Response of Soil Microbiota, Enzymes, and Plants to the Fungicide Azoxystrobin

The present study was aimed at assessing the impact of azoxystrobin-a fungicide commonly used in plant protection against pathogens (Amistar 250 SC)-on the soil microbiota and enzymes, as well as plant growth and development. The laboratory experiment was conducted in three analytical terms (30, 60, and 90 days) on sandy clay (pH-7.0). Azoxystrobin was applied to soil in doses of 0.00 (C), 0.110 (F) and 32.92 (P) mg kg-1 d.m. of soil. Its 0.110 mg kg-1 dose stimulated the proliferation of organotrophic bacteria and actinobacteria but inhibited that of fungi. It also contributed to an increase in the colony development index (CD) and a decrease in the ecophysiological diversity index (EP) of all analyzed groups of microorganisms. Azoxystrobin applied at 32.92 mg kg-1 reduced the number and EP of microorganisms and increased their CD. PP952051.1 Bacillus mycoides strain (P), PP952052.1 Prestia megaterium strain (P) bacteria, as well as PP952052.1 Kreatinophyton terreum isolate (P) fungi were identified in the soil contaminated with azoxystrobin, all of which may exhibit resistance to its effects. The azoxystrobin dose of 0.110 mg kg-1 stimulated the activity of all enzymes, whereas its 32.92 mg kg-1 dose inhibited activities of dehydrogenases, alkaline phosphatase, acid phosphatase, and urease and stimulated the activity of catalase. The analyzed fungicide added to the soil at both 0.110 and 32.92 mg kg-1 doses inhibited seed germination and elongation of shoots of Lepidium sativum L., Sinapsis alba L., and Sorgum saccharatum L.