How to Cultivate Mushrooms in a Greenhouse? Detailed Growing Techniques
Greenhouse vegetable techniques help people eat the foods they want all year round, and growing mushrooms in greenhouses also makes it possible for people to enjoy the deliciousness of mushrooms in large quantities. Below, the editor will explain how greenhouse mushrooms are actually grown, to help everyone further deepen their understanding of mushrooms.
Greenhouse Mushroom Cultivation Techniques
1. Site Selection and Greenhouse Construction
Growing mushrooms in rice fields means using the idle winter paddy fields after the rice harvest to grow mushrooms. After the rice has formed grains, drain the paddy field and begin preparing the land into beds, including: the 2-ditch 3-bed style, with the middle bed 1.5 m, the side beds 1 m, the bed ditches 0.3 m wide and 0.3 m deep, and a length of 10-15 m; and the 3-ditch 2-bed style, with beds 1.5 m wide and ditches 0.3 m wide. When making the beds, dig out the field soil from the ditches and pile it on the edges of the beds to form earth ridges, which are used to hold back the growing substrate. The bed ditches also serve as walkways for the operators and for drainage. Build an inverted-V (A-frame) shed over the bed surface. In the middle of the A-frame shed, use bamboo or wooden poles as supports to form the central upright posts of the shed, 2.4 m high. Connect the upright posts with large bamboo poles to form the top beam. Cover the top beam with plastic film, pulling both sides straight to form a natural triangle. Then use thin rice and wheat straw, clamped with heavy-duty clips into large straw fans, leaned on the top beam to provide shading. Black plastic film can also be used; after passing over the top beam, it is stretched on both sides to form an A-frame triangular shed, without using straw fans for shading. At both ends of the A-frame shed, use straw curtains for shading. Drainage ditches should be made around the outside of the shed.
2. Fermentation of the Growing Substrate
The substrate formula is the same as for indoor mushroom growing. Either the one-time fermentation method or the two-time fermentation method can be used. The outdoor two-time fermentation method does not use fuel for heating; instead, it uses the natural high temperatures of early autumn to achieve the effect of two-time fermentation, reducing production costs. The method is to use bricks and stones as support piers, about 20 cm high. Place wooden poles on the hot piers, and place bamboo strips on the wooden poles, just like a bed frame, making a base 1.5 m wide and of indefinite length. Take the pile that has undergone pre-fermentation, adjust the water so that squeezing the substrate by hand yields 5-6 drops of water, then use lime powder to adjust the pH value to 7.8-8. Then pile the substrate on the base, and pre-place wooden poles or bamboo to form ventilation holes. The pile is 0.8-1 m high, and the ventilation holes are made in a T shape. After the pile is built, pull out the wooden poles or bamboo, and natural cavities form, serving as channels for air exchange within the substrate. Spray the surface of the pile with 0.5% dichlorvos or dicofol to kill insects.
Then, around the pile, use bamboo to build a simple frame, about 20 cm away from the pile, to prevent the plastic film from sticking directly to the growing substrate and affecting fermentation. Finally, cover with film. With the pile tightly sealed under the film, making full use of the daytime sunlight for warming, plus the fermentation heat accumulated in the pile, the pile temperature rises rapidly to above 62°C. After the high-temperature phase ends, lower the temperature by 1-2°C each day, ventilate 3-4 times, 30 minutes each time. Keep the temperature at around 50°C; fermentation ends in 6-7 days. Finally, when the temperature drops below 45°C, the substrate can be moved into the A-frame shed.
3. Spreading the Substrate and Sowing
Two days before the substrate enters the shed, spray the entire cultivation bed with 0.5% dichlorvos to kill insects, in preparation for the substrate entering the shed. When the substrate is spread on the bed surface, keep the substrate moisture content at 63%-65%, so that squeezing it by hand yields 1 drop of water; the substrate pH should be 7-7.5, with no ammonia smell. The spreading thickness is 13-17 cm; mix while spreading, with even force. After the substrate is spread, use a thermometer to measure the substrate temperature. If the substrate temperature is below 28°C, it is safe to sow. For sowing, granular spawn is mostly used, and each bottle of spawn can sow 0.7-0.8 sq m. Before sowing, the operators should disinfect their hands, tools and spawn bottles with 0.1% potassium permanganate. When sowing, sprinkle 2/3 of the spawn on the surface of the growing substrate, then turn it over by hand into the substrate, and then sprinkle the remaining 1/3 of the spawn on the substrate surface, and gently press it firm with a clean wooden board.
Management During the Mushroom Fruiting Period
After casing soil is applied, focus mainly on keeping the soil layer moist; the soil material is required to be moist, and generally no water spraying is needed. In the morning, adjust by turning over the dew-covered straw curtains. If the soil material is too wet, replace it with dry straw curtains at noon for adjustment. As long as the moisture is suitable, the straw curtains do not need to be turned for a week.
To prevent heavy rain from accumulating water and flooding the substrate, keep the walkways and surrounding drainage ditches clear, and open more field gaps lower than the drainage ditches.
Three days after sowing, the mycelium begins to grow toward the substrate and soil layer; in about 10 days it can reach the middle layer of the substrate and soil, and in about 18 days it fills the entire substrate and soil layer and begins to form mushroom buds. At this time, pay even more attention to moderate management. If the soil material on the bed surface turns white, water must be sprayed to increase humidity; only in this way can the mushroom buds expand and more mushrooms be produced.
Covering with film: In autumn and spring, covering the bed surface with film can prevent rainwater from seeping into the substrate layer and drowning the mycelium, prevent wind from killing the small mushrooms on the bed surface, and maintain moisture. In winter, covering the bed surface with film can increase humidity, prolong the fruiting period, and increase yield. Generally, the film is required to be placed over the straw curtains on the bed surface; only during windy conditions should it be placed underneath, and after the wind passes it should be put back on top promptly to allow ventilation. But it is worth noting that in late spring and early autumn, film must not be placed at noon on sunny days, to prevent burning the mycelium to death and causing dead mushrooms.
Water adjustment: At the end of each flush of mushrooms, water should be adjusted once to facilitate the formation of the next batch of small mushrooms. When there are mushrooms as small as rice grains on the bed surface, heavy watering is strictly prohibited.
After applying nutrient solution or spraying pesticide, promptly rinse once with clean water to prevent spotted mushrooms.
Mushroom Harvesting Methods
Mushrooms can only mature 5-7 days after budding. When the stipe rises and they are 80% mature (caps not yet opened), they should be picked promptly. When picking, press the cap and shake left and right twice, then twist up together with the base of the mushroom and the old mycelial root, and fill the bed surface level. When picking mushrooms, be sure to pull out the old roots, and take the mushroom bases out of the field for disposal, which can reduce pests and diseases. After picking, adding soil helps cultivate strong mycelium and increase yield.
Grading Standards for Mushroom Processing
Grade 1 mushrooms: cap diameter 1.8-4 cm, stipe length 1-1.5 cm. The mushroom color is pure white, the shape is round and neat, the stipe is trimmed flat with no hollow or white-core phenomenon, and the cap has no spots, insect damage, black base, green root, etc.
Grade 2 mushrooms: cap diameter 2-6 cm, stipe length 1.5 cm. The mushroom color is pure white, with slight spots, the shape is basically round and neat, slightly deformed, the stipe is somewhat loose, with a white core, the trimming is less flat, the cap has stains, with no insect damage or green root phenomenon.
Grade 3 mushrooms: While meeting the requirements of the grade 2 standard, the cap diameter is allowed to reach 4-6 cm, with mild mechanical damage and a small number of spots; they may be deformed mushrooms, hollow mushrooms, and mushrooms whose gills have not changed color and which have just opened.
Through understanding mushroom cultivation, we can find that although greenhouse-grown mushrooms are not as extremely delicious as wild mushrooms, they are by no means not green and safe, so we can eat mushrooms on the market with confidence, and at the same time we can also use the mushroom grading method in this article to identify the quality of mushrooms.