Detailed Explanation of Key Techniques for Cultivating Straw Mushrooms on Wheat Straw

Straw mushroom is a high-quality edible fungus and a typical high-temperature mushroom species, suitable for summer cultivation. The optimum temperature for straw mushroom mycelium growth is 30-39°C, with the optimum at 36°C; below 15°C or above 42°C growth is extremely weak, at 10°C growth stops, and below 5°C the mycelium dies. The optimum temperature for fruiting bodies is 28-33°C, and below 24°C fruiting bodies are difficult to form. Therefore, temperature management in straw mushroom cultivation is quite strict.

1. Site selection and preparation. Choose a leeward, sunny, high and dry, organic-rich loamy soil to make an east-west oriented sun-facing bed, bed width 80 cm, length unlimited, depth 30 cm, with walls built around it; the north wall rises 30-35 cm above the ground, the south wall rises 15 cm above the ground, sloping naturally from north to south. Bamboo poles are laid horizontally across the bed surface, covered with plastic film and straw mats to control temperature and retain moisture. The bed bottom is tamped firm, the four walls are smoothed flat, and a 60-70 cm walkway that also serves as a drainage ditch is left inside the bed. After completion, water according to soil moisture, and spray lime water at pH 8-9 for disinfection.

2. Treatment of the growing substrate and sowing. Substrate formula: wheat straw powder 50%, cottonseed hull 45%, wheat bran 5%, lime 5%, 50% carbendazim 0.05%. (1) Fermentation. Crush the wheat straw, mix with lime water at pH 8-9 at a material-to-water ratio of 1:1.8, then pile the material for fermentation. Fermentation method: pile the material into a cone about 1 m high, or a long pile 1.5 m wide and 1 m high, and use wooden sticks 5-6 cm in diameter to make two rows of ventilation holes on the surrounding sides, spaced 30 cm apart. When the material temperature rises to 60-70°C, turn the pile, turning once every 24 hours for a total of 4 turns. During turning, pay attention to the moisture content of the substrate; replenish promptly if insufficient, keeping the moisture content at about 60%. After the last turning, spray an insecticide once on the surface of the material, then cover tightly with plastic woven sheets soaked in lime water to prevent contamination by mosquitoes and flies. After the above fermentation, high-quality substrate has the following characteristics: brownish, with no manure or ammonia odor; loose and soft in texture, forming a ball when squeezed in the hand and scattering when gently shaken; pH 7-7.5; moisture content 60%, that is, when the substrate is squeezed in the hand, water seeps out between the fingers but does not drip; free of insects and mites. (2) Sowing. Spread the fermented material evenly in the bed at 15 g per square meter, shape it into a steamed-bun shape slightly higher in the middle and slightly lower on both sides, then evenly broadcast the spawn on the surface, with a slightly larger sowing rate at the 5-6 cm edges, press firm, and cover with plastic film and straw mats.

If bag cultivation is used, first loosen the fermented material, cool it to below 40°C and fill into bags, with a spawn amount of 15%-20% of the dry material weight, inoculate in 4 layers, tie the two ends of the bag tightly with rope, puncture 8-10 small holes with a needle, and place in a 32-35°C environment for cultivation; after 3-4 days, untie one end.

3. Management during the cultivation period. After sowing, temperature is mainly controlled by uncovering and covering the straw mats. When the bed temperature is low, uncover the mats during the day to raise the temperature, and cover them in the morning and evening to keep warm. Generally, the material temperature begins to rise on the first or second day after sowing, and after 4-5 days the temperature at the center of the material can reach 40-60°C, with the material surface at 30-40°C, then gradually declining; when it drops to 30-40°C, after about 8 days the mycelium begins to knot and form fruiting body primordia. If the temperature is too high, ventilate to exchange air. During the growth stage, generally do not water; if the humidity is too low, water once 5-6 days after sowing, or cover the material surface with a 1-2 cm layer of fertile loam. After the fruiting body primordia appear, prop up the covering to ventilate and exchange air and increase light, which favors fruiting. At this time, if the moisture content of the substrate is insufficient, spray water promptly. After the first flush is harvested, if the pH is less than 8-9, spray 1% lime water to adjust it.