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%.

Response of microorganisms and enzymes to soil contamination with a mixture of pethoxamid terbuthylazine

“…To conclude, it can be stated that the values of the CD and EP indices prove that the tested herbicide Successor T 550 SE had an effect on the structure of microorganisms. The changes in diversity of microorganisms, observed in our studies, in soil supplemented with herbicide, are concordant with the literature data (Kucharski et al 2016;Lone et al 2014;Ratcliff et al 2006). Organotrophic bacteria, as opposed to fungi, were characterised by the greatest diversity in soil with an addition of the herbicide Boreal 58 WG (flufenacet ?…”

“…If the plant did not affect the soil microbiota, the commonly known rhizosphere effect (R:S ratio) would not be experienced. Thus, both our own studies and the literature Kucharski et al 2016;Sebiomo et al 2011) demonstrate that herbicides are not always toxic to soil microbiome. Some species or strains may display increased tolerance to herbicides.…”

“…The differentiated response of microorganisms to the excessive content of herbicides in soil may result from both their species characteristics and morphological characteristics. The effect of herbicides on microbiological properties is dictated by the type of active substance, its dose and physicochemical properties of soil (Kucharski et al 2016). For example: carfentrazone-ethyl (the active substance of the preparation Aurora 40 WG) had an effect on an increase in the counts of total oligotrophic bacteria and organotrophic bacteria, while it decreased the counts of Azotobacter, fungi, oligotrophic sporulating bacteria and actinomycetes .…”

“…The common use of pesticides in plant protection has an effect not only on a change in the count of autochthonous microorganisms in soil, but it can cause physiological and biochemical changes in soil microorganisms and change their diversity (Kucharski et al 2016). In our own studies, in order to determine the diversity of soil microorganisms, the colony development index (CD) and the ecophysiological diversity index (EP) of microorganisms were computed.…”

“…The exact assay procedure of enzyme activity is described in the publication Kucharski et al (2016).…”