Reducing plant pathogens could increase crop yields after plastic film mulching

Area of Science:

• Agricultural Microbiology
• Soil Ecology
• Plant Pathology

Background:

• Soil fungi are crucial for crop growth, influencing nutrient uptake and disease development.
• Plastic film mulching (PM) is widely used to enhance crop yields in dryland agriculture.
• The impact of PM on soil fungal communities and their functional guilds is not well understood.

Purpose of the Study:

• To investigate the effects of short-term (2 years) and long-term (10 years) plastic film mulching on soil fungal abundance, diversity, community composition, and functional guilds.
• To elucidate the relationship between fungal community shifts, functional guilds, and maize yield under PM.
• To provide microbial insights into the sustainability of continuous maize mulching.

Main Methods:

• Exploration of absolute fungal abundance, diversity, community composition, and functional guilds in soil under short- and long-term PM.
• Analysis of fungal pathogen and biocontrol agent abundance, including specific genera like Gibberella and Glomeromycota.
• Application of structural equation modeling to determine the influence of PM on fungal guilds and crop yield.

Main Results:

• Short-term PM initially decreased absolute fungal abundance but varied in response across sites, especially under poor hydrothermal conditions.
• PM significantly reduced the abundance of potential fungal pathogens (e.g., Gibberella) while increasing beneficial plant biocontrol fungi (e.g., Glomeromycota, AMF).
• Long-term PM decreased phytopathogen guilds and increased arbuscular mycorrhizal fungi (AMF) guilds, correlating with higher maize yields.

Conclusions:

• Plastic film mulching alters soil fungal community structure, primarily by reducing pathogens and promoting beneficial fungi like AMF.
• The reduction in fungal pathogens and increase in AMF functional guilds under PM contribute to enhanced maize yields.
• Microbial shifts induced by PM, particularly pathogen reduction, explain a significant portion of maize yield variation, offering guidance for sustainable agriculture.