Małgorzata Baćmaga

Enzyme activity and microorganisms diversity in soil contaminated with the Boreal 58 WG herbicide

ABSTRACT Next-generation herbicides are relatively safe when used properly, but the recommended rates are relatively low, which can lead to overdosing. This study evaluated the responses of soil-dwelling microorganisms and soil enzymes to contamination with the Boreal 58 WG herbicide. The analyzed product contains active ingredients flufenacet and isoxaflutole. All tests were performed under laboratory conditions. The analyzed material was sandy clay. Boreal 58 WG was introduced to soil in four doses. Soil without the addition of the herbicide served as the control. The soil was mixed with the tested herbicide, and its moisture content was maintained at 50% of capillary water capacity. Biochemical and microbiological analyses were performed on experimental days 0, 20, 40, 80 and 160. Accidental contamination of soil with the Boreal 58 WG herbicide led to a relatively minor imbalance in the soil microbiological and biochemical profile. The herbicide dose influenced dehydrogenase activity in only 0.84%, urease activity in 2.04%, β-glucosidase activity in 8.26%, catalase activity in 12.40%, arylsulfatase activity in 12.54%, acid phosphatase activity in 42.11%, numbers of organotrophic bacteria in 18.29%, actinomyces counts in 1.31% and fungi counts in 6.86%.

The effect of carfentrazone-ethyl on soil microorganisms and soil enzymes activity / Wpływ karfentrazonu etylu na mikroorganizmy i aktywność enzymów glebowych

Abstract The aim of this study was to determine the effect of carfentrazone-ethyl (CE) doses of 0.265, 5.280, 10.560, 21.180, 42.240 μg kg-1 soil DM on fungi, Acnomycetes, organotrophic bacteria, total oligotrophic bacteria and spore-forming oligotrophic bacteria, and on the activity of dehydrogenases, catalase, urease, alkaline phosphatase, acid phosphatase, arylsulfatase and β-glucosidase. Carfentrazone-ethyl had a stimulating effect on total oligotrophic bacteria and organotrophic bacteria, but it inhibited the growth of Azotobacter, fungi, spore-forming oligotrophic bacteria and Actinomycetes. The analyzed substance modified the structure of soil microbial communities, and it induced the most profound changes in fungi. The highest values of the colony development (CD) index and the eco-physiological (EP) index were observed in organotrophic bacteria. The optimal dose of carfentrazone-ethyl stimulated the activity of dehydrogenases, catalase, urease, alkaline phosphatase, acid phosphatase and β-glucosidase, but it had no effect on arylsulfatase. The highest doses of the analyzed substance inhibited the activity of dehydrogenases (reduction from 11.835 to 11.381 μmol TPF), urease (reduction from 0.545 to 0.500 mmol N-NH4) and arylosulfatase (reduction from 0.210 to 0.168 mmol PNP). Dehydrogenases were most resistant to CE, whereas acid phosphatase and arylsulfatase were least resistant to the analyzed compound Streszczenie W pracy określono wpływ karfentrazonu etylu zaaplikowanego w dawkach 0,265, 5,280, 10,560, 21,180, 42,2 40 μg kg-1s.m. gleby na grzyby, promieniowce, bakterie organotrofi czne, oligotrofi czne ogółem i oligotrofi czne przetrwalnikujące oraz aktywność dehydrogenaz, katalazy, ureazy, fosfatazy alkalicznej, fosfatazy kwaśnej, arylosulfatazy i β-glukozydazy. W wyniku badań stwierdzono stymulujące działanie karfentrazonu etylu na bakterie oligotrofi czne ogółem i bakterie organotrofi czne, natomiast inhibicyjne na Azotobacter, grzyby, bakterie oligotrofi czne przetrwalnikujące oraz promieniowce. Preparat ten zmieniał strukturę zespołu drobnoustrojów. Największe zmiany wywoływał u grzybów. Najwyższe wartości wskaźników rozwoju kolonii (CD) i ekofi zjologicznej różnorodności (EP) odnotowano u bakterii organotrofi cznych. Karfentrazon etylu w dawce optymalnej zwiększał aktywność dehydrogenaz katalazy, ureazy, fosfatazy alkalicznej, fosfatazy kwaśnej i β-glukozydazy, a nie oddziaływał na arylosulfatazę, natomiast najwyższe dawki zmniejszały aktywność dehydrogenaz (obniżenie z 11,835 do 11,381 μmol TPF), ureazy (obniżenie z 0,545 do 0,500 mmol N-NH4) i arylosulfatazy (obniżenie z 0,210 do 0,168 mmol PNP). Najbardziej opornymi enzymami na działanie KE okazały się dehydrogenazy, a najmniej fosfataza kwaśna i arylosulfataza.

Implication of zinc excess on soil health

ABSTRACT This study was undertaken to evaluate zincs influence on the resistance of organotrophic bacteria, actinomyces, fungi, dehydrogenases, catalase and urease. The experiment was conducted in a greenhouse of the University of Warmia and Mazury (UWM) in Olsztyn, Poland. Plastic pots were filled with 3 kg of sandy loam with pHKCl – 7.0 each. The experimental variables were: zinc applied to soil at six doses: 100, 300, 600, 1,200, 2,400 and 4,800 mg of Zn2+ kg−1 in the form of ZnCl2 (zinc chloride), and species of plant: oat (Avena sativa L.) cv. Chwat and white mustard (Sinapis alba) cv. Rota. Soil without the addition of zinc served as the control. During the growing season, soil samples were subjected to microbiological analyses on experimental days 25 and 50 to determine the abundance of organotrophic bacteria, actinomyces and fungi, and the activity of dehydrogenases, catalase and urease, which provided a basis for determining the soil resistance index (RS). The physicochemical properties of soil were determined after harvest. The results of this study indicate that excessive concentrations of zinc have an adverse impact on microbial growth and the activity of soil enzymes. The resistance of organotrophic bacteria, actinomyces, fungi, dehydrogenases, catalase and urease decreased with an increase in the degree of soil contamination with zinc. Dehydrogenases were most sensitive and urease was least sensitive to soil contamination with zinc. Zinc also exerted an adverse influence on the physicochemical properties of soil and plant development. The growth of oat and white mustard plants was almost completely inhibited in response to the highest zinc doses of 2,400 and 4,800 mg Zn2+ kg−1.

The effect of nitrogen on the microbiological and biochemical properties of zinc-contaminated soil

AbstractThe aim of these studies was to determine the influence of excessive zinc doses on the microbiological and enzymatic properties of soil. Also, an evaluation of the possibility to stimulate remediation processes by nitrogen fertilisation of the soil was attempted. Zinc was applied to loamy sand in the amounts of 0, 250, 500, 750, 1000, 1250 mg Zn2+ kg–1 DM soil, while nitrogen in the form of urea in doses of 0, 250, 500 mg N kg–1 DM soil. Soil samples were incubated at a temperature of 25 °C, maintaining a constant humidity equal to 50% of the maximum water capacity. In the 2nd and 20th week of the experiment, the following factors were determined: activity of dehydrogenases and catalase, and number of organotrophic bacteria, copiotrophic bacteria, oligotrophic bacteria, actinomycetes, and fungi. Zinc inhibited the enzymatic activity of the soil, while causing a slight increase in populations of microorganisms. Only fungi reacted unequivocally positively to contamination of the soil with zinc, ther...

The effect of the Falcon 460 EC fungicide on soil microbial communities, enzyme activities and plant growth

Fungicides are considered to be effective crop protection chemicals in modern agriculture. However, they can also exert toxic effects on non-target organisms, including soil-dwelling microbes. Therefore, the environmental fate of fungicides has to be closely monitored. The aim of this study was to evaluate the influence of the Falcon 460 EC fungicide on microbial diversity, enzyme activity and resistance, and plant growth. Samples of sandy loam with pHKCl 7.0 were collected for laboratory analyses on experimental days 30, 60 and 90. Falcon 460 EC was applied to soil in the following doses: control (soil without the fungicide), dose recommended by the manufacturer, 30-fold higher than the recommended dose, 150-fold higher than the recommended dose and 300-fold higher than the recommended dose. The observed differences in the values of the colony development index and the eco-physiological index indicate that the mixture of spiroxamine, tebuconazole and triadimenol modified the biological diversity of the analyzed groups of soil microorganisms. Bacteria of the genus Bacillus and fungi of the genera Penicillium and Rhizopus were isolated from fungicide-contaminated soil. The tested fungicide inhibited the activity of dehydrogenases, catalase, urease, acid phosphatase and alkaline phosphatase. The greatest changes were induced by the highest fungicide dose 300-fold higher than the recommended dose. Dehydrogenases were most resistant to soil contamination. The Phytotoxkit test revealed that the analyzed fungicide inhibits seed germination capacity and root elongation. The results of this study indicate that excessive doses of the Falcon 460 EC fungicide 30-fold higher than the recommended dose to 300-fold higher than the recommended dose) can induce changes in the biological activity of soil. The analyzed microbiological and biochemical parameters are reliable indicators of the fungicide’s toxic effects on soil quality.

Response of actinomycetes, phosphatases and urease to soil contamination with herbicides

Abstract A laboratory experiment was completed to determine the effect of the herbicides Alister Grande 190 OD, Fuego 500 SC and Lumax 537.5 SE on counts of actinomycetes as well as the activity of enzymes and their resistance to herbicides. Sandy loam was mixed with appropriate doses of the herbicides, such as: 0 - the control, 1 - technological dose and doses 20-, 40-, 80- and 160-fold higher than recommended. On day 20, 40, 80 and 160, counts of actinomycetes and activity of urease, acid phosphatase and alkaline phosphatase were determined. For 160 days, soil was incubated at 25°C and its moisture content was maintained on a constant level equal 50% of water capillary capacity. On days 20 and 80 of the experiment, the ecophysiological (EP) and colony development (CD) indices were computed. Additionally, the resistance (RS) of enzymes to the herbicides was assessed on day 20 and their resilience index (RL) was determined on day 160. It has been found out that soil contamination with herbicides contributed to elevated counts of actinomycetes. The highest number of these microorganisms was observed in soil with Lumax 537.5 SE, and the lowest one appeared in soil with Alister Grande 190 OD. The CD for actinomycetes was the highest in treatments with Fuego 500 SC and the highest EP was determined in soil with Alister Grande 190 OD. Application of the herbicides in doses from 20- to 160-fold higher than recommended by the manufacturer significantly increased the activity of acid and alkaline phosphatases. With respect to the activity of urease, the herbicides produced variable effects. The strongest inhibitory effect on the activity of urease was produced by Fuego 500 SC, which reduced the activity of this enzyme by 13.39% when added to soil in a dose exceeding by 160-fold the recommended rate. The RS of the enzymes to the herbicides ranged from 0.461 to 0.955. Urease was the most tolerant to soil contamination with the herbicides.

The sensitivity of soil enzymes, microorganisms and spring wheat to soil contamination with carfentrazone-ethyl

ABSTRACT Herbicides pose a significant threat to the natural environment, in particular in soils that are most exposed to plant protection agents. Prolonged herbicide use leads to changes in soil metabolism and decreases soil productive potential. In this study, the influence of carfentrazone-ethyl (CE) on the microbiological and biochemical properties of soil and the yield of Triticum aestivum L. was evaluated. Carfentrazone-ethyl was applied to sandy loam (pHKCl – 7.0) in doses of 0.000, 0.264, 5.280, 10.56, 21.18, 42.24, 84.48 and 168.96 µg kg−1 DM soil. Soil samples were subjected to microbiological and biochemical analyses on experimental days 30 and 60. Carfentrazone-ethyl disrupted the biological equilibrium in soil by decreasing the abundance and biodiversity of soil-dwelling microorganisms, the activity of soil enzymes, the values of the biochemical activity indicator and spring wheat yields. Carfentrazone-ethyl had the most adverse effects when applied in doses many fold higher than those recommended by the manufacturer. The toxic effects of CE were also determined by its soil retention time. Soil treated with CE was characterized by higher counts of oligotrophic bacteria, organotrophic bacteria, bacteria of the genus Azotobacter, actinomycetes and fungi on day 60, and spore-forming oligotrophic bacteria on day 30. The activity of dehydrogenases, urease, alkaline phosphatase and β-glucosidase was higher on day 30 than on day 60.

The influence of chlorothalonil on the activity of soil microorganisms and enzymes

As one of the most widely used pesticides in agriculture, chlorothalonil can pose threat to soil ecosystems. Therefore, the impact of this substance on the development of microbiological and biochemical properties of the soil as well as on the growth of spring wheat was evaluated. The study was conducted with two soils (loamy sand with pHKCl 5.6 and sandy loam with pHKCl 7.00), to which fungicide was used in the following doses: 0.00, 0.166 (recommended dose), 1.660, and 16.60 mg kg−1 dry matter of soil (DM of soil). In addition, we determined the effectiveness of fertilizing substances (Lignohumat Super and Bioilsa N 12.5) in the restoration of soil homeostasis and chlorothalonil degradation in the soil. Chlorothalonil caused modifications in the count and biological diversity of soil microorganisms. It stimulated the growth of heterotrophic bacteria and actinobacteria, and inhibited the growth of fungi. This pesticide was a potent inhibitor of dehydrogenase, catalase and acid phosphatase activities. It showed variable effects on urease and alkaline phosphatase. The fungicide also a reduction the yield of dry matter of the aboveground parts of spring wheat. It should, however, be noted that these changes in the soil environment occurred after the introduction of higher doses of chlorothalonil. The fertilizing substances used contributed to enhanced microbial and biochemical activities of soils, while they did not significantly affect plant yields. The Bioilsa N 12.5 preparation was effective in chlorothalonil degradation, while Lignohumat Super reduced the degradation rate of the tested fungicide. Based on the conducted experiment, an ecological risk assessment of chlorothalonil was made by estimating the changes occurring in the soil environment evaluated through the microbiological and biochemical analyses of the soil.