An Evaluation of Recycled Mushroom Compost as an Alternative Casing Material, and the Utilization of Carbon Dioxide as a Crop Management Technique in Agaricus bisporus Cultivation Systems.
Open Access
- Author:
- Gabel, Nicholas
- Graduate Program:
- Plant Pathology
- Degree:
- Master of Science
- Document Type:
- Master Thesis
- Date of Defense:
- June 04, 2024
- Committee Members:
- David Meigs Beyer, Thesis Advisor/Co-Advisor
Alyssa A. Collins, Committee Member
Maria Del Mar Jimenez Gasco, Program Head/Chair
Kari Anne Peter, Committee Member
John Andrew Pecchia, Committee Member
Michael Fidanza, Committee Member
Shirin Ghatrehsamani, Committee Member - Keywords:
- Mushrooms
fungi
Agaricus bisporus
Mushroom compost
Carbon Dioxide - Abstract:
- Pennsylvania produces ~66% of the total Agaricus bisporus mushrooms for the United States market. This study was developed to examine an alternative cropping material and management method to address two major constraints facing the current industry. A. bisporus cultivation relies on a cropping practice called casing. Casing involves the application of a low nutrient soil like media to trigger a transition from vegetative growth to sexual fruit body development. Peat moss (Sphagnum spp.) is the most widely used material worldwide as a casing layer substrate. However, increased costs and lack of availability due to environmental policies, unpredictable weather patterns, and transportation expenses have led to a need for alternative materials and management methods. The first objective of this project was to evaluate the use of recycled mushroom compost (RMC) in the casing mixture. RMC is recycled material from a mushroom crop that has been pasteurized, weathered in a field for 1-3 years, pasteurized again, and then reused as casing material or in horticulture practices. By including 20% or 30% RMC in the casing layer there will be no significant difference in physicochemical properties or fresh mushroom yield. To test this hypothesis a (2x2) factorial experimental design was developed with treatments consisting of either 20% or 30% inclusion of RMC sourced from two different suppliers. The experiments were replicated over six individual cropping trials with seven replicates per cropping trial. Samples of the mixtures were collected on casing day and at end of cropping for physicochemical analyses. Yield data (reported as kg/m2) was collected during each flush and analyzed using analysis of variance (ANOVA) to assess differences between treatments followed by a post hoc Tukey test for pairwise comparison. Results for the combined six crops revealed a significant decrease in the average total fresh mushroom yield for all RMC casing mixtures (p<.05). RMC treatments displayed a reduction of >10% fresh mushroom yield when compared to the control. RMC mixtures also displayed trends of increased soluble salts, nitrogen, bulk density, particle density, and porosity when compared to the control. More research is necessary on this material's composition and management in the casing layer for future application. Along with material availability, labor shortages are a major constraint currently facing the global A. bisporus industry. The second objective of this study was aimed at addressing this issue by using a crop management technique to promote increased harvesting speeds and lower labor costs. This can be done by influencing the rate of mushroom development using abiotic factors of the growing environment. Some of these factors include air temperature, fan speed, relative humidity, and carbon dioxide concentrations. The research question proposed was: “Would elevating the CO2 concentration >10,000 ppm (.1%) 13 days after casing for either 24 or 48 hours influence fresh mushroom yield?” To conduct this experiment, a semipermeable cover was designed and tested to raise the CO2 concentrations for each individual growing bin. Once a system was developed, three experimental crops were conducted using a standard casing mixture. Each crop consisted of a control, a 24-hour, and a 48-hour treatment replicated three times. Environmental data inside the cover was collected using an Industrial IoT Wireless CO2 Temperature Humidity Sensor and relayed to an online database (https://dev.cropsmarts.com/login). Yield data (reported as kg/m2) was collected during each flush and analyzed using analysis of variance (ANOVA) to assess differences between treatments followed by a post hoc Tukey test for pairwise comparison. Results presented no significant difference in fresh mushroom yield between treatments (p>.05). Both CO2 treatments displayed a significant decrease in the number of mushrooms harvested (p<.05). These results indicate that the CO2 treatments produced less mushrooms but at a similar yield, implying the technique could potentially promote faster harvesting rates and heavier mushrooms.