Detailed Explanation of How to Make Mushroom Casing Materials

At present, foreign industrialized mushroom production all uses peat, which has high water content, good water-holding capacity, and large porosity, as the casing material. There are roughly five types of casing materials used in China, namely coarse and fine soil, mixed soil, river mud and rice chaff soil, fine mud and rice chaff soil, and fermented soil. Fine mud and rice chaff soil and fermented soil are two casing materials developed according to China's current mushroom cultivation methods and rural conditions, and they are simple to make and have good casing effects. These two casing materials have relatively high saturated water content, good water-holding capacity, and relatively large porosity, and contain an appropriate amount of organic matter, making them the most ideal artificial casing materials at present. The methods for making these two soils are introduced separately below.

1. Fermented soil

Fermented soil is made by adding a certain amount of organic matter such as dry cow (pig) manure and other substances to soil and, under certain temperature conditions, carrying out anaerobic fermentation so that the physical properties of the soil and the content of certain substances change, thereby making it a casing material with good casing 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 is labor-saving and simple to make, and can increase mushroom yield by 10%-15%. There are three points to the production method.

(1) Turning the soil for fermentation Under natural conditions, turning the soil for fermentation is required to be carried out in July-August. In a field after wheat or rapeseed or near a water source, take about 15 sq m of land (enough to cultivate 111 sq m of mushrooms), and dig the soil to a depth of 25-30 cm. Crush and break up the dug-out soil until there are no clods, then add 125-150 kg of crushed dry cow manure, 200 kg of wheat husks or rice chaff, 10 kg of lime, and 20 kg of superphosphate, and mix thoroughly. Then add water until the water surface is about 5 cm above the fermenting soil, and cover with a layer of plastic film to increase temperature and retain heat. After 2-3 days, bubbles can be seen rising.

(2) Puddling the soil Its purpose is to allow the fermented soil to ferment fully and evenly. When puddling the soil, the soil on top should be turned to the bottom and the soil on the bottom turned to the top, so that the upper and lower soil are mixed evenly. Clods must be broken up, and water should not be drained during puddling. The first puddling is generally carried out on the 7th day after fermentation begins, and the second puddling is carried out 7 days later. Before the second puddling, measure the pH value of the mud water in the fermentation pit. If the pH value is less than 8, add some lime to adjust the pH value to 8. If there is a lot of foaming during fermentation, then 2 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 level should always be 5 cm above the surface of the fermenting soil.

(3) Taking out the soil After the soil has fermented well, 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 out. After the fermented soil is taken out, dry it until it is half-dry and half-moist, then break it up. The diameter of the broken soil particles must not be greater than 1 cm. After breaking it up, dry it in the sun. Soil that has not been dried must not be piled in ridges for storage, to prevent the growth of contaminating microorganisms.

2. Fine mud and rice chaff soil

Fine mud and rice chaff soil is made by mixing fine mud and rice chaff in a certain ratio to change the physical properties of the soil, so that it not only has relatively high saturated water content but also relatively large porosity and water-holding capacity. Using this material for casing, the mycelium climbs the soil quickly, the amount of mycelium stored in the soil layer is large, mushrooms emerge early, and the flushes turn quickly, with an obvious yield-increasing effect. Fine mud and rice chaff soil is easy to obtain and convenient to make. Its production method focuses on the following two points.

(1) Preparation of fine mud 8-10 days before casing, dig up clean vegetable garden soil 30 cm below the surface that has no grass roots or debris, break it up, and sieve it through a sieve of 27 mesh 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 dried in the sun.

(2) Mixing fine mud with rice chaff To prevent the growth of contaminating microorganisms and brown rot pathogens in the soil, 5-6 days before casing, carry out sterilization treatment on the fine mud, generally using the formaldehyde disinfection method. The rice chaff should be fresh and free of mold. A few days before casing, expose it to sunlight for 2 days, then soak it in lime water with a pH value of 10 for 24 hours. Two days before casing, the rice chaff also needs insecticide treatment. A 0.5% dichlorvos solution can be evenly sprayed on the rice chaff, and after mixing well, cover it with a film and fumigate for 12 hours, then uncover the film to promote evaporation of the dichlorvos. One day before casing, mix the rice chaff and fine mud thoroughly in a weight ratio of 1:24, then mix in lime powder equal to 1%-2% of the weight of the fine mud, and mix the casing material until it is half-dry and half-moist. The next day it can be used for covering mushroom beds. For every 111 sq m of mushroom cultivation area, about 3000 kg of fine mud, 125 kg of dry rice chaff, and 50 kg of lime are needed.