Gypsum - Calcium Sulfate Dihydrate

1. Improvement of substrate structure: Gypsum helps improve the physical structure of the growing medium. It prevents the substrate from becoming compacted, which allows for better aeration and water circulation. This is crucial for the development of fungal mycelium.

2. pH Regulation: Gypsum helps stabilize the pH of the substrate: it can be used to alkalinize a substrate that is too acidic and to acidify a substrate that is too alkaline. A stable pH is important for optimal mushroom growth. Although gypsum is not a strong buffer, it can help maintain the pH within a range suitable for mushroom growth.

3. Source of calcium and sulfur: Gypsum provides essential nutrients, such as calcium and sulfur. Calcium is important for cell development and cell wall structure, while sulfur is essential for the synthesis of amino acids and proteins.

4. Reduced unwanted growth: Gypsum can help inhibit the growth of certain unwanted organisms in the substrate. By improving the structure and condition of the substrate, it can make the environment less favorable for contaminants.

Practical Applications of Gypsum in Mushroom Cultivation

• Substrate preparation: Gypsum is often added to the growing medium before sterilization or pasteurization. It is mixed thoroughly with other components of the medium, such as straw, compost, sawdust, etc.

• Dosage: The amount of gypsum to use may vary depending on the type of substrate and the mushrooms being grown. A common recommendation is to add approximately 2–5% gypsum based on the dry weight of the substrate.

• Safety / Precautions

  • Dust: Avoid inhalation; wear a dust mask during heavy use.

  • Avoid prolonged contact with the eyes (safety goggles are recommended).

   

Name: Gypsum / Calcium sulfate dihydrate
Formula: CaSO₄·2H₂O
CAS No.: 10101-41-4
Physical state: powder
Color: grayish white
Particle size: ~100 µm (maximum particle size: 100 µm)

Gypsum is permitted in organic farming.