Pencycuron application to soils: degradation and effect on microbiological parameters

Area of Science:

• Soil Science
• Environmental Chemistry
• Microbiology

Background:

• Pencycuron is a fungicide used in agriculture.
• Understanding its environmental fate and impact on soil microbial communities is crucial for sustainable practices.

Purpose of the Study:

• To investigate the degradation of pencycuron in different soil types (alluvial and coastal saline).
• To assess the effects of pencycuron application rates and decomposed cow manure (DCM) on soil microbial variables.
• To evaluate the ecophysiological response of soil microbial communities to pencycuron.

Main Methods:

• Laboratory incubation of clay loam soils (alluvial and coastal saline) with pencycuron at field rate (FR), 2FR, and 10FR.
• Application with and without decomposed cow manure (DCM).
• Analysis of soil microbial biomass-carbon (MBC), ergosterol content, fluorescein diacetate hydrolyzing activity (FDHA), microbial metabolic quotient (qCO2), and microbial respiration quotient (Q(R)).

Main Results:

• Pencycuron degraded faster in coastal saline (CS) soil and in soil amended with DCM.
• Pencycuron exhibited a short-lived, transitory toxic effect on MBC, ergosterol, and FDHA, with slightly longer duration at 10FR.
• DCM amendment did not counteract pencycuron's toxicity.
• Pencycuron induced temporary changes in qCO2 and Q(R), indicating short-term disturbance, particularly at 10FR.
• Fungi were more sensitive to pencycuron's toxic effects.

Conclusions:

• Pencycuron's side effects on the studied soil microbial variables at 10FR were short-lived.
• The observed disturbances are likely of minor ecological significance.
• Pencycuron degradation is influenced by soil type and organic matter amendment.