Technical methods and key points for growing edible mushrooms with biogas residue
Biogas residue has comprehensive nutrients, a loose texture, good moisture-retention properties and moderate acidity and alkalinity, making it a good growing medium for cultivated edible mushrooms. The growing medium left after edible mushrooms are harvested can also be used as feed for pigs or cattle. Pig and cattle manure can in turn serve as raw material for biogas fermentation.
Growing button mushrooms
1. Seasonal arrangement. For high-temperature types of mushrooms, composting is generally carried out in mid-April, spawning in early May, casing soil in late May, fruiting in mid-June, and harvesting in August; for autumn mushrooms, composting is generally carried out in late September, spawning in October, fruiting in November, and harvesting in April of the following year.
2. Raw material selection. For every 100 sq m of mushrooms grown, use 2400 kg of rice straw, 2400 kg of biogas residue, 50 kg of soybean cake powder, 40 kg of urea, 50 kg of superphosphate, 50 kg of gypsum powder, 50 kg of lime and 25 kg of calcium carbonate.
3. Pre-fermentation (compost fermentation). Composting is generally carried out 25 days before spawning; 2~3 days before composting, wet or soak the rice straw so it absorbs enough water. (1) Building the pile. First spread a layer of rice straw 2 m wide and 0.3 m thick, then spread a layer of biogas residue 0.02 m thick, and continue piling one layer of rice straw and one layer of biogas residue in this way, adding water as you pile and evenly mixing in auxiliary materials such as urea and superphosphate. After piling 10~12 layers, make the pile about 1.8 m high. Shape the top of the pile into a turtle-back form, keep the sides vertical, and then cover it with straw curtains or plastic film to prevent rain from soaking it. (2) Turning the pile. According to the weather and changes in pile temperature, usually turn the pile 4 times, with intervals of 4, 4, 3 and 2 days respectively, loosening and turning the biogas residue and rice straw evenly and moving the outer material to the middle. The first turning should replenish water sufficiently; the second turning should reduce the pile to 1.8 m wide and 1.6 m high, and add 1/3 of the gypsum powder; on the day before entering the room for fermentation, evenly spray the surroundings of the pile and the site once with 0.5% dichlorvos, and seal it with plastic film for 6~12 hours, so that the compost has a slight manure smell, the rice straw is neither too raw nor too decomposed, and is tough, not easily broken, soft and glossy; the standard to reach is a water content of about 62% and a pH of 7.5~8.
4. Post-fermentation (indoor fermentation). (1) Loading and piling. After pre-fermentation is finished, shake the growing medium loose from top to bottom and inside to outside, and evenly spread it on the mushroom beds, leaving the bottom two layers without material, and close the doors and windows tightly. (2) Heating the growing medium. Start heating on the second day after the material enters the room, raising the room temperature to 60°C in about 10 hours and maintaining it for more than 7 days. Then let the temperature naturally drop to about 50°C and keep it there for 5~7 days, ventilating for 15 minutes every 3~10 hours. (3) At the end of post-fermentation, the growing medium should be covered with white beneficial microbial mycelium. The following conditions should also be met: no ammonia smell, a sweet bread-like smell, dark brown color, soft and elastic, not sticky to the hand, a water content of about 62%, and a pH of 7.2~7.5.
5. Turning the beds. Evenly spread the growing medium on each layer of the bed frames, pick out impurities, and as you turn the material, loosen it and level it, so that the thickness is uniform, the tightness is moderate and the surface of the material is level.
6. Spawning. When the material temperature drops below 28°C, spawning can begin. Each sq m requires 1.2~1.5 bottles of "grain spawn". Spawning method: use a combination of mixed spawning and surface spawning; first evenly broadcast 1/2 of the spawn into the material, then gently pat the surface of the material with a clean tool so that the spawn grains fall into the material layer, then evenly broadcast the remaining spawn on the surface of the material, and press it firm with a flat board, with moderate tightness. After spawning is completed, clean the mushroom house and keep it clean.