Gypsum - Calcium Sulfate Dihydrate

1. Improvement of substrate structure: Gypsum helps improve the physical structure of the growing substrate. It prevents the substrate from compacting, allowing better aeration and water flow. This is crucial for the development of mushroom mycelium.

2. pH regulation: Gypsum helps stabilize the substrate’s pH: it can be used to raise the pH of an overly acidic substrate and to lower the pH of an overly alkaline substrate. A stable pH is important for optimal mushroom growth. Although gypsum is not a strong buffer, it can help maintain the pH within an acceptable range 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. Reduction of 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 use of gypsum in mushroom cultivation

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

• Dosage: The amount of gypsum to use can vary depending on the type of substrate and mushrooms cultivated. A common recommendation is to add about 2-5% gypsum by dry weight of the substrate.

• Safety / precautions

  • Dust: avoid inhalation; wear a dust mask if handling intensively.

  • Avoid prolonged contact with eyes (goggles recommended).

   

Designation: Gypsum / Calcium sulfate dihydrate
Formula: CaSO₄·2H₂O
CAS No.: 10101-41-4
Physical state: powder
Colour: greyish white
Grain size: ~100 µm (maximum particle size: 100 µm)

Gypsum is permitted in organic farming.