Reducing peat in growing media: impact on nitrogen content, microbial activity, and CO₂ and N₂O emissions

Renewable materials including coir, biochar, and composts are investigated worldwide in the horticultural industry to partially substitute peat growing media. In this study, we assessed effects of biochar vermicompost as partial substitution compared these peat-based media with coir terms NH 4 + -N NO 3 − content, CO 2 -C N O-N emissions their microbial biomass carbon nitrogen. Six mixtures (peat; 9:1 v/v; coir; v/v) replicated three times were incubated growth chambers during a 60 d period. At day 0 incubation (DAI), amended retained around 12.81% alone. The concentrations peaked at 275 mg·kg −1 33 DAI for 552 46 vermicompost. resulted large [2070 μg -C·g dry weight (DW)] (62.78 O-N·g DW) emissions, but not coir. increased much lower level (47.53 than (111.82 DW). Our results showed that supplements improved supply which could benefit plant growth, while substituting part emissions. contrast, no effect was observed is beneficial environmental footprint short-cycle crops.