Key Technical Points for Cultivating Oyster Mushrooms with a Mixture of Corncobs and Tofu Residue

    Using corncobs and tofu residue as a growing medium to cultivate oyster mushrooms: because tofu residue and corncobs are rich in crude protein, crude fat, amino acids and other nutrients, each square meter can produce 50-75 kg of fresh mushrooms, with a biological efficiency of 150%-200% and considerable economic returns. The high-yield, high-efficiency technique for cultivating oyster mushrooms with a mixture of corncobs and tofu residue is described below.

    1. Formula of the growing substrate. Crushed corncobs 100 kg, wet tofu residue 80 kg, white lime 6 kg.

    2. Mixing the substrate and filling bags. First dilute the wet tofu residue and white lime with water, then pour into the corncobs and mix evenly, adjusting until the moisture content of the substrate reaches 65%. Use low-pressure polyethylene plastic tubes measuring 50x25x0.05 cm for filling; fill while pressing firmly (each bag holds about 1.25 kg of dry material), and tie both ends tightly with string.

    3. Sterilisation. The mushroom bags are sterilised under normal pressure, with the temperature reaching 100°C, held for 8-10 hours, and after the fire is stopped, left to steam for another 8-10 hours. After removal from the cooker, wait until the substrate temperature cools below 30°C before inoculating. The inoculation room must be disinfected twice. Before the mushroom bags are moved into the inoculation room, fumigate with potassium permanganate and formaldehyde (1:3); after the mushroom bags are moved in, disinfect once with a mist disinfection box.

    4. Selection of spawn. Varieties such as Nanjing No. 1, Shengming No. 1, ccef89 and Jiuping No. 1 are all suitable for cultivation, with vigorous mycelial growth, fast flushing and high yield and quality. For third-grade spawn, a spawn age of 30 to 40 days is appropriate.

    5. Inoculation method. Use the method of punching 3 holes at both ends and in the middle of the substrate bag for inoculation. Break the spawn into small pieces about the size of peanut kernels; they should not be too finely broken. The inoculation amount is about 15% of the dry material weight. This method allows the spawn to germinate quickly, rapidly colonise the substrate surface and reduce contamination by competing microorganisms.

    6. Mycelial growth management. Move the inoculated mushroom bags to the cultivation room and lay them flat in rows, with the inoculation holes of two bags facing each other, stacking 5-7 layers high, with 50 cm between rows. The room temperature should preferably be around 15°C; if it exceeds 25°C, ventilate immediately to cool down, keeping the substrate temperature below 25°C. After about 10 days of cultivation, turn the stack once, swapping the upper and lower layers. After about 30 days the bags will be fully colonised.

    7. Treatment of competing microorganisms. During mycelial growth in the bags, if competing microorganisms are found growing, use one of the following sterilising agents: 95% alcohol, 5% formaldehyde, 20% lime water, 5% carbolic acid or diesel oil, and inject it with a syringe into the substrate where the contaminants are growing, so that the area and depth penetrated by the solution are greater than the area where the contaminants are growing, so as to effectively control them. If the contaminated area inside the bag is too large to be treated with the solution, pick it out and take it outdoors to dispose of it.

    8. Bed-style soil-covering cultivation. Dig soil to make a bed 1 m wide and 35 cm deep, of unlimited length, and spray the bottom and surrounding sides of the bed once with insecticide and fungicide (80% dichlorvos emulsion at 1000 times dilution and 10% lime water). Then remove the plastic bags from the fully colonised mushroom bags and stand them upright in the bed, with the mushroom columns 2 m apart, fill the gaps with moist soil and press firm, and water thoroughly with nutrient solution (nutrient solution formula: water 100 kg, urea 500 g, monopotassium phosphate 300 g, magnesium sulfate 200 g, lime 4 kg). The covering soil should be level with the substrate surface; rinse away the residual soil on the substrate surface with water to expose the end face, then cover with plastic film, without pressing down the edges, so as to allow ventilation. 

    9. Fruiting management. To promote the formation of fruiting bodies, ventilate for 1 hour each day; when the air temperature is above 15°C, ventilate in the evening; when the air temperature is below 10°C, ventilate at noon. At the same time, uncover the plastic film on the bed surface to ventilate and exchange air. After a few days a large number of primordia will grow rapidly, with the initial cap forming at the tip; uncover the film on the bed surface and spray water into the air every day, maintaining a relative humidity in the room of about 95%. From the formation of fruiting bodies to harvesting takes about 7-10 days.

    10. Harvesting. Harvest when the edge of the cap takes on a gong shape; at this time the mushrooms are of good quality, heavy, and flush quickly. After harvesting, clean the bed surface thoroughly, stop spraying water for 3-5 days, then water the bed thoroughly once, keeping the bed surface moist. After about 1 week, primordia will grow again on the bed surface, and manage them according to the same method as the first flush. Generally 4-6 flushes are harvested, and the whole growing period is 4-6 months.