Assessment of the biochemical degradability of crop derived biochars in trace elements polluted soils

This study assesses the biochemical degradability of biochars produced from five contrasting crop residues (rice husk, olive pit, almond shell, maize straw and wood chips) in acidic soils contaminated with trace elements. For this purpose, highly moderately acid were amended each proposed subjected to a microbial degradation experiment under controlled conditions for 155 days. CO2 production pure fitted single exponential model, indicating that they only had one C pool. Among studied, those derived pit shell showed greatest stability, mean residence times (MRT) 293 214 years, respectively, whereas, biochar revealed MRT 82 years. Despite average all tested shorter than usually reported, addition increased recalcitrant pool studied by factor 2x 13 × . Solid-state 13C NMR spectra confirmed partial cracking aromatic network during due or physical alteration processes. It was further noted depended on its aromaticity but we have also observed metal-contaminated is less degraded, probably difficulties development at these soils.