A Detailed Explanation of Straw Mushroom Cultivation Methods and Technical Key Points
The straw mushroom, also known as the orchid mushroom, delicious straw mushroom, delicious volva mushroom, hemp mushroom, and Chinese mushroom, originated in China, with a cultivation history of more than 200 years. Inspired by the natural phenomenon of straw mushrooms growing on piles of rotting rice straw, the monks of Nanhua Temple in Shaoguan City, Guangdong Province, created a method for cultivating straw mushrooms, which is why it is also called the "Nanhua mushroom."
Preparation and management before cultivation:
I. Cultivation materials The raw materials used for straw mushroom production are mainly crop straw, known as the carbon source. Generally, cottonseed hulls as the raw material give the highest yield, followed by rice straw, while sugarcane bagasse performs relatively poorly; supplementary materials such as wheat bran, rice bran, and cornmeal serve as the nitrogen source.
II. Cultivation methods and cultivation sites Depending on the cultivation site, straw mushroom cultivation is divided into indoor cultivation and outdoor cultivation. Indoor straw mushroom cultivation can be carried out in specially built straw mushroom houses, or in mushroom houses converted from idle farmhouses, pig sheds, and the like. Converted mushroom houses can be fitted with bed frames, or cultivation can be done directly on the ground. Brick-style cultivation is mainly carried out in plastic greenhouses, under fruit trees, in open spaces in front of and behind houses, and in rice fields, etc.
III. Cultivation season The straw mushroom is a straw-rotting mushroom type that thrives in high temperature and high humidity. The optimal temperature for mycelial growth is 28-35°C, and the optimal temperature for fruiting is 30-35°C. In Guangxi, summer cultivation can be carried out from April to October. If heating equipment is used, year-round production is possible. At present, most cultivation in our region is year-round.
(1) Outdoor cultivation
(1) Site selection: Choose a wind-sheltered, sunny spot with convenient water supply, easy drainage, and fertile sandy soil as the site for building mushroom beds. When temperatures are relatively low, choose a south-facing site with ample sunlight and shade materials on the west and north sides; in midsummer, choose a cool, well-ventilated place for the mushroom bed. When making the mushroom bed, plow the soil, sun-dry it for 1-2 days, rake it level, and mix in lime to kill insects and earthworms. When sowing, moisten the bed surface to prevent the culture material from losing too much water, and leave a 20 cm wide fruiting surface around the perimeter of the bed. Choose a wind-sheltered, sunny sandy field or orchard site with convenient irrigation and drainage, plow and sun-dry it, apply lime powder to disinfect and dress the soil, form raised beds about 1.2 m wide, dig drainage ditches well, and set up a shade shed. (2) Material treatment and sowing: Choose fresh, mold-free, dry rice straw, soak the straw in 2-3% lime water for 24 hours, take it out, twist it into straw bundles, lay them out to form the bed surface, and press them firmly. At 5 cm from the edge of the straw layer, scatter a ring of mixed spawn (wheat bran and spawn mixed 1:1). On the outer edge of the first straw layer, lay the second layer of straw bundles inset by 5 cm, press firmly, and scatter a ring of mixed spawn 5 cm around the edge. Repeat this operation for each subsequent layer. Generally, 4-5 layers of straw bundles are laid. After the last layer of straw bundles is laid and pressed firmly, evenly scatter a 1 cm thick layer of sterilized burnt soil and cover with plastic film. The usual spawn dosage is 10 bags of spawn per 100 jin of dry straw. (3) Management and harvesting: After sowing, pay attention to shading and spraying water to lower the temperature and maintain moisture. When the material surface temperature exceeds 45°C, promptly uncover the film for ventilation and spray water to cool it down. In hot seasons, generally uncover the film and spray water 2-3 times a day, with intervals of 1-2 hours each time. After about 3 days, the mycelium covers the bed surface; on days 7-10, small white dot-like young buds can be seen; and every 10-15 days, the first batch of mushrooms can be harvested. After harvesting, stop watering for 3-5 days before resuming spraying and management; after about 5 days, a second batch of mushrooms can be harvested. Generally, 3-4 batches of mushrooms can be harvested.
(4) Precautions: 1. After soaking in lime water, the rice straw is best composted and fermented for 5 days (with one turning during this period). When the material temperature drops to 40°C, spread the material and sow while hot; this can reduce contamination by competing fungi (especially ink cap mushrooms). 2. During cultivation, if competing fungi contamination is found, promptly apply lime slurry for disinfection. 3. When uncovering the film for ventilation and cooling, prevent the temperature from dropping too much. 4. Straw mushrooms like to grow in a slightly alkaline environment, with a pH of around 8, generally adjusted with lime powder or lime water.
1. Construction of the mushroom house: (1) Button mushroom house Most rural areas use the mushroom houses and bed frames left from cultivating button mushrooms in winter and spring to cultivate straw mushrooms in summer. (2) Foam board mushroom house The mushroom house is built with wood as the support, using polystyrene foam boards as the walls and roof, with the inner layers of the walls and roof lined with polyethylene film. At each end of the mushroom house, three convection ventilation windows measuring 0.3-0.4 m square and two lower ventilation windows are set up, with an aisle in the middle. The cultivation bed frames are placed on both sides but not directly against the foam board walls. The bed frames are divided into 5-6 layers, and the bed surface is woven from nylon netting so that mushrooms can fruit on both the upper and lower surfaces, expanding the fruiting area. (3) Brick and tile house First build a brick house with the following specifications: 6 m long, 4 m wide, 2.8 m side height, 3.5 m ridge height, covered with asbestos tiles. Inside the mushroom house, set up 2 rows of bed frames, one door, and upper and lower rows of windows. After the brickwork is completed, seal 3 cm of foam board on the roof, then seal a layer of film, and finally set up the bed frames.
2. Preparation of culture material,
Fermentation: (1) Using rice straw as the main raw material Cut the rice straw into 5-10 cm lengths or crush it with a grinder. Soak the chopped straw in lime water, using 5 kg of lime per 100 kg of straw; after soaking for 6 hours, take it out and drain it, then mix in gypsum, livestock and poultry manure, compound fertilizer, phosphate fertilizer, plant ash, etc., and build a pile for fermentation. After 5 days of piling, turn the pile once. During turning, fine rice bran or wheat bran may be added (or mixed in evenly before spreading the material), with the total amount added not exceeding 5%.
When composting and fermenting rice straw, the pile is generally 1.2 m wide, 1 m high, and more than 1 m long, and ventilation holes should be made appropriately in the pile. After the pile is built, cover it with film to retain moisture while preventing pest invasion. The finished culture material should be soft in texture, with a water content of 70%, and the pH adjusted to around 9. After composting and fermentation, secondary fermentation is best carried out; especially for materials to which rice bran, wheat bran, or dried cow dung has been added, secondary fermentation must be carried out.
(2) Using waste cotton residue or cottonseed hulls as the main raw material Soak the waste cotton in lime water, adding 5 kg of lime per 100 kg of waste cotton residue; after thorough soaking, take it out and pile it up, cover with film, and ferment for about 2 days. When the water content is about 70%, it can be moved into the mushroom house. Before entering the house, if the pH is below 8, usually add an appropriate amount of lime to adjust it to around 9.
(3) Using sugarcane as the main raw material Soak the sugarcane in lime water, loosen and mix well per 100 kg of sugarcane, move it into the mushroom house, and spread it on the cultivation racks. Rice straw and sugarcane bagasse culture material is spread 15-18 cm thick, and waste cotton residue culture material is spread 5-10 cm thick. The material on the upper layers of the bed frames can be spread thinner, and the layers below in sequence slightly thicker, so that the material temperature in each layer is uniform, which is conducive to mycelial growth. After the culture material is leveled and slightly compacted, close the doors and windows, introduce steam for secondary fermentation, bring the material temperature to 65°C, maintain for 4-6 hours, then allow it to cool naturally. When it drops to about 45°C, open the doors and windows, and sow when the material drops to about 36°C. 3. Sowing: When the material temperature drops to about 36°C, sow while hot (38-40°C during low-temperature off-season cultivation). Sowing methods include hole sowing, furrow sowing, and broadcast sowing. In production, hole sowing and ridge-style furrow sowing are mostly used. When using hole sowing, the spawn is best broken into walnut-sized pieces, with holes 3-5 cm deep and 8-10 cm apart; ridge-style furrow sowing is a new high-yield method for straw mushrooms (more than 60 kg of fresh straw mushrooms can be produced per 100 kg of dry material). Sowing adopts three-layer ridge-style cultivation: first spread material on the ground or bed frames, 30-40 cm wide and 10 cm thick, with unlimited length; sow a layer of spawn along the perimeter; mix wheat bran with 3% lime water to moisten it and place it in the mushroom house for secondary fermentation. In the sowing center, scatter inward a 10 cm wide band of wheat bran. Using the same method, lay the second layer of material, sow, and scatter wheat bran; on top, lay a layer of material, sow a layer of spawn on the material surface, and cover. Spawn should be mixed together and sown in advance, because mixing different varieties together will cause antagonism, resulting in fewer mushrooms and seriously affecting yield.
4. Management: After sowing, maintain the material temperature at about 36°C; do not let it fall below 30°C or exceed 40°C. Keep this for about 4 days, then uncover the film; in hot summer seasons, about 2 days is enough. After sowing, cover the bed surface with a thin layer (about 1 cm) of burnt soil or fertile sandy loam, and spray an appropriate amount of 1% lime water on the soil layer to keep it moist, then cover with plastic film to retain heat. After covering with soil, control the room temperature at about 30°C and maintain the material temperature at 35°C. If the daytime temperature is high, the plastic film can be lifted, and some water sprayed to keep the material surface moist and cool it down; when the temperature is low at night, cover the film again. While ensuring the material temperature, provide appropriate ventilation. On days 4-5 after sowing, spray fruiting water once; after spraying, ventilate appropriately. Avoid closing doors and windows immediately after spraying, otherwise the mycelium will grow excessively. In winter, increase light, and a large number of straw mushroom fruit body primordia will form. Under normal conditions, young mushrooms begin to form 6-7 days after sowing. At this time, pay attention to heat and moisture retention, and provide appropriate ventilation.
Maintain the material temperature at 33-35°C, the relative air humidity at about 90%, and a certain amount of scattered light. At this time, the temperature inside the mushroom house should not fluctuate too much, and strong winds should not blow directly onto the bed surface. Above all, do not let north winds blow directly into the mushroom house, otherwise a large number of young mushrooms will die. Do not spray water directly on young mushrooms; when the humidity is insufficient, use water at about 30°C for mist spraying. Usually, mushrooms are ready for harvest about 10 days after sowing.
(1) Culture material formula: 100 kg dry rice straw, 5 kg rice bran, 5-8 kg dried cow dung, 2 kg plant ash, 2-3 kg lime, 1 kg calcium carbonate.
(2) Culture material composting: Choose golden-yellow, mold-free, dry rice straw, cut it into small pieces about 3 cm long, soak in 1% lime water for 1 day, take it out and drain it, then build a pile. The pile is 1.5 m wide and 1.5 m high, with length depending on circumstances, generally not exceeding 10 m. First spread the rice straw 20 cm thick, then scatter cow dung (cow dung powder should be pre-moistened 3 days in advance), rice bran, calcium carbonate, plant ash, and lime (the amount of lime added should be suitable for adjusting pH to 7-8). In this way, layer straw and layer materials until the pile is built. After 3 days, turn the pile; during turning, mix the supplementary materials and rice straw evenly. After another 2 days, bricks can be made.
(3) Method for making straw bricks: Make several square wooden frames 40 cm long and 15 cm high. Place a sheet of film on the wooden frame (about 150 cm long and wide, with a 10 cm hole punched every 15 cm in the middle to facilitate water and air passage). Load the fermented culture material into the frame, press it firmly, cover the surface with film, lift the wooden frame, and a straw brick is made.
(4) Sterilization and inoculation: The made straw bricks must undergo normal-pressure sterilization (maintained at 100°C for 8-10 hours). After sterilization, move them into the cultivation room (the cultivation room should be cleaned in advance and fumigated with 1500-fold dichlorvos). When the material temperature drops below 37°C, inoculate. During inoculation, first open the surface film, sow by the broadcast method, immediately cover the film back, and move them onto the mushroom bed to grow mycelium.
(5) Cultivation management: 5 days after inoculation, untie the surface film and cover with 1-2 cm thick burnt soil. After another 3 days, spray water to maintain the spatial humidity at 85%-95%, so as to promote the growth and development of primordia. Generally, mushrooms can be harvested 5 days after budding. After the first flush of mushrooms is harvested, check the water content of the culture material, and if necessary, use lime water at pH 8-9 to adjust it. Then raise the temperature of the mushroom house to promote mycelial recovery (if conditions permit, sow again). Then manage according to the above method until the end of the harvest. Generally, the entire cultivation cycle is 30 days, and 2-3 flushes of mushrooms can be harvested.