Dose-Dependent Evaluation of Salicornia Biomass on Growth Performance and Yield of Pleurotus sapidus in Sorghum Stover Substrates
Abstract
Integrating underutilized sorghum stover and coastal Salicornia biomass exemplifies sustainable agriculture within a circular bioeconomy by transforming regional waste into high-value food while addressing Namibia’s agricultural and saline-land challenges. This study evaluated the effects of amending sorghum stover with Salicornia at different levels (0%, 5%, 10%, and 20%) on substrate physicochemical properties, fungal vegetative growth, and fruiting performance of Pleurotus sapidus. A negative correlation was observed between pH and electrical conductivity in both media and substrates. The Petri dish experiment showed that potato dextrose agar amended with Salicornia extracts significantly accelerated mycelial growth (P < 0.05), with the highest growth recorded at 5% amendment (59.9 ± 1.69 mm/12 days), representing a 47% increase compared to the control. The bag experiment showed no significant differences across the treatments during the primordial stage, whereas a negative correlation was observed in the yield and biological efficiency relative to the inclusion levels of Salicornia sp. Significant variation was observed in the second flush (P < 0.05), where the 20% treatment produced only 88.2 ± 42.8 g compared to 250-257 g in the 0-10% amended treatments. The total yield was highest at 5% amendment (723 ± 42.6 g), comparable to the control, while the biological efficiency reached 72.3 ± 4.26% compared to 46.0 ± 5.30% at 20% amendment (P < 0.05). The electrical conductivity threshold for P. sapidus yield inhibition was identified as 0.848 S/m, which was consistent with the 20% Salicornia treatment group. The findings of this study suggest that the inclusion of Salicornia in sorghum stover should be considered primarily to valorize it rather than to enhance the growth or yield of P. sapidus. The findings of this study highlight the importance of maintaining substrate electrical conductivity and pH within a suitable tolerance range when integrating halophytic biomass into mushroom cultivation systems. These findings provide practical low-input guidance for integrating halophyte biomass into mushroom cultivation systems, supporting waste valorization and sustainable agriculture in Namibia.