Imidacloprid application changes microbial dynamics and enzymes in rice soil.

Area of Science:

• Agricultural Science
• Environmental Science
• Soil Microbiology

Background:

• Extensive imidacloprid use in rice may disrupt soil microbial dynamics and biochemical functions.
• Understanding these impacts is crucial for sustainable agricultural practices.

Purpose of the Study:

• To assess the effects of varying imidacloprid doses on microbial growth and activity in tropical rice soil.
• To evaluate changes in soil biochemical properties following imidacloprid application.

Main Methods:

• Controlled experiments were conducted with five treatments: control, recommended dose (RD), 2RD, 5RD, and 10RD of imidacloprid.
• Microbial populations (bacteria, actinomycetes, fungi, PSB), microbial biomass carbon, and soil enzyme activities were analyzed.

Main Results:

• Imidacloprid application negatively affected bacteria, actinomycetes, fungi, and phosphate solubilizing bacteria populations.
• Soil microbial biomass carbon decreased, and most soil enzyme activities (except dehydrogenase and alkaline phosphatase) were inhibited.
• Dissipation half-lives ranged from 19.25 to 33.00 days, indicating persistence.
• Bacterial community diversity indices were significantly altered, showing dose-dependent effects.

Conclusions:

• Imidacloprid application exerts transient negative effects on soil microbial communities and enzyme activities in rice ecosystems.
• The extent of these impacts is influenced by the insecticide's dose and the duration of exposure.