Eco-friendly Plant Disease Management Using Spent Mushroom Substrate

This review is the first comprehensive synthesis covering two and a half decades. Mushroom cultivation has grown rapidly in the past four decades, driven by rising consumer demand for functional foods, health supplements, and protein-rich diets. Spent mushroom substrate (SMS), a lignocellulosic by product generated after mushroom cultivation, has traditionally been considered an agricultural waste material requiring disposal. It is estimated that for every kilogram of fresh mushrooms harvested, between 4 and 5 kilograms of SMS are produced. However, in recent decades, SMS has emerged as a resource with significant potential in sustainable crop production systems, particularly for plant disease management. Being rich in organic matter, nutrients, beneficial microorganisms, and bioactive compounds. It can suppress soilborne pathogens, and enhance crop resilience. The objective of this review is to provide a comprehensive synthesis of SMS research in the context of plant disease suppression. This review synthesises global research findings from 2000 to January, 2025, discussing SMS composition, mechanisms of disease suppression, and its integration into plant disease management strategies. We examine case studies from diverse agroecological zones, evaluate environmental and economic implications, and highlight policy measures for broader adoption. Challenges such as variability in quality, pathogen carryover risk, and limited farmer awareness are also discussed, alongside emerging innovations such as SMS-based biochar and fortified microbial inoculants. By framing SMS as a key element in the circular bioeconomy, this review underscores its role in aligning agricultural productivity with environmental sustainability. The use of SMS aligns well with circular economy principles, reducing waste disposal problems for mushroom producers while lowering dependency on synthetic pesticides and fertilisers for farmers.