Stacked Functionality Greenhouse Use for Mushroom Production: Utilizing space under transplant tables to diversify crops and income

View the project final report

Commodities

• Miscellaneous: mushrooms

Practices

• Crop Production: greenhouses, multiple cropping

This project was conducted to evaluate the feasibility of mushroom production as a stacked use function with transplant production in a heated greenhouse, where mushroom production occurs under transplant production tables in space not normally utilized/occupied. Potential for stacked use or synergistic production systems that more fully utilize fixed assets/resources in small farming operations has the ability to increase the economic and environmental sustainability of such operations by generating more food production and economic activity from existing heated transplant production spaces thereby increasing carbon and capital use efficiency.  The project evaluated different mushroom species/strains (Oyster, Wine Cap, and Shiitake) as well as production techniques to assess their suitability for use under transplant tables in heated transplant production greenhouses. This analysis included evaluation of yield, as well as economics of labor, material costs and potential revenues. Results have been distributed to area and regional farmers through an educational “zine,” or handbook detailing methods, findings, and recommendations.

We grew three different types of mushrooms (Wine Caps, Shiitakes, and Oysters) in a heated greenhouse beneath transplant production tables. These varieties were selected because the inoculum are relatively inexpensive, heat tolerant/loving strains exist, are relatively quick to fruit, and have competitive market prices (each at about $5-10/lb). We grew these three varieties with a total of five different “treatments” with three replicates of each treatment: Treatment 1: shiitakes will be grown only on logs; Treatment 2: oysters in totems; Treatment 3 oysters on logs; Treatment 4 wine caps on chipped invasive (buckthorn) substrate; Treatment 5: wine caps on straw. We began the process of  all five treatments in the spring of 2021, and watched them throughout the summer and fall. By December of 2021, we had not seen many results from the treatments listed above, however, still had 6 months to work on our project. Wine caps on straw substrate was the fastest growing and least resource dependent, so we decided to inoculate three more beds. The next months involved lots of transplant production at the Campus farm, so we hoped that the increase in frequency of watering would lead to more moisture available to the mushrooms. By June, we realized that no mushrooms were going to grow, and began gathering what we had learned  to compile into our handbook for distribution to farmers. 

For a farm of our size and due to other staff and resource restrictions, this type of mushroom production may require too much hands-on maintenance, and be more feasible for a non-diversified farm with transplants on a table in the greenhouse for most of the year.

Though we have not yet distributed our educational zine to nearby, small farms, our tour and workshop inspired other student farmers to experiment with mushroom cultivation. 

• Evaluate feasibility of growing mushrooms under transplant production tables in heated greenhouses.
  
• Identify which mushroom types and production systems work best in this environment (wine caps mushrooms on straw or wood chips; oyster mushrooms in totems or in logs; shiitake mushrooms in logs).
  
• Evaluate potential economic benefits from this stacked/dual use system that utilizes previously un-utilized space to offset greenhouse heating costs, diversify production and increase economic and environmental sustainability.
• Disseminate findings and recommendation to farmers in our area though field day and further with a digital workbook detailing techniques, findings and recommendations.