Method for Making Fermented Soil and Other Materials for Agaricus bisporus

At present, foreign factory-based mushroom production all uses peat with high saturated water content, good water-holding capacity and high porosity as the casing soil material, and the yield per unit area is relatively high. There are roughly five types of casing soil materials used in China, namely coarse and fine soil, mixed soil, river mud and rice husk soil, fine mud and rice husk soil, and fermented soil. Fine mud and rice husk soil and fermented soil are two casing soil materials developed according to China's current mushroom cultivation methods and rural conditions, with simple preparation and good casing soil effects. These two casing soil materials have relatively high saturated water content, good water-holding capacity and relatively large porosity, and contain an appropriate amount of organic matter. They are currently the most ideal artificial casing soil materials. Their preparation methods are as follows.

(1) Fine mud and rice husk soil. Fine mud and rice husk soil is made by mixing fine mud and rice husk in a certain proportion to change the physical properties of the soil, so that the casing soil of this mixed material not only has relatively high saturated water content, but also has relatively large porosity and water-holding capacity. After casing, the mycelium climbs the soil quickly, the amount of mycelium stored in the soil layer is large, mushrooms emerge early, and flushes turn quickly, with an obvious yield-increasing effect. Fine mud and rice husk soil is easy to obtain and convenient to prepare. The key technical points of preparation are as follows:

① Preparation of fine mud: 8-10 days before casing, dig up clean vegetable garden soil 30 cm below the surface that is free of grass roots and debris, break it up, and sieve it through a sieve with 27 meshes per 10 cm. The sieved mud is called fine mud, and the unsieved mud is called soybean soil (used for later soil replenishment). Both fine mud and soybean soil need to be sun-dried.

② Treatment and ratio of fine mud and rice husk: To prevent the breeding of miscellaneous fungi in the soil and the occurrence of brown rot disease, 5-6 days before casing, the fine mud should be sterilized, generally by formaldehyde disinfection. Fresh rice husk without mold should be selected. A few days before casing, sun-dry it in sunlight for two days, then soak it in lime water with a pH of 10 for 24 hours. Two days before casing, the rice husk also needs insecticidal treatment. Evenly spray a 0.5% dichlorvos solution on the rice husk, mix well, cover with plastic film and fumigate for 12 hours, then uncover the film and wait for the dichlorvos to evaporate. One day before casing, thoroughly mix the rice husk and fine mud at a weight ratio of 1:24, then mix in lime powder amounting to 1%-2% of the weight of the fine mud. Then mix the casing soil to a semi-dry, semi-wet state, and it can be used on the mushroom bed the next day. For 111 sq m of cultivation area, 3000 kg of fine mud, 125 kg of dry rice husk, and 50 kg of lime are needed.

(2) Fermented soil. Fermented soil is made by adding a certain amount of dry cow (pig) manure and other substances to soil, and through anaerobic fermentation under certain temperature conditions (July and August), the physical properties of the soil and the content of certain substances are changed, thereby making it a casing soil material with good casing soil characteristics. Fermented soil contains an appropriate amount of organic matter, has relatively high saturated water content and relatively large porosity, and has good water-holding capacity. It saves labor and is simple to prepare, and the yield increase range is 10%-15%. The key technical points of its preparation are as follows:

① Turning the soil for fermentation: Under natural conditions, soil and organic matter are mixed and effectively subjected to anaerobic fermentation, which has certain requirements for the external natural temperature. Turning the soil for fermentation is required to be carried out in July and August. In a field after wheat or rapeseed, or near a water source, take a small plot of land. To cultivate mushrooms over an area of 111 sq m, take 15 sq m of land. The land for fermentation should be loose farmland. Dig 25-30 cm deep, break and crush the soil, and try to ensure there are no soil clods. Then add 125-150 kg of crushed dry cow manure, 200 kg of wheat husk or rice husk, 10 kg of lime, and 20 kg of superphosphate. Thoroughly mix these substances with the soil, then irrigate so that the water surface is about 5 cm above the fermented soil, and cover it with a layer of plastic film to increase temperature. After 2-3 days, bubbles can be seen rising.

② Puddling the soil: Its function is to allow the fermented soil to ferment fully and evenly. When puddling the soil, the upper soil should be turned to the lower part, and the lower soil turned to the upper part, so that the upper and lower soil are mixed evenly. Clods should be broken up, and the water should not be drained during puddling. The first puddling is generally carried out on the seventh day after fermentation begins, and the second puddling is carried out 7 days later. Before the second puddling, measure the pH of the mud water in the fermentation pit. If the pH is less than 8, add some lime to adjust the pH to 8. If there are many bubbles during fermentation, then two puddlings are sufficient. The entire fermentation stage generally takes about 30 days. If the soil is sandy, the fermentation time can be increased by 3-5 days. During fermentation, the water should always be 5 cm above the surface of the fermented soil.

③ Taking out the soil: After the soil is well fermented, the water can be drained and the field left to dry. When cracks appear on the surface of the fermented soil and a person can walk on it, it can be dug up. After the fermented soil is taken out, when it is sun-dried to a semi-dry, semi-wet state, it needs to be crushed. The largest diameter of the crushed soil particles should not exceed 1 cm. After crushing, sun-dry it. Undried soil must not be piled in ridges for storage, otherwise miscellaneous fungi will breed.