Detailed Explanation of the New Technique for Cultivating Button Mushrooms with Corncobs
A large amount of corn is grown in northern China, and after crushing, corncobs can be used for button mushroom cultivation. In recent years, the area used for cultivating button mushrooms with corncobs has grown rapidly. Corncobs contain 91.3% organic matter and 51.8% soluble carbohydrates, with a carbon-to-nitrogen ratio of 56.70:1. For a button mushroom cultivation area of 100 sq m, 200...
A large amount of corn is grown in northern China. After crushing, corncobs can be used for button mushroom cultivation, and in recent years the area used for cultivating button mushrooms with corncobs has grown rapidly. Corncobs contain 91.3% organic matter and 51.8% soluble carbohydrates, with a carbon-to-nitrogen ratio of 56.70:1. For a button mushroom cultivation area of 100 sq m, 2000 kg of corncobs, 2000 kg of cow manure, 20 kg of urea, 150 kg of gypsum powder, 100 kg of superphosphate, 100 kg of cake fertilizer and 200 kg of cottonseed hulls can be used.I. Stack fermentation of the cultivation material (the stacking and fermentation time should be flexibly adjusted according to actual local temperature changes). Primary fermentation technique. The first fermentation generally requires a stacking time of about 22 days, with 5 turnings, and mainly includes such technical steps as pre-wetting the fermentation material, building the stack and turning the stack.
(1) Pre-wetting. To allow the corncobs and cow manure to fully absorb water, pre-wetting is carried out 3 days before building the stack. The pre-wetting method can be as follows: on a clean, tidy hardened road surface, spread the corncobs on the bottom layer, cover them with cow manure, and according to the size of the site, build a large stack about 1.0 m high, with unlimited length and width, and sprinkle lime water with a pH of about 8.5 on top every day until water overflows from the bottom, so that the material is fully soaked through.
(2) Building the stack. The fermentation site should be chosen on higher ground, close to a water source and near the mushroom house. It is best if the site surface is hardened to prevent clods of mud from mixing into the cultivation material during stacking. The stack width is 2.0 m, the height is 1.5 m, and the length is unlimited. The material and cow manure should be mixed as evenly as possible. If the material is too dry, water can be added thoroughly during stacking. After the stack is built, start measuring the temperature the next day. Normally the stack temperature should rise to 70°C on the third day. If it does not reach this, the cause should be identified as early as possible and remedied in time.
(3) Turning the stack. The specific timing of turning is determined by the temperature changes within the material. When the material temperature rises above 70°C, stops rising, remains for 1-2 days and then tends to decline, turn the stack immediately. The principle of turning is to alternate the top and bottom and the inner and outer parts, but because corncobs are relatively broken, this is somewhat difficult in actual operation. On the first turning, all the urea should be scattered into the material and mixed evenly, and water should be sprayed appropriately according to the dryness or moisture of the material. Auxiliary materials should be added in batches during the first and second turnings. If there is a certain degree of "white bloom" in the material, it is normal; if the proportion of "white bloom" is too large, it indicates that the material is short of water and should be watered in time to adjust moisture. During turning, if the material becomes sticky and has a sour, foul odor, it indicates that the material is too wet and the stack temperature is low; it should be turned and dried in time, and lime and gypsum should be added appropriately. Material infected by insect pests or partially raw should be turned as much as possible into the central high-temperature zone of the stack. Pay attention to testing the pH value; if the material is too acidic, it can be adjusted with quicklime or lime water.
After primary fermentation ends, the criteria for judging high-quality cultivation material are as follows: the cultivation material is dark brown, the corncobs have fully softened, they do not prick the hand when squeezed and have a luster, and in slightly drier cultivation material white actinomycetes can be seen. The moisture content of the cultivation material is moderate; when squeezed, 5-6 drops of water can fall, and the moisture content is about 70%. There is a slight ammonia smell and a faint fresh fragrance, not sour and not foul. The pH value is about 8.0.
2. Secondary fermentation technique. While still hot, transport the cultivation material that has finished primary fermentation onto the bed frames, close the doors and windows tightly, and use a boiler or a modified oil drum to introduce hot steam into the shed. When the temperature rises to about 63°C, damp down the fire to control the temperature, and when necessary introduce fresh air to cool it, keeping the temperature at about 60°C for 12-24 hours. During the day this temperature can generally be maintained, but the key is to continuously introduce an appropriate amount of hot steam at night. When the temperature drops to about 50°C, maintain it for 5-7 days, and finally ventilate to cool down so that the waste gases and residual ammonia produced during fermentation are discharged. When the material temperature drops below 28°C, spread the material and sow.
(1) After the material enters the shed, decide whether to adjust water according to the degree of dryness or moisture of the material. Because a large amount of water in the cultivation material is consumed during secondary fermentation, this water adjustment is intended to avoid adjusting water again after secondary fermentation ends, so as to reduce the probability of contamination by foreign microorganisms.
(2) The cultivation material should be piled as much as possible in the middle and upper layers. In principle, it should not be piled on the topmost layer or the bottommost layer; the upper layer has condensed water and the lower layer has low temperature. The cultivation material should be piled loosely on the bed frames, and must not be compacted.
(3) Strictly control the material temperature during secondary fermentation. The temperature should not exceed 65°C in the early stage of heating, so as to avoid the cultivation material becoming too dry and producing a large amount of actinomycetes, causing excessive nutrient loss. The average temperature should be maintained at about 60°C as far as possible.
II. Management during the spawn-running period. 1. Sowing. Flexibly determine the sowing amount according to whether the sowing season is early or late and whether the material is thick or thin; generally 1.5-2.5 bottles per sq m. Before sowing, all tools must be thoroughly disinfected with potassium permanganate solution, and at the same time the cultivation material should be loosened and leveled, generally to a thickness of 20-25 cm. Sow according to the local climatic conditions in real time; in Heze, Jining, Liaocheng and other cities in Shandong Province, the general sowing time is in August, while in Taiyuan, Lvliang and other places in Shanxi Province it is generally in late August to early September. In actual practice, the direct sowing method is generally used, that is, all the spawn is scattered on the surface. This method is simple and quick, and the mycelium can seal the surface of the material within just a few days, making it difficult for foreign microorganisms to invade. After sowing, gently compact it with a sterilized wooden board, and then cover it with plastic film. If the material is slightly too wet, newspaper or other sterilized paper can also be used as a cover. Close the doors and windows tightly and enter the spawn-running period.
2. Spawn running. During the spawn-running period, frequently shake off the water droplets attached to the plastic film gently onto the ground. After about 7-10 days of mycelial germination, the film can be uncovered. If there is contamination by foreign microorganisms on the surface of the material or the humidity in the covered space is too high, the film can be uncovered earlier.
(1) During the spawn-running period, frequently observe the mycelial growth and the speed at which the mycelium colonizes the material, and deal with problems promptly so as not to delay the optimal treatment period, causing the spread of insect pests and foreign microorganisms and thus reducing yield. If the cultivation material is too dry or too wet, the mycelium will fail to colonize the material or will recede. If too dry, spray water into the air to increase air humidity; if the cultivation material is too wet, reverse-drill rods or pry the material and increase ventilation.
(2) Always pay attention to observing changes in material temperature. If the material temperature is higher than 30°C, take measures such as drilling holes and compacting the surface of the material, and ventilation at night can also be used. Also prevent excessive ammonia in the material from inhibiting normal mycelial growth. If ammonia in the material is heavy, take measures such as inserting rods and lifting and loosening the cultivation material, and at the same time spray 2% formaldehyde solution on the ground, walls, aisles and other places to neutralize it. If the ammonia smell in the material is indeed too strong and has already caused the mycelium to shrink beyond remedy, then the material must be steamed again and then reseeded.
(3) If foreign microorganisms or insect pests are found, deal with them promptly; apply chemicals when chemicals should be applied, and dig out when digging out is required. If mite damage occurs, be sure not to be careless; treat it promptly and, when necessary, fumigate with chemicals. This requires us, after primary and secondary fermentation end, to pay close attention to the quality of the cultivation material, take timely measures when problems are found, and avoid as much as possible various problems after sowing that delay the optimal treatment period.
(4) From 1-5 days of spawn running, focus on heat preservation and moisture retention. When mycelial germination is normal, do not ventilate or ventilate little, to promote early mycelial germination and establishment and to seal the surface of the material. From 6-10 days of spawn running, the mycelium has basically covered the surface; as the mycelium colonizes deeper into the material, gradually increase the ventilation. From 11-18 days of spawn running, when the mycelium has colonized 1/2 of the material layer, promptly insert rods for aeration and at the same time increase ventilation to raise the oxygen content in the material. When the mycelium has colonized more than 2/3 of the material layer, prepare for casing soil (it is best if it has grown over the entire material layer).
III. Casing soil and management after casing soil
1. Selection of casing soil material. The soil texture, soil particle size and casing layer thickness all directly affect the timing of fruiting, the level of yield and the quality. Overall, the casing soil material should have a good crumb structure and good water-holding and air-permeability. The nutrients in the casing soil must not be too rich; nutrient-poor soil is somewhat better. Soil below 20 cm of the surface layer that contains no pathogens or insect pests should be selected, and alkaline soil with a high concentration of soluble salts must be avoided. At present, the best casing soil material is peat soil, followed by sandy loam. Peat soil has good water-holding and air-permeability. The following briefly introduces the management method using peat soil as the casing soil material.
2. Preparation of peat casing soil material. For each cubic meter of peat soil, add 10 kg of quicklime (lime water with a pH of 7.5-8.0 can also be prepared to spray the peat soil) and 0.2 m3 of sand. First mix the sand, quicklime and peat soil together, turn them twice, mix the three as evenly as possible, pile them into a large heap, and water from the top with clean water until water overflows from the bottom; start turning the heap the next day. Generally turn 4-5 times until the entire soil heap is uniform and consistent, and finally cover tightly with plastic film and keep sealed for 24 hours.
3. Treatment of the bed surface before casing soil. Before casing soil, if there are foreign microorganisms on the bed surface, spray a 300-500 times fungicide; if the bed surface is too dry, it can be combined with spraying 0.5% lime water, then ventilate to dry. If the surface of the material is too wet, ventilate earlier and keep the surface of the material slightly dry.
4. Casing soil and management after casing soil. Flexibly determine the casing soil thickness according to the thickness of the material; the soil layer thickness is generally controlled at 3.5-4.5 cm. Adjust the degree of dryness or moisture of the soil until water seeps out when squeezed and it crumbles when dropped. During this period, the key is to observe the material temperature and strive to keep it below 28°C. When necessary, ventilation at night or rod insertion in the material can be adopted, and water can often be sprayed on the walls, doors and windows in the shed to control temperature. The humidity in the shed is best controlled within the range of 65-70%.
IV. Fruiting management
1. Knotting and fruiting. When the mycelium begins to climb the soil, spray water lightly; if it climbs quickly, spray water frequently. As the mycelium rises higher, gradually increase the amount of water sprayed. When spraying water, combine it with ventilation. When the mycelium climbing the soil is 1 cm from the surface, water thoroughly to the maximum limit, and at the same time ventilate heavily to lower the temperature so that the material temperature is controlled below 20°C, so that the mycelium can effectively knot. Control mycelial growth well to prevent mycelial outgrowth. Once mycelial outgrowth occurs, increase ventilation and lower the temperature, and spray 0.5% lime water. If mycelial outgrowth is severe and forms a mycelial mat, use a small knife or rake to break up the mycelial mat, then combine this with the above management methods. When the mycelium begins to knot, close the ventilation holes according to the actual conditions in the shed, or ventilate as little as possible.
2. Regulation of air, temperature and humidity. When the mushroom buds generally grow to the size of soybean grains, spray one heavy watering. For peat soil, from the time the mycelium climbs the soil to the beginning of knotting, the amount of water sprayed should reach 7-9 kg. Because the mushrooms are small and yet water needs to be sprayed, this requires that the water not be sprayed too quickly or too heavily, and that it be completed within three days. At this time the temperature in the shed should be controlled at 14-16°C, and as far as possible not exceed 20°C. However, in actual operation, due to the constraints of natural conditions, the first flush of mushrooms often emerges unevenly, especially in the upper and lower layers, at the doorway and in the corners; the fruiting time is very inconsistent, and the size and number of mushrooms on the bed surface also differ, which brings inconvenience to management. Therefore, we must apply methods flexibly in practice. For the first flush of mushrooms, generally when spraying the mushroom-knotting water, spray the full amount in several applications so that the water content of the casing soil reaches saturation, then close the ventilation holes for 3-5 days, and start spraying water again when the mushrooms have grown to about 1.5-2 cm; spray more when there are many mushrooms and less when there are few. When spraying water, avoid high temperatures as much as possible, and spray in the morning and evening. When spraying water, be sure to ventilate, and never spray with the doors and windows closed. When spraying water, combine it with external weather conditions: spray more on sunny and dry days and less on cloudy and rainy days. But do not spray water before harvesting mushrooms, so as to avoid the mushroom bodies turning red and reducing commercial quality. However, water can be sprayed the day before harvesting, or after harvesting and replenishing the soil. After 80% of the mushrooms on the bed surface have been harvested, spray one more heavy watering, then remove dead mushrooms and mushroom roots, tidy the bed surface, close the ventilation holes and wait for the next flush of mushrooms to emerge.
3. In daily management, be sure to accurately grasp the relationship among ventilation and air exchange, heat preservation and moisture retention according to weather changes.
(1) In the early stage of autumn fruiting, the temperature is high, the mycelium and fruiting bodies grow quickly, ventilation should be strengthened and moisture adjusted in time, and the humidity of the mushroom shed should be maintained well; ventilation and watering are generally carried out in the morning and evening. In the later stage of autumn, the temperature gradually decreases, fruiting gradually becomes sparse and growth is slow; water spraying and ventilation should be reduced, and ventilation and water spraying are generally carried out at noon when the temperature is relatively high. When the temperature in the shed is below 8°C, natural fruiting should be maintained, with only occasional small amounts of water sprayed at noon when the temperature is high and short periods of ventilation.
(2) As the temperature falls day by day, when the temperature is below 5°C it is time to enter overwintering management; basically stop spraying water, and it is enough to keep the casing soil from turning white. Ventilate at noon when the temperature is high, keep the soil dry, then begin to tidy the bed surface, remove dead mushrooms, and remove old roots and aged, yellowed mycelial strands.
(3) If the autumn fruiting amount is large and the mycelium is vigorous, the surface soil should be lightly raked with a rake, then a small amount of lime powder should be scattered on the surface; scatter 4 kg of quicklime per 100 sq m, and then thoroughly enter overwintering.