Enzymatic activities and microbial biomass in black soil as affected by azoxystrobin

Responses of Soil Microorganisms and Enzymatic Activities to Azoxystrobin in Cambisol

“…Although our results were in accord with those of butachlor [21] and Funaben T [22], high concentrations of mefenoxam significantly increased bacteria populations [23]. Soil bacteria, fungi, and actinomycete were all inhibited by Azoxystrobin [11][12]. In this study, although soil bacterial and actinomycete numbers were drastically depressed, no significant effects on fungal population were also observed.…”

“…In contrast to the above, no significantly stimulated or inhibited effects were observed in dehydrogenase activity polluted by tebuconazole [29]. Although dehydrogenase activities were all reduced, incubation time point causing decrease and inhibitory degree were different from this [11][12]. Similarly, Bending et al [10] discovered that all fungicides (chlorothalonil, azoxystrobin, and tebuconazole) obviously decreased dehydrogenase activity to different degrees in the low OM/biomass soil, but not in the high OM/biomass soil.…”

“…Above all, different fungicides have various effects on soil respiration. Even in different types of soils the inhibition of soil respiration were also observed in treatments with azoxystrobin [11][12], which indicated that soil types did not influence the responses of soil respiration to azoxystrobin.…”

“…It was interesting that there were significant different responses of urease activity in azoxystrobintreated soils with different properties. Azoxystrobin had no effect on urease activity in loam soil [12], but the fungicide in black soil inhibited urease activity only in the 10.0 mg·kg -1 concentration group on days 14, 21, and 28 [11], and in sandy loam with a pH 7.0 from 0.075 to 22.50 mg kg -1 [6]. This revealed that the responses of urease activity to fungicide depend on soil types.…”

“…Soil respiration increased with increasing azoxystrobin doses and decreased with increasing incubation time [7]. It obviously decreased the cultivable bacterial, fungal, and actinomycetic populations, soil respiration intensity, protease, and dehydrogenase activities after 7 days of treatment, and inhibited urease activity with 10 mg·kg -1 and stimulated catalase activity with 1.0 and 10 mg·kg -1 of azoxystrobin in black soil [11]. Slightly different from the above results, it decreased soil cultivable microbial numbers, soil respiration, dehydrogenase and protease activities at the beginning of the experiment, and no obvious effects on urease activity and decreased catalase activity were observed in brown soil with azoxystrobin [12].…”