Detailed Explanation of the Key Points of the Two-Stage Cultivation Technique for Straw Mushrooms

Straw mushroom, also known as orchid mushroom or bud-foot mushroom. It is rich in nutrients and delicious. In the hot summer, making soup with a few straw mushrooms gives a unique and distinctive flavor, with an endless aftertaste after eating, and it is deeply welcomed by consumers.

The growing season for straw mushrooms is from June to September. It is a variety that grows quickly, has a short production period, and brings quick returns, producing mushrooms 8-10 days from spawning. Using the new two-stage cultivation technique, every 100 kg of raw material can produce 50 kg of fresh mushrooms in 40 days, with an output value of 300-400 yuan.

The two-stage cultivation technique for straw mushrooms is a practical, high-yield new technique successfully tested by the author over many years of production practice, drawing on the principle that covering oyster mushrooms with soil can significantly increase yield. Using this method, after many years of large-scale promotion, the yield can be increased by 1-2 times compared with traditional heap cultivation, bed cultivation, and block-pressing cultivation methods. The average biological efficiency reaches 58%, with a maximum of 65%. This technique is introduced as follows:

1. Select superior spawn. The selected varieties are preferably straw mushroom V238 (large-grain type), V20, and V35 (medium-grain type). The above varieties have the characteristics of being large and round, with dense flushes and high yield, and are suitable both for fresh sale and for processing into cans. The spawn age of the cultivation spawn used should preferably be kept at 15-20 days; aged spawn can hardly achieve high yield.

2. Raw material treatment. Select golden-yellow, dry rice or wheat straw free of mildew, expose it to the sun for 2-3 days, and use machinery or a cattle-drawn stone roller to repeatedly crush and press the straw stems into soft, cotton-like straw fragments. Formula: 100 kg of rice straw or wheat straw, plus 10 kg of dried cow dung powder, 5 kg of plant ash, 3 kg of wheat bran or rice bran, 1 kg of compound fertilizer, and 2 kg of gypsum powder. When mixing, first mix the various auxiliary materials evenly, pre-wet them with 1:500 carbendazim solution, then mix them evenly with the straw material, and then repeatedly pre-wet the straw material with 5% limewater (based on dry material ratio) so that the moisture content reaches 70%. It is suitable when the material is gripped tightly in the hand and 5-6 drops of water drip from between the fingers. The pH value is 12. Then build a heap for fermentation, cover with film to keep warm and retain moisture. After the material temperature rises above 60°C, maintain it for 24 hours, then turn the heap once; after the material temperature rises again to 60°C, maintain it for 24 hours. When the material turns brown and there is a large amount of white actinomycetes, spread the heap to cool it, evenly spray 0.1% carbendazim solution into the material, mix thoroughly and evenly. The fermentation period is 7-8 days.

3. Bagging and fermentation. For cultivation bags, it is preferable to use low-pressure polyethylene bags of 50 cm × 24 cm × 0.03 cm (length × width × thickness). First tie one end of the bag tightly with a slip knot, sow a layer of spawn at the bottom of the bag, fill a layer of material, then sow another layer of spawn, fill another layer of material, cover the surface of the material with spawn, for a total of 2 layers of material and 3 layers of spawn, and finally tie the bag mouth tightly with rope. The material should be packed with moderate tightness, pressing firmly while filling. Each bag holds about 800 g of dry material, with a total spawning rate of 15%. After inoculation, place the bags in a clean, ventilated room for fermentation, stack them in 1-2 layers, with 20 cm spacing between bags, keep the room temperature at about 32°C, and the relative humidity of the space at 70%. After the spawn survives and becomes established, loosen the tying rope to increase oxygen inside the bag and promote mycelial growth. Under suitable temperature conditions, the mycelium can fill the bag in about 10 days. After pink chlamydospores appear on the surface of the material, it enters the fruiting period.

4. Land preparation and site construction. Sites for fruiting can be built in places such as in front of and behind houses, at the edges of fields, under various woods or under melon and bean trellises. The requirements are flat terrain, close to a water source, clean and sanitary, and convenient for drainage and irrigation. After selecting the site, turn the soil 5-10 cm deep, break it up, pick out weeds, tree roots, stones, and other objects, and make a bed 1 m wide with a surrounding ridge 20 cm high and unlimited length, and wet the soil with 5% limewater. Then spray 1:800 dichlorvos and cover with film for 24 hours to kill pests and diseases in the soil.

5. Removing bags for fruiting. After removing the bags from the fungus cylinders that are already full of mycelium, place them flat in the bed with 5 cm spacing between cylinders, and fill the gaps with fertile soil (fertile soil formula: 92.5% garden soil, plus 5% plant ash, 0.5% compound fertilizer, and 2% lime powder). The fertile soil should first be pre-wetted with 1% limewater until it forms a ball when gripped in the hand and breaks apart when touched to the ground. Cover the surface of the material with fertile soil 1-1.5 cm thick. After finishing one bed, use bamboo strips to build an arched shed, cover and press down plastic film and straw curtains to retain moisture and shade light. Keep the temperature inside the film at 30-34°C and the humidity at 90-95%. After the fungus cylinders are covered with soil, the mycelium can grow into the soil layer in 2 days, and small mushroom buds can appear on the soil surface in 5-7 days.

6. Management and harvesting. After the fungus cylinders are covered with soil, water should be sprayed 1-2 times a day to keep the soil layer moist, and ventilation should be provided appropriately. After a large number of mushroom buds have formed, spray water 2-3 times a day. The water temperature should be the same as the natural temperature, and it is essential to avoid causing a large temperature difference that would kill the mushrooms. Ventilation should be carried out slowly to keep the bed surface humidity stable. After the young mushrooms grow for 3-5 days, harvest them promptly when the partial veil is about to break and the cap inside the veil has not yet expanded. When harvesting, pick the large ones and leave the small ones, pick and place them gently, and sell or process them promptly. After each flush of mushrooms is harvested, spray 0.1% compound fertilizer solution on the surface of the material. After 3 days, the second flush of mushrooms can form buds. Generally, 4-5 flushes of mushrooms can be harvested.