Alternate mushroom casing substrate casing/blends with alternative materials (MU24001)

Challenge 

Producing commercially viable quantities of white and brown mushrooms in Australia requires a continuous supply of casing-soil, primarily derived from deep-dug peat imported from Western and Eastern Europe. However, geopolitical issues, environmental concerns, and negative consumer sentiment towards peat use in Australian horticulture are likely to impact the availability and cost of imported casing soil over the next decade, thereby threatening mushroom production.  

Currently, the Australian mushroom industry is entirely dependent on peat-based casing-soils for production, posing a significant risk. Viable alternatives must ensure acceptable crop yield and quality within narrowly acceptable cost and availability windows. Effective mushroom fructification (process by which mycelium produces mushrooms) requires a suitable casing microbiome, and any alternatives must support microbiomes with the appropriate attributes. Additionally, alternatives with increased carbohydrate levels could foster the growth of human pathogenic bacteria, such as Listeria monocytogenes, and may lack organisms that control competitive green moulds, which needs to be considered when proposing alternatives. 

Response  

This project will future-proof the Australian mushroom industry by identifying alternative casing-soil substrates using local sustainable materials or blends with sustainably sourced brown peat imports. These alternatives must support mushroom production and deliver yields and quality comparable to those achieved with deep-dug peat-based casing soils.  

Key activities include:  

Benefit  

The project will provide growers with results from small, medium, and large-scale trials of alternative casing soils in an easily understood manner. It will also recommend economical, safe, and proven sustainable alternatives to deep-dug peat-based casing soils, ensuring the Australian mushroom industry’s resilience in the face of potential future supply disruptions.  

The resulting final report will include cost estimates for the best alternative casing soil mixes, raw input availability, and equipment requirements for preparing blends, and biosecurity considerations for inter-state material movement. This will equip growers with the confidence to adopt commercially viable, trial-tested alternative casing mixes, using Australian materials exclusively or blended with imported sustainably mined brown peat, ready for immediate use in the event of a crisis.