Effects of different fermentation assisted enzyme treatments on the composition, microstructure and physicochemical properties of wheat straw used as a substitute for peat in nursery substrates

Abstract

To solve the central problems caused by traditional composting treatments, such as long-time consumption and poor regulation effects, this study used three fermentation methods and four enzymes to develop rapid and directional regulation methods to convert wheat straw into a suitable substrate. The results showed that the mixed anaerobic method led to better pH (4.39–5.75) and EC values (1.27–1.89 mS/cm) in the straw substrates, while the aerobic method retained more nutrients and increased lignin and cellulose contents by 5.07–8.04% and 1.52–3.32%. The cellulase mixed with hemicellulase or laccase treatments all increased the crystallinity by 0.45–7.23%. The TG/DTG results showed that all treatments decreased the initial straw glass transition temperature, particularly when using the mixed anaerobic method, with decreases of 10.63–25.48 °C. Overall, mixed anaerobic fermentation and multiple enzymes, including cellulase, have been suggested as alternative biological modification methods for straw substrates.