Increasing pesticide diversity impairs soil microbial functions

Area of Science:

• Soil microbiology
• Agricultural science
• Ecology

Background:

• Pesticide application is crucial for agricultural stability.
• The impact of diverse pesticide use on soil microbial functions and networks, especially with nitrogen (N) fertilizer, is not well understood.

Purpose of the Study:

• To investigate how increasing pesticide diversity affects soil microbial communities, multitrophic networks, and soil functions under different nitrogen (N) fertilizer levels.
• To characterize bacterial life history strategies in response to pesticide diversity and N addition.

Main Methods:

• Amplicon sequencing to assess microbial community structure and stochasticity.
• Metagenomics to determine bacterial life history strategies.
• Analysis of soil functions related to carbon (C), nitrogen (N), phosphorus (P), and sulfur (S) cycling.

Main Results:

• Higher pesticide diversity increased specialist and opportunist bacteria, decreasing generalists without N addition.
• Pesticide diversity led to smaller bacterial genomes and enhanced C, N, P, S metabolism, potentially increasing nutrient loss.
• Nitrogen addition reduced bacterial niche differentiation and mitigated negative impacts of pesticide diversity on microbial networks and soil functions.

Conclusions:

• Pesticide diversity significantly alters soil microbial communities and functions, with impacts varying based on nitrogen fertilizer management.
• Strategic nitrogen fertilizer application can counteract the ecological disruptions caused by diverse pesticide use in agricultural systems.