Straw return counteracted constraints caused by microplastics and enhanced soil multifunctionality by regulating...

Area of Science:

• Agricultural Science
• Environmental Science
• Soil Science

Background:

• Microplastic (MP) pollution poses a significant threat to agricultural soil multifunctionality (SMF).
• The efficacy of straw return in counteracting MP-induced SMF decline and the underlying microbial mechanisms are not well understood.

Purpose of the Study:

• To investigate the impact of polyethylene microplastics (PE) and corn straw (CS) on soybean soil SMF.
• To elucidate the microbial pathways involved in straw return's mitigation of MP pollution effects.

Main Methods:

• A 90-day soybean pot experiment with four treatments: control (CK), PE, CS, and PE combined with CS (PC).
• Measurements included soil physicochemical properties, enzyme activities, microbial biomass, soybean growth, SMF, microbial diversity, keystone taxa, and predicted functions.

Main Results:

• PE significantly reduced SMF, enzyme activities, microbial biomass, and soybean growth, while intensifying phosphorus limitation.
• Straw return (CS and PC) significantly increased SMF, microbial biomass, and enzyme activities, restoring microbial functional complementarity.
• MPs impaired SMF by altering microbial diversity and functions, whereas straw return counteracted these effects by supplying nutrients and carbon.

Conclusions:

• Straw return effectively mitigates microplastic pollution's negative effects on agricultural soil multifunctionality.
• Straw return rebuilds microbial diversity, function, and resource acquisition, offering a sustainable strategy for managing MP-contaminated soils.