Chemical Characteristics Analysis and Quality Assessment of Reed-Based Spent Mushroom Substrate

Abstract

Chemical characteristics analysis and quality assessment is necessary before choosing a sustainable utilization way for spent mushroom substrate (SMS) disposal. Therefore, three varieties SMS of Pleurotus spp. cultivated on reed were taken as samples to analyze chemical characteristics on the feed and fertilizer nutrients, and mineral elements. All SMS were acidic, pH was 5.26–5.51. There was no significant difference on the contents of fiber, carbon, pH, Pb, Cd, Hg, and As in three SMS, but they were lower than that in substrate (S), expect of Pb and Cd. The principal component analysis based on 25 variables showed that 2 components explained 72.2% of the quality variation in SMS. The first component (56.8%) differentiated S, SMS of Pleurotus eryngii (SMS-P.E) from SMS of P. ostreatus and P. citrinopileatus (SMS-P.C, SMS-P.O). The second component (15.4%) differentiated SMS-P.C from SMS-P.O. The contents of total sugar, total amino acids, total potassium, crude polysaccharide, and crude lipid were similar between S and SMS-P.E. The contents of crude protein, ash, total nitrogen, Ca, Zn, Cu, and Mn in SMS-P.E were even more than that in S. The feed and fertilizer parameters of total sugar, amino acids, crude protein, total nitrogen, and total phosphorus were much lower in SMS-P.C than SMS-P.O. Therefore, a utilization suggestion was provided: according to the contents of total carbon and nitrogen, neutral detergent fiber and Ca, SMS-P.E grown on reed could be considered as materials for secondary cultivation of mushroom; based on the parameters of crude protein, amino acids, total sugar, SMS-P.O was more fit for utilization as feed and fertilizer than that of P. citrinopileatus; SMS-P.C could be used as fertilizer.