Local plant biomass and biodegradable organic waste-derived compost as a sustainable alternative to peat in casing layers for Agaricus bisporus cultivation

Abstrakt

Progressive restrictions on peat extraction in Europe create the need for sustainable alternatives for casing layers in Agaricus bisporus cultivation. This study evaluated compost-based peat-free humus casing as a substitute for conventional peat casing under commercial conditions. Physicochemical properties, yield performance, and mineral composition of fruit bodies from white and brown strains were analyzed across two flushes. Compared with peat, the humus casing showed lower water-holding capacity, higher pH, and higher electrical conductivity. Nevertheless, colonization dynamics and fruit body initiation proceeded similarly in both systems. In the white strain, first-flush yield under humus casing was significantly higher than under peat one, while in the brown strain yields were statistically equivalent. Mineral composition responses were strain- and flush-dependent. In the brown strain, humus increased Ca, Fe, and Se concentrations, particularly in the second flush. No consistent evidence of reduced mineral quality was observed. under humus. The second flush showed intensified positive effects, suggesting dynamic interactions between casing properties and nutrient availability. Overall, compost-derived humus casing provides yield performance comparable to peat and may enhance selected mineral traits, supporting its potential in sustainable peat-free mushroom production.