Effects of mulches on greenhouse gas emissions and soil microbial communities in cabbage production

Agricultural plastic mulches are widely used for their agronomic benefits, but their impact on greenhouse gas (GHG) emissions and soil microbes remains unclear. This study examines the effects of mulching on soil properties, microbial communities, and GHG emissions in cabbage cultivation using four treatments: NF (no mulching), FT (black traditional mulch, 0.015 mm), FBS (black biodegradable mulch, 0.010 mm), and FBB (black biodegradable mulch, 0.015 mm). The results showed no significant differences in cabbage biomass and yield across treatments. However, FT and FBB significantly reduced cumulative CO₂ emissions by 32.07 % and 26.70 %, respectively, compared to NF, while FT increased N₂O emissions and FBB reduced them (p < 0.05). Biodegradable mulch enhanced bacterial network complexity and stability, whereas traditional mulch strengthened fungal network stability. Soil properties, including porosity (19.82 %), NH₄⁺ (18.55 %∼20.19 %), and dissolved organic nitrogen (42.29 %∼85.61 %), improved under biodegradable mulch. Bacterial communities were positively correlated with soil nutrients, while fungal communities showed negative correlations. The reduction in GHG emissions could be attributed to the blocking effect of the mulch during the early stages of crop growth. Partial least squares path modeling analysis revealed that mulching-induced changes in soil hydrothermal conditions can influence soil nutrients and microbial communities, ultimately affecting GHG emissions. These findings offer insights into sustainable agricultural practices that promote soil health and reduce GHG emissions.