What types of mushroom compost are there for straw mushrooms? How to prepare them

The raw materials needed for cultivating straw mushrooms come from a wide range of sources. Currently, the most commonly used are rice straw, wheat straw, waste cotton, and cottonseed hulls. Some spent substrate left over from cultivating other edible fungi can also be used to grow straw mushrooms.

1. Rice straw

Choose golden-yellow, mold-free dry rice straw, and sun-dry it for 1-2 days before use to prevent the appearance of coprinus or other contaminating fungi during cultivation. There are generally two ways to treat rice straw. One is to cut the rice straw into pieces about 5 cm long, then soak them in 3% limewater for 1-2 days, then add dry pig manure or dry cow manure equal to 20%-25% of the straw weight and compost for 2-3 days. During this period, turn the pile once when the material temperature rises to 60°C, then move it into the growing room for high-temperature sterilization, that is, raise the room temperature and material temperature to 58-62°C and hold for 2-4 hours. Generally, about 6 kg of rice straw is used per sq m of cultivation area. The second method is to spread whole rice straw on the mushroom bed with the root ends facing outward; then spray the rice straw thoroughly with 2% limewater, heat the growing room, hold at 58-62°C for 2-4 hours, then maintain at 48-52°C for 3-4 days; finally cover the rice straw with sun-dried, crushed cow manure or pig manure adjusted to about 50% moisture.

For cultivating straw mushrooms with rice straw, it is generally best to schedule it in July and August when the average temperature is above 26°C.

2. Wheat straw

The treatment method for wheat straw is basically the same as for rice straw. Wheat straw has a waxy layer on the outside and is not easy to soak, so the soaking time should be appropriately longer.

3. Waste cotton

Waste cotton is the best compost for straw mushroom cultivation. Waste cotton contains large amounts of cellulose and an appropriate amount of nitrogen, and has good moisture retention and absorption. Treatment method for waste cotton: soak it in 5%-6% limewater for 12-20 hours, then take it out and drain off the excess water. When it goes onto the bed, the moisture content of the material should preferably be about 70%. Cultivating straw mushrooms with waste cotton generally does not require adding other supplements. Generally, 9-13 kg of waste cotton is needed per sq m of cultivation area. When the temperature is high (above 30°C), the material thickness should be about 10 cm; when the temperature is low (below 26°C), the material thickness should preferably be about 15 cm; when grown on the ground, the material can be appropriately thicker.

4. Cottonseed hulls

Cottonseed hulls are also a relatively good raw material for cultivating straw mushrooms. When treating them, first sun-dry the cottonseed hulls for 1-2 days, then pre-wet them thoroughly. After 12-15 hours, add 5%-6% lime powder and 1% superphosphate, mix well, then add about 70% water, and then build a pile 1.5 m wide and 1 m high, surround the sides of the pile with plastic film, and cover the top of the pile with rice straw. The piling period is generally 3-5 days; in summer the piling period can be shorter, while in spring and autumn it should preferably be longer. During the piling period, turn the pile 1-2 times, and replenish water when turning to keep the moisture content of the material at about 70%.

5. Mixed material

Mixed material is made by mixing two or more kinds of compost and using the advantages of each kind of compost to cultivate straw mushrooms. For example, when cultivating straw mushrooms in July and August, it is best to use a mixture of waste cotton and rice straw or cottonseed hulls and rice straw, generally mixing 60%-70% waste cotton or cottonseed hulls with 30%-40% rice straw, which can achieve the purpose of lowering temperature and improving aeration.