Evaluation of hydrothermal treatment in enhancing rice straw compost stability and maturity

•Bin-scale composting (90L) was performed following a pilot-scale (200L) HTT.•HTT with mild reaction condition (180°C, 1.0MPa, 30min) enhanced rice straw composting process.•Rice straw compost with HTT can reach stability within 6weeks of composting.•Rice straw compost with HTT may be phytotoxic if used as growing media for EC sensitive plants. In order to evaluate the hydrothermal treatment (HTT) in enhancing compost stability and maturity of lignocellulosic agricultural residues, a bin-scale (90L) composting of rice straw with and without “HTT” was performed. The rice straw compost product with “HTT” after 6weeks of composting can be considered stable and adequate for field application as expressed by pH of 8.4, “EC value” of 2.96dSm−1, C/N ratio of 12.5, microbial activity of 83%. However, compost may prove phytotoxic if used as growing media for EC sensitive plants. As for rice straw compost product without “HTT”, the high microbial activity (>12.28mg CO2g−1 OMd−1) even after 14weeks of composting suggests that the residue has not stabilized yet and is far away from stability and maturity, although a higher GI (>100%) was observed.