Peat alternative casing materials for the cultivation of Agaricus bisporus mushrooms – A systematic review

Agaricus bisporus mushrooms are an economically important crop in Ireland and globally. Currently black peat plays a key role in mushroom production and the industry is under pressure to find alternatives. Peat is the primary component of mushroom ‘casing’, which is a layer applied on top of the growing substrate. This provides moisture and induces the fungal reproductive phase. Further to producing mushroom yield and quality comparable to peat, alternative materials must also be easily sourced and economically viable for growers. This systematic review was based on articles related to mushroom production on alternative casing materials published between 1970 and 2023. A wide range of alternative materials have been tested, with varying degrees of success. Specific combinations of alternative materials may offer superior performance. Additionally, there was little consistency in both experimental approach and materials utilised. For example, while peat is used as a control, the properties of this peat vary depending on origin. The same was true of ostensibly similar alternative casing materials, which frequently had been processed differently or had different origins potentially divergently altering their properties. These inconsistencies hamper the compilation and evaluation of findings from previous studies, which is vital in informing the direction of future research.