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The effect of bentonite on the quantity change of soil microorganisms, the CO2-production and the activity of saccharase enzyme
Published July 16, 2007
287-293

We 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 D...ebrecen, 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.

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The effect of lead and copper heavy metal salts on soil microorganisms under laboratory circumstances
Published March 20, 2013
55-59

...5); font-variant-ligatures: normal; font-variant-caps: normal; -webkit-text-stroke-width: 0px; text-decoration-style: initial; text-decoration-color: initial;">he 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.

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The influence of fertilization on the soil characteristics of a calcareous chernozem in a long term experiment
Published November 3, 2010
47-52

In 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 cont...ent 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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Evaluation some important microbiological parameters of the carbon cycle in chernozem soils profiles
Published October 24, 2016
33-39

Some chemical and microbiological properties of the carbon cycle were investigated in three chernozem soil profiles. The soil profiles originated from a long term fertilization experiment (potato) of the University of Debrecen, Látókép, Kryvyi Rig Botanic Garden (grassland) and a large-scale farm (sunflower) of Ukraine. The results of the or...ganic C-content, total number of bacteria, microscopical fungi, cellulose decomposing bacteria, CO2-production, microbial biomass carbon and saccharase and dehydrogenase activities were compared and evaluated with the help of correlation analyses. Close correlation was found between the organic carbon content and the number of microscopical fungi,, saccharase and dehydrogenase enzymes’ activities, as well as close correlation was found between the dehydrogenase activity and microbial biomass-C and saccharase activity.

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