Gypsum - Calcium Sulfate Dihydrate

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

2. pH regulation: Gypsum helps stabilize the substrate pH: it can be used to raise the pH of an overly acidic substrate and to lower the pH of an overly basic substrate. A stable pH is important for optimal mushroom growth. Although gypsum is not a strong buffer, it can help maintain 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 the mushrooms cultivated. A common recommendation is to add about 2-5% gypsum by dry weight of the substrate.

Gypsum is allowed in organic farming.

Food grade (code E516)