Microbiological and biochemical properties of soil polluted with a mixture of spiroxamine, tebuconazole, and triadimenol under the cultivation of Triticum aestivum L.

Abstract

Pesticide contamination is one of the most serious threats for agricultural soils. Excessive pesticide levels in soil can exert negative effects on soil-dwelling organisms by decreasing their bioavailability and, consequently, lowering soil quality. This study aimed to evaluate the effect of a mixture of spiroxamine, tebuconazole, and triadimenol (S + Te + Tr) on the biological activity of soil determined based on the proliferation of microorganisms and their diversity, enzymatic activity of soil, and resistance of Triticum aestivum L. A pot experiment was performed on sandy loam (pH 7.0) treated with four doses of the tested active ingredients: 0.000, 0.092, 2.76, 13.80, and 27.60 mg kg −1 . Soil without the fungicide served as the control sample. The tested fungicide induced changes in the biological activity of soil. When administered to the soil in the highest dose (27.60 mg kg −1 DM of soil), it inhibited its biological activity. It significantly inhibited the proliferation of organotrophs, actinomycetes, and fungi, but still the most susceptible to its effects turned out to be fungi. Fungicide dose of 27.60 mg kg −1 decreased counts of organotrophic bacteria, actinomycetes, and fungi by on average 0.009 log, 0.100 log, and 0.282 log, respectively, compared to the control sample. Administration of the S + Te + Tr mixture to soil decreased also values of colony development index (CD) determined for all tested groups of microorganisms. Values of the ecophysiological diversity index (EP) decreased in the case of organotrophs and actimomycetes and increased in the case of fungi. The S + Te + Tr mixture inhibited activities of dehydrogenases, urease, and acid phosphatase. Significant changes were also reported in the growth of spring wheat. The resistance index (RS) calculated based on plant yield demonstrated spring wheat to be very susceptible to the tested preparation administered to soil in doses of 13.80 and 27.60 mg kg −1 .

Changes in fatty acid composition as a response to glyphosate toxicity in Pseudomonas fluorescens

“…The excessive use of different pesticides has the consequences of decreasing biodiversity and soil fertility ( Baćmaga et al., 2019 ). From the biofilms formed in storage tanks of water used for washing pesticide containers ( Lima et al., 2020 ), 33 bacterial strains were isolated in our work, and 12 were considered sensitive to glyphosate, 21 were tolerant up to 1x the herbicide, 14 were tolerant up to 10x, and 6, including P. fluorescens CMA-55, were tolerant up to 50x the herbicide, even without prior selective pressure for this molecule in the water tanks where it was isolated.…”

“…The excessive use of different pesticides has the consequences of decreasing biodiversity and soil fertility ( Baćmaga et al., 2019 ), and the literature on xenobiotic response systems is mainly focused on the presence of the selective agents in the environment, as in the case of herbicide degradation genes ( Lima et al., 2020 ). Therefore, it is uncertain whether response systems based on non-degradation genes require specific selective pressure to be effective against contaminants.…”

Protetor De Sementes, Períodos De Armazenamento E Emergência De Arroz Irrigado

“…No entanto, na emergência no campo, o efeito do inseticida + fungicida + protetor de sementes não foi pronunciado. De acordo com Baćmaga et al (2019), no solo a fitotoxicidade pode não ocorrer, pois, parte do produto está sujeito a adsorção nos colóides. E ainda uma parte dos produtos químicos podem ser lixiviado ou diluído na ocorrência de precipitação pluvial (FAGUNDES et al, 2017).…”

Chemical Structure of Stabilizing Layers of Negatively Charged Silver Nanoparticles as an Effector of Shifts in Soil Bacterial Microbiome under Short-Term Exposure

“…In general, the destructive effects of mixtures of fungicides on the bacterial community and their biochemical activity in the soil and aquatic environments have already been confirmed [ 54 , 55 ]. However, the effects of Ag + ions and AgNPs in a soil environment are diverse and not fully understood [ 29 , 56 , 57 ].…”