in reduced electric field which in turn yielded fewer fibers. Conclusions: The results obtained in a pump free set-up were comparable to those eletrospun in the presence of a pump.


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