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The effect of different herbicide on the number and activity of living microorganisms in soil
76-82Views:136Sustainable plant growth, considering the difficulties of weed elimination, cannot be effective without the application of herbicides. However, these chemicals have enormous ecological implications, including effects on the microbiological communities of soils. It is advisable to use herbicides that have minimal secondary effects on the environment and soil-living microorganisms. In contrast, herbicides with prolonged growth stimulating or inhibiting effects are not suitable, because both types have strong influences on the number and activity of bacteria, thus causing changes in the ecological equilibrium.
Preceding small plot experiments, laboratory tests were carried out to study the effect of herbicides used in maize cultures on the number of bacteria and growth of microscopic fungi.
Substances that were observed to have stronger influences were applied in small plot experiments set up in the experimental garden of the Department of Plant Protection of the University of Debrecen. We studied the effects of four herbicides (Acenit A88EC, Frontier 900 EC, Merlin SC and Wing EC) on the microbiological properties of the soil. These herbicides were used in different concentrations in maize culture, and we investigated the effects in different soil layers.
In the laboratory experiments, we determined the total number of bacteria and microscopic fungi and examined the growth of Aspergillus niger, Trichoderma sp. and Fusarium oxysporum on peptone-glucose agar containing herbicides.
During the small plot experiments, soil samples were collected 3 times a year from 2-20 cm depth. The total numbers of bacteria and microscopic fungi were determined by plate dilution method, while the method of most probable number (Pochon method) was used to determine the numbers of nitrifying bacteria and cellulose decomposing bacteria. To evaluate the microbiological activity of the soil samples we measured carbon-dioxide release (after 10 days incubation), nitrate production (after 14 days incubation) and the concentration of C and N in the biomass.
We can summarize our results as follows:
• In laboratory experiments, herbicides caused a decrease in the number of bacteria and inhibited the growth of microscopic fungi.
• Frontier 900 EC and Acenit A 880 EC had the strongest inhibiting effect on microorganisms.
• In small plot experiments, herbicide treatment decreased the total number of bacteria and microscopic fungi.
• Herbicides caused a significant increase in the number of nitrifying and cellulose decomposing bacteria.
• Different herbicides containing the same active compound had similar influences on soil microoorganisms.
• A significant increase was observed in the physiological processes of tolerant microorganisms surviving the effects of herbicides -
The impact of different fertilization methods on some microbiological soil characteristics
119-126Views:114In our experiment, we studied the impact of an organic fertilizer, Bactofil® A10 (half- and full dosage applied in field practice) and an artificial fertilizer of Ca(NO3)2 content in different dosages (20-40 mg kg-1) – in addition to control treatments – on two different soils (calcareous chernozem, humus sandy soil) in 2005-2006, the experiment was complemented with treatments applying 250% dosage (100 mg kg-1 N, Bactofil® A10 2.5 times the field dosage) and a compost from urban sewage (25 g kg-1 compost) was also tested on these two soil types. In the
experiment, several soil microbial parameters were studied. The experiment was set up at the Department of Agrochemistry and Soil Science using 1-kg pots.
Our laboratory experiments were performed at the soil microbiology laboratory of UD CAS Department of Agrochemistry and Soil Science, the total number of bacteria, microscopic fungi, nitrifying and aerob cellulose-decomposing bacteria were determined together with the CO2-production of soil, N content of the biomass and urease enzyme activity.
Statistical analysis of the data was done using the program SPSS 13.0, means of the measurements, deviation and significance values were calculated.
In 2005-2006, the effect of the different dosages of Bactofil® A10, and the Ca(NO3)2 fertilizer on the examined microbial parameters of calcareous chernozem and humus sandy soils can be summarized as follows:
• Concerning the total number of bacteria, both treatments were effective on calcareous chernozem soil, the higher (significant) increment in bacteria number was observed in the artificial fertilizer treatments, while in the humus sandy soil Bactofil treatments had a beneficial effect. The number of microscopic fungi also increased in both treatments, higher numbers were observed in the average of two years in the Bactofil treatments.
• The number of nitrifying bacteria was 2.5 times higher in both high-dosage treatments on calcareous chernozem soil, while on humus sandy soil a slight (not significant) increment was observed only int he high-dosage Bactofil treatment. The amount of aerob cellulose-decomposing bacteria significantly increased on calcareous chernozem soil in both the highdosage artificial fertilizer and the small-dosage Bactofil treatment, however, on humus sandy soil no significant increase was observed in either treatment.
• The CO2-production increased in both soil types, although it was not significant in either treatment. A higher (though not significant) soil respiration was observed in the Bactofil treatments in both soil types.
• The microbial biomass N values were significantly higher in the high-dosage Bactofil treatments, however, the high-dosage artificial fertilizer treatment also increased these values significantly on calcareous chernozem soil.
• On calcareous chernozem soil, urease activity was significantly increased and reduced by high-dosage artificial fertilizer treatments and Bactofil treatments, respectively. On humus sandy soil, urease activity was also reduced except for the high-dosage artificial fertilizer treatment. In 2007, the pot experiment with 250% dosages was complemented with the application of compost rich in organic matter, the results of these treatments are sumnmarized as follows:
• In the case of the total number of bacteria, all three treatments resulted in a significant increase on calcareous chernozem soil with the highest values in the Bactofil treatment. The Bactofil treatment was the most effective on the humus sandy soil, but the artificial fertilizer treatment also
resulted in a significant increment. In the case of the total number of fungi, Bactofil treatments resulted in the highest values on both soils, but the compost treatment also increased the number of fungi in calcareous chernozem significantly.
• The number of nitrifying bacteria was increased most (significantly) by the Bactofil and compost treatments on both soil types. The amount of cellulose-decomposing bacteria was significantly increased by he compost treatment on calcareous chernozem soil, while its effect was not significant on humus sandy soil. The number of these bacteria was increased significantly by the Bactofil treatment on humus sandy soil.
• On calcareous chernozem soil, all three treatments significantly increased CO2-production, while the compost treatments had the resulted in the largest increment in soil respiration on both soil types.
• The soil biomass N content was significantly increased in both soils by the compost treatment, while in the case of the humus sandy soil, the Bactofil treatment also resulted in a significant increment.
• Urease enzyme activity was significantly increased by the artificial fertilizer treatment on both soils. In calcareous chernozem soil, the Bactofil treatment resulted in a slight (not significant) reduction in enzyme activity. In humus sandy soil, the Bactoful treatment also resulted in a slight reduction, while the compost treatment increased (though not significantly) the urease activity.
Based on our results, it can be stated that all three treatments were effective with respect to the studied soil microbial parameters. For both the calcareous chernozem and the humus sandy soil, the organic fertilizer Bactofil and the compost with high organic matter content had a stronger effect on some soil microbial parameters than the artificial fertilizer. -
Effect of cadmium and zinc contamination on the population dynamics of soil microorgani
73-77Views:124Changes in the population dynamics of microorganisms in a soil artificially contaminated with various doses of cadmium and zinc was examined from a quantitative point of view, under laboratory circumstances. The research was based on a chernozem soil originating from the area of a long-term microelement contamination model experiment (Nagyhörcsökpuszta, Hungary), which was carried out during 1991 in the Experimental Site of the Institute of Soil Science and Agricultural Chemistry, Centre for Agricultural Researche Hungarian Academy of Sciences, Budapest, Hungary. According to the amount of bacteria, microscopic fungi and nitrifying bacteria, it can be stated that the effect of contamination can be observed even in the perspective of nearly two decades. In more cases significant changes in the number of soil bacteria and microscopic fungi could be observed, and the nitrification activity increased in case of both microelements. Therefore the further research of changes in microbial activity of these soils can provide novel scientific results.
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The potential of biological control on invasive weed species
73-75Views:101Sorghum halepense is one of the invasive species in Europe. This study was made to identify the morphology of fungi on invasive weed species samples on the roots of Sorghum halepense. The samples were collected in the region of Debrecen. The experiment was conducted under laboratory conditions to determine the microscopic form of fungi. The samples were put on PDA and for identification of fungi is based on the morphological characteristics of the features and colonies of conidia that were developed in Petri dishes.
The examination of the culture revealed that the fungus from the root of Sorghum halepense was Aspergillus niger. Pathogenicity and the relationship between the fungus and Sorghum halepense are still uncertain so in the future pathogenicity tests and re-isolations from plants are very important steps.
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The effect of bentonite on the quantity change of soil microorganisms, the CO2-production and the activity of saccharase enzyme
287-293Views:96We examined the impact of bentonite – the perspective improving material of sandy soils – and treatments of livestock manure composted with bentonite on sandy soils, within the framework of a small-plot experiment.
The adjustment of the experiment was made on the Experiment Site of the Nyíregyháza Research Centre of the University of Debrecen, Centre of Agricultural Sciences (UD CAS). We collected soil samples from parcels treated with increasing bentonite doses (5, 10, 15, 20 t/ha) on the one hand, and from the parcels treated with livestock manure composted with increasing doses of bentonite, on the other.
We performed laboratory research in the soil microbiology laboratory of the Soil Science Faculty of UD CAS DAS, during which we determined the total number of bacteria, the quantity of microscopic fungi, the number of cellulose-decomposing bacteria, the CO2-production of the soil and the activity of saccharase enzyme.
During the evaluation of the examinations, we made a statistical analysis using SPSS 9.0. We determined the average of measurements, the standard deviation of controls, the standard deviation, the significance value and we also performed a correlation analysis.
Concerning the impacts of bentonite treatment and the treatment of livestock manure composted with bentonite on the examined microbiological features of sandy soil, we can summarize the following:
• Our results prove that the microbiologic activity of the soil has increased owing to the impact of bentonite treatments regarding total number of bacteria and the quantity of microscopic fungi. ”Pure bentonite” treatments – although not significantly in every case – increased these values, but larger doses decreased them. The treatments of livestock manure composted with bentonite resulted in a larger increase regarding both parameters.
• The number of cellulose-decomposing bacteria was increased by the low doses of both series, and was decreased by the higher doses. Higher bentonite doses decreased it in a higher – significant – degree than those of treatments of livestock manure composted with bentonite, whose low dose caused salient number of bacteria.
• Regarding the carbon-dioxide formation, we have experienced an increase even in the case of low dose treatments (nevertheless, the increase did not prove to be significant), but – similarly to the quantitative changes in the number of cellulose-decomposing bacteria – the large doses of both series of treatment decreased the CO2-production of the soil.
• Bentonite also increased the activity of saccharase enzyme significantly. We learned that”pure bentonite” treatments increased the activity of the enzyme to a higher degree than composted treatments. Moreover, it can be stated that the treatments of larger doses of both bentonite and livestock manure composted with bentonite have decreased the enzyme activity – not significantly, though.
• Based on the correlation analysis, it can be stated that as an impact of the treatments, the microbiological activity of the soil has also increased with the increase of the number of soil microbes, as in both treatment series we have experienced a tight positive correlation (r=0.81-0.82) between the change of total number of bacteria and the CO2-production of soil. In both treatments, there was a medium correlation between the total number of fungi and soil respiration (r=0.63-0.63). Furthermore, it can be stated that the usage of organic manure had a positive effect on the activity of cellulose-decomposing bacteria, as in this treatment series there was a positive correlation (r=0.65) between this physiological group and CO2-production. Both treatments prosperously impacted the activity of saccharase enzyme, because there was a medium correlation (r=0.62-0.64) between the activity of the enzyme and soil respiration. -
A dual infection of two microscopic fungi on common milkweed (Asclepias syriaca) in Hajdúság region (East-Hungary)
189-195Views:195Common milkweed (Asclepias syriaca L.) is one of the most noxious and invasive weed species in Hungary. A. syriaca invades arable lands, horticultural and forestry plantations, natural and semi-natural habitats too. In cases of field crops it can cause considerable yield losses mostly in maize (2–10%), soybean (12–32%) and sorghum (4–29%), but only with high rate of coverage. It can also increase these problems that the common milkweed can be serve as reservoir and host for viruses, other pathogens and pests.
Because of the importance of common milkweed and in spite of demand to develop effective biological control, until now has not been developed a proper control program against A. syriaca. The aim of our research was to identify the necrotrophic fungal pathogens, which were involved in notable disease occurrence on this weed in different parts of Hajdúság region of Eastern-Hungary in 2016.
To the isolation of fungi from leaves and their identification were based on morphological colony characters on potato dextrose agar (PDA) and Sabouraud dextrose agar (SDA). To the description of conidia features were used PDA for Alternaria and synthetic low-nutrient agar (SNA) for Fusarium species, respectively. The examination of axenic cultures revealed that the fungi isolated from the leaves of common milkweed were Fusarium sporotrichioides and Alternaria alternata. -
Comparative examination of a mineral fertiliser and a bacterial fertilizer on humic sandy soil
111-116Views:100In our pot experiment, the impact of a bacterial fertilizer, Bactofil® A10 and a mineral fertilizer Ca(NO3)2 applied in different rates was studied on some soil chemical and microbiological characteristics of a humic sandy soil (Pallag). Perennial rye-grass (Lolium perenne L.) was used as a test-plant. Samples were collected four and eight weeks after sowing in each year. The experiment was set up in 2007-2009 in the greenhouse of
the UD CASE Department of Agrochemistry and Soil Science. The available (AL-extractable) nutrient contents of soil, among the microbial parameters the total number of bacteria, the number of microscopic fungi, cellulose-decomposing and nitrifying bacteria, the sacharase and urease enzyme activity, as well as the soil respiration rate were measured.
Statistical analyses were made by means of the measurements deviation, LSD values at the P=0.05 level and correlation coefficients were calculated. Results of our experiment were summarised as follows:
− The readily available nutrient content of humic sandy soil increased as affected by the treatments, in case of the available (AL-extractable) phosphorus and potassium content the higher value was measured in high-dosage artificial fertilizer treatment.
− The treatments had also positive effect on several soil microbial parameters studied. The higher-dosage mineral fertilizer treatments had a beneficial effect on the total number of bacteria, cellulose-decomposing and nitrifying bacteria. No significant differences were obtained between the effect of treatment in case of the total-number of bacteria, the number of microscopic fungi and nitrifying bacteria.
− On the sacharase enzyme activity the artificial fertiliser treatments proved to be unambiguously stimulating, the urease activity significantly increased on the effect of the lower-dosage Ca(NO3)2 artificial fertilizer treatment.
− The soil respiration increased in all treatments in related to the amounts applied, significantly increased in the highest rate of Ca(NO3)2 fertilizer addition.
− Some medium and tight positive correlations were observed between the soil chemical and microbiological parameters studied in case of both nutrient sources.
Summarizing our results, it was established that the organic and all the mineral fertilizer treatments had beneficial effects on the major soil characteristics from the aspect of nutrient supply. In majority of the examined soil parameters (AL-extractable phosphorus- and potassium, total number of bacteria, number of cellulose-decomposing and nitrifying bacteria, activity of sacharase enzyme) the high rate of Ca(NO3)2 mineral fertilizer treatment proved to be more stimulating, but at the same time the high rate bacterium fertilizer resulted in significant increases in
the nitrate-N content, the AL-potassium content of soil, the total number of bacteria, the number of cellulose-decomposing and nitrifying bacteria and the urease enyme activity.
Our examinations showed that the mineral fertilizer treatments proved to be more stimulating on most of the soil parameters studied but according to our results, it was established that Bactofil is efficiently applicable in the maintenance of soil fertility and the combined application of
mineral fertilizer and bacterium fertilizer may be a favourable opportunity – also in aspect of the environmental protection – in maintaining soil fertility. -
A tárolási feltételek hatása a kukorica Fusarium fertőzöttségére és toxin szennyezettségére
28-32Views:290Corn samples harvested in 1997, 1998 and 1999 from different soil types were stored at different conditions (temperature, moisture content, state of kernels) for six months. The Fusarium contamination was examined by plate dilution method and the amount of mycotoxins (F-2, T-2, HT-2, DON, DAS) were determined applying HPLC method immediately after harvesting and in the third and sixth month of storage. The aim of our study was to find correlation between the ecological factors, storage conditions and the examined parameters mentioned above, as well as to prove them statistically. According to the examinations carried out after harvesting we could state that the soil type had no effect on the parameters. Analysing the effect of the years we found considerable differences. The Fusarium infection of corn samples in 1998, while the toxin contamination in 1999 was the highest. The results of storage experiment show that year (number of microscopic fungi, F-2, T-2, HT-2, DAS and total toxin content) and moisture content of kernels (F-2, T-2, and total toxin content) have a significant effect on the examined parameters. We could prove the effect of temperature on the T-2 content (samples with natural moisture content) and DON content (samples with 14% moisture content). Higher values were found at higher temperature storage. The ratio of damaged kernels influenced the DON concentration in the non- wetted samples and the number of microscopic fungi in the wetted samples.
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Identification of the Slovak traditional cheese “Parenica” microflora
227-239Views:266Numerous studies have demonstrated the higher accuracy, faster time-to-results and lower costs provided by MALDI Biotyper systems compared to classical methods. In this study, the culturable population of total count of bacteria, enterococci, coliforms bacteria, lactic acid bacteria (LAB) and microscopic fungi and yeasts from cow’s dairy products was identified using the MALDI-TOF MS Biotyper. Altogether, 50 samples of the Slovak cheese “Parenica” were examined. Total numbers of bacteria were cultured on Plate count agar at 37 °C for 24–48 h, aerobically; enterococci were cultured on Enterococcus selective agar at 37 °C for 24–48 h, aerobically; coliforms bacteria were cultured on Violet Red Bile lactose agar at 37 °C for 24–48 h, aerobically. The LAB were cultured on MRS (Main Rogosa agar), MSE and APT agar at 30 °C in microaerophilic conditions. The microscopic fungi and yeasts were cultured on Malt extract agar at 25 °C for 5 days, aerobically. Isolated strains (total 669) were subjected to identification by the MALDI-TOF MS. Among total count the identified bacteria mostly were Acinetobacter baumannii, Bacillus cereus, Micrococcus luteus and Staphylococcus warneri. Escherichia coli and Enterobacter cloacae were the most abundant coliform bacteria representatives identified. Coliform bacteria included Citrobacter, Hafnia and Klebsiella. Altogether three genera belonged to the LAB – Lactobacillus, Lactococcus and Leuconostoc were identified with Lactococcus lactis, Lactobacillus plantarum, Lactobacillus coryniformis, L. fructivorans and Leuconostoc mesenteroides were considered as the dominated LAB species in dairy products. Among yeasts, Kluyveromyces lactis, Candida zeylanoides and Yarrowia lipolytica were among the most isolated.
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In memory of József Vörös mycologist (1929–1991) on the 25th anniversary of his death
33-37Views:161Twenty five years ago died professor József Vörös, internationally recognized mycologist, phytopathologist. On the field of microscopic fungi research, especially on taxonomy of plant pathological conidial fungi (Deuteromycetes, Coelomycetes, Hyphomycetes) gained imperishable reputation during his more than 40 years research activity. As author of 17 fungus taxa and publisher of numerous mycological data J. Vörös took place in the history of mycology.
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The effect of different microbial preparations on some soil characteristics
83-86Views:113In pot experiment the effect of different microbial inoculants and their combinations with NPK fertilizer and wheat straw on some soil properties (physical, chemical, and microbiological parameters) were studied. The experiment was set up in 2011 at the Institute of Agricultural Chemistry and Soil Science, in a three replications, in a random block design. The studied soil type was calcareous chernozem soil from Debrecen (Látókép) with ryegrass (Lolium perenne, L.) test plant.
At the end of the experiment in our laboratory the nitrate-nitrogen content of soil, the AL-soluble phosphorus and potassium content of soil, the urease enzyme activity of soil, the total number of bacteria and the number of microscopical fungi were determined.
The results of the study were the following:
– The straw treatment and the straw + biofertilizer combinations influenced positively the nitrate content of soil.
– The NPK fertilization and the straw+bacterial fertilizer combinations had significant positive effect on the AL-soluble phosphorus content of the soil.
– The biofertilization and the straw+biofertilizer combinations stimulated the AL-soluble potassium content of soil occasionally.
– The total number of bacteria was influenced by the NPK fertilization, the bacterial fertilization and the straw+bacterial fertilizer combinations significantly.
– In case of the number of microscopic fungi caused in some cases significant changes the NPK+bacterial fertilizer and straw+bacterial fertilizer combinations.
– The soil urease enzyme activity was increased in all cases strongly especially by the straw+bacterial preparation combinations. -
The influence of fertilization on the soil characteristics of a calcareous chernozem in a long term experiment
47-52Views:95In the long term fertilization experiment of the University of Debrecen, Centre for Agricultural and Applied Economic Science(CAAEC) (Debrecen Látókép), the effects of a 25-year-long fertilization were examined in terms of some chemical and microbiological properties of soil. With the growing doses of fertilizers, the available nutrient content of soil increased. At the same time the pH significantly decreased, while the hidden acidity increased. Moreover, the ratio between the soil bacteria and microscopic fungi, and the occurrence of microbes also changed. The number of sensitive physiological bacteria groups decreased dramatically. These changes indicate the reactions of living organisms; they correspond to the „resistance stage” of stress effects, but in the case of nitrifying bacteria, they reach the „exhaustion stage”.
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Effects of cultivation methods on some soil biological parameters of a meadow chernozem soil (Vertisols)
61-66Views:85The effect of extended drought conditions on soil, the unfavourable cultivation technologies and the application of chemicals have been enhancing the processes of physical and biological soil degradation, so the fertility of soil is gradually declining.
The effects of two cultivation methods – traditional ploughing (TP) and conservation tillage (CT) – on the biological activity of a meadow
chernozem soil were examined in a long term experiment. Different parameters of the biological activity of soil were determined. These are
the numbers of total bacteria, microscopic fungi, aerobic cellulose decomposing bacteria, as well as the activities of some important soil
enzymes and CO2 production.
Conservation tillage seemed to be a more favourable cultivation method for the majority of microorganisms, the activities of urease and
dehydrogenase enzymes and CO2 production, compared to the traditional ploughing system. These parameters increased significantly,
especially in the upper layer of conservation tillage plots. Concerning the plant cultures, the majority of microbiological parameters were
higher in the soil of vetch (Vicia sativa L.) depending on the cultivation methods, so involving the pulses to the crop-rotation seems to be
very important in this soil type.
According to the ninth year’s results, the importance of conservation tillage as a means of protecting the soil biological activity in meadow
chernozem (Vertisols) can be established; it was proven by microbiological investigations. -
The effect of lead and copper heavy metal salts on soil microorganisms under laboratory circumstances
55-59Views:165he population dynamics of calcareous chernozem soils polluted with different concentrations of lead and copper heavy metal saline solutions was examined.
The experiment was carried out in the soil biological laboratory of the Institute of Agricultiral Chemistry and Soil Science at DE AGTC MÉK in 2012. For the determination of the concentration of the undiluted stock solutions we multiplied the smallest toxic concentration values of the MSZ 08-1721/1-86 Hungarian standard by forty. The intermediary concentrations of the treatments were produced with adequate dilution of the stock solutions until a dilution level equal to the values of the standard. The statistical evaluation of the data was performed with ANOVA (Analysis of Variance) including the determination of the standard deviation and significant difference. Investigating the effects of the different treatments on the soil microbes we established that both heavy metal saline solutions had a negative effect on the population dynamics of bacteria and microscopic fungi living in the soils. The negative effect of copper – as a potential toxic micro nutrient – turned out to be less strong than the negative effect of the toxic lead. According to our results the correction of the treatment levels is recommended in order to further tolerance examinations and the determination of the tolerance levels.