Effects of crop rotation and organic amendments on carbon sequestration and greenhouse gas emissions in greenhouse organic leafy vegetable production

Greenhouse organic leafy vegetable production systems play an increasingly important role in supplying fresh produce but are characterized by intensive soil and nutrient management that can accelerate soil organic carbon (SOC) turnover and increase greenhouse gas (GHG) emissions.Management practices that simultaneously enhance SOC sequestration and mitigate GHG emissions are therefore needed to improve the sustainability of these systems.This study investigated the effects of crop rotation and organic amendments on SOC dynamics and GHG emissions in greenhouse-based organic leafy vegetable production.Field experiments compared repeated-cultivation of mustard greens (RC) with a crop-rotation system of spinach-hairy vetch-mustard greens (CR), combined with three organic inputs: animal compost (AC), organic fertilizer (OrF), and biochar (BC).SOC accumulation was higher under crop rotation, particularly in the CR-OrF treatment, where SOC increased by approximately 30.5 Mg C ha -1 .Although biochar improved SOC storage, it also caused the highest CO 2 emissions and global warming potential (GWP), mainly due to a priming effect that stimulated microbial respiration.While absolute SOC levels remained higher in RC plots, SOC increase rates were significantly greater under CR plots (p < 0.05), indicating stronger long-term sequestration potential under rotational systems.Overall, crop rotation combined with organic fertilizer enhanced carbon sequestration but also led to short-term increases in CO 2 and N 2 O emissions.These findings suggest that rotational cropping with optimized nutrient management can support long-term carbon storage in Korean greenhouse farming systems; however, short-term mitigation of GHG emissions should accompany carbon-focused management.