Technical methods for growing edible mushrooms with biogas residue
Biogas residue has comprehensive nutrients, a loose texture, good moisture-retention properties and moderate pH, making it a good growing medium for cultivating edible mushrooms artificially. The growing medium left after cultivating edible mushrooms can also be used as feed for pigs or cattle. Pig and cattle manure can in turn serve as raw material for biogas fermentation.
Cultivating button mushrooms
1. Seasonal arrangement. For high-temperature-type mushrooms, the compost is generally stacked in mid-April, sown in early May, cased with soil in late May, fruiting in mid-June, and harvested in August; autumn mushrooms are generally stacked in late September, sown in October, fruiting in November, and harvested in April of the following year.
2. Raw material selection. For every 100 sq m of mushrooms planted, 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). The stacking time is generally arranged 25 days before sowing; 2-3 days before stacking, wet the rice straw or soak it so it absorbs enough water. (1) Building the stack. 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; stack in this way, one layer of rice straw and one layer of biogas residue, adding water as you stack and evenly adding auxiliary materials such as urea and superphosphate. After 10-12 layers, make the stack about 1.8 m high. Shape the top of the stack into a turtle-back form, keep the sides vertical, then cover it with straw matting or plastic film to prevent rain. (2) Turning the stack. According to the weather and changes in stack temperature, usually turn the stack 4 times, at 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 enough water; the second turning should shrink the stack to 1.8 m by 1.6 m and add 1/3 of the gypsum powder; on the day before entering the room for fermentation, evenly spray the area around the stack 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 fertilizer smell, the rice straw is neither too raw nor too decomposed, and is tough, not easily broken, soft and glossy; reaching the standard of about 62% moisture content and pH 7.5-8.
4. Post-fermentation (indoor fermentation). (1) Loading and stacking. After pre-fermentation ends, shake the growing medium loose from top to bottom and inside to outside, mix it evenly and place it on the mushroom beds, leaving the bottom two layers without material, and close the doors and windows tightly. (2) Heating the growing medium. Begin heating on the second day after the material enters the room, bringing the room temperature to 60°C in about 10 hours and maintaining it for more than 7 days. Then let the temperature drop naturally 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. It must also meet certain conditions: no ammonia smell, a sweet bread-like aroma, dark brown color, soft and elastic, not sticky to the hand, about 62% moisture content, and pH 7.2-7.5.
5. Turning the beds. Spread the growing medium evenly on each layer of the bed frames, pick out impurities, loosen while turning, and level while loosening, so that the thickness is uniform, the firmness is moderate and the surface is level.
6. Sowing. Once the material temperature drops below 28°C, sowing can begin. Each sq m requires 1.2-1.5 bottles of "grain spawn". Sowing method: use mixed sowing plus surface sowing; first evenly broadcast 1/2 of the spawn into the material, then gently pat the surface with a clean tool so the spawn grains fall into the material layer, then evenly broadcast the remaining spawn on the surface, press it firm with a flat board to moderate firmness, and after sowing clean the mushroom house and keep it clean and hygienic.
7. Management during the spawn-running period. On the second day after sowing, close the doors and windows. Ventilate in the morning and evening, with the duration determined by the air temperature; generally do not ventilate below 25°C, ventilate moderately above 28°C, and ventilate more above 30°C. Under normal conditions, ventilate for 1-2 hours a day to allow the mycelium to germinate and grow. From the 5th day after sowing, gradually increase the ventilation, and after 25-30 days the mycelium will cover the material layer.
8. Casing soil management. For every 100 sq m of planting area, 3 cubic m of pond mud and about 500 jin of coarse rice bran are needed. Soak the coarse rice bran in 0.5% lime water one day before casing. When casing, mix the treated coarse rice bran thoroughly with the pond mud, use it as it is mixed, and scatter it on the surface of the material to a thickness of 2.5 cm, ventilating day and night. Generally after about 7 days, small mushroom buds can be seen; at this time no spraying is needed, only keeping the air humidity at 90%-95%, and after 3-4 days a large number of mushrooms will appear on the bed surface, which can then be harvested.
Cultivating oyster mushrooms
The oyster mushroom is one of the mushroom types with the largest cultivated area and the highest yield in China. Cultivating oyster mushrooms with biogas residue has a high success rate, stable yield and good economic benefits.
1. Seasonal arrangement. High-temperature-type oyster mushrooms are planted and grown from April to August; medium- and low-temperature-type oyster mushrooms are planted in August and harvested in June of the following year.
2. Raw material selection. The raw materials for growing oyster mushrooms come from a wide range of sources, such as crop materials, corncobs, peanut shells, sawdust, rice straw, spent wood mushroom substrate, sugarcane bagasse, leaves and vegetables, various manures, biogas residue, spent edible mushroom substrate, etc. Raw material requirements: fresh, dry, free of mold and free of debris.
3. Scientific ingredient mixing. Crop straw (such as corncobs, sawdust, rice straw, etc.) 53%, biogas residue or spent edible mushroom substrate 30%, rice bran or wheat bran 10%, peanut bran 2%, gypsum powder 1%, lime powder 2%, compound fertilizer 2%, material-to-water ratio 1:1.25.
4. Bagging. Mix the above raw materials evenly and put them into 22 cm x 45 cm x 10 cm polyethylene plastic bags, and sterilize at normal pressure for 10 hours.
5. Spawn-running management. After inoculation, spawn can run either indoors or outdoors; the maximum temperature must not exceed 28°C. Check the temperature inside the bags frequently; if it is higher than 28°C, turn the stacks immediately, and never let high temperature kill the mycelium. Under normal conditions, the mycelium can fill the bags in about 25-30 days.
6. Fruiting management. During the fruiting period, pay attention to ventilation and air exchange, making sure no corners are missed in ventilation, and provide a certain amount of scattered light. Continue until they have fully grown.
Cultivating wood ear mushrooms
Traditional wood ear mushroom cultivation uses log cultivation, which consumes large amounts of wood and damages the ecological balance. As China's forestry resources become increasingly scarce, wood ear mushroom production has also been restricted. Using biogas residue and agricultural and forestry crop residues to cultivate wood ear mushrooms has wide raw material sources, low production cost, a short cycle, high biological efficiency and good ecological benefits; after cultivation, the residue can be broken out of the bags and used as raw material for biogas fermentation or continue to be used to grow other edible mushrooms.
1. Cultivation season. The optimum temperature for wood ear mushroom mycelium growth is 22-28°C, and the optimum temperature for fruiting body formation is 20-28°C. The optimum growth period for spring wood ear mushrooms is April to June, and the time for bagging and inoculation is January to March. The optimum growth season for autumn wood ear mushrooms is September to November, and bagging and inoculation should be arranged in July to August.
2. Mixing material and bagging. Thoroughly mix rice straw (bagasse or corncobs) or miscellaneous sawdust 50%, biogas residue 30%, wheat bran 15%, sucrose 1%, lime 2% and superphosphate 2%, then add water to 55-60%. Then put it into plastic bags with a diameter of 17 cm and a length of 45-50 cm. After bagging, press firm and tie the bag opening tightly, otherwise inoculation is unfavorable and contamination by unwanted microbes is likely.
3. Sterilization. Normal-pressure sterilization is generally used. Normal-pressure sterilization stoves are built differently in different places, but no matter what kind of sterilization stove is used, it must be ensured that all bagged material in the cylinder reaches 100°C, and then sterilization continues for 10-12 hours.
4. Inoculation. Move the sterilized spawn bags into a room that has been previously cleaned and disinfected, and stack them in a cross-hatch pattern, generally no more than 12 layers high. After the spawn bags cool, they can be disinfected and inoculated. Before inoculation, three checks must be made: first, check whether the spawn is pure white and uncontaminated, and disinfect the spawn bag by bag. Second, check whether the inoculation room meets the requirements. Third, check whether the inoculation workers are wearing work clothes or clean clothes and masks, and whether they talk during inoculation. After inoculation, the focus of management is heat preservation, light avoidance and ventilation. Generally, after 30-40 days of cultivation, when the mycelium has run through the spawn bags, the ear-fruiting management period can begin.
5. Ear-fruiting management. Choose a place with adequate water and good ventilation and sunlight to build a shed, and set up racks inside the shed for cultivation. Place the spawn bags that have finished running spawn on the racks, use a blade to cut about 2-4 holes of about 1 cm in a "V" shape in the film, then cover with plastic film to retain moisture and stimulate budding. Before the ear base forms, maintain air humidity and avoid opening holes at high temperature to stimulate budding. When the ear base has formed and opened into blades, in order to allow the wood ear mushrooms to grow fully, management should focus on moisture retention, spraying water 2-3 times a day, using alternating high and low humidity. After harvesting the wood ear mushrooms, stop watering for 2-3 days.
6. Harvesting and processing. When the ear blades are fully expanded, the edges begin to curl, the ear stem becomes smaller and white spore powder is visible on the underside, they can be harvested. After harvesting, pile the wood ear mushrooms for another 5-8 hours, so that visually the fuzz becomes longer and whiter, then rinse and sun-dry them.