Introduction. The edible Mushrooms have emerged as a globally important non-animal protein source in human-diet. Nevertheless, monitoring data on raw materials used in mushroom production and their effects on yield remain scarce. Hence, a clear understanding of how consumed raw materials influence production outcomes, alongside an assessment of potential improvements, is necessary. The production and productivity of button mushrooms is controlled by several factors such as compost quality, mushroom strain, spawn, growing medium, environmental conditions and irrigation. The type of medium and its quality components are the most important factors affecting the productivity of edible mushrooms. Wheat straw, chicken manure and gypsum are the most widely used materials for the production of button mushroom compost. The nutrient content of these materials varies greatly depending on the source, which in turn leads to different yields. The industry currently faces multiple challenges: declining quality and availability of raw materials, rising costs of both materials and energy, narrow profit margins, and limited access to labor in rural areas. This study aims to investigate and monitor the raw materials employed in mushroom compost production and to evaluate their impact on production performance indicators at an industrial scale.

Materials and Methods. The investigation was conducted at the Negin-e-Fasal Compost and Mushroom Production Factory in Shahrekord, Chaharmahal and Bakhtiari Province, across five production periods (spring 2022, summer 2022, autumn 2022, winter 2022, spring 2023, and summer 2023). A total of 258 observations were recorded, each in triplicate; certain traits were measured in the compost production section, while others were assessed in the mushroom production halls. An overall quality index for mushroom production was established by selecting indicators through factor analysis and multiple correlation analysis to form a minimum data set. The selected indicators were interpreted, transformed into standardized scores (0 to 1) using linear functions, integrated into a single composite index, and a weighted quality index was subsequently computed.

Results and Discussion. The results showed that the mushroom production facility employed varying combinations of raw materials throughout the study period, leading to differences in yield, biological efficiency, and production rate. Button mushroom yield was highest in period 5 (spring 2023), increasing by approximately 25.6% relative to period 4 (winter 2022). Principal component analysis (PCA) revealed that approximately 65% of the total variance was explained by four principal components with eigenvalues exceeding one, individual variance contributions below 5%, and cumulative explained variance exceeding 53%. The first principal component exhibited strong positive correlations with the quantities of sugarcane bagasse (0.57), poultry manure (0.60), and urea (0.65), as well as with the electrical conductivity (0.65) and water-holding capacity (0.44) of the cover soil. PCA further highlighted the significant effects of sugarcane bagasse, urea, ammonium sulfate, and straw.

Conclusion. This study demonstrates that mushroom production periods and seasons are influenced by raw material composition and environmental conditions, which collectively determine button mushroom yield. Among the raw materials evaluated, sugarcane bagasse, chicken manure, and urea consumption exhibited the most pronounced effects on yield. The yield, quality, and uniformity of harvested mushrooms depend on the physical, environmental, chemical, nutritional, and microbiological properties of both the compost and the casing soil layer, underscoring the importance of investigating the factors that govern mushroom quantity and quality. Optimizing compost composition and environmental conditions during preparation therefore represents a viable strategy for enhancing the yield of cultivated button mushrooms. Using principal component analysis (PCA) and Pearson correlation analysis, this study comprehensively evaluated the effects of different raw materials on button mushroom production characteristics. The results highlight the pivotal roles of sugarcane bagasse, poultry manure, and gypsum, as reflected by their dominant loadings along the PC1 axis, which captured a substantial proportion of the total variance. Correlation analyses further substantiate the contribution of these primary raw materials as key determinants of mushroom yield and quality. Collectively, these findings demonstrate that appropriate raw material formulations can significantly increase mushroom production while supporting specific nutritional and productivity targets in mushroom cultivation systems.

Acknowledgements. This research was funded by Shahrekord Negin Fasal Mushroom Cultivation and Industry Company and Shahrekord University under contract number 490D/100 dated 06/11/1400. The authors wish to thank the company's CEO, Mr. Kazemi, for his generous assistance in conducting the research and for providing a research platform at the company.