Detailed Explanation of Key Techniques for Off-Season Soil-Covered Bag Cultivation of Shiitake Mushrooms

Soil-covered bag cultivation of shiitake mushrooms is a new model of shiitake cultivation. Shiitake mushrooms cultivated with this model have the advantages of good mushroom shape, high yield, easy fruiting, and savings in time and labor. It is also a relatively advanced method in current shiitake cultivation, especially off-season soil-covered bag cultivation of shiitake, which produces high-quality summer and autumn shiitake mushrooms with high market prices and good economic returns. This technique has been tested and promoted in the northern Guangdong region of our province, with good results. The off-season soil-covered bag cultivation technique for shiitake mushrooms is introduced as follows:

1. Seasonal Arrangement

Select shiitake varieties with high-temperature tolerance, large round and regular mushrooms, thick mushroom flesh, stout mushroom stipes, relatively high yield, and suitability for fresh preservation or drying for export, such as Guangxiang No. 1. The material formula is: dry miscellaneous wood sawdust 74.5%, wheat bran 14%, corn flour 4%, brown sugar 1%, gypsum powder 1%, calcium carbonate 0.5%, slaked lime 0.5%, monopotassium phosphate 0.02%, magnesium sulfate 0..1%, table salt 0.1%, activated carbon 0.1%. Using conventional processes, produce the mushroom logs from December of the previous year to February of the following year, carry out soil covering and color conversion from March to April, and arrange management for fruiting from May to December.

2. Mushroom Yard Construction

1. Site selection requirements: First, a mountain gully with relatively high altitude, a clean environment, cool summers, and surrounding bamboo and trees; second, a late rice field with ample water sources, clean water quality, loose soil, easy drainage and irrigation, no termites, and a square, large plot; third, convenient transportation and a wide range of raw material sources.

1. Bed preparation: The bed width is 1.4 m, the bed depth is 0.5 m, and the bed height is 0.5 m, and the bed surfaces of the whole yard are required to remain at the same level.

3. Shed building: Generally, for every two beds, set up a row of posts at the edge of the bed ditch, with a post height of 2.7 m, of which 0.5 m is buried underground, and the inner shed height is 2.2 m. Then use bamboo tips, bamboo strips, thin wooden sticks, bamboo branches, etc. to build a dense crisscross frame, cover the top with rice straw, and plant vine-type (beans, melons, fruits) cash crops around the outside of the shed.

3. Soil Covering and Color Conversion

1. Soil covering material: Select silt soil and mix in 3% lime powder or burned soil at a ratio of 5000 kg per mu, mix thoroughly, and set aside for use.

2. Bed surface treatment: After the bed is leveled and straightened, spread a layer of lime powder, then spread a layer of coarse sand, and scatter a small amount of tea seed cake powder on the sand surface (old mushroom yards or sites with many termites should first be treated with pesticides for prevention and control).

3. Bag removal and arrangement: After the mushroom logs are removed from the bags, lay them tightly and flat on the bed surface (with the better-colored side facing up), arrange them horizontally on both sides of the bed and longitudinally in the center of the bed, leaving a 5-7 cm gap around the bed.

4. Soil covering: First shovel the soil from the bed ditch onto the gaps around the bed and level it, then spread the moist, prepared soil covering material onto the surface of the mushroom logs to a thickness of more than 1 cm.

5. Film covering: Arch a bamboo strip every 0.8 m on the bed surface, and tie a bamboo strip lengthwise at the highest point of the arched bamboo strips, then cover with plastic film on the bamboo strips. Fix the plastic film on top with plastic bands, tie both ends of the plastic bands to the outer curved parts of the bamboo strips, and keep the film edges 15-20 cm away from the mushroom logs.

After the above treatment, generally no management is needed, and after more than 10 days the mushroom logs can normally complete color conversion (uniform, standard reddish-brown).

4. Fruiting Management

1. Temperature regulation: For off-season soil-covered bag cultivation of shiitake mushrooms, emphasis should be placed on cooling in summer, such as appropriately thickening the shade shed covering material. It is best to plant vine-type plants around the outside of the shade shed, which both lowers temperature and increases oxygen, and also allows spring water to flow freely in the bed ditches, while appropriately increasing the frequency of watering.

2. Humidity regulation: After the mushroom logs are covered with soil, a certain water level should be maintained in the bed ditches. When the water content of the mushroom logs is high, the water level should be lower; when the water content of the mushroom logs is low, the water level should be higher (it must not soak the mushroom logs). When the mushroom logs are relatively dry, the clear water in the bed ditches can be poured directly onto the mushroom logs, generally once a day; in summer and on sunny days, water more, and in autumn and winter and on cloudy days, water less or not at all.

3. Air regulation: The plastic film should not be covered tightly. Covering with film is only to block rain, and ventilation should be ensured. In hot and humid seasons, large ventilation should be maintained even more, so as to prevent the mushroom logs from rotting, prolong the fruiting period, and improve yield and quality.

4. Light regulation: The most suitable light for fruiting is "three yang and seven yin"; in summer, for cooling, it can be adjusted to "two yang and eight yin"; in winter, for warming, it can be adjusted to "four yang and six yin".